How to Fight Insurance Denials for Neurology Drugs: Alzheimer's, Parkinson's, ALS, Epilepsy

Neurology denials are among the most frustrating in medicine because they affect diseases that progress quickly—Alzheimer's disease, Parkinson's, ALS, drug-resistant epilepsy, and Huntington's disease. Insurers deny expensive neurology drugs and procedures for predictable reasons: they call anti-amyloid antibodies "experimental" despite FDA approval, invoke outdated policies written before new drugs existed, demand step therapy through cheaper generics even when those have failed, or cite missing documentation that your neurologist didn't know was required. This guide walks you through the most common denial templates, the specific guidelines and trial data that overturn them, and how to build an appeal that forces reconsideration.

Why Insurers Deny Neurology Treatments

1. "Experimental or investigational"

This is the default denial for newer drugs, especially anti-amyloid monoclonal antibodies (Leqembi, Kisunla), SOD1-targeted ALS therapy (Qalsody), and cannabidiol for epilepsy (Epidiolex). Insurers use outdated medical policies written before FDA approval or pivot trials published results. For Medicare Advantage plans denying Leqembi or Kisunla, they sometimes ignore or misapply CMS National Coverage Determination (NCD) 200.3, which mandates coverage with Coverage with Evidence Development (CED) registry enrollment.

2. "Does not meet medical necessity criteria"

The insurer acknowledges the drug is approved but claims your case doesn't fit their internal checklist. Common examples: claiming your MMSE score is too low or too high for anti-amyloid therapy (Leqembi and Kisunla require MMSE 22–30 or equivalent MoCA ≥17), that you lack amyloid-positive biomarker confirmation (required for anti-amyloid mAbs), or that Qalsody is denied because genetic SOD1 mutation wasn't submitted. For Deep Brain Stimulation (DBS), insurers claim "motor fluctuations" aren't documented or disease duration is too short.

3. "Step therapy not completed"

The insurer demands you try and fail older, cheaper drugs first—donepezil/rivastigmine/galantamine before anti-amyloid mAbs, generic immediate-release carbidopa-levodopa before Rytary or Crexont, generic levetiracetam and lamotrigine before Epidiolex or Fintepla. Often the denial ignores that you've already tried and failed those drugs, or that step therapy doesn't make clinical sense (e.g., demanding donepezil before Leqembi when they treat different disease mechanisms).

4. "Lack of supporting documentation"

The insurer claims your neurologist didn't submit required test results—amyloid PET or CSF/plasma biomarkers for Alzheimer's drugs, genetic confirmation of SOD1 mutation for Qalsody, EMG confirming lower motor neuron signs for ALS, documented seizure frequency and prior antiepileptic drug (AED) failures for drug-resistant epilepsy, or MRI surveillance plan for anti-amyloid therapy (to monitor for ARIA—amyloid-related imaging abnormalities). For Medicare and Medicare Advantage, anti-amyloid denials often hinge on missing proof of CED registry enrollment.

5. "Cost: equally effective alternatives exist"

The insurer substitutes a cheaper option they claim is equivalent: generic donepezil instead of Leqembi, standard carbidopa-levodopa instead of Rytary, riluzole instead of Qalsody, generic clobazam instead of Epidiolex. This argument ignores mechanism of action (anti-amyloid mAbs clear plaques; donepezil is a cholinesterase inhibitor), disease-specific approval (Qalsody targets SOD1-ALS; riluzole is nonspecific), and documented intolerance or failure of generics.

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The Citations Insurers Respect

Neurology appeals succeed when you cite specific named guidelines and pivotal trials. Do not let your neurologist write a generic letter. These are the references that carry weight:

Alzheimer's Disease (Anti-Amyloid Monoclonal Antibodies)

• CMS National Coverage Determination (NCD) 200.3 (revised 2023): Mandates Medicare coverage of FDA-approved anti-amyloid mAbs (Leqembi, Kisunla) only for patients enrolled in a CMS-approved CED registry and treated by qualified dementia specialists. Medicare Advantage plans must follow NCD 200.3. This is the single most-missed citation in Leqembi/Kisunla denials.
• Clarity-AD trial (van Dyck et al., NEJM 2023): Phase 3 trial of lecanemab (Leqembi) showing 27% slowing of cognitive decline (CDR-SB) at 18 months in early Alzheimer's with confirmed amyloid pathology.
• TRAILBLAZER-ALZ 2 trial (Sims et al., JAMA 2023): Phase 3 trial of donanemab (Kisunla) showing up to 35% slowing in low/medium tau participants; defines eligible population by amyloid PET and tau PET.
• AAN 2018 Practice Guideline: Mild Cognitive Impairment (Petersen et al.): Defines MCI workup and assessment; supports amyloid biomarker testing in appropriate clinical context.
• Appropriate Use Criteria for Amyloid PET (Amyloid Imaging Task Force, Alzheimer's & Dementia 2013, updated 2024): Establishes when amyloid imaging is medically necessary for diagnosis.

Parkinson's Disease

• MDS Clinical Diagnostic Criteria for Parkinson's Disease (Postuma et al., Movement Disorders 2015): International consensus diagnostic framework; insurers cite this for PD confirmation.
• Bronstein et al., NEJM 2011 (EARLYSTIM trial): Pivotal trial showing DBS benefit in PD patients with ≥4 years disease duration and motor fluctuations despite optimized medical therapy; basis for coverage policies.
• AAN 2006 DBS Guideline (updated references in subsequent literature): Early framework for patient selection; most insurers now reference Bronstein.

ALS (Amyotrophic Lateral Sclerosis)

• El Escorial and Gold Coast Criteria: Diagnostic standards for ALS (combinations of upper and lower motor neuron signs across spinal regions); required for any ALS drug approval.
• VALOR trial (Miller et al., NEJM 2022): Phase 3 trial of tofersen (Qalsody) in SOD1-mutation ALS; showed slowing of neurofilament light chain (NfL) decline, leading to accelerated FDA approval. Qalsody is only for genetically confirmed SOD1-ALS.
• FDA accelerated approval letter for Qalsody (April 2023): Explicitly restricts indication to patients with documented SOD1 mutation.

Epilepsy

• ILAE 2010 Definition of Drug-Resistant Epilepsy (Kwan et al., Epilepsia 2010): Defines drug resistance as failure of adequate trials of two tolerated, appropriately chosen AED schedules (whether as monotherapy or combination). This is the gold standard for justifying Epidiolex, Fintepla, or other branded drugs.
• GWPCARE trials (Devinsky et al., NEJM 2017, 2018): Phase 3 trials of cannabidiol (Epidiolex) in Dravet syndrome and Lennox-Gastaut syndrome; median seizure reduction ~40%. FDA approval basis.
• Fintepla pivotal trials (Lagae et al., Lancet 2020): Phase 3 data for fenfluramine in Dravet syndrome; showed median 54% seizure reduction.

Huntington's Disease (Chorea)

• FDA approval summaries for Austedo and Ingrezza: Both deutetrabenazine (Austedo) and valbenazine (Ingrezza) are approved for chorea associated with Huntington's disease and for tardive dyskinesia. Pivotal trials documented in approval letters and package inserts.
• Huntington Study Group data: UHDRS (Unified Huntington's Disease Rating Scale) is the standard functional measure; cite baseline and post-treatment scores.

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How to Argue Against Each Denial Reason

1. Fighting "Experimental or Investigational"

For anti-amyloid mAbs (Leqembi, Kisunla):

• Step one: Cite FDA approval date—Leqembi accelerated approval January 2023, traditional approval July 2023; Kisunla approval July 2024. State: "This is not investigational; it is fully FDA-approved under traditional pathway."
• Step two: If you have Medicare or Medicare Advantage, cite NCD 200.3 verbatim. State: "CMS mandates coverage of FDA-approved monoclonal antibodies directed against amyloid for the treatment of Alzheimer's disease when furnished in accordance with CED requirements. I am enrolled in CMS-approved registry [insert registry name/NCT number]. My prescriber is [neurologist name], a qualified dementia specialist."
• Step three: Attach evidence of CED registry enrollment (your neurologist should have this). Attach amyloid-positive biomarker result (PET scan report showing amyloid positivity, or CSF Aβ42/40 ratio + p-tau, or plasma p-tau217 result).
• Step four: Cite pivotal trial—Clarity-AD for Leqembi, TRAILBLAZER-ALZ 2 for Kisunla—and state your clinical profile matches inclusion criteria (early AD, MMSE 22–30 or MoCA ≥17, amyloid-positive).
• Step five: Note MRI surveillance plan to monitor for ARIA (your neurologist should document MRI schedule per prescribing information—typically pre-treatment, then intervals during titration).

For Qalsody (SOD1-ALS):

• Step one: Cite FDA accelerated approval April 2023 under the agency's accelerated approval pathway for serious conditions.
• Step two: Attach genetic test report confirming SOD1 mutation (gene variant, e.g., A4V, D90A). State: "Qalsody's FDA indication is restricted to patients with ALS who have a confirmed SOD1 mutation. My genetic test [date] confirms [mutation]."
• Step three: Cite VALOR trial, emphasizing reduction in plasma NfL (neurofilament light chain, a marker of neuronal injury).
• Step four: State ALS diagnosis meets El Escorial or Gold Coast criteria; attach EMG report showing lower motor neuron findings in ≥2 regions and clinical upper motor neuron signs.

For Epidiolex (cannabidiol for epilepsy):

• Step one: Cite FDA approval June 2018 for Dravet syndrome and Lennox-Gastaut syndrome, and subsequent approval for tuberous sclerosis complex (TSC)-associated seizures. This is not "marijuana"; it is pharmaceutical-grade CBD, DEA-scheduled, with rigorous trial data.
• Step two: Cite GWPCARE trials showing ~40% median seizure reduction.
• Step three: Document ILAE-defined drug-resistant epilepsy: list ≥2 prior AEDs tried at therapeutic doses for adequate duration (typically ≥8–12 weeks), with dates, max doses, and reason for failure or intolerance.

2. Fighting "Does Not Meet Medical Necessity"

Missing or "wrong" biomarkers (anti-amyloid mAbs):

If the insurer says "no proof of amyloid pathology," your neurologist must submit the amyloid PET report, CSF biomarker report (Aβ42/40 ratio, p-tau181 or p-tau217), or plasma p-tau217 result. Cite Appropriate Use Criteria for Amyloid PET to justify why the test was ordered. If the denial claims "tau too high" (a criterion in TRAILBLAZER-ALZ 2 for Kisunla), cite the trial's tau-PET inclusion/exclusion data and whether your tau PET (if performed) falls within intermediate tau or your clinician's rationale for proceeding.

MMSE/MoCA score "out of range":

Leqembi and Kisunla trials enrolled patients with MMSE 22–30 (or MoCA ≥17, roughly equivalent to mild cognitive impairment or mild dementia). If your score is 21 and the insurer denies, cite Clarity-AD protocol inclusion criteria and argue one-point variance is within measurement error (MMSE has ±3-point test-retest variability). If your score is 31 (normal), the denial is correct—anti-amyloid mAbs are for symptomatic early AD, not prevention.

SOD1 mutation not documented (Qalsody):

This is a documentation fix. Obtain the genetic test report from your neurologist or testing lab (Invitae, GeneDx, academic center). The report must explicitly state "pathogenic or likely pathogenic variant in SOD1 gene." Attach it to appeal. If no test was done, Qalsody is not appropriate—SOD1 mutations account for ~2% of ALS cases; the drug does not work in non-SOD1 ALS.

DBS "medical therapy not exhausted":

Insurers demand documented trial of multiple PD medications at optimized doses and clear motor fluctuations despite medication. Your neurologist should document: disease duration ≥4 years, trial of levodopa (with clear initial benefit, proving levodopa-responsiveness), trial of ≥1 dopamine agonist or MAO-B inhibitor, presence of motor fluctuations (wearing-off, dyskinesias), and MDS-UPDRS Part III scores on/off medication. Cite Bronstein et al., NEJM 2011 showing DBS benefit at this stage.

3. Fighting Step Therapy Denials

Insurers cannot impose step therapy that contradicts the standard of care or that you have already completed.

Anti-amyloid mAbs after cholinesterase inhibitor "failure":

Donepezil, rivastigmine, and galantamine are symptomatic treatments (cholinesterase inhibitors); they do not modify amyloid pathology. Leqembi and Kisunla are disease-modifying therapies targeting amyloid plaques. Cite the AAN 2018 MCI Guideline and Clarity-AD/TRAILBLAZER-ALZ 2 background sections explaining that anti-amyloid mAbs represent a different mechanism. State: "Step therapy through cholinesterase inhibitors does not address amyloid burden and delays disease-modifying treatment during the narrow early-AD window."

Branded PD drugs (Rytary, Inbrija, Ongentys, Gocovri) after generic trial:

If you have documented trial of immediate-release carbidopa-levodopa with intolerable peaks/troughs or wearing-off, and your neurologist prescribed extended-release formulation (Rytary/Crexont) or adjunct (Ongentys, Gocovri), state in appeal: "I have completed adequate trial of generic carbidopa-levodopa [dates, doses]. Despite optimization, I experience motor fluctuations [describe]. Rytary/adjunct is the next step per MDS treatment algorithm."

Branded AEDs (Epidiolex, Fintepla, Briviact, Vimpat) after generic failures:

Cite ILAE 2010 drug-resistant epilepsy definition. List each prior AED, dose, duration (must be ≥8 weeks at therapeutic level), and outcome. Example: "Levetiracetam 1500 mg twice daily for 12 weeks—continued seizures 4/month. Lamotrigine titrated to 200 mg twice daily over 8 weeks—rash, discontinued. This constitutes drug-resistant epilepsy per ILAE. Epidiolex is FDA-approved for this indication, supported by GWPCARE trial data."

4. Fighting "Lack of Supporting Documentation"

This is the easiest denial to fix but requires your neurologist's cooperation.

Checklist for anti-amyloid mAb appeals:

• Diagnosis: early Alzheimer's disease (mild cognitive impairment due to AD or mild dementia due to AD)
• MMSE and/or MoCA score (with date)
• Amyloid biomarker: PET report stating "amyloid positive," or CSF Aβ42/40 + p-tau or plasma p-tau217 above threshold
• ApoE4 genotype (optional but strengthens case; ApoE4 carriers have higher ARIA risk but also greater plaque burden)
• MRI surveillance plan (pre-treatment MRI, then per prescribing info—typically after doses 5, 7, 14 for Leqembi)
• CED registry enrollment confirmation (Medicare/MA only)
• Prescriber attestation: neurologist or other dementia specialist per NCD 200.3

Checklist for Qalsody appeals:

• ALS diagnosis per El Escorial or Gold Coast criteria
• EMG report showing LMN signs ≥2 regions
• Genetic test report: SOD1 pathogenic variant
• ALSFRS-R score (functional scale) and FVC (forced vital capacity, respiratory function)

Checklist for DBS appeals:

• PD diagnosis per MDS criteria
• Disease duration (≥4 years preferred)
• Levodopa responsiveness documented (on/off UPDRS scores)
• Motor fluctuations or dyskinesias despite optimized meds
• MDS-UPDRS Part III score
• Neuropsychological testing ruling out significant cognitive impairment (relative contraindication)

Checklist for drug-resistant epilepsy appeals (Epidiolex, Fintepla):

• Epilepsy syndrome diagnosis (Dravet, Lennox-Gastaut, TSC)
• EEG reports, MRI
• Seizure frequency log (baseline)
• Prior AED log: drug name, max dose, duration ≥8 weeks, outcome
• Statement: "Patient meets ILAE criteria for drug-resistant epilepsy."

5. Fighting "Equally Effective Alternatives Exist"

Anti-amyloid mAbs vs. donepezil/memantine:

"Donepezil and memantine are symptomatic treatments; they do not remove amyloid plaques or slow disease progression as measured by amyloid PET. Leqembi/Kisunla are the first disease-modifying therapies for Alzheimer's disease, supported by Clarity-AD and TRAILBLAZER-ALZ 2 showing statistically significant slowing of cognitive and functional decline. There is no generic equivalent."

Qalsody vs. riluzole:

"Riluzole is a nonspecific glutamate modulator with modest survival benefit (~2–3 months) across all ALS. Qalsody is a targeted antisense oligonucleotide that reduces SOD1 protein production in patients with SOD1 mutations, addressing the genetic cause of disease. VALOR trial showed reduction in NfL, a biomarker of neuronal injury. There is no alternative SOD1-targeted therapy."

Epidiolex vs. generic clobazam or other AEDs:

"Epidiolex is FDA-approved specifically for Dravet syndrome, Lennox-Gastaut syndrome, and TSC-related seizures, with Level A evidence from GWPCARE trials. The patient has failed [list prior AEDs including clobazam if applicable]. Cannabidiol's mechanism (modulation of GPR55, TRPV1, and other targets) is distinct from other AEDs. There is no generic pharmaceutical-grade CBD."

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What We Do

We generate neurologist-ready appeal letters that cite the exact guidelines, NCD language, pivotal trials, and biomarker data your insurer's medical director will recognize. You answer intake questions about your diagnosis, test results, prior treatments, and denial reason; we draft a letter your neurologist can review, sign, and submit. The letter includes all necessary documentation references and a clear argument tailored to your denial template. We do not provide legal or medical advice, but we give you the evidence-based framework to fight back.

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Sources

1. CMS National Coverage Determination (NCD) 200.3: Monoclonal Antibodies Directed Against Amyloid for the Treatment of Alzheimer's Disease. Revised April 2023. [CMS.gov/medicare-coverage-database]

2. van Dyck CH, Swanson CJ, et al. Lecanemab in Early Alzheimer's Disease (Clarity-AD). New England Journal of Medicine 2023;388:9-21.

3. Sims JR, Zimmer JA, et al. Donanemab in Early Symptomatic Alzheimer Disease (TRAILBLAZER-ALZ 2). JAMA 2023;330(6):512-527.

4. Petersen RC, et al. Practice guideline update summary: Mild cognitive impairment. Neurology 2018 Jan 16;90(3):126-135. American Academy of Neurology.

5. Johnson KA, Minoshima S, et al. Appropriate use criteria for amyloid PET: A report of the Amyloid Imaging Task Force. Alzheimer's & Dementia 2013;9(1):e1-16. Updated 2024.

6. Postuma RB, Berg D, et al. MDS clinical diagnostic criteria for Parkinson's disease. Movement Disorders 2015 Oct;30(12):1591-1601.

7. Schuepbach WMM, Rau J, et al. Neurostimulation for Parkinson's Disease with Early Motor Complications (EARLYSTIM). New England Journal of Medicine 2013;368:610-622. [Note: Commonly cited as Bronstein et al., 2011, for the STN-DBS early PD data; reference should match insurer policy.]

8. Brooks BR, Miller RG, et al. El Escorial revisited: revised criteria for the diagnosis of amyotrophic lateral sclerosis. Amyotrophic Lateral Sclerosis and Other Motor Neuron Disorders 2000;1(5):293-299.

9. Miller TM, Cudkowicz ME, et al. Trial of Antisense Oligonucleotide Tofersen for SOD1 ALS (VALOR). New England Journal of Medicine 2022;387:1099-1110.

10. FDA Approval Letter: QALSODY (tofersen). Biogen. April 25, 2023. [accessdata.fda.gov]

11. Kwan P, Arzimanoglou A, et al. Definition of drug resistant epilepsy: Consensus proposal by the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies. Epilepsia 2010;51(6):1069-1077.

12. Devinsky O, Cross JH, et al. Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome (GWPCARE Part 1). New England Journal of Medicine 2017;376:2011-2020.

13. Devinsky O, Patel AD, et al. Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial. Lancet Neurology 2016;15(3):270-278. [GWPCARE background and Part B data, NEJM 2018.]

14. Lagae L, Sullivan J, et al. Fenfluramine hydrochloride for the treatment of seizures in Dravet syndrome: a randomised, double-blind, placebo-controlled trial. Lancet 2020 Jan 18;394(10216):2243-2254.

15. FDA Approval Summaries: AUSTEDO (deutetrabenazine) and INGREZZA (valbenazine). [accessdata.fda.gov; Drugs@FDA database.]

16. Huntington Study Group. Unified Huntington's Disease Rating Scale: reliability and consistency. Movement Disorders 1996;11(2):136-142.

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Disclaimer: This guide is for informational purposes. It does not constitute medical or legal advice. Always work with your treating neurologist and consider consulting a patient advocate or attorney if your appeal is denied at multiple levels.