Citation Nr: A23002785 Decision Date: 02/09/23 Archive Date: 02/09/23 DOCKET NO. 221130-300231 DATE: February 9, 2023 ORDER Service connection for right upper extremity peripheral neuropathy, to include as due to herbicide exposure, is denied. Service connection for left upper extremity peripheral neuropathy, to include as due to herbicide exposure, is denied. Service connection for right lower extremity peripheral neuropathy, to include as due to herbicide exposure, is denied. Service connection for left lower extremity peripheral neuropathy, to include as due to herbicide exposure, is denied. Restoration of the 50 percent disability rating for the service-connected migraine headaches associated with neurocognitive disorder with TBI and vertigo is granted, effective February 23, 2022. A disability rating in excess of 70 percent for the service-connected neurocognitive disorder with TBI is denied. A separate disability rating of 30 percent, but no higher, for the TBI-related vertigo is granted for the full period on appeal (from September 29, 2020). A disability rating in excess of 40 percent for the service-connected bilateral hearing loss disability for the period on appeal prior to February 15, 2022 is denied. A disability rating in excess of 60 percent for the service-connected bilateral hearing loss disability for the period on appeal from February 15, 2022 is denied. A disability rating in excess of 10 percent for the service-connected tinnitus is denied. A compensable disability rating for the service-connected deviated septum is denied. A total disability rating based on individual unemployability (TDIU) due to service-connected disabilities for the period on appeal prior to September 29, 2020 is denied. Eligibility for Dependents' Educational Assistance (DEA) benefits under 38 U.S.C. Chapter 35 for the period prior to September 29, 2020 is denied. Assignment of special monthly compensation (SMC) at the statutory housebound rated under 38 U.S.C. § 1114(s) is granted, effective February 15, 2022. FINDINGS OF FACT 1. The Veteran's right and left upper and lower extremity peripheral neuropathy did not begin during active service or within one year of separation and are not otherwise related to an in-service injury or disease, to include as due to in-service herbicide exposure. 2. The evidence does not persuasively demonstrate that the service-connected migraine headaches associated with mid neurocognitive disorder with TBI and vertigo had actually improved such that the improvement reflects improvement in the ability to function under the ordinary conditions of life. 3. The Veteran's service-connected neurocognitive disorder with TBI approximated occupational and social impairment with deficiencies in most areas, such as work, school, family relations, judgment, thinking, or mood or, alternatively, cognitive impairment with a highest facet evaluation of "3"; however, the neurocognitive disorder with TBI did not more nearly approximate total occupational and social impairment or cognitive impairment with a highest facet evaluation of "total". 4. For the entire period on appeal, the Veteran's TBI-related vertigo is a distinct diagnosis that may be evaluated under another diagnostic code, and it is manifested by occasional dizziness and staggering. 5. Prior to February 15, 2020, the Veteran's bilateral hearing loss disability was manifested by hearing acuity of no worse than Level VI in the right ear and no worse than Level IX in the left ear. 6. From February 15, 2020, the Veteran's bilateral hearing loss disability was manifested by hearing acuity of no worse than Level VII in the right ear and Level X in the left ear. 7. The 10 percent rating is the maximum rating available for tinnitus, and the Veteran's tinnitus does not result in an exceptional or unusual disability picture such that referral for consideration of an extraschedular rating is warranted. 8. The Veteran's service-connected deviated septum does not more nearly approximate 50-percent obstruction of the nasal passage on both sides or complete obstruction on one side. 9. It was not factually ascertainable within the one-year period preceding the September 29, 2020 claim for increased rating that the Veteran was unable to maintain substantially gainful employment due to his service-connected disabilities. 10. The Veteran had permanent total disability no earlier than September 29, 2020. 11. As of February 15, 2022, the Veteran was in receipt of a TDIU solely due to the TBI-related neurocognitive disorder, in addition to additional separate and distinct service-connected disabilities independently ratable as at least 60 percent disabling. CONCLUSIONS OF LAW 1. The criteria for service connection for right and left upper and lower extremity peripheral neuropathy, to include as due to herbicide exposure, are not met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 2. The reduction of the disability rating for the Veteran's service-connected migraine headaches associated with neurocognitive disorder with TBI and vertigo from 50 percent to noncompensable was not proper and the 50 percent disability rating is restored from February 23, 2022. 38 U.S.C. § 1155, 5103, 5103A, 5107; 38 C.F.R. §§ 3.105, 3.344(c), 4.124a, Diagnostic Code 8100. 3. The criteria for a disability rating in excess of 70 percent for the service-connected neurocognitive disorder with TBI have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.124a, Diagnostic Code 8045-9304. 4. The criteria for a separate disability rating of 30 percent for vertigo have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.87, Diagnostic Code 6204. 5. Prior to February 15, 2022, the criteria for a disability rating in excess of 40 percent for the service-connected bilateral hearing loss disability have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.85, 4.86, Diagnostic Code 6100. 6. From February 15, 2022, the criteria for a disability rating in excess of 60 percent for the service-connected bilateral hearing loss disability have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.85, 4.86, Diagnostic Code 6100. 7. The criteria for a disability rating in excess of 10 percent for the service-connected tinnitus have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.87, Diagnostic Code 6260. 8. The criteria for a compensable disability rating for the service-connected deviated septum have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.97, Diagnostic Code 6502. 9. The criteria for assignment of a TDIU prior to September 29, 2020 have not been met. 38 U.S.C. § 1155; 38 C.F.R. §§ 3.340, 3.341, 3.400(o), 4.16, 4.19. 10. The criteria for assignment of eligibility for DEA under 38 U.S.C. Chapter 35 prior to September 29, 2020 have not been met. 38 U.S.C. § 5110; 38 C.F.R. §§ 3.807(a), 21.3020, 21.3021. 11. From February 15, 2022, the criteria for assignment of SMC at the statutory housebound rated under 38 U.S.C. § 1114(s) have been met. 38 U.S.C. §§ 1114 (s), 5103A, 5107; 38 C.F.R. §§ 3.350, 3.351, 3.352. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from November 1953 to November 1973. This case is before the Board of Veterans' Appeals (Board) on appeal from a May 2022 Department of Veterans Affairs (VA) Regional Office (RO) rating decision. In that decision, the RO granted an effective date of September 29, 2020 for the grant of a TDIU due to service-connected disabilities and eligibility for DEA benefits under 38 U.S.C. Chapter 35, but denied service connection for right and left upper and lower extremity peripheral neuropathy on the merits; found that the reduction of the disability rating for the service-connected migraine headaches associated with neurocognitive disorder with TBI and vertigo, effective February 23, 2022, was proper; denied disability ratings in excess of 70 percent for the service-connected neurocognitive disorder with TBI and vertigo, 60 percent for the service-connected bilateral hearing loss disability, a disability rating in excess of 10 percent for the service-connected tinnitus; and a compensable disability rating for the service-connected deviated septum. By way of history, on September 29, 2020, VA received a VA Form 21-526EZ, Application for Disability Compensation and Related Compensation Benefits for the issues of increased ratings for the service-connected neurocognitive disorder with TBI and vertigo and bilateral hearing loss disability. In a January 2021 rating decision, the RO increased the disability rating for the neurocognitive disorder with TBI and vertigo from 50 percent to 70 percent, effective September 29, 2020 and denied a disability rating in excess of 40 percent for the service-connected bilateral hearing loss disability. In January 2021, VA received the Veteran's VA Form 21-526EZ initial claim for a TDIU. In a June 2021 rating decision based on special review of the claims file due to concession of herbicide exposure, the RO readjudicated the claims of service connection for right and left upper and lower extremity peripheral neuropathy based on new and relevant evidence but denied the claims on the merits. In a second June 2021 rating decision, the RO inferred claims for increase based on the January 2021 TDIU claim for the issues of increased ratings for the neurocognitive disorder with TBI and vertigo, bilateral hearing loss disability, headaches, and tinnitus but denied disability ratings in excess of 70 percent, 60 percent, 50 percent, and 10 percent, respectively. Furthermore, the RO denied entitlement to a TDIU. In a January 2022 VA Form 20-0995 Supplemental Claim specifying the January 2021 rating decision, the Veteran sought increased ratings for the service-connected neurocognitive disorder with TBI and vertigo and bilateral hearing loss disability, to include assignment of a TDIU. In January 2022, VA also received a VA Form 21-8940, Veterans Application for Increased Compensation Based on Unemployability. In a March 2022 rating decision, the RO increased the disability rating for the bilateral hearing loss disability from 40 percent to 60 percent, effective February 15, 2022; granted a TDIU due to service-connected disabilities and eligibility for DEA under 38 U.S.C. Chapter 35, both effective March 23, 2021; and denied a disability rating in excess of 70 percent for the neurocognitive disorder with TBI and vertigo. However, the RO also denied a disability rating in excess of 10 percent for tinnitus, a compensable disability rating for the deviated septum and, finally, reduced the rating for the migraine headaches associated with neurocognitive disorder with TBI and vertigo from 50 percent to noncompensable, effective February 23, 2022. In May 2022, VA received the Veteran's VA Form 20-0996, Request for HLR requesting review of all issues adjudicated by the March 2022 rating decision. The RO thereafter issued the May 2022 HLR rating decision. In November 2022, VA received the Veteran's 10182 Notice of Disagreement (NOD). The Veteran selected the Direct Review docket. Therefore, the Board will decide the appeal based on the evidence of record at the time of the March 2022 rating decision for which the Veteran sought HLR. 38 C.F.R. § 20.301. Finally, given that the May 2022 rating decision, in essence, readjudicated the previously denied claims of service connection for right and left upper and lower extremity peripheral neuropathy based on receipt of new and relevant evidence by adjudicating the claims on the merits, the claims are considered readjudicated and the Board is bound by this favorable finding. 38 C.F.R. § 3.104(c). (continued on next page) Service Connection 1. Entitlement to service connection for right upper extremity peripheral neuropathy, to include as due to herbicide exposure. 2. Entitlement to service connection for left upper extremity peripheral neuropathy, to include as due to herbicide exposure. 3. Entitlement to service connection for right lower extremity peripheral neuropathy, to include as due to herbicide exposure. 4. Entitlement to service connection for left lower extremity peripheral neuropathy, to include as due to herbicide exposure. Service connection may be granted for disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. § 3.303. The three-element test for service connection requires evidence of: (1) a current disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the current disability and the in-service disease or injury. Shedden v. Principi, 381 F.3d 1163, 1166-67 (Fed. Cir. 2004). Pursuant to 38 C.F.R. § 3.303(b), where a chronic disease is shown as such in service, subsequent manifestations of the same chronic disease are generally service-connected; if a chronic disease is noted in service but chronicity in service is not adequately supported, a showing of continuity of symptomatology after separation is required. Entitlement to service connection based on chronicity or continuity of symptomatology pursuant to 38 C.F.R. § 3.303(b) applies only to a disease enumerated on the list of chronic diseases in 38 U.S.C. § 1101(3) or 38 C.F.R. § 3.309(a). Walker v. Shinseki 708 F.3d 1331 (Fed. Cir. 2013). In addition, such chronic diseases are presumed to have been incurred in service if they manifested to a compensable degree within one year of separation from service. 38 U.S.C. §§ 1101(3), 1112(a)(1), 1113; 38 C.F.R. §§ 3.307(a), 3.309(a). At the outset, the RO has conceded that the Veteran was exposed to herbicides during service. See VA memorandum dated May 28, 2021. The Board is bound by this favorable finding. 38 C.F.R. § 3.104(c). Absent clear evidence to the contrary, early-onset peripheral neuropathy is presumed to be related to in-service herbicide exposure if it manifested to a degree of 10 percent or more within one year of last known herbicide exposure during active service. 38 C.F.R. §§ 3.307 (a)(6)(ii); 3.309(e). In this case, last known in-service herbicide exposure occurred on August 25, 1967, the day of the Veteran's departure from the Republic of Vietnam. See record of assignments dated on September 13, 1993. Notwithstanding the above, service connection for a disability claimed as due to exposure to Agent Orange may be established by showing that a disability was in fact causally linked to such exposure (actual causation). See Combee v. Brown, 34 F.3d 1039, 1044 (Fed. Cir. 1994); Brock v. Brown, 10 Vet. App. 155, 162-64 (1997). The Veteran has not received a VA examination for his right and left upper and lower extremity peripheral neuropathy. VA must provide an examination when the record: (1) contains competent evidence of a current disability, (2) indicates that the signs and symptoms of the disability may be associated with active service, and (3) does not contain sufficient information to decide the claim. 38 U.S.C. § 5103A; McLendon v. Nicholson, 20 Vet. App. 79 (2006). The Veteran has a current diagnosis of unspecified idiopathic peripheral neuropathy. See VA optometry E & M note dated December 16, 2021. However, service treatment records (STRs) provide no evidence of any upper or lower extremity neurological symptoms occurring within one year of August 25, 1967. Similarly, remaining STRs provide no evidence of upper or lower extremity neurological symptoms. There is no lay or medical evidence of peripheral neuropathy of the upper and lower extremities until 2012, or approximately forty-five years after last confirmed herbicide exposure and thirty-nine years after separation from service. In this regard, in March 2013, the Veteran reported tingling and numbness in the entire foot, ankle, and leg bilaterally with onset of symptoms approximately one year prior. See private treatment note dated March 18, 2013. With regard to the upper extremities, private treatment records from April 2014 include an assessment of brachial neuritis/radiculitis. See private treatment note dated April 30, 2014. However, a May 2014 EMG of the upper extremities was within normal limits. See private EMG report dated May 14, 2014. Neither the Veteran nor his representative has provided any argument with regard to the issues of service connection for bilateral upper and lower extremity peripheral neuropathy. Although the Veteran may believe that the bilateral upper and lower extremity peripheral neuropathy are related to service, to include as due to herbicide exposure, presumptive service connection is only available for early-onset peripheral neuropathy; as noted above, there is no lay or medical evidence indicating onset of peripheral neuropathy within one year of last exposure on August 25, 1967. There is no competent evidence showing any relationship between the peripheral neuropathy, which manifested no less than thirty-nine years following service, and herbicide exposure. Although the Veteran may believe that his bilateral upper and lower extremity peripheral neuropathy is related to herbicide exposure, his opinion is not competent in this regard. Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007); Kahana v. Shinseki, 24 Vet. App. 428 (2011). Although neither the Veteran nor his representative have contended as such, to the extent that the Veteran may believe that the bilateral upper extremity peripheral neuropathy is related to a cervical spine disability, the Veteran is not currently in receipt of service connection for a cervical spine disability, and service connection was most recently denied in an unappealed July 2019 rating decision. As such, given that the issue of service connection for a cervical spine disability is not on appeal and is not otherwise reasonably raised, no further development is required with regard to any theory of secondary entitlement. Furthermore, there is no indication that the bilateral upper and lower extremity peripheral neuropathy may be related to the service-connected neurocognitive disorder with TBI; in this regard, none of the numerous VA examinations provided to assess the severity and etiology of the neurocognitive disorder have identified peripheral neuropathy as a complication. In this case, there is no adequate evidence indicating that the Veteran experienced symptoms of peripheral neuropathy during service and there is no competent evidence showing any relationship between his current symptoms and service, to include as due to in-service herbicide exposure. Accordingly, even the low threshold under McLendon has not been met here and VA's duty to provide VA examinations has not been triggered. See 38 U.S.C. § 5103A; 38 C.F.R. §§ 3.159(c), 3.326; McLendon, 20 Vet. App. at 79. Given the above, the evidence persuasively weighs against a finding that the Veteran's bilateral upper and lower extremity peripheral neuropathy had onset within one year of last known herbicide exposure or subsequently during service, or is otherwise related to service, to include as due to in-service herbicide exposure. The benefit of the doubt doctrine, see 38 U.S.C. § 5107(b), 38 C.F.R. § 3.102, is therefore not for application, and service connection for bilateral upper and lower extremity peripheral neuropathy is not warranted. Lynch v. McDonough, 21 F.4th 776 (Fed. Cir. 2021) (only when the evidence persuasively favors one side or another is the benefit of the doubt doctrine not for application). Rating Reduction 5. The propriety of the rating reduction for the service-connected migraine headaches associated with neurocognitive disorder with TBI and vertigo. In general, prior to reducing a veteran's disability rating, VA is required to comply with pertinent VA regulations applicable to all rating reduction cases, regardless of the rating level or the length of time that the rating has been in effect. When reduction in the rating of a service-connected disability is contemplated and the lower evaluation would result in a reduction or discontinuance of compensation payments, a rating decision proposing the reduction or discontinuance will be prepared setting forth all material facts and reasons. The beneficiary must be notified at his or her latest address of record of the contemplated action and furnished detailed reasons thereof. The beneficiary must be given 60 days for the presentation of additional evidence to show that compensation payments should be continued at the present level. 38 C.F.R. § 3.105(e). In the advance written notice, the beneficiary will be informed of his or her right for a pre-determination hearing, and if a timely request for such a hearing is received (i.e., within 30 days), benefit payments shall be continued at the previously established level pending a final determination. 38 C.F.R. § 3.105(i)(1). In certain rating reduction cases, VA benefits recipients are to be afforded greater protections, set forth in 38 C.F.R. § 3.344. Rating agencies will handle cases affected by change of medical findings or diagnosis, to produce the greatest degree of stability of disability evaluations consistent with the laws and VA regulations governing disability compensation and pension. These considerations apply to ratings that have continued for long periods at the same level (five years or more). See Brown v. Brown, 5 Vet. App. 413, 418 (1993). Notably, 38 C.F.R. § 3.344(a) requires that the disability in question has materially improved, and that it is reasonably certain that such improvement will be maintained under the ordinary conditions of life. Nonetheless, for both reductions of disability ratings in place for less than 5 years and 5 years or more and irrespective of § 3.344(a), Brown requires that the disability in question reflects: (1) actual improvement in the disability and (2) that improvement reflects improvement in the ability to function under the ordinary conditions of life and work. See id. at 421; see also Stern v. McDonough, 34 Vet. App. 51 (2021). When a reduction is effectuated without following the applicable regulations, to include procedural and substantive provisions, the reduction is void ab initio. See Greyzck v. West, 12 Vet. App. 288, 292 (1999). The Veteran's migraine headaches associated with neurocognitive disorder with TBI and vertigo are rated under 38 C.F.R. § 4.124a, Diagnostic Code 8100. Under Diagnostic Code 8100, migraine headaches with characteristic prostrating attacks averaging one in two months over the last several months are rated as 10 percent disabling. A 30 percent disability rating is warranted for migraine headaches with characteristic prostrating attacks occurring on an average once a month over the last several months. Migraine headaches manifested by very frequent completely prostrating and prolonged attacks productive of severe economic inadaptability warrant a 50 percent disability rating. 38 C.F.R. § 4.124a, Diagnostic Code 8100. Notably, the regulation does not specifically define a "characteristic prostrating migraine;" however, "prostration" is defined as extreme exhaustion or powerlessness. DORLAND'S ILLUSTRATED MEDICAL DICTIONARY 1531 (32nd ed. 2012). VA regulations also do not define "economic inadaptability." The Court, however, has noted that nothing in Diagnostic Code 8100 requires the Veteran to be completely unable to work to qualify for a 50 percent rating. See Pierce v. Principi, 18 Vet. App. 440, 445-46 (2004). In this case, the rating reduction for the service-connected migraine headaches associated with neurocognitive disorder with TBI and vertigo did not result in a decrease in the Veteran's overall compensation. Therefore, the RO was not required to submit a rating decision proposing the reduction prior to implementing the reduction. Furthermore, the effective date of the rating reduction (February 23, 2022) was within 5 years of the original grant of service connection for migraine headaches associated with neurocognitive disorder with TBI and vertigo, effective January 10, 2018, and assignment of a 50 percent disability rating. Therefore, the provisions of 38 C.F.R. § 3.344, pertaining to stabilization of disability ratings, do not apply in this appeal. The narrative portion of the March 2022 rating decision that reduced the rating for the migraine headaches associated with neurocognitive disorder with TBI and vertigo concluded only that a VA examination performed on February 23, 2022 demonstrated "factually ascertain[ed] improvement of this condition," a finding restated in the May 2022 HLR rating decision. However, neither the March 2022 nor May 2022 rating decisions addressed whether the migraine headaches associated with neurocognitive disorder with TBI and vertigo had actually improved such that the improvement reflects improvement in the ability to function under the ordinary conditions of life. See Brown, 5 Vet. App. at 418; see also Stern, 34 Vet. App. at 51. In this case, the evidence does not persuasively show that the migraine headaches associated with neurocognitive disorder with TBI and vertigo had actually improved such that the improvement reflects improvement in the ability to function under the ordinary conditions of life. In this regard, the frequency, duration, and severity of migraine symptoms as reported by the Veteran during a January 2021 VA examination supporting assignment of a 50 percent rating and the February 2022 examination supporting the reduction are substantially similar. During the February 2022 examination, the Veteran reported that his symptoms had worsened, rather than abated. There was no significant change in the Veteran's medication regimen. Finally, the February 2022 examiner seemed to ascribe some of the Veteran's migraine symptoms to an alcohol use disorder without any rationale in support and may therefore have understated the severity of the migraine symptoms. In conclusion, the reduction in this case was not proper and restoration of the 50 percent rating for the service-connected neurocognitive disorder with TBI and vertigo is warranted, effective from February 23, 2022. Increased Rating 6. Entitlement to a disability rating in excess of 70 percent for the service-connected neurocognitive disorder with TBI and vertigo. The Veteran's service-connected neurocognitive disorder with TBI and vertigo is rated under 38 C.F.R. § 4.124a, Diagnostic Code 8045-9304. Hyphenated diagnostic codes are used when a rating under one diagnostic code requires use of an additional diagnostic code to identify the basis for the evaluation assigned; the additional code is shown after the hyphen. The hyphenated codes for the Veteran's neurocognitive disorder with TBI and vertigo reflect that residuals of TBI is the service-connected disability under 38 C.F.R. § 4.124a, Diagnostic Code 8045 and major or neurocognitive disorder due to TBI is the basis of the rating assigned under 38 C.F.R. § 4.130, Diagnostic Code 9304. Diagnostic Code 8045 states that there are three main areas of dysfunction that may result from traumatic brain injuries and have profound effects on functioning: cognitive (which is common in varying degrees after a traumatic brain injury), emotional/behavioral, and physical. Each of these areas of dysfunction may require evaluation. 38 C.F.R. § 4.124a, Diagnostic Code 8045. Here, in accordance with Diagnostic Code 8045, the Veteran's TBI residuals are rated based on emotional/behavioral impairment under 38 C.F.R. § 4.130. Under the General Rating Formula for Rating Mental Disorders (General Rating Formula), 70 percent rating is assigned for occupational and social impairment with deficiencies in most areas, such as work, school, family relations, judgment, thinking, or mood, due to such symptoms as: suicidal ideation; obsessional rituals which interfere with routine activities; speech intermittently illogical, obscure, or irrelevant; near-continuous panic or depression affecting the ability to function independently, appropriately and effectively; impaired impulse control (such as unprovoked irritability with periods of violence); spatial disorientation; neglect of personal appearance and hygiene; difficulty in adapting to stressful circumstances (including work or a work like setting); inability to establish and maintain effective relationships. 38 C.F.R. § 4.130, General Rating Formula. A 100 percent rating is assigned for total occupational and social impairment, due to such symptoms as: gross impairment in thought processes or communication; persistent delusions or hallucinations; grossly inappropriate behavior; persistent danger of hurting self or others; intermittent inability to perform activities of daily living (including maintenance of minimal personal hygiene); disorientation to time or place; memory loss for names of close relatives, own occupation, or own name. Id. The use of the phrase "such symptoms as," followed by a list of examples, provides guidance as to the severity of symptomatology contemplated for each rating. The use of such terminology permits consideration of items listed as well as other symptoms and contemplates the effect of those symptoms on the Veteran's social and work situation. See Mauerhan v. Principi, 16 Vet. App. 436 (2002). In other words, in applying the General Formula for Mental Disorders (General Formula), the Board must conduct a "holistic analysis" that considers all associated symptoms, regardless of whether they are listed as criteria. Bankhead v. Shulkin, 29 Vet. App. 10, 22 (2017); 38 C.F.R. § 4.130. The analysis must include a determination as to whether unlisted symptoms are similar in severity, frequency, and duration to the listed symptoms associated with specific disability percentages. 38 C.F.R. § 4.126. Then, the Board must determine whether the associated symptoms, both listed and unlisted, caused the level of impairment required for a higher disability rating. Vazquez-Claudio v. Shinseki, 713 F.3d 112, 114-118 (Fed. Cir. 2013). In this case, the evidence persuasively shows that a disability rating in excess of 70 percent for the service-connected neurocognitive disorder with TBI and vertigo is not warranted. Specifically, the Veteran's neurocognitive disorder with TBI and vertigo does not more nearly approximate total occupational and social impairment. During a February 2022 VA psychiatric examination, the Veteran reported "profane and belligerent conduct" towards a VA nurse "whom he though was attitudinal with him." He indicated that he ruminates about his Vietnam experiences, has problems "thinking," and must work "hard to pay attention and has to write things down and draw maps or he's in trouble." He reported that he forgets where he has placed certain objects, even if they are nearby. Finally, the Veteran reported "verbal hostility" towards his children. Symptoms noted by the examiner indicated depressed mood, anxiety, chronic sleep impairment, memory loss, impairment of short and long term memory, disturbances of motivation and mood, difficulty in establishing and maintaining effective work and social relationships, and difficulty in adapting to stressful circumstances, including work or a work like setting. During the examination, the Veteran was "dressed meticulously neat in business casual attire" and was "cooperative and attentive during the evaluation." He was "oriented to person, time, place, and situation." Speech was "clear and spontaneous" Motor activity was "calm and purposeful." The Veteran denied current suicidal ideation, intent plan, and behavior. He endorsed concentration, memory and attention problems. Given the above, the Veteran's psychiatric symptoms, taken together, are consistent with the 70 percent rating criteria and below, and no more than occupational and social impairment with deficiencies in most areas, such as work, school, family relations, judgment, thinking, or mood, due to such symptoms as: suicidal ideation; obsessional rituals which interfere with routine activities. Notably, there is no evidence of persistent delusions or hallucinations; grossly inappropriate behavior; persistent danger of hurting self or others; intermittent inability to perform activities of daily living (including maintenance of minimal personal hygiene); disorientation to time or place; memory loss for names of close relatives, own occupation, or own name; or other symptoms of sufficient frequency, duration, and severity as to more closely approximate total and occupational impairment. Although the Veteran's symptoms include a memory impairment that causes him to forget appointments, tasks, and where he has placed objects, there is no indication that the Veteran's memory loss is of sufficient severity such that he forgets information including names for close relatives, his own occupation, or his own name. Similarly, although the Veteran has credibly reported experiencing agitation towards family members, there is no indication that his agitation rises to the level of persistent danger of hurting self or others. During the February 2022 examination, the Veteran appeared well-dressed and groomed, was oriented to person, time, place, and situation, and was cooperative and attentive. These behavioral findings are not consistent with total occupational and social impairment. Given the above, the criteria for a disability rating in excess of 70 percent for the service-connected neurocognitive disorder with TBI and vertigo based on behavioral/emotional impairment have not been met, and the benefit of the doubt doctrine is inapplicable. See 38 U.S.C. § 5107(b); Lynch, 21 F.4th at 776 (Fed. Cir. 2021). Given that the Veteran's sole psychiatric diagnosis is a neurocognitive disorder associated with his TBI, the Veteran does not have a psychiatric disorder that is separate and distinct from his TBI residuals. 38 C.F.R. § 4.14. Nonetheless, the Veteran's TBI residuals may be rated, in the alternative, based on cognitive and/or physical impairment. As explained under 38 C.F.R. § 4.124a, Diagnostic Code 8045, cognitive impairment is defined as decreased memory, concentration, attention, and executive functions of the brain. Executive functions are goal setting, speed of information processing, planning, organizing, prioritizing, self-monitoring, problem solving, judgment, decision making, spontaneity, and flexibility in changing actions when they are not productive. Not all of these brain functions may be affected in a given individual with cognitive impairment, and some functions may be affected more severely than others. In a given individual, symptoms may fluctuate in severity from day to day. Under Diagnostic Code 8045, cognitive impairment is evaluated under the table titled "Evaluation of Cognitive Impairment and Other Residuals of TBI Not Otherwise Classified." Subjective symptoms may be the only residual of a traumatic brain injury or may be associated with cognitive impairment or other areas of dysfunction. Under Diagnostic Code 8045, subjective symptoms that are residuals of a traumatic brain injury, whether or not they are part of cognitive impairment, are to be evaluated under the subjective symptoms facet in the table titled "Evaluation of Cognitive Impairment and Other Residuals of TBI Not Otherwise Classified." Physical (including neurological) dysfunction is to be evaluated based on the following list, under an appropriate diagnostic code: Motor and sensory dysfunction, including pain, of the extremities and face; visual impairment; hearing loss and tinnitus; loss of sense of smell and taste; seizures; gait, coordination, and balance problems; speech and other communication difficulties, including aphasia and related disorders, and dysarthria; neurogenic bladder; neurogenic bowel; cranial nerve dysfunctions; autonomic nerve dysfunctions; and endocrine dysfunctions. Ratings for cognitive impairment and other residuals of traumatic brain injury not otherwise classified are based on a table of 10 important facets related to cognitive impairment and subjective symptoms. A 100 percent evaluation is assigned if "total" is the level of evaluation for one or more facets. If no facet is "total," then the overall percentage evaluation is based on the highest facet. A 70 percent evaluation is assigned if "3" is the highest level of evaluation for any facet. If the highest level of evaluation for any facet is "2," then the appropriate disability rating is 40 percent. A 10 percent evaluation is warranted when the highest level of evaluation for any facet is "1." Finally, a noncompensable (0 percent) rating is assigned when the level of the highest facet is "0." There may be an overlap of manifestations of conditions evaluated under the table titled "Evaluation Of Cognitive Impairment And Other Residuals Of TBI Not Otherwise Classified" with manifestations of a comorbid mental or neurologic or other physical disorder that can be separately evaluated under another diagnostic code. In such cases, no more than one evaluation based on the same manifestations is to be assigned. If the manifestations of two or more conditions cannot be clearly separated, a single evaluation is assigned under whichever set of diagnostic criteria allows the better assessment of overall impaired functioning due to both conditions. However, if the manifestations are clearly separable, separate evaluations for each condition should be assigned. 38 C.F.R. § 4.124a, Diagnostic Code 8045 Note (1). The table titled "Evaluation Of Cognitive Impairment And Other Residuals Of TBI Not Otherwise Classified" provides evaluations (numeric designations of 0, 1, 2, 3, and total) for the following 10 facets: Impairment of memory, attention, concentration, executive functions; Impairment of Judgment; Impairment of Social Interaction; Impairment of Orientation; Impairment of Motor Activity; Impairment of Visual Spatial Orientation; Subjective Symptoms; Neurobehavioral Effects; Communication; and, Consciousness. However, the diagnostic criteria also note that any residual with a distinct diagnosis may be rated separately under another diagnostic code. In this case, the evidence persuasively shows that a disability rating in excess of 70 percent for the service-connected neurocognitive disorder with TBI and vertigo based on cognitive impairment and other residuals of traumatic brain injury not otherwise classified under 38 C.F.R. § 4.124a, Diagnostic Code 8045. During the rating period, in January 2021, April 2021, and February 2022, the Veteran received VA examinations regarding cognitive impairment and other residuals of TBI. The January 2021 examiner provided the highest level of evaluation for facets of disability; in this regard, the examiner made evaluations of "3" for the "orientation" and "neurobehavioral effects" facets. The April 2021 and February 2022 examiners did not make any facet evaluations in excess of "1." Accordingly, as no examiner during the rating period has evaluated any facet as "total," the criteria for a rating in excess of 70 percent for the service-connected neurocognitive disorder with TBI and vertigo based on cognitive impairment and other residuals of traumatic brain injury have not been met, and the benefit of the doubt doctrine is inapplicable. See 38 U.S.C. § 5107(b); Lynch, 21 F.4th at 776 (Fed. Cir. 2021). However, given that the Veteran has received a distinct diagnosis of vertigo as a symptom of his TBI, a separate disability rating for this symptom may be assigned under the criteria for rating peripheral vestibular disorders under 38 C.F.R. § 4.87, Diagnostic Code 6204. Under that code, a 30 percent, but no higher, is warranted. Diagnostic Code 6204 indicates that a 10 percent rating is assigned for occasional dizziness, and a maximum schedular 30 percent rating is warranted for occasional dizziness and staggering. Here, a February 2022 examiner for inner ear conditions noted that the Veteran had vertigo associated with his neurocognitive disorder that resulted in vertigo and staggering more than once weekly for a duration of 1 to 24 hours. As such, the criteria for the maximum 30 percent rating under Diagnostic Code 6204 are approximated. Next, application of 38 C.F.R. § 4.87, Diagnostic Code 6205, which rates Meniere's disease, would not result in a higher rating because Diagnostic Code 6205 requires cerebellar gait for disability ratings in excess of 30 percent; here, a cerebellar gait is not present. See February 2022 VA ear examination report. Given that the Veteran's neurocognitive disorder is rated based on emotional/behavioral impairment, rather than cognitive impairment, no symptoms associated with the now separately-rated vertigo overlap with the rating under 38 C.F.R. § 4.130, Diagnostic Code 9304, and as such, separate ratings do not constitute impermissible pyramiding. 38 C.F.R. § 4.14. Effective Date prior to September 29, 2020 for Assignment of a 70 Percent Rating The Veteran, through his representative, contends that an effective date of April 15, 2020 is warranted for assignment of a 70 percent rating for the service-connected neurocognitive disorder with TBI. He also contends that assignment of a TDIU, to include as due solely to the neurocognitive disorder with TBI, is warranted as of April 15, 2020; this contention is addressed in a separate section later in the decision. An effective date for an increased disability rating claim may date back as much as one year before the date of the claim for increase if it is factually "ascertainable that an increase in disability had occurred" within that timeframe. 38 U.S.C. § 5110(b)(2); 38 C.F.R. § 3.400(o)(2); Harper v. Brown, 10 Vet. App. 125, 126 (1997) (stating that § 3.400(o)(2) applies to claim where increase in disability precedes claim, providing that that claim is received within one year after increase, otherwise general rule in § 3.400(o)(1) applies). Nevertheless, the effective date for an increased disability rating, initial rating, or staged rating is predicated on when the increase in the level of disability can be ascertained. Swain v. McDonald, 27 Vet. App. 219, 224 (2015). Initially, as noted in the Introduction, the Veteran's claim for increased rating for the neurocognitive disorder with TBI was received on September 29, 2020. Therefore, September 29, 2020 is considered to be the date of claim. The Veteran contends that an April 15, 2020 private treatment record demonstrates that his neurocognitive disorder had ascertainably worsened since his last evaluation. In this regard, the treatment record in question indicates that the Veteran's "memory and cortical functions are grossly reduced" to the extent that the Veteran required written reminders to complete tasks and attend appointments. See private treatment record dated April 15, 2020. See also November 2022 Appellate Brief. However, the Veteran's remaining medical records suggest that the impairments noted by the April 2020 private treatment provider were present more than one year prior to the date of claim. In this regard, during an April 2019 VA TBI examination, the Veteran reported that "he loses keys, misplaces items, forgets names and numbers." Furthermore, he indicated that he "[w]rites himself notes [and] uses calendars." Notably, an earlier March 2016 private treatment note from the same provider indicated that the Veteran's "memory and other cortical functions are grossly reduced with [mini-mental state examination] (MMSE) of 28/30. See private treatment record dated March 1, 2016. Private treatment records dated during the year prior to the April 15, 2020 claim provide nearly identical assessments of the Veteran's memory and cortical function, to include identical results on MMSE exams. See, e.g., private treatment record dated May 13, 2020. Given the above, the evidence persuasively shows that the Veteran's neurocognitive disorder with TBI did not worsen during the one-year period prior to the April 15, 2020 increased rating claim; rather, the evidence suggests that the Veteran's neurocognitive disorder did not worsen within the one-year period prior to the claim, or alternatively, worsened prior to the one year period preceding the claim. Therefore, the proper effective date for the assignment of a 70 percent rating for the cognitive disorder with TBI is the date of claim, or April 15, 2020, and the benefit of the doubt doctrine is inapplicable. See 38 U.S.C. § 5107(b); Lynch, 21 F.4th at 776 (Fed. Cir. 2021). 7. Entitlement to a disability rating in excess of 40 percent for the service-connected bilateral hearing loss disability for the period on appeal prior to February 15, 2022. 8. Entitlement to a disability rating in excess of 60 percent for the service-connected bilateral hearing loss disability for the period on appeal from February 15, 2022. Impaired hearing is defined as a disability under VA law when the auditory threshold in any of the frequencies 500, 1000, 2000, 3000, 4000 Hertz is 40 decibels (dB) or greater; or when the auditory thresholds for at least three of the frequencies 500, 1000, 2000, 3000, or 4000 Hertz are 26 decibels or greater; or when speech recognition scores using the Maryland CNC Test are less than 94 percent. 38 C.F.R. § 3.385. The threshold for normal hearing is from 0 to 20 decibels; higher threshold levels indicate some degree of hearing loss. Hensley v. Brown, 5 Vet. App. 155, 157 (1993). Relevant laws and regulations stipulate that evaluations of defective hearing range from noncompensable to 100 percent based on the organic impairment of hearing acuity. Hearing impairment is measured by the results of controlled speech discrimination tests together with the average hearing threshold levels (which in turn, are measured by pure tone audiometric tests in the frequencies of 1000, 2000, 3000 and 4000 cycles per second (Hertz)). See Lendenmann v. Principi, 3 Vet. App. 345, 349 (1992) (defective hearing is rated based on a mere mechanical application of the rating criteria). The provisions of 38 C.F.R. § 4.85 establish eleven auditory acuity levels from I to XI. If hearing loss is service-connected for only one ear, in order to determine the percentage evaluation from Table VII, the non-service-connected ear will be assigned a Roman numeral designation for hearing impairment of I. 38 C.F.R. § 4.85(f). Tables VI and VII as set forth in section 4.85(h) are used to calculate the rating to be assigned. For cases involving exceptional patterns of hearing impairment, the schedular criteria provides that, when the pure tone threshold at each of the four specified frequencies (1000, 2000, 3000 and 4000 Hertz) is 55 decibels or more, the rating specialist will determine the Roman numeral designation for hearing impairment from either Table VI or Table VIa, whichever results in the higher numeral. 38 C.F.R. § 4.86(a). Each ear is evaluated separately. Additionally, when the pure tone threshold is 30 decibels or less at 1000 Hertz, and 70 decibels or more at 2000 Hertz, the rating specialist will determine the Roman numeral designation for hearing impairment from either Table VI or Table VIa, whichever results in the higher numeral. The numeral will then be elevated to the next higher Roman numeral. 38 C.F.R. § 4.86(b). Each ear will be evaluated separately. In addition to dictating objective test results, a VA audiologist must fully describe the functional effects caused by a hearing disability in his or her final report. See Martinak v. Nicholson, 21 Vet. App. 447, 455 (2007). In this case, the evidence persuasively weighs against assignment of a disability rating in excess of 40 percent prior to February 15, 2022 and a disability rating in excess of 60 percent from February 15, 2022 for the service-connected bilateral hearing loss disability. During the rating period, the Veteran received an initial VA examination for his bilateral hearing loss disability in January 2021. The puretone thresholds in decibels recorded during the examination were as follows: Hertz 500 Hz 1000 Hz 2000 Hz 3000 Hz 4000 Hz Right 35 40 75 100 105 Left 40 65 85 95 95 Average puretone thresholds were 80 decibels for the right ear and 85 decibels for the left ear. Speech discrimination testing using the Maryland CNC word list revealed scores of 70 percent for the right ear and 72 percent for the left ear. The examiner certified that use of speech discrimination was appropriate. Finally, functional impairments documented by the examiner included, as stated by the Veteran, the need for people to repeat themselves, resulting in frustration to the Veteran. The Veteran next received a VA examination for his bilateral hearing loss disability in April 2021. The puretone thresholds in decibels recorded during the examination were as follows: Hertz 500 Hz 1000 Hz 2000 Hz 3000 Hz 4000 Hz Right 25 45 75 90 100 Left 45 75 85 100 105 Average puretone thresholds were 78 decibels for the right ear and 91 decibels for the left ear. Speech discrimination testing using the Maryland CNC word list revealed scores of 84 percent for the right ear and 70 percent for the left ear. The examiner certified that use of speech discrimination was appropriate. Finally, functional impairments documented by the examiner included, as stated by the Veteran, "[p]eople always sound as if they are mumbling" with regard to "[s]peech, speech in noise, the TV, and the phone." The Veteran most recently received a VA examination for his bilateral hearing loss disability in February 2022. The puretone thresholds in decibels recorded during the examination were as follows: Hertz 500 Hz 1000 Hz 2000 Hz 3000 Hz 4000 Hz Right 45 50 80 105+ 105+ Left 40 70 85 105 105 Average puretone thresholds were 85 decibels for the right ear and 91.25 decibels for the left ear. Speech discrimination testing using the Maryland CNC word list revealed scores of 70 percent for the right ear and 38 percent for the left ear. The examiner certified that use of speech discrimination was appropriate. Finally, functional impairments documented by the examiner included, as stated by the Veteran, "without my aids in I cannot understand TV or people." Initially, there is no evidence that the Veteran suffers from an exceptional pattern of hearing impairment in his right ear as defined by 38 C.F.R. § 4.86; however, as noted in each audiogram result listed above, the left ear puretone thresholds in decibels at 1000 Hz, 2000 Hz, 3000 Hz and 4000 Hz are all above 55. Accordingly, the Veteran's left ear hearing loss meets the criteria for an exceptional pattern of hearing under 38 C.F.R. § 4.86(a). First, regarding the period prior to February 15, 2022, application of the Veteran's puretone threshold averages and speech discrimination scores from the January 2021 VA examination to 38 C.F.R. § 4.85, Table VI results in numerical hearing impairments of Level VI for the right ear and Level VII for the left ear. Application of the puretone threshold average for the left ear from the January 2021 VA examination using 38 C.F.R. § 4.85, Table VIa results in a hearing impairment of Level VIII for the left ear. Combining Level VI impairment for the right ear and Level VIII impairment for the left ear using 38 C.F.R. § 4.85, Table VII results in a 30 percent disability rating. Next, application of the Veteran's puretone threshold averages and speech discrimination scores from the April 2021 VA examination to 38 C.F.R. § 4.85, Table VI results in numerical hearing impairments of Level III for the right ear and Level VII for the left ear. Application of the puretone threshold average for the left ear from the April 2021 VA examination using 38 C.F.R. § 4.85, Table VIa results in a hearing impairment of Level IX for the left ear. However, combining the numerical hearing impairment of Level VI for the right ear during the January 2021 examination and Level IX for the left ear during the April 2021 examination using 38 C.F.R. § 4.85, Table VII results in a 40 percent disability rating. Combining Level III impairment for the right ear and Level IX impairment for the left ear using 38 C.F.R. § 4.85, Table VII results in a 20 percent disability rating. Finally, regarding the period from February 15, 2022, application of the Veteran's puretone threshold averages and speech discrimination scores from the February 2022 VA examination to 38 C.F.R. § 4.85, Table VI results in numerical hearing impairments of Level VII for the right ear and Level X for the left ear. Application of the puretone threshold average for the left ear from the February 2022 VA examination using 38 C.F.R. § 4.85, Table VIa results in a hearing impairment of Level X for the left ear. Combining Level VII impairment for the right ear and Level X for the left ear using 38 C.F.R. § 4.85, Table VII results in a 60 percent disability rating. Importantly, as noted above, the assignment of disability ratings for hearing impairment is derived primarily from a mechanical formula based on levels of puretone threshold average and speech discrimination. See Lendenmann, 3 Vet. App. at 345. All examinations described above recorded findings regarding the functional impact of the Veteran's bilateral hearing loss disability on his daily life and occupational functioning. Martinak, 21 Vet. App. at 455-56. In particular, functional impairments included difficulty understanding in-person speech, phone speech, and speech on the television. However, functional impairment such as difficulty hearing speech is contemplated by the schedular criteria for hearing loss. See Doucette v. Shulkin, 28 Vet. App. 366 (2017). Accordingly, there is no basis for consideration of an extraschedular rating. Given the above, the evidence persuasively shows that the criteria for a disability rating in excess of 40 percent prior to February 15, 2022 and a disability rating in excess of 60 percent from February 15, 2022 for the service-connected bilateral hearing loss disability have not been met. Accordingly, a disability rating in excess of 40 percent prior to February 15, 2022 and in excess of 60 percent from February 15, 2022 is not warranted, and the benefit of the doubt doctrine is inapplicable. 38 U.S.C. § 5107(b); Lynch, 21 F.4th at 776. 9. Entitlement to a disability rating in excess of 10 percent for the service-connected tinnitus. The Veteran's tinnitus is currently assigned a 10 percent rating under 38 C.F.R. § 4.87, Diagnostic Code 6260. The 10 percent rating under Diagnostic Code 6260 is the only and highest rating available for tinnitus. There is no legal basis for assignment of a higher schedular disability rating. Neither the Veteran nor his representative have submitted any evidence or argument as to why a higher disability rating is warranted. During the April 2021 VA examination, the Veteran reported that he finds the "ringing very tiring and disturbing at night" and during the February 2022 examination, he reported that his tinnitus "drives me up a wall if I focus on it." There is no lay or medical evidence indicating that the aggravation that the Veteran feels due to tinnitus results in an exceptional disability picture warranting consideration of an extraschedular rating. Furthermore, the rating criteria specifically contemplates ringing in the ears, which one would expect to be bothersome. See Doucette, 28 Vet. App. at 366. Because the schedular criteria contemplate ringing in the ears and there are no other symptoms not contemplated by the rating criteria for tinnitus, referral for consideration of the assignment of a disability evaluation on an extraschedular basis is not warranted. See Long v. Wilkie, 33 Vet. App. 167, 173 (2020); Thun v. Peake, 22 Vet. App. 111, 115-116 (2008). Given the above, the evidence persuasively weighs against assignment of a disability rating in excess of 10 percent for the service-connected tinnitus, and the benefit of the doubt doctrine is inapplicable. 38 U.S.C. § 5107(b); Lynch, 21 F.4th at 776. 10. Entitlement to a compensable disability rating for the service-connected deviated septum. The Veteran's service-connected deviated septum is rated under 38 C.F.R. § 4.97, Diagnostic Code 6502. Under Diagnostic Code 6502, a 10 percent rating is warranted with 50-percent obstruction of the nasal passage on both sides or complete obstruction on one side. In this case, the evidence persuasively shows that a compensable disability rating for the service-connected deviated septum is not warranted. In this regard, there is no evidence of at least 50-percent obstruction of the nasal passage on both sides or complete obstruction on one side. Specifically, a February 2022 examiner indicated that, while the deviated septum was traumatic in origin, there was not at least 50-percent obstruction of the nasal passage on both sides or complete obstruction on one side due to traumatic nasal septal deviation. There was no evidence of respiratory complications, such as acute respiratory distress or obstructive sleep apnea (OSA), due to the deviated septum and no documented functional impact. Finally, there is no evidence that the service-connected deviated septum results in an exceptional disability picture warranting consideration of an extraschedular rating. There is no evidence of any symptom related to the deviated septum that is not contemplated by the rating criteria. See Doucette, 28 Vet. App. at 366. Given the above, referral for consideration of an extraschedular rating is not warranted. See Long, 33 Vet. App. at 173; Thun, 22 Vet. App. at 115-116. Accordingly, the criteria for a compensable disability rating for the service-connected deviated septum have not been met, and the benefit of the doubt doctrine is inapplicable. 38 U.S.C. § 5107; Lynch, 21 F.4th at 776(b). TDIU 11. Entitlement to a TDIU due to service-connected disabilities for the period on appeal prior to September 29, 2020. The Veteran, through his representative, contends that the effective date for assignment of a TDIU should be April 15, 2020, the date of the treatment record cited by the Veteran's representative as evidence of worsening of the neurocognitive disorder with TBI, instead of the currently assigned date of September 29, 2020. As noted above, an effective date for an increased disability rating claim (including TDIU) may date back as much as one year before the date of the claim for increase if it is factually "ascertainable that an increase in disability had occurred" within that timeframe. 38 U.S.C. § 5110(b)(2); 38 C.F.R. § 3.400(o)(2); Harper, 10 Vet. App. at 126 (1997). Total disability ratings for compensation may be assigned where the schedular rating is less than total, when the disabled person is unable to secure or follow a substantially gainful occupation as a result of service-connected disabilities, provided that, if there is only one such disability, this disability shall be ratable at 60 percent or more, or if there are two or more disabilities, there shall be at least one ratable at 40 percent or more, and sufficient additional disability to bring the combined rating to 70 percent or more. 38 C.F.R. §§ 3.340, 3.341, 4.16(a). Even when the percentage requirements are not met, entitlement to a total rating, on an extraschedular basis, may nonetheless be granted in exceptional cases, when the veteran is unable to secure and follow a substantially gainful occupation by reason of service-connected disabilities. 38 C.F.R. § 4.16(b). In Faust v. West, 13 Vet. App. 342 (2000), the Court defined "substantially gainful employment" as an occupation that provides an annual income that exceeds the poverty threshold for one person, irrespective of the number of hours or days that a veteran actually works and without regard to a veteran's earned annual income. In Hatlestad v. Derwinski, 5 Vet. App. 524, 529 (1993), the Court held that the central inquiry in determining whether a veteran is entitled to TDIU is whether a veteran's service-connected disabilities alone are of sufficient severity to produce unemployability. The determination as to whether a total disability is appropriate should not be based solely upon demonstrated difficulty in obtaining employment in one particular field, which could also potentially be due to external bases such as economic factors, but rather to all reasonably available sources of employment under the circumstances. See Ferraro v. Derwinski, 1 Vet. App. 326, 331-32 (1991). The sole fact that a veteran is unemployed or has difficulty obtaining employment is not enough. The Veteran first met the schedular threshold percentage requirements for consideration of a TDIU under 38 C.F.R. § 4.16(a) as of January 10, 2018. As of that date, the Veteran's service-connected disabilities included neurocognitive disorder with TBI and vertigo, rated as 50 percent disabling, migraine headaches, rated as 50 percent disabling, a bilateral hearing loss disability, rated as 40 percent disabling, tinnitus, rated as 10 percent disabling, and a forehead scar, rated as 10 percent disabling. The combined disability rating was 90 percent. As noted above in the effective date discussion regarding the neurocognitive disorder with TBI, VA received the Veteran's claim for increased rating for neurocognitive disorder with TBI and vertigo on September 29, 2020. During the course of appeal, in January 2021, VA received the Veteran's claim for a TDIU. As such, the claim for TDIU was taken as part and parcel of the increased rating appeal; ultimately, a May 2022 rating decision assigned an effective date of September 29, 2020 for assignment of a TDIU. The Veteran, through his representative, contends that the April 15, 2020 private treatment record indicates that the Veteran's neurocognitive disorder with TBI and vertigo had ascertainably worsened to the point that the Veteran could no longer maintain substantially gainful employment, to include as due to the neurocognitive disorder with TBI and vertigo alone. To reiterate, the treatment record in question indicates that the Veteran's "memory and cortical functions are grossly reduced" to the extent that the Veteran required written reminders to complete tasks and attend appointments. See private treatment record dated April 15, 2020. In a VA Form 21-8940 Veteran's Application for Increased Compensation Based on Unemployability, the Veteran indicated that he had last worked as a cashier and operator at a bait and tackle shop in September 1996. He had prior experience as a branch manager at a financial services company. He completed high school to the eleventh grade and also had several months of real estate agent training. Nonetheless, the treatment record cited by the Veteran's representative does not indicate that the Veteran's neurocognitive disorder with TBI and vertigo had ascertainably worsened within the one year prior to the September 29, 2020 claim for increased rating such that the Veteran would have been unable to maintain substantially gainful employment. As discussed above, the symptoms and impairment described by the April 15, 2020 were factually ascertainable more than one year prior to the September 29, 2020 date of claim. See April 2019 VA TBI examination report; private treatment record dated March 1, 2016. As discussed above, the April 15, 2020 treatment note does not discuss symptoms that were ascertainably more severe than symptoms previously documented prior to the one-year period preceding the September 29, 2020 claim, to include as relates to occupational impairment. Given the above, the evidence persuasively suggests that the Veteran's service-connected neurocognitive disorder with TBI and vertigo did not ascertainably worsen within the one year prior to the September 29, 2020 claim such as to demonstrate inability to maintain substantially gainful employment; as such, the proper effective date for the assignment of a TDIU is the September 29, 2020 date of claim for increase, and the benefit of the doubt doctrine is inapplicable. 38 U.S.C. § 5107(b); Lynch, 21 F.4th at 776. Nonetheless, discussion of whether the Veteran's TDIU is based solely on the neurocognitive disorder with TBI and vertigo is discussed in the "SMC" section below. DEA 12. Entitlement to eligibility for DEA benefits under 38 U.S.C. Chapter 35 for the period on appeal prior to September 29, 2020. DEA benefits are payable to the child, spouse, or surviving spouse of a veteran if the following conditions are met: (1) the veteran was discharged from service under conditions other than dishonorable, or died in service; and (2) the veteran has a permanent total service-connected disability; or (3) a permanent total service-connected disability was in existence at the date of the Veteran's death; or (4) the Veteran died as a result of a service-connected disability. 38 U.S.C. § 3510; 38 C.F.R. § 3.807(a). In this case, a TDIU has been assigned, September 29, 2020; as such, as of September 29, 2020, the Veteran had a permanent total service-connected disability. However, as discussed above, September 29, 2020, or the date of claim for the TDIU, is the earliest date that a permanent total rating may be assigned. Accordingly, there is no basis under which to award DEA eligibility under 38 U.S.C. Chapter 35 prior to the current effective date of September 29, 2020. SMC 13. Entitlement to assignment of SMC at the statutory housebound rate under 38 U.S.C. § 1114(s). As noted above, the Veteran, through his representative, contends that his TDIU is due solely to his service-connected neurocognitive disorder with TBI and, therefore, that SMC at the statutory housebound rate under 38 U.S.C. § 1114(s) is warranted. Under subsection 1114(s), SMC housebound benefits are not available to a veteran who has a combined 100 percent disability rating unless at least one of the service-connected disabilities is singly rated at 100 percent (and there are additional service-connected disabilities independently ratable at 60 percent or higher). However, the United States Court of Appeals (Court) has held that 38 U.S.C. § 1114 (s) for housebound benefits does not limit "a service-connected disability rated as total" to only a schedular rating of 100 percent, and that 38 C.F.R. § 3.350 (i) permits a TDIU rating based on a single disability to satisfy the statutory requirement of a single service-connected disability rated as total. Bradley, 22 Vet. App. at 293 (2008). In other words, if the TDIU is predicated on a single service-connected disability rated less than 100 percent, it may nevertheless serve as a single 100 percent disability rating for purposes of establishing entitlement under 38 U.S.C. § 1114(s). A TDIU rating based on a single disability that satisfies the total (100 percent) rating requirement must be separate and distinct from the additional service-connected disability or disabilities independently ratable at 60 percent or more for purposes of establishing entitlement to SMC at the housebound rate. Id.; see also, Buie, 24 Vet. App. at 250-51. The Court also declared that the direction to treat multiple disabilities as one under 38 C.F.R. § 4.16(a) was specifically limited to TDIU ratings. A TDIU rating based on multiple service-connected disabilities does not satisfy the criteria for one total disability rating in considering entitlement to housebound benefits under 38 U.S.C. § 1114(s). Bradley, 22 Vet. App. at 290-91. In this case, the evidence is at least evenly balanced as to whether the Veteran's TDIU is due solely to his service-connected neurocognitive disorder with TBI. As noted in the Introduction, a March 2022 rating decision granted entitlement to a TDIU, effective March 23, 2021, and the subsequent May 2022 decision granted an earlier effective date of September 29, 2020 for the assignment of a TDIU. Review of the March 2022 rating decision indicates that the RO granted a TDIU based on the "neurocognitive disorder and vertigo and bilateral hearing loss." Although the decision noted an audiological finding of "sloping to profound hearing loss," the remaining findings are related to the neurocognitive disorder with the TBI and vertigo, including "falling down periodically, anxiety, depression, irritability/anger, short-term memory problems and sleep disturbance." Regarding the bilateral hearing loss disability, there is no evidence that the functional impact of the hearing loss could not be remedied in an occupational environment with correction or by reasonable accommodations consistent with Americans with Disabilities Act (ADA) guidelines. There was no discussion of the Veteran's remaining disabilities not associated with his TBI in the March 2022 decision. Given the above, and resolving reasonable doubt in the Veteran's favor, the Veteran's TDIU is due solely to the service-connected neurocognitive disorder with TBI and vertigo. Based on the above finding, assignment of SMC payable at the statutory housebound rate under 38 U.S.C. § 1114(s) is warranted from February 15, 2022, but no earlier. Specifically, prior to February 15, 2022, the Veteran did not have a single disability rated at 100 percent and additional separate and distinct disabilities independently ratable as at least 60 percent disabling. Here, service connection for Veteran's migraine headaches and vertigo was granted as complications of the service-connected neurocognitive disorder with TBI. These disabilities stem from the same anatomical segment or bodily system the brain; and, they are essentially symptoms or disabilities associated with the TBI, the same disability for which the TDIU is assigned. 38 C.F.R. § 3.350(i). As such, the Veteran's additional disabilities of migraine headaches and vertigo are not separate and distinct from the service-connected neurocognitive disorder with TBI and cannot combine to an additional 60 percent rating to support assignment of SMC at the statutory housebound rate prior to February 15, 2022. However, as of February 15, 2022, the Veteran has a single service-connected disability and additional separate and distinct disabilities independently ratable at 60 percent disabling. Specifically, as of February 15, 2022, the Veteran's bilateral hearing loss disability is rated as 60 percent disabling. The bilateral hearing loss disability is service-connected based on in-service noise exposure rather than as proximately due to the neurocognitive disorder with TBI, see July 2004 rating decision, and involves the auditory, rather than neurological, anatomical segment or bodily system. Accordingly, as of February 15, 2022, the criteria for assignment of SMC at the statutory housebound rated under 38 U.S.C. § 1114(s) have been met. L. B. CRYAN Veterans Law Judge Board of Veterans' Appeals Attorney for the Board D. Small, Attorney Advisor The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.