ModifiedUnitedHealthcarePolicy CS129ID.B

Vagus and External Trigeminal Nerve Stimulation (for Idaho Only)

Clinical policy governing coverage of implantable vagus nerve stimulators and non‑implantable vagus and trigeminal nerve stimulation devices for members in Idaho, including Idaho Medicaid Plus.

Policy Summary

PayerUnitedHealthcare

PolicyVagus and External Trigeminal Nerve Stimulation (for Idaho Only)

Policy CodePolicy CS129ID.B

Change TypeRevisions to coverage language and device examples

Effective DateMay 1, 2026

Next Review DateN/A

Key ActionObtain prior authorization with documentation of indication, prior treatment trials, and device FDA information when requesting coverage.

SourceLink

POLICY UPDATE CHANGES

Replaced language indicating 'conventional implantable vagus nerve stimulators... are proven and medically necessary' with 'implantable vagus nerve stimulators are proven and medically necessary for treating epilepsy in individuals with all of the [listed conditions]'.

Removed 'responsive vagus nerve stimulation implants (closed loop technology) that allow detection and stimulation based upon increased heart rate (e.g., AspireSR Model 106, SenTiva Model 1000) for treating epilepsy'.

Replaced 'transcutaneous (non-implantable) vagus nerve stimulation (e.g., gammaCore® for headaches)' with 'transcutaneous (non-implantable) vagus nerve stimulation devices'.

Removed list of examples of external or transcutaneous (non-implantable) trigeminal nerve stimulation devices.

Updated documentation requirements language emphasizing that medical records may be required to assess whether the member meets clinical criteria and must fully support medical necessity.

Updated Supporting Information sections: Description of Services, Clinical Evidence, FDA, and References to reflect current information.

EpilepsyCovered indication

Not coveredNoninvasive devices

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Key CPT/HCPCSCodes referenced

MultipleReferences updated

Coverage Criteria and Evidence Basis

Implantable VNS for Epilepsy (Medical Necessity)

Covered when ALL of the following are met:

Implantable VNS coverage criteria: 1) Medically refractory epileptic seizures with failure of two or more trials of single or combination antiepileptic drug therapy or intolerable side effects of antiepileptic drug therapy; AND 2) The individual is not a candidate for epilepsy surgery, has failed epilepsy surgery, or refuses epilepsy surgery after Shared Decision Making discussion; AND 3) No history of left or bilateral cervical vagotomy (contraindication per FDA).

Supported by AAN and NICE guidance cited in policy.

Indication‑specific coverage logic (evidence summaries)

Coverage considerations and evidence summaries by indication (from this section):

Epilepsy: VNS is considered an option for individuals with drug‑resistant epilepsy when seizures are not controlled despite multiple antiseizure medications or when resective surgery is not viable; shared decision‑making is recommended.

Supported by NICE and AAN guidance

Treatment‑Resistant Depression: Evidence is mixed: registry and long‑term observational data show improved cumulative response/remission rates with adjunctive VNS versus treatment‑as‑usual, but randomized trial evidence is limited and primary endpoints were not consistently met; use only in treatment‑resistant depression and consider research/registry settings.

Based on systematic reviews and registry data

Cluster Headache (nVNS): Noninvasive VNS (nVNS) has evidence of benefit for episodic cluster headache (eCH) in RCTs and meta‑analyses (superior to sham in eCH) but not for chronic cluster headache (cCH); prophylactic nVNS showed reductions in attack frequency in some trials but long‑term data are limited.

ACT1/ACT2 and meta‑analysis findings

Migraine and Other Indications: There is insufficient evidence to support nVNS or VNS for migraine and many other investigated conditions (Alzheimer's disease, anxiety, autism, OCD, chronic pain, sleep disorders, heart failure, asthma, fibromyalgia, stroke rehabilitation, autoimmune disorders); further trials are needed.

Policy lists multiple conditions as unproven

Coverage-informing evidence nodes

Summary of coverage-relevant evidence and key points influencing coverage decisions

nVNS for episodic cluster headache: RCT evidence showed significantly higher response rates and sustained response with nVNS versus sham for episodic cluster headache (eCH); studies report nVNS is safe and well tolerated with no serious ADEs.

Supportive evidence for eCH (meta‑analysis and trial data)

nVNS for migraine (preventive/acute): Evidence is mixed: some RCTs (PREMIUM, Tassorelli, Diener) showed benefits for particular endpoints or in adherent subgroups, but ITT analyses were often negative due to active sham, suboptimal adherence, or small samples; overall preventive nVNS was not superior to sham in ITT in PREMIUM.

Adherence and sham activity influenced results

eTNS for migraine: Systematic reviews and RCTs indicate potential reductions in migraine/headache intensity and days versus sham for acute treatment, but overall evidence quality and long‑term data are limited and optimal protocols are uncertain.

ACME and other eTNS trial data

Evidence summaries and guideline positions relevant to covered indications

Summary of findings and guideline positions relevant to covered indications

Acute migraine: A randomized sham‑controlled trial (ACME) showed 1‑hour eTNS (Cefaly) produced significantly greater reduction in pain intensity versus sham in adults with an acute migraine attack (n=106); no serious adverse events reported, but sample size and baseline imbalances limit certainty.study‑defined primary outcome

Chou et al. (ACME) trial results

Migraine prevention: NICE concludes evidence for preventive use of supraorbital transcutaneous stimulation is inadequate in quality and recommends use for prevention only in research or special arrangements; for acute treatment evidence is adequate but recommends use with governance and audit.NICE guidance

NICE IPG guidance informs coverage considerations

Major depressive disorder (MDD):

Implantable vagus nerve stimulators are medically necessary for treating epilepsy only when all policy criteria are met (see Implantable VNS coverage criteria). The policy explicitly states that implantable VNS systems are unproven and not medically necessary for treating all other conditions (examples include Alzheimer disease, anxiety, autism spectrum disorder, chronic pain, cluster headaches, depression, heart failure, migraine, obesity, sleep disorders, and others). Transcutaneous (non‑implantable) vagus nerve stimulation devices are also listed as unproven and not medically necessary for preventing or treating all indications.

Requests for implantable VNS for indications other than epilepsy should therefore be considered not covered unless clear, high‑quality evidence and criteria supporting medical necessity for that non‑epilepsy indication are provided; similarly, claims for transcutaneous VNS devices for any indication are considered unproven and may be denied.

Noninvasive vagus nerve stimulation (nVNS) for migraine and many other indications is not supported by sufficient high‑quality evidence. The policy summary notes that for migraine headaches there is insufficient evidence to establish safety, efficacy, and long‑term outcomes and that larger, higher‑quality trials are needed before routine coverage can be considered.

Because the current evidence base is limited by small trials, variable protocols, and inconsistent results, the policy treats nVNS for migraine and other low‑evidence conditions as not medically necessary pending stronger clinical data.

The policy considers use of transcutaneous vagus nerve stimulation and external/transcutaneous trigeminal nerve stimulation for indications outside well‑studied headache areas to be investigational and unsupported. Multiple sections note that these noninvasive modalities have been investigated across a wide range of conditions (for example, cardiac arrhythmias, heart failure, tinnitus, schizophrenia, and others) but that study limitations, small sample sizes, and heterogenous protocols prevent conclusions about safety or effectiveness.

Accordingly, claims for tVNS or eTNS used for non‑headache conditions (or for headache indications lacking robust evidence) are at risk for denial as unproven and not medically necessary.

External trigeminal nerve stimulation (eTNS) is not recommended by the American Academy of Pediatrics for treatment of pediatric ADHD because the supporting evidence is sparse and does not approach the strength of established medication or behavioral therapies. The policy cites the AAP guideline that eTNS cannot be recommended for ADHD, implying standard therapies should be preferred and that eTNS use for ADHD is not supported for routine coverage.

More broadly, systematic reviews and randomized trials for eTNS in other indications (including migraine and depression) show low‑quality or limited evidence, so routine coverage is not supported outside research settings.

Policy language has been updated to generalize device listings: external/transcutaneous device categories are now referred to as transcutaneous (non‑implantable) vagus nerve stimulation devices and external/transcutaneous trigeminal nerve stimulation devices rather than enumerating specific brand examples. The revised policy reiterates that these device categories are considered unproven and not medically necessary for preventing or treating indications until higher‑quality evidence or FDA‑cleared indications support coverage.

Operationally, this change removes example device names while retaining the non‑coverage stance for these external/transcutaneous device classes.

Implantable VNS is explicitly not covered for non‑epilepsy indications; the policy lists examples including but not limited to Alzheimer disease, depression, cluster headache, migraine, ADHD, autism spectrum disorder, chronic pain, heart failure, and obesity as conditions for which implantable VNS is considered unproven and not medically necessary.

Providers requesting implantable VNS for these non‑epilepsy indications should expect denial unless robust evidence demonstrating safety and effectiveness for the specific indication is supplied and policy criteria are revised to support coverage.

Noninvasive VNS for migraine is considered unsupported by sufficient evidence in this policy. The document states there is insufficient evidence to support nVNS for migraine due to study limitations, and therefore nVNS for both acute and preventive migraine treatment is treated as not medically necessary for routine coverage.

NICE and several randomized trials are discussed in the evidence summary, but inconsistent trial results, small sample sizes, and methodological concerns mean the policy does not consider current nVNS evidence adequate to approve routine use for migraine.

Both nVNS and eTNS are considered not proven for many migraine and other investigated conditions because the evidence is limited, heterogeneous, or low quality. The policy explicitly states that nVNS and external/transcutaneous TNS for migraine and other indications where evidence is insufficient are not medically necessary until higher‑quality data become available.

This position is reinforced by systematic reviews and evidence assessments that report potential benefits in small trials but overall low confidence in effect estimates and uncertainty regarding optimal protocols and long‑term outcomes.

The policy highlights areas where evidence remains insufficient: systematic reviews conclude there are inadequate data to support trigeminal nerve stimulation for drug‑resistant epilepsy, and small pilot randomized trials (for example, a 24‑subject TNS trial in major depressive disorder) report preliminary symptom improvements but have limited sample size and follow‑up. These findings support classifying several indications as investigational rather than established.

Because of these limitations, routine clinical adoption of TNS/nVNS for indications such as drug‑resistant epilepsy or major depressive disorder outside research or registry settings is not supported by the current evidence base.

The policy updated nomenclature to refer to device classes rather than specific branded examples: transcutaneous (non‑implantable) vagus nerve stimulation devices and external/transcutaneous trigeminal nerve stimulation devices. This revision removed individual device examples from the policy text while reiterating the non‑coverage stance that these external/transcutaneous device categories are considered unproven and not medically necessary for routine clinical use until better evidence is available.

Providers should document device marketing/clearance information when requesting coverage, but absence of strong evidence for these device classes remains the basis for non‑coverage.

Coding and Product Codes

Covered/Referenced CPT CodesCPT

61885	Insertion or replacement of cranial neurostimulator pulse generator or receiver; with connection to a single electrode array.
61886	Insertion or replacement of cranial neurostimulator pulse generator or receiver; with connection to 2 or more electrode arrays.
64553	Percutaneous implantation of neurostimulator electrode array; cranial nerve.
64568	Open implantation of cranial nerve (e.g., vagus nerve) neurostimulator electrode array and pulse generator.
64570	Removal of cranial nerve (e.g., vagus nerve) neurostimulator electrode array and pulse generator.

Referenced HCPCS / DME CodesHCPCS

A4541	Monthly supplies for use of device coded at E0733.
E0733	Transcutaneous electrical nerve stimulator for electrical stimulation of the trigeminal nerve.
E0735	Noninvasive vagus nerve stimulator.
E0770	Functional electrical stimulator, transcutaneous stimulation of nerve and/or muscle groups, any type, complete system, not otherwise specified.
E1399	Durable medical equipment, miscellaneous.

Referenced L-Codes for Implantable DevicesHCPCS

L8679	Implantable neurostimulator, pulse generator, any type.
L8680	Implantable neurostimulator electrode, each.
L8682	Implantable neurostimulator radiofrequency receiver.
L8683	Radiofrequency transmitter (external) for use with implantable neurostimulator radiofrequency receiver.
L8685	Implantable neurostimulator pulse generator, single array, rechargeable, includes extension.
L8686	Implantable neurostimulator pulse generator, single array, nonrechargeable, includes extension.
L8687	Implantable neurostimulator pulse generator, dual array, rechargeable, includes extension.
L8688	Implantable neurostimulator pulse generator, dual array, nonrechargeable, includes extension.

No explicit CPT/HCPCS/ICD-10 codes listed in this sectionmixed

No codes listed

Implantable VNS device product codesmixed

LYJ	FDA product code referenced for implantable Vagus Nerve Stimulator devices
MUZ	FDA product code referenced for implantable Vagus Nerve Stimulator devices
QPY	FDA product code referenced for implantable Vagus Nerve Stimulator devices

Transcutaneous VNS device product codesmixed

PKR	FDA product code referenced for transcutaneous (non-implantable) VNS devices
QAK	FDA product code referenced for transcutaneous (non-implantable) VNS devices

External/Transcutaneous TNS device product codesmixed

PCC	FDA product code referenced for external/transcutaneous trigeminal nerve stimulation devices
QGL	FDA product code referenced for external/transcutaneous trigeminal nerve stimulation devices

Provider Actions, Prior Authorization, and Documentation

Prior Authorization

Prior Authorization Required

Prior authorization is required for implantable neuromodulation devices and other listed codes when requested for members in Idaho (including Idaho Medicaid Plus). Requests must include a clear clinical justification addressing the indication, prior conservative and pharmacologic treatments tried (including number and names of antiseizure or psychiatric medications), reasons for treatment failure or intolerance, and device-specific rationale. Verify member benefit coverage and any federal, state, or contractual requirements before submitting an authorization request.

State-specific PA requirement: Idaho (includes Idaho Medicaid Plus)
Provide indication, prior conservative treatments, and device rationale
Verify federal/state/contractual benefit requirements before applying policy

Prior Authorization

Prior Authorization — Neuromodulation Devices

Prior authorization for neuromodulation devices (implantable VNS, noninvasive VNS, external TNS/eTNS) must include detailed clinical history: diagnosis subtype (e.g., focal vs generalized epilepsy; episodic vs chronic cluster headache; migraine with/without aura), prior medication failures (number of antiseizure drugs tried and response), prior surgical candidacy or evaluations (for epilepsy), and documentation of shared decision making where applicable. For headache indications include baseline headache/migraine frequency and severity, duration of symptoms, prior preventive and acute therapies tried, and adherence during a run-in period when applicable.

Background and Description of Services

Vagus nerve stimulation delivers electrical impulses to the brain via the vagus nerve and is used primarily as an adjunctive therapy for drug‑resistant epilepsy. Implantable VNS systems have evidence supporting reduction in seizure frequency over time but rarely produce complete seizure remission; coverage for implantable VNS in epilepsy requires failure of at least two or more trials of antiepileptic drug therapy, documentation that the patient is not a candidate for—or has failed or refused—resective epilepsy surgery after a Shared Decision Making discussion, and no history of left or bilateral cervical vagotomy (an FDA‑listed contraindication).

Noninvasive modalities (transcutaneous VNS and external TNS) are noninvasive alternatives under investigation for multiple indications, but current evidence is insufficient to establish routine effectiveness or long‑term benefit for most uses.

Definitions and Device Types

Shared Decision Making — definition entry

DefinitionShared Decision Making is a collaborative process in which a provider/clinician and a patient (including caregivers and family) work together to make healthcare decisions that consider evidence-based information about options, the provider's experience, and the patient’s values, goals, preferences, and circumstances.

ComponentsIncludes comparing benefits, harms, and risks of each option and discussing what matters most to the patient (AHRQ, About Shared Decision Making, 2023).

Clinical useRecommended when considering invasive or preference-sensitive therapies such as implantable VNS vs surgical options to ensure informed patient choice.

Transcutaneous (Non‑Implantable) Vagus Nerve Stimulation (nVNS) — definition and evidence note

DefinitionTranscutaneous (Non-Implantable) Vagus Nerve Stimulation (nVNS/tVNS) refers to non-implantable external devices that deliver stimulation to vagal branches via the skin; devices have been studied for acute and preventive treatment of headache disorders but evidence is limited for many indications.

Policy Revision Notes

2026-05-01policy_revisionLatest

Revised coverage rationale: replaced prior phrasing about 'conventional implantable vagus nerve stimulators' with a clarified statement that 'implantable vagus nerve stimulators are proven and medically necessary for treating epilepsy' and updated the list of unproven devices (removed responsive/closed‑loop examples, generalized transcutaneous VNS wording, and removed examples of transcutaneous trigeminal devices).

2026-05-01documentation_update

Updated medical records/documentation language emphasizing that medical records may be required to assess clinical criteria, must fully support medical necessity, be legible, maintained in the patient's record, and made available upon request.

Policy Summary

PayerUnitedHealthcare

PolicyVagus and External Trigeminal Nerve Stimulation (for Idaho Only)

Policy CodePolicy CS129ID.B

Change TypeRevisions to coverage language and device examples

Effective DateMay 1, 2026

Next Review DateN/A

Key ActionObtain prior authorization with documentation of indication, prior treatment trials, and device FDA information when requesting coverage.

SourceLink

On This Page

Other indications (epilepsy, depression, ADHD, cardiac, etc.): Available studies are small, heterogeneous, or observational; evidence is insufficient to conclude safety and effectiveness for many non‑headache indications.

Policy rates these indications as investigational or unproven

A randomized phase II TNS trial (n=24) reported significant HDRS‑17 score reductions after a 10‑day protocol with sustained effect at 1 month, but small sample size and limited follow‑up make routine coverage premature.

Generoso et al. phase II results

Drug‑resistant epilepsy (DRE) and TNS: Systematic review(s) found insufficient data to support trigeminal nerve stimulation for DRE and recommend additional data collection before adoption.systematic review conclusion

Boon et al. and related reviews

ADHD (pediatric): The American Academy of Pediatrics states eTNS cannot be recommended for ADHD due to sparse supporting evidence compared with established medication and behavioral therapies.AAP guideline statement

AAP guideline informs exclusion for ADHD

Diagnosis subtype and severity (e.g., drug-resistant epilepsy definition; episodic vs chronic cluster headache; migraine with/without aura)
Prior medication trials: list agents, doses, durations, and reasons for discontinuation (failure/intolerance)
Epilepsy surgical evaluation status: not candidate / failed surgery / refused after shared decision making
Headache documentation: baseline headache frequency, 4-week run-in diary when applicable, prior acute and preventive therapies, adherence

Documentation Required

Device-Specific Prior Authorization Documentation

Device-specific prior authorization documentation should reference the applicable FDA marketing clearance or approval status (PMA or 510(k)/PMN) and, when available, include product identifiers or model names. For implantable VNS, include operative reports, device model and pulse generator identifiers. For noninvasive devices, include manufacturer, device name, and supporting documentation of intended use for the requested indication.

Provide FDA marketing clearance/approval details (PMA or 510(k)/PMN) or product codes when available
For implantable devices: operative reports and device model/pulse generator identifiers (e.g., L8679/L8680 billing correspondence)
For noninvasive devices: manufacturer and device name (e.g., gammaCore, Cefaly, Monarch) and intended use

Prior Authorization

Verify Benefit Coverage and Documentation

Verify benefit coverage and applicable documentation requirements prior to submission. Benefit determination is governed by federal, state, or contractual requirements, which may supersede this policy. Medical records may be requested to confirm medical necessity and do not guarantee coverage.

Check federal/state/contractual benefit requirements before applying policy
Medical records may be required and do not guarantee coverage

Denial Risk

Denial Triggers

Denial triggers include insufficient documentation of refractory disease (e.g., fewer than two adequate antiseizure trials for implantable VNS), candidacy for resective epilepsy surgery not addressed, history of contraindications (e.g., prior left or bilateral cervical vagotomy), requests for devices or indications deemed unproven (see below), or lack of requisite device-specific information.

Implantable VNS: denial risk if criteria not met (not refractory, candidate for resection, <2 AED trials)
Requests for transcutaneous/non-implantable VNS or external TNS for indications lacking evidence may be denied
Absence of device model, FDA clearance info, or operative documentation may trigger denial

Denial Risk

Denial Risk for Insufficient Evidence

Requests for indications with insufficient or conflicting evidence (for example, nVNS for migraine prevention, many non-headache or neuropsychiatric uses, or eTNS for ADHD) are at higher risk of denial. Provide high-quality evidence or rationale when requesting coverage for less-established indications.

nVNS for migraine prevention: insufficient evidence — likely denial without strong supporting data
nVNS for many non-headache conditions: insufficient evidence
eTNS for ADHD: AAP does not recommend — high risk for noncoverage

Note

Governance / Research-Only Safeguards (NICE)

When using supraorbital tSNS (eTNS) or other procedures where NICE recommends special arrangements, ensure governance, consent, and audit/research protocols are in place. For procedures NICE designates for use only with special arrangements, document clinical governance processes and that the use is within approved research or audit frameworks when applicable.

Follow NICE recommendations for special arrangements (clinical governance, consent, audit/research) for supraorbital tSNS
Document shared decision-making discussions for VNS when indicated

Documentation Required

Required Medical Record Documentation

Medical record documentation must fully support the requested service and be available on request. Records should include relevant medical history, physical exam findings, diagnostic test results, prior therapy trials (names, doses, durations, and outcomes), operative notes (for implants), device identifiers, and documentation of contraindications or surgical candidacy assessments.

Medical records must be legible, maintained in the patient's chart, and available upon request
Include history, physical exam, diagnostics, prior AED or psychiatric medication trials (>=2 for implantable VNS), and operative/device documentation

Documentation Required

Required Clinical History and Prior Treatments

Required clinical history and prior treatments must demonstrate prior attempts at standard therapies and reasons for failure or intolerance. For implantable VNS in epilepsy, document failure of two or more adequate antiepileptic drug (AED) trials (single or combination), or intolerable side effects; for depression, document prior adequate trials (including ECT status if relevant).

Epilepsy: failure of >=2 adequate AED trials (single or combination) or intolerable side effects
Depression: document prior treatment history; include number of failed treatments and ECT history when relevant
Document reasons for medication discontinuation (inefficacy vs intolerance)

Documentation Required

Required Clinical Documentation for Headache Indications

For headache indications, include baseline headache frequency (e.g., monthly migraine days), a 4‑week run-in diary when used by the supporting clinical trial design, prior acute and preventive therapies tried, adherence data, and treatment response history. For cluster headache, specify episodic vs chronic subtype and prior therapies.

Baseline headache/migraine frequency and severity (monthly headache/migraine days)
Run-in headache diary documentation when applicable (typically 4 weeks)
Prior acute and preventive medication trials and adherence
Specify cluster headache subtype (episodic vs chronic)

Evidence summaryThere is insufficient evidence to support general use of transcutaneous VNS due to study limitations; some RCTs in migraine and cluster headache show mixed results with benefits in adherent subgroups or for episodic cluster headache but overall data are inconsistent.

Regulatory noteFDA-cleared transcutaneous VNS devices exist; device-specific marketing listings are cited (product codes PKR, QAK).

Implantable Vagus Nerve Stimulation (VNS) — definition

DefinitionImplantable Vagus Nerve Stimulation (VNS) is a surgically implanted system that delivers periodic electrical stimulation to the vagus nerve as adjunctive therapy for drug‑resistant epilepsy and has been studied in treatment‑resistant depression.

Evidence contextImplantable VNS is supported by long-term observational and guideline evidence for use in medically refractory epilepsy; FDA-approved implantable VNS devices and PMA/510(k) listings are available (product codes LYJ, MUZ, QPY).

Clinical considerationsTypically considered after failure of multiple antiseizure medications or when resective surgery is not an option; Shared Decision Making is recommended prior to implantation.

nVNS (gammaCore) — device-specific definition/mention

DevicegammaCore (nVNS) is a noninvasive vagus nerve stimulation device studied for acute and preventive treatment of migraine and cluster headache.

Stimulation regimensStudies used specific regimens (e.g., two 120‑second bilateral stimulations three times daily for prevention; acute use at onset with repeat dosing if no improvement).

Evidence noteRCTs report mixed results: supportive evidence for acute migraine pain relief and for episodic cluster headache in some trials, but overall preventive efficacy in ITT populations has been inconsistent due to factors like sham activity and adherence issues.

eTNS (Cefaly / external trigeminal nerve stimulation) — device-specific definition

DeviceCefaly (eTNS) is an external/transcutaneous trigeminal nerve stimulation device applied to the forehead to stimulate supraorbital/trigeminal branches for acute or preventive migraine treatment.

Trial evidenceSham‑controlled trials (e.g., Chou et al., ACME) showed statistically significant reductions in pain intensity at 1 hour and meta-analyses report reductions in migraine days and headache days versus sham, but overall evidence quality is low and optimal protocols are uncertain.

SafetyNo serious adverse events reported in cited eTNS trials; adverse events were generally minor and transient.

External/Transcutaneous Trigeminal Nerve Stimulation (eTNS/TNS) — general definition

DefinitionExternal/Transcutaneous Trigeminal Nerve Stimulation (eTNS/TNS) involves noninvasive stimulation of supraorbital/trigeminal nerve branches using external devices (for example, the Cefaly device) for acute or preventive migraine treatment.

Evidence summarySystematic reviews and RCTs indicate reductions in migraine days, headache days, and acute pain versus sham, but overall evidence is low quality and long‑term benefits and optimal treatment parameters remain uncertain.

GuidanceNICE and assessments note potential benefit for acute treatment but recommend research‑only or special arrangements for some uses due to limited quality of evidence.

Transcutaneous (Non-Implantable) Vagus Nerve Stimulation (tVNS/nVNS) — definition and distinction

DefinitionTranscutaneous (Non-Implantable) Vagus Nerve Stimulation (tVNS/nVNS) denotes noninvasive stimulation of auricular or cervical vagal branches via external devices distinct from surgically implanted VNS systems.

Regulatory noteThe FDA has cleared multiple transcutaneous VNS devices; product codes PKR and QAK are cited for locating marketing listings.

Policy stancePolicy indicates insufficient evidence to support broad clinical use; many indications remain investigational pending larger, higher-quality trials.

Implantable Vagus Nerve Stimulator — definition and regulatory context

DefinitionAn Implantable Vagus Nerve Stimulator is a surgically implanted neurostimulation system that delivers programmed electrical pulses to the vagus nerve and is used as adjunctive therapy for drug‑resistant epilepsy and investigated in other disorders.

Regulatory contextThe FDA has approved multiple implantable VNS devices; product codes LYJ, MUZ, and QPY can be used to locate PMA listings and device information on the FDA website.

Clinical implicationImplantable VNS is considered proven and medically necessary for treating epilepsy when specified clinical criteria are met (see coverage criteria).

Shared Decision Making — updated policy definition preserved

Policy applicationThe policy explicitly references Shared Decision Making when discussing alternatives to implantation (for example candidacy for epilepsy surgery) and documents requirement for informed patient choice.

DocumentationMedical records should document Shared Decision Making discussions as part of the documentation that supports medical necessity for device therapies.

2026-05-01definitions_update

Updated definition for 'Shared Decision Making' in the policy definitions section.

2026-05-01supporting_information_update

Updated supporting information sections including Description of Services, Clinical Evidence, FDA, and References to reflect current information.