Microvascular vestibular nerve palsy may be a cause of acute vestibular syndrome in older patients.

Abstract

BACKGROUND: Patients with persistent acute vertigo and normal horizontal head impulse test (hHIT) are often referred for MRI looking for stroke or other central pathology. Recent literature does not support a peripheral pathology even if brain MRI is normal. Video head impulse testing (vHIT) may confirm a peripheral vestibulopathy. METHODS: Adult patients with suspected acute vestibular neuritis were examined with a structured physical examination and then the eye movement response to rapid head impulses using the ICS Impulse vHIT device on each day of their hospital admission. We compared data on those patients with normal range vestibule-ocular (VOR) gain ≥ 0.8 on the affected side with those having more sever VOR gain reductions < 0.8. RESULTS: Amongst 21 patients with acute vestibular syndrome there were 10 patients with acute vertigo, fixation-suppressible second degree spontaneous nystagmus, and either a subtle positive hHIT, equivocal or normal hHIT and a vHIT VOR gain of ≥ 0.8. Clear asymmetry of the VOR gain on vHIT testing was present in the minority. Catch-up saccades on the affected side were evident in all patients. These mild vestibulopathy patients were older, mean age 70, versus mean age 49 for the more severely affected patients with VOR gain < 0.08 (p=0.002). CONCLUSION: Mild vestibulopathies with subtle clinical signs may be more difficult to differentiate from vertebrobasilar stroke. We found that these are more likely to be seen in older patients. VHIT testing can confirm a peripheral pathology but this may not be vestibular neuritis. We propose that these may be microvascular vestibular nerve palsies.