Trigeminal Neuralgia¶

VERSION: 1.0 CREATED: January 29, 2026 REVISED: January 29, 2026 STATUS: Approved

DIAGNOSIS: Trigeminal Neuralgia

ICD-10: G50.0 (Trigeminal neuralgia), G50.1 (Atypical facial pain), G50.8 (Other disorders of trigeminal nerve), G44.847 (Trigeminal autonomic cephalalgia)

CPT CODES: 85025 (CBC), 80053 (CMP), 85652 (ESR), 86235 (ANA), 62270 (CSF analysis), 82164 (ACE level), 70553 (MRI brain with dedicated trigeminal protocol), 70544 (MRA), 70450 (CT head), 95933 (Trigeminal reflex testing (blink reflex)), 96365 (Fosphenytoin (severe exacerbation)), 64400 (Peripheral nerve block (V2/V3))

SYNONYMS: Trigeminal neuralgia, TN, tic douloureux, facial neuralgia, facial pain, CN V neuralgia, trigeminal neuropathy, classical trigeminal neuralgia, idiopathic trigeminal neuralgia, secondary trigeminal neuralgia, painful trigeminal neuropathy

SCOPE: Evaluation and management of trigeminal neuralgia in adults including classical TN (with or without neurovascular compression), secondary TN, and painful trigeminal neuropathy. Covers medical management, procedural interventions, and surgical options. Applies to ED, hospital, and outpatient settings.

DEFINITIONS: - Classical Trigeminal Neuralgia: Recurrent unilateral brief electric shock-like pains in trigeminal distribution; with or without neurovascular compression on MRI - Secondary Trigeminal Neuralgia: TN caused by underlying disease (MS, tumor, AVM, other) - Idiopathic Trigeminal Neuralgia: Classical TN without MRI evidence of neurovascular compression - Trigeminal Neuralgia with Concomitant Pain: TN attacks plus continuous/near-continuous pain between attacks - Painful Trigeminal Neuropathy: Facial pain with sensory abnormalities (numbness, dysesthesia); suggests structural cause - Refractory TN: Inadequate pain relief despite adequate trials of ≥3 medications - V1, V2, V3: Ophthalmic, maxillary, and mandibular divisions of trigeminal nerve

PRIORITY KEY: STAT = Immediate | URGENT = Within hours | ROUTINE = Standard | EXT = Extended/atypical cases | - = Not applicable to this setting

1. LABORATORY WORKUP¶

1A. Core Labs (Baseline Before Treatment)¶

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
CBC (CPT 85025)	-	ROUTINE	ROUTINE	-	Baseline for carbamazepine (bone marrow suppression)	Normal
CMP (CPT 80053) (sodium, LFTs)	-	ROUTINE	ROUTINE	-	Carbamazepine: hyponatremia, hepatotoxicity	Normal
HLA-B*1502 (Asian ancestry)	-	ROUTINE	ROUTINE	-	SJS/TEN risk with carbamazepine in Asian populations	Negative

1B. Extended Labs (Atypical Presentations)¶

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
ESR (CPT 85652), CRP (CPT 86140)	-	ROUTINE	EXT	-	If vasculitis or GCA suspected (elderly, V1)	Normal
ANA (CPT 86235), SSA/SSB	-	-	EXT	-	Sjögren syndrome can cause trigeminal neuropathy	Negative
CSF analysis (CPT 62270)	-	EXT	EXT	-	If MS or CNS infection suspected	Normal; or MS-consistent findings
ACE level (CPT 82164)	-	-	EXT	-	Neurosarcoidosis	Normal

2. DIAGNOSTIC IMAGING & STUDIES¶

2A. Neuroimaging¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
MRI brain with dedicated trigeminal protocol (CPT 70553)	-	ROUTINE	ROUTINE	-	All patients; before treatment	Identify neurovascular compression, tumor, MS plaques	Pacemaker, metal
MRA (CPT 70544) (if MRI equivocal)	-	ROUTINE	EXT	-	Evaluate vascular loop	Define vessel relationship	Same
CT head (CPT 70450) (if MRI unavailable)	URGENT	ROUTINE	-	-	Emergent exclusion of mass	No mass	None (contrast: renal)

2B. Specialized Protocols¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
3D-CISS/FIESTA sequence	-	-	ROUTINE	-	Pre-surgical planning	Define nerve-vessel relationship	MRI contraindications
High-resolution MRI trigeminal nerve	-	-	ROUTINE	-	If painful neuropathy; atypical features	Nerve atrophy, enhancement, mass	Same

2C. Additional Studies¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
Trigeminal reflex testing (blink reflex) (CPT 95933)	-	-	EXT	-	If sensory loss; differentiate from neuropathy	Normal in classical TN; abnormal in secondary	None
Dental/maxillofacial evaluation	-	-	ROUTINE	-	Exclude dental pathology as pain source	No dental cause	None

3. TREATMENT¶

3A. First-Line Pharmacotherapy¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Carbamazepine (Tegretol)	PO	-	100-200 mg :: PO :: BID :: 100-200 mg BID; increase by 100-200 mg q3-7 days; target 400-1200 mg/day divided BID-TID	AV block, bone marrow suppression, MAOIs, Asian ancestry (check HLA-B*1502)	CBC, LFTs, Na q2-4 weeks initially, then q3-6 months; drug levels optional	ROUTINE	ROUTINE	ROUTINE	-
Oxcarbazepine (Trileptal)	-	-	150-300 mg :: PO :: BID :: 150-300 mg BID; increase by 300 mg/week; target 600-1800 mg/day	Severe hyponatremia; less drug interactions than CBZ	Na (hyponatremia more common); CBC, LFTs less critical	ROUTINE	ROUTINE	ROUTINE	-

3B. Second-Line Pharmacotherapy¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Baclofen	PO	-	5 mg :: PO :: TID :: 5 mg TID; increase by 5 mg q3 days; target 30-80 mg/day divided TID	Renal impairment (dose reduce)	Sedation, weakness; taper slowly to avoid withdrawal	-	ROUTINE	ROUTINE	-
Lamotrigine	-	-	25 mg :: PO :: daily :: 25 mg daily × 2 weeks, then 50 mg daily × 2 weeks, then increase by 50 mg q2 weeks; target 200-400 mg/day	History of rash with AEDs	Rash (SJS risk with rapid titration); slow titration mandatory	-	ROUTINE	ROUTINE	-
Gabapentin	-	-	300 mg :: - :: TID :: 300 mg TID; titrate to 1800-3600 mg/day; less effective than CBZ/OXC	CrCl <60: reduce dose	Sedation; renal dosing	ROUTINE	ROUTINE	ROUTINE	-
Pregabalin	PO	-	75 mg :: PO :: BID :: 75 mg BID; titrate to 150-300 mg BID	CrCl <60: reduce dose	Sedation, weight gain; renal dosing	-	ROUTINE	ROUTINE	-

3C. Combination Therapy¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Carbamazepine + Baclofen	-	-	N/A :: - :: per protocol :: If monotherapy inadequate; use lower doses	Per individual agents	Per individual agents	-	ROUTINE	ROUTINE	-
Carbamazepine + Lamotrigine	-	-	N/A :: - :: per protocol :: Additive efficacy; CBZ induces lamotrigine metabolism (need higher LTG dose)	Per individual agents	Drug interactions	-	ROUTINE	ROUTINE	-
Oxcarbazepine + Gabapentin	-	-	N/A :: - :: per protocol :: If CBZ not tolerated	Per individual agents	Hyponatremia, sedation	-	ROUTINE	ROUTINE	-

3D. Acute Exacerbation Management¶

Treatment	Route	Indication	Dosing	Pre-Treatment Requirements	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Fosphenytoin (severe exacerbation) (CPT 96365)	IV	-	15-20 mg :: IV :: TID :: 15-20 mg PE/kg IV at 100-150 mg/min; then phenytoin 100 mg TID	-	Sinus bradycardia, heart block, Adams-Stokes syndrome	ECG, BP during infusion; phenytoin levels	STAT	STAT	-	-
IV lidocaine (CPT 96365)	IV	-	1-3 mg/kg :: IV :: - :: 1-3 mg/kg IV over 20-30 min (monitored setting); for severe refractory pain	-	Cardiac conduction abnormalities	Continuous cardiac monitoring	-	STAT	-	-
Peripheral nerve block (V2/V3) (CPT 64400)	-	-	N/A :: - :: once :: Lidocaine/bupivacaine at foramen rotundum/ovale	-	Infection, coagulopathy	Short-term relief	ROUTINE	ROUTINE	ROUTINE	-

3E. Interventional Procedures (Refractory to Medical Therapy)¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Percutaneous balloon compression	-	-	N/A :: - :: per protocol :: Outpatient/short-stay; compresses gasserian ganglion	Coagulopathy	Facial numbness; recurrence 20-30% at 5 years	-	ROUTINE	-	-
Percutaneous glycerol rhizolysis	-	-	N/A :: - :: per protocol :: Injection into Meckel's cave	Same	Same; less sensory loss	-	ROUTINE	-	-
Percutaneous radiofrequency thermocoagulation	-	-	N/A :: - :: per protocol :: Thermal lesion of trigeminal ganglion	Same	Corneal anesthesia risk (V1); recurrence	-	ROUTINE	-	-
Stereotactic radiosurgery (Gamma Knife)	-	-	N/A :: - :: once :: Single high-dose radiation to trigeminal root; effect delayed 1-3 months	None absolute; prior radiation relative	Delayed response; facial numbness (10-30%)	-	-	ROUTINE	-
Microvascular decompression (MVD)	-	-	N/A :: - :: once :: Definitive surgery; move offending vessel; craniotomy	High surgical risk; no vascular compression	Hearing loss (1-2%), facial numbness (3%), stroke (<1%), recurrence 15-20% at 10 years	-	ROUTINE	-	-

3F. Treatment for Specific Subtypes¶

Subtype	Preferred Treatment
Classical TN with clear vascular compression	MVD offers best long-term cure (70-80% pain-free at 10 years); consider if medically refractory
Classical TN without compression/idiopathic	Medical therapy; if refractory, percutaneous procedures or radiosurgery
TN due to MS	Medical therapy first; percutaneous procedures if refractory (MVD less effective)
TN due to tumor	Treat underlying tumor; medical therapy for pain
TN with concomitant continuous pain	Often more difficult to treat; may need combination therapy
V1 distribution	Avoid procedures with high corneal anesthesia risk (protect eye)

4. OTHER RECOMMENDATIONS¶

4A. Referrals & Consults¶

Recommendation	ED	HOSP	OPD	ICU	Indication
Neurology	-	ROUTINE	ROUTINE	-	Diagnosis confirmation; medication management; atypical cases
Neurosurgery	-	ROUTINE	ROUTINE	-	Refractory to medical therapy; MVD evaluation
Pain management	-	-	ROUTINE	-	Interventional procedures; multimodal pain
Dentistry/oral surgery	-	-	ROUTINE	-	Exclude dental pathology
Ophthalmology	-	-	ROUTINE	-	V1 involvement; corneal protection if sensory loss
Neuro-oncology	-	ROUTINE	ROUTINE	-	If tumor-related TN
MS specialist	-	ROUTINE	ROUTINE	-	If MS-related TN

4B. Patient/Family Instructions¶

Recommendation	ED	HOSP	OPD
TN is a chronic condition; medications can control but rarely cure	-	ROUTINE	ROUTINE
Identify and avoid triggers (cold wind, chewing, talking, touching face)	-	ROUTINE	ROUTINE
Take medications consistently; do not stop suddenly (taper)	-	ROUTINE	ROUTINE
Report rash immediately (especially with carbamazepine, lamotrigine) - may indicate SJS	-	ROUTINE	ROUTINE
Report excessive drowsiness, confusion, difficulty walking	-	ROUTINE	ROUTINE
Soft diet if chewing triggers attacks	-	ROUTINE	ROUTINE
Surgical options exist for medication-refractory cases	-	ROUTINE	ROUTINE
Trigeminal Neuralgia Association (tna-support.org) resources	-	-	ROUTINE

4C. Pre-Procedure Considerations¶

Recommendation	ED	HOSP	OPD
Discuss risks/benefits of all surgical options	-	ROUTINE	ROUTINE
MVD: Craniotomy risks (hearing loss, stroke, infection, CSF leak, facial numbness)	-	ROUTINE	ROUTINE
Percutaneous procedures: Facial numbness expected (30-50%); anesthesia dolorosa rare	-	ROUTINE	ROUTINE
Radiosurgery: Delayed onset (weeks-months); facial numbness (10-30%)	-	-	ROUTINE
V1 involvement: Discuss corneal protection if sensory loss anticipated	-	ROUTINE	ROUTINE

5. DIFFERENTIAL DIAGNOSIS¶

Alternative Diagnosis	Key Distinguishing Features	Tests to Differentiate
Dental pain	Related to specific tooth; continuous; percussion tenderness	Dental exam, X-ray
TMJ disorder	Jaw pain; clicking; related to chewing; bilateral possible	Clinical exam; MRI TMJ
Cluster headache	Periorbital; autonomic features (tearing, rhinorrhea, ptosis); longer attacks	History; ICHD-3 criteria
SUNCT/SUNA	Very brief attacks; prominent autonomic features	History; ICHD-3 criteria
Post-herpetic neuralgia	History of zoster; dermatomal; continuous	History; rash history
Glossopharyngeal neuralgia	Throat/ear pain; triggered by swallowing	History; carbamazepine response
Migraine	Longer attacks; photophobia, phonophobia; nausea	History
Atypical facial pain	Continuous; crosses trigeminal boundaries; psychiatric comorbidity	Diagnosis of exclusion
Giant cell arteritis	Age >50; V1 distribution; jaw claudication; elevated ESR	ESR, CRP; temporal artery biopsy
Nasopharyngeal carcinoma	Numbness (painful neuropathy); cranial nerve palsies	MRI; biopsy
Acoustic neuroma	V5 distribution numbness; hearing loss	MRI with IAC protocol

6. MONITORING PARAMETERS¶

Parameter	ED	HOSP	OPD	ICU	Frequency	Target/Threshold	Action if Abnormal
Pain frequency/severity (diary)	-	Daily	Every visit	-	Ongoing	<3 attacks/day; NRS <3	Adjust medications; consider procedures
CBC (carbamazepine)	-	ROUTINE	q2-4 weeks × 3 months, then q3-6 months	-	Per schedule	WBC >3000, ANC >1500, platelets >100K	Hold CBZ if low
LFTs (carbamazepine)	-	ROUTINE	q2-4 weeks × 3 months, then q3-6 months	-	Per schedule	<3× ULN	Hold if significantly elevated
Sodium (oxcarbazepine)	-	ROUTINE	q2-4 weeks initially, then q3 months	-	Per schedule	>130 mEq/L	Reduce dose; fluid restrict
Carbamazepine level	-	-	ROUTINE	-	If breakthrough pain, toxicity, or compliance concern	4-12 mcg/mL	Adjust dose
Rash surveillance	STAT	STAT	Every visit	STAT	Ongoing	None	STOP carbamazepine/lamotrigine immediately; evaluate for SJS
Neurologic exam (post-procedure)	-	Daily	Every visit	-	Post-procedure	Stable sensory; no new deficits	Evaluate for complications

7. DISPOSITION CRITERIA¶

Disposition	Criteria
Outpatient management	Diagnosis confirmed; pain controlled with oral medications
Admit to hospital	Severe uncontrolled pain requiring IV therapy; severe medication side effects; post-surgical monitoring
Neurology follow-up	q1-2 weeks during medication titration; q3-6 months when stable
Neurosurgery follow-up	If refractory to medical therapy; post-procedural
Urgent follow-up	Status trigeminus (continuous attacks); medication failure; new sensory loss

8. EVIDENCE & REFERENCES¶

Recommendation	Evidence Level	Source
Carbamazepine first-line for TN	Class I, Level A	Multiple RCTs; AAN/EFNS Guidelines 2008, reaffirmed
Oxcarbazepine as effective alternative	Class I, Level B	Multiple RCTs
MVD most effective long-term for classical TN with compression	Class II, Level B	Multiple case series; long-term outcome data
Percutaneous procedures effective for refractory TN	Class II, Level B	Multiple case series
Stereotactic radiosurgery effective	Class II, Level B	Multiple case series
HLA-B*1502 testing before carbamazepine in Asians	Class I	FDA recommendation
Lamotrigine effective as add-on therapy	Class II, Level B	RCTs
Baclofen effective as add-on	Class III, Level C	Small studies

NOTES¶

Trigeminal neuralgia is a clinical diagnosis; MRI identifies secondary causes and surgical planning
Classical TN: Brief (seconds to 2 minutes), electric shock-like, triggered by touch/chewing/talking
Carbamazepine or oxcarbazepine are FIRST-LINE; 70-80% initial response
Oxcarbazepine may be better tolerated but causes more hyponatremia
HLA-B*1502 screening REQUIRED in patients of Asian ancestry before carbamazepine (SJS/TEN risk)
Lamotrigine requires SLOW titration (SJS risk); useful as add-on therapy
If sensory loss or continuous pain present → consider secondary TN (tumor, MS)
MVD is most effective long-term treatment for classical TN with vascular compression (70-80% pain-free at 10 years)
Percutaneous procedures and radiosurgery are alternatives for high surgical risk or no vascular compression
V1 (ophthalmic) TN is least common; if present, ensure corneal protection if procedures cause sensory loss
Pain remission can occur spontaneously; some patients may be able to taper medications
MS-related TN is often bilateral and more difficult to treat

CHANGE LOG¶

v1.0 (January 29, 2026) - Initial template creation - Complete medical management algorithm (first, second-line, combinations) - All interventional/surgical options with outcomes - HLA-B*1502 screening emphasized - Monitoring parameters for carbamazepine/oxcarbazepine - Secondary TN causes addressed