What are the symptoms and treatment options for vestibular paroxysmia?

Vestibular Paroxysmia: Symptoms and Treatment

Vestibular paroxysmia presents with recurrent, spontaneous, extremely brief attacks of spinning or non-spinning vertigo lasting seconds to less than one minute, occurring up to 30 or more times per day, often accompanied by unilateral tinnitus or hyperacusis. 1, 2

Core Clinical Features

Attack Characteristics:

• Duration: Attacks last seconds to less than 1 minute (typically 5-60 seconds) 1, 2, 3
• Frequency: Multiple attacks per day, often 10-30+ episodes daily in a series pattern 1, 2, 3
• Quality: Either spinning (rotational) or non-spinning vertigo with unsteadiness 1, 3
• Onset: Attacks occur spontaneously in most cases, though head movements or hyperventilation can trigger episodes 1, 3

Associated Audiovestibular Symptoms:

• Unilateral tinnitus (same side as the affected nerve) 1, 2
• Hyperacusis (increased sensitivity to sound) 1
• Attacks are stereotyped—meaning each episode feels identical in a particular patient 3

Epidemiology:

• Mean age of onset: 47-51 years with equal sex distribution 1
• Diagnosed in approximately 3% of patients in tertiary vertigo centers 1
• Rarely affects children 1

Pathophysiology

The condition results from neurovascular cross-compression of the eighth cranial nerve in the cerebellopontine angle, causing ephaptic discharges (abnormal electrical cross-talk between nerve fibers) or conduction blocks from pulsatile arterial compression 1, 2. The anterior inferior cerebellar artery is most commonly involved, followed by the posterior inferior cerebellar artery, vertebral artery, or occasionally veins 2, 4.

Diagnostic Approach

Clinical Diagnosis Requires (Definite VP): 3

• At least 10 attacks of spontaneous vertigo
• Duration less than 1 minute
• Stereotyped phenomenology in each patient
• Response to carbamazepine/oxcarbazepine treatment
• Not better explained by another diagnosis

Probable VP Criteria: 3

• At least 5 attacks of vertigo
• Duration less than 5 minutes
• Spontaneous or provoked by certain head movements
• Stereotyped attacks
• Not better explained by another diagnosis

Imaging:

• High-resolution MRI with 3D-CISS/FIESTA sequences of the cerebellopontine angle is mandatory to distinguish classical VP (neurovascular compression), secondary VP (tumor/cyst compression), and idiopathic VP (no identifiable cause) 1, 2
• Critical caveat: Vascular contact with the eighth nerve appears in approximately 30% of healthy asymptomatic individuals, so MRI findings alone are NOT diagnostic 3
• MRI reveals neurovascular compression in more than 95% of VP cases when present 2

Treatment Algorithm

First-Line Medical Treatment:

Sodium channel blockers are the definitive treatment, with response to medication being the most reliable clinical sign for VP diagnosis: 1, 2

1. Carbamazepine: 200-600 mg/day in divided doses 2, 5

   • Highly effective even at low dosages
   • Proven efficacy in children as well 2

2. Oxcarbazepine: 300-900 mg/day in divided doses 2, 5

   • Alternative to carbamazepine with potentially fewer side effects
   • Lower incidence of adverse effects compared to carbamazepine 5

3. Augmentation Strategy: Adding betahistine mesilate tablets to either carbamazepine or oxcarbazepine provides superior reduction in attack frequency, duration, and vertigo scores compared to sodium channel blockers alone 5

   • Carbamazepine + betahistine showed highest response rates 5
   • Oxcarbazepine + betahistine had lowest side effect profile 5

Alternative Medications (when first-line agents not tolerated): 2

• Lacosamide 1
• Lamotrigine 2
• Phenytoin 2
• Gabapentin 2
• Topiramate 2
• Baclofen 2

Surgical Treatment:

Microvascular decompression is reserved for: 1, 2, 4

• Medically intractable cases where medications are not tolerated
• Secondary VP with tumor or cyst compression (where surgery is more clearly indicated)
• "Ultima ratio" (last resort) for classical or idiopathic VP
• Surgery has demonstrated complete symptom relief in properly selected cases 4

Critical Differential Diagnoses

VP must be distinguished from: 3

• Menière's disease (attacks last hours, not seconds)
• Vestibular migraine (attacks last minutes to hours)
• BPPV (positional triggers, different nystagmus pattern)
• Vestibular epilepsy (other epileptic features present)
• Paroxysmal brainstem attacks (in multiple sclerosis or post-stroke)
• Superior canal dehiscence syndrome (sound/pressure-induced symptoms)
• Transient ischemic attacks (other neurological deficits)
• Panic attacks (psychological triggers, different symptom pattern)

Common Pitfalls to Avoid

• Do not rely solely on MRI findings: Vascular contact with the eighth nerve occurs in 30% of asymptomatic healthy individuals, making imaging alone insufficient for diagnosis 3
• Do not confuse with BPPV: VP attacks are spontaneous and last seconds, while BPPV is strictly positional and lasts 10-60 seconds only with position changes 6, 1
• Do not delay imaging: Posterior fossa imaging including inner ear is mandatory to exclude secondary causes (tumors, cysts) that require different management 1
• Do not abandon treatment prematurely: Response to sodium channel blockers is diagnostic and therapeutic—lack of response should prompt reconsideration of the diagnosis 1, 3