What are the causes of peripheral vestibular lesions?

Causes of Peripheral Vestibular Lesions

The most common causes of peripheral vestibular lesions include benign paroxysmal positional vertigo (BPPV), vestibular neuritis, Ménière's disease, labyrinthitis, posttraumatic vertigo, and ototoxicity from medications such as aminoglycosides. 1

Otologic Disorders

• Benign Paroxysmal Positional Vertigo (BPPV): The most common cause of peripheral vertigo, accounting for 42% of cases in general practice settings. Characterized by brief episodes of vertigo triggered by changes in head position 1
• Vestibular Neuritis: Accounts for approximately 41% of peripheral vertigo cases in non-specialty settings. Presents with acute onset of severe vertigo lasting days to weeks 1
• Ménière's Disease: Characterized by episodic vertigo, fluctuating hearing loss, tinnitus, and aural fullness. May account for 10% of vertigo cases in general practice and up to 43% in specialty settings 1
• Labyrinthitis: Inflammation of the inner ear causing vertigo with associated hearing loss 1
• Superior Canal Dehiscence Syndrome: Abnormal opening in the bone covering the superior semicircular canal 1
• Posttraumatic Vertigo: Can present with various clinical manifestations including vertigo, disequilibrium, tinnitus, and headache following head trauma 1
• Perilymphatic Fistula: Abnormal connection between the middle and inner ear 1

Medication-Induced Peripheral Vestibular Lesions

• Ototoxic Medications: Particularly aminoglycosides like gentamicin can cause vestibular toxicity, which may be irreversible 2
  • Symptoms include dizziness, vertigo, tinnitus, and hearing loss
  • Risk factors include renal impairment, prolonged therapy, higher doses, advanced age, and concurrent use of other ototoxic drugs 2
• Other Medications: Anticonvulsants (Mysoline, carbamazepine, phenytoin), antihypertensives, and cardiovascular medications can also cause dizziness and vertigo 1

Vascular Causes

• Vertebrobasilar Insufficiency: Can present with isolated attacks of vertigo lasting less than 30 minutes without associated hearing loss 1
  • May precede stroke in the vertebrobasilar artery by weeks or months
  • Distinguished from BPPV by nystagmus characteristics (typically gaze-evoked) and presence of additional neurological signs 1

Other Peripheral Vestibular Causes

• Inner Ear Lesions: Various pathologies affecting the inner ear structures 1
• Toxic Conditions: Chemical exposure affecting the vestibular system 1
• Infectious Conditions: Viral or bacterial infections affecting the inner ear 1
• Metabolic Conditions: Systemic disorders affecting vestibular function 1

Distinguishing Features of Peripheral vs. Central Vestibular Lesions

• Nystagmus Patterns: Peripheral lesions typically produce horizontal-torsional nystagmus that fatigues and can be suppressed by visual fixation 3, 4
• Duration: Peripheral vertigo episodes from vestibular neuritis typically last days to weeks, while BPPV episodes last seconds to minutes 3, 5
• Associated Symptoms: Peripheral lesions often present with hearing loss, tinnitus, or aural fullness, which are uncommon in central lesions 4
• Response to Treatment: Failure to respond to standard vestibular treatments should raise concern for central pathology 1, 6

Clinical Pitfalls to Avoid

• Misdiagnosis of Stroke: Brainstem and cerebellar strokes can sometimes mimic peripheral vestibular disorders. In one series, 10% of cerebellar strokes presented similar to peripheral vestibular disorders 1, 6
• Overlooking Medication Side Effects: Always review patient medications for potential vestibulotoxic agents 1, 2
• Incomplete Evaluation: Relying solely on patient-reported symptoms without objective testing can lead to misdiagnosis 7, 5
• Assuming All Positional Vertigo is BPPV: Central positional vertigo can mimic BPPV but typically presents with purely vertical nystagmus (upbeating or downbeating) and associated neurological findings 3

Proper identification of the cause of peripheral vestibular lesions is crucial for appropriate management and to avoid missing potentially serious central causes that may require urgent intervention.