# Trigeminal Neuralgia > Trigeminal neuralgia for NEET-MDS Oral Surgery: diagnostic criteria, carbamazepine therapy, surgical ladder from blocks to microvascular decompression. - Canonical URL: https://prepelephant.com/topics/neet-mds/oral-surgery/trigeminal-neuralgia-mds - Exam / course: NEET-MDS · Subject: Oral Surgery - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Trigeminal Neuralgia", PrepElephant, https://prepelephant.com/topics/neet-mds/oral-surgery/trigeminal-neuralgia-mds ## Direct answer Trigeminal neuralgia is the archetype of neuropathic orofacial pain: recurrent, unilateral, brief electric shock-like stabs in the distribution of one or more trigeminal divisions — the third more often than the second, the first rarely — triggered by innocuous stimuli such as chewing, washing the face or cold wind, with no neurological deficit between attacks. Classic (idiopathic) cases usually reflect neurovascular compression of the nerve root entry zone, most often by the superior cerebellar artery; the drug of choice remains carbamazepine, and the surgical ladder runs from peripheral alcohol blocks through percutaneous radiofrequency rhizotomy up to microvascular decompression. ## What you must remember - Diagnostic core: paroxysms lasting seconds (occasionally up to two minutes), a refractory period after each attack, identifiable trigger zones, and absence of sensory loss or motor deficit in classic disease — a deficit means "secondary" neuralgia until proved otherwise. - Demographics: age above 50, female predominance of roughly 3:2, right side slightly more often affected; new-onset pain in a young adult should prompt a search for demyelination (multiple sclerosis) or a cerebellopontine angle tumour. - First-line drugs: carbamazepine 100-200 mg twice daily titrated upward (effect is often dramatic and diagnostic); oxcarbazepine spares the enzyme-induction burden; add-ons and alternatives include baclofen, gabapentin, pregabalin and lamotrigine. - Investigate with MRI when the picture is atypical, the patient is young, deficits appear, or surgery is planned — to exclude tumour and demonstrate neurovascular conflict. - Surgical ladder in order of escalation: peripheral neurectomy or alcohol blocks (short-lived relief), percutaneous radiofrequency thermocoagulation of the trigeminal ganglion (Sweet and Wepsic technique — sensory loss traded for pain relief), percutaneous balloon compression (Mullan), glycerol rhizolysis, stereotactic radiosurgery, and microvascular decompression (Jannetta) via retrosigmoid craniectomy — the most durable, offering the best long-term pain control by separating the offending vessel with a Teflon pledge. - Multidisciplinary reality: many "treatment-resistant trigeminal neuralgia" referrals to Indian oral surgery clinics are actually myofascial pain, irreversible pulpitis or atypical odontalgia — the teeth must be cleared as the source before neuralgia is diagnosed. ## How to work through a suspected case A 58-year-old woman reports six months of stabbing right cheek pain, "like an electric wire," brought on by brushing teeth and chewing, each spell a few seconds, with pain-free gaps; multiple extractions have not helped. Step one, characterise against the checklist above: unilateral, divisional, brief, triggered, no interictal deficit — compatible with classical trigeminal neuralgia. Step two, examine trigeminal sensory thresholds in all three divisions and the corneal reflex, and inspect the oral cavity: repeated extractions in these patients are tragically common because the pain is projected to a tooth-bearing division, and a pulpitis or a partially erupted third molar must be excluded before blaming the nerve. Step three, image: MRI brain with thin slices through the cerebellopontine angle to exclude a vestibular schwannoma or meningioma, ideally with sequences sensitive to neurovascular conflict. Step four, treat medically — carbamazepine started low and titrated, with haemoglobin, sodium and liver function monitoring; a clear response supports the diagnosis. Step five, if drugs fail or produce intolerable hyponatraemia or sedation, stage the surgical discussion: radiofrequency thermocoagulation for the medically frail patient wanting quick relief and accepting numbness, microvascular decompression for the fit patient wanting the most durable answer. Document each step; the write-up itself is a mark-earning structure in orofacial pain papers. ## Where students slip The trap is treating every facial pain as neuralgia. Answering "trigeminal neuralgia" to pain that is continuous, bilateral, dull or present for hours walks into the examiner's hands — neuralgia pain is paroxysmal and stereotyped, and between attacks the patient is normal. The reverse trap is extracting teeth for projected pain: because V3 neuralgia radiates to the lower molars, patients arrive edentulous in one quadrant before anyone thought of the nerve; the history of brief, triggerable stabs — not chewing-induced dull ache — is what separates it. Finally, know your eponyms precisely: Sweet and Wepsic gave thermocoagulation, Mullan balloon compression, Jannetta microvascular decompression — mixing them is an instantly visible error. ## Frequently asked questions ### Which trigeminal division is most commonly involved? V3 (mandibular), followed by V2; ophthalmic involvement is rare enough to demand imaging. ### What is the first-line drug and its starting dose? Carbamazepine, 100-200 mg twice daily titrated to response, monitoring for hyponatraemia, drowsiness and rash. ### Which vessel most commonly compresses the root entry zone? The superior cerebellar artery, though the anterior inferior cerebellar artery, veins and tumours are also implicated. ### What is radiofrequency thermocoagulation? A percutaneous stereotactic lesion of the Gasserian ganglion — the Sweet and Wepsic procedure — trading hypoesthesia for analgesia in the affected division. ### When should microvascular decompression be chosen? In a fit patient with medication-refractory classic neuralgia and demonstrated neurovascular conflict, since it offers the most durable relief without deliberate numbness. ### Which features suggest secondary neuralgia? Onset before 40, bilateral pain, sensory deficit between attacks, absent triggers, carbamazepine failure — all warrant MRI.