ENT · Vestibular Disorders
The facts most likely to be tested
Vestibular neuritis presents as the acute onset of continuous, severe vertigo often following a recent viral upper respiratory infection.
Physical examination reveals unidirectional horizontal nystagmus that beats away from the affected side.
The head impulse test is abnormal on the affected side, demonstrating a corrective saccade when the head is turned toward the lesion.
Patients with vestibular neuritis maintain normal auditory function, which distinguishes the condition from labyrinthitis.
The HINTS exam (Head Impulse, Nystagmus, Test of Skew) is used to differentiate peripheral vestibular neuritis from central causes like cerebellar stroke.
A positive test of skew or direction-changing nystagmus indicates a central etiology rather than vestibular neuritis.
First-line treatment for acute symptoms includes short-term vestibular suppressants such as meclizine or benzodiazepines followed by early vestibular rehabilitation.
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A 34-year-old male presents to the emergency department with a 2-day history of severe, constant vertigo, nausea, and vomiting. He reports a recent viral illness two weeks ago. On physical exam, he has spontaneous horizontal nystagmus beating toward the right. The head impulse test shows a corrective saccade when the head is turned rapidly to the left. His hearing is intact bilaterally, and he has no focal neurologic deficits.
What is the most likely diagnosis?
Vestibular neuritis
The patient's presentation of acute, continuous vertigo with a positive head impulse test on the affected side and preserved hearing is classic for vestibular neuritis, which is distinguished from labyrinthitis by the absence of auditory symptoms.
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Etiology / Epidemiology
Common in 30-50 year olds following a viral URI. Inflammation of the vestibular nerve (CN VIII).
Clinical Manifestations
Acute onset continuous vertigo, nausea, and horizontal nystagmus. No hearing loss distinguishes this from labyrinthitis.
Diagnosis
Clinical diagnosis. Head impulse test shows a corrective saccade toward the affected side.
Treatment
Corticosteroids are first-line to reduce inflammation. Avoid long-term vestibular suppressants.
Prognosis
Symptoms typically resolve within weeks as the brain undergoes vestibular compensation.
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Epidemiology & Etiology
Most common in adults aged 30-50. Often follows a recent viral upper respiratory infection. It represents an inflammatory process affecting the vestibular division of CN VIII.
Pertinent Anatomy
The condition involves the vestibular nerve within the internal auditory canal. Unlike labyrinthitis, the cochlea is spared, preserving normal hearing.
Pathophysiology
Viral infection or post-viral inflammatory response causes unilateral vestibular hypofunction. This creates a sensory mismatch between the two labyrinths, leading to the sensation of vertigo. The brain eventually adapts through the process of vestibular compensation.
Clinical Manifestations
Patients present with acute, continuous vertigo lasting days. Physical exam reveals unidirectional horizontal nystagmus beating away from the affected side. Red flags include focal neurologic deficits, which suggest a central cause like a stroke.
Diagnosis
Diagnosis is primarily clinical. The head impulse test is the gold standard bedside maneuver; a positive result (corrective saccade) indicates peripheral vestibular hypofunction. MRI is indicated if central pathology is suspected.
Treatment
Corticosteroids (e.g., prednisone) are the first-line treatment to improve vestibular recovery. Antihistamines (e.g., meclizine) may be used for symptom relief but must be discontinued after 3 days to prevent impaired central compensation.
Prognosis
Most patients recover fully within 1-3 weeks. Persistent symptoms may require vestibular rehabilitation therapy to facilitate central compensation.
Differential Diagnosis
Labyrinthitis: presence of hearing loss or tinnitus
Meniere's disease: episodic vertigo with fluctuating hearing loss
BPPV: brief, positional vertigo triggered by head movement
Cerebellar stroke: vertical nystagmus or abnormal gait
Vestibular migraine: history of migraines with photophobia