Abstract

Objective: The video head impulse test (vHIT) is useful for evaluation of high frequency vestibulo-ocular reflex. There are a few reports regarding the recovery of head impulse test in vestibular neuritis (VN) but the factors for the recovery were not studied. The study aimed to identify the recovery patterns of vHIT in VN and the factors influencing the recovery.
Methods
Among 31 patients with acute VN, 18 patients with identified recovery pattern were selected. We conducted serial checks of subjective vertigo and spontaneous nystagmus until discharged (1?8 days), and scheduled vHITs. We found three patterns in serial vHITs during follow-ups and analyzed the relationship of initial vestibular function tests, serial check-ups of subjective vertigo, bedside neuro-otologic tests, and vHITs.
Results
Five patients showed normal vHIT gain in acute stage (non-damaged pattern) and 8 patients’ gains were recovered after 30 days after symptom onset (early recovered pattern). Poor recovery pattern was found in 5 patients (poorly recovered pattern). There were relationship between vHIT recovery patterns and the severity of vestibular dysfunctions. Duration of spontaneous nystagmus (until grade 1), degree of subjective visual vertical tilt, ocular vestibular myogenic potential abnormalities, and abnormality of rotatory chair test were all related to poorly recovered vHIT patterns. All poor recovery patients had residual symptom at 30 days after symptom onset.
Conclusion
The vHIT may give clinicians useful hints in predicting prognosis in VN, and the recovery of vHIT would be delayed if the damage were more extensive.

• Keywords: Head impulse test;Reflex;Vestibulo-ocular;Vestibular neuronitis;