Trigeminal Neuralgia

Note: The textbook library does not contain a "Piyush" oral medicine textbook (no such title is indexed). The content below is drawn from Bradley and Daroff's Neurology in Clinical Practice and Goldman-Cecil Medicine - both authoritative sources that cover trigeminal neuralgia in detail consistent with what oral medicine textbooks typically present.

Definition

• Goldman-Cecil Medicine, p. 1072

Epidemiology

• Incidence: ~4 per 100,000 individuals
• Most common between 50-70 years of age
• Slightly more common in women (1.5:1 female-to-male ratio)
• Begins after age 40 in 90% of patients
• Incidence progressively increases with age
• Rare familial cases have been described
• Bradley and Daroff's Neurology, p. 2497-2498

Classification (ICHD-3)

• Bradley and Daroff's Neurology, p. 2498

Pathogenesis & Etiology

• Classical TN is related to neurovascular compression of the trigeminal nerve by neighboring vessels:
  • Superior cerebellar artery (most common)
  • Anterior and posterior inferior cerebellar arteries
  • Superior petrosal vein
• Vascular compression increases with age and leads to focal demyelination of primary trigeminal afferents near the nerve root entry zone (at the pons)
• Demyelination leads to focal hyperexcitability and ectopic/repetitive neuronal discharges
• In younger patients: Multiple sclerosis is an important cause
• In older patients: Ectatic vertebrobasilar artery compression
• Bradley and Daroff's Neurology, p. 2498

Clinical Features

• Paroxysmal, electric shock-like, shooting, lancinating pain
• Lasts only seconds (up to 2 minutes per attack)
• May repeat at short intervals so attacks blur together
• After many attacks, a residual lingering facial pain may persist
• Usually unilateral

• V2 + V3 combination is the most common
• V2 (cheek/upper teeth) alone or V3 (chin/lower teeth) alone also common
• V1 (ophthalmic division) - extremely rare to be involved alone
• Pain during sleep is uncommon but can occur

• Most commonly near the nasolabial fold
• Trigger zone may be remote from the site of pain
• Common triggers: touching the face, chewing, teeth brushing, talking, swallowing, cool breeze striking the face

• Frequent attacks may cause weight loss, dehydration, or depression
• Goldman-Cecil Medicine, p. 1081; Bradley and Daroff's Neurology, p. 2497-2498

Physical Findings

• Classical TN: No sensory impairment; motor division of the nerve is intact
• Presence of sensory loss or masticatory muscle weakness suggests a secondary cause (more accurately called trigeminal neuropathy)
• Secondary causes to think about: lesion/mass affecting the gasserian ganglion, main sensory root, or root entry zone in the pons
• Bradley and Daroff's Neurology, p. 2498

Diagnosis

• Paroxysmal attacks of pain lasting seconds to 2 minutes
• Affects one or more divisions of the trigeminal nerve
• Pain is intensely sharp, stabbing, or precipitated by a trigger
• Each attack is stereotypical
• No other neurological deficits (in classical/idiopathic TN)

• MRI: Primary investigation - to look for structural lesions (pontine lacunar infarct, demyelinating plaque, meningioma, schwannoma, skull base malignancy)
• High-resolution MRI/MRA: May identify vascular compression
• EMG and blink reflex studies: Normal in idiopathic TN
• No accompanying laboratory or radiographic abnormalities in idiopathic TN

• Trigeminal autonomic cephalgia (has autonomic accompaniments)
• Atypical facial pain
• Idiopathic stabbing headache
• Tolosa-Hunt syndrome (inflammatory, anterior cavernous sinus)
• Glossopharyngeal neuralgia
• Goldman-Cecil Medicine, p. 1086; Bradley and Daroff's Neurology, p. 2498

Course & Prognosis

• Frequently exacerbating and remitting course over many years
• Spontaneous or medication-induced remissions are possible
• Microvascular decompression (MVD) can provide long-term relief

Treatment

Medical Management

• Carbamazepine side effects: vertigo, drowsiness, ataxia (especially if introduced quickly in elderly); agranulocytosis risk
• Monitoring: CBC, LFTs, serum sodium for first few months, then annually

Acute/Emergency Treatment

• IV fosphenytoin at 15-20 mg PE/kg for a patient in the midst of a severe attack
• Anesthetizing the ipsilateral conjunctival sac with proparacaine (topical ophthalmic anesthetic) - provides relief for several hours to days

Surgical Management

• Young, healthy patient refractory to medications: Posterior fossa MVD is the procedure of choice - longest pain relief, preserves sensation
• Elderly or medically compromised patient: Percutaneous procedures (radiofrequency thermocoagulation or balloon compression) are preferred
• Treatment must be individualized
• Bradley and Daroff's Neurology, p. 2498-2499; Goldman-Cecil Medicine, p. 1091

Summary Table

Regarding the "Piyush" textbook specifically: The medical library database does not contain any textbook by an author named "Piyush" or a standalone oral medicine title under that name. If you have a specific edition (e.g., "Textbook of Oral Medicine by Anil Govindrao Ghom" or similar), please let me know and I can refine the search. The content above covers trigeminal neuralgia comprehensively as it is presented in standard clinical textbooks.