Vestibular Migraine (VM) is a frequent cause of recurrent spontaneous vertigo. While some report a normal Video Head Impulse Test (vHIT) in VM, others observed abnormal results on this test. Whether or not methodological discrepancies could be the cause of these differences is not known. There are 2 vHIT methods: subjects fixating an earth-fixed target (HIMP paradigm) or a head-fixed target, the suppression head impulse test (SHIMP paradigm).
The present study aimed to compare VM patients against healthy controls on both HIMP and SHIMP in order to unravel any differences between them.
Forty-eight VM patients and 27 healthy controls tested with both the HIMP and SHIMP paradigm. Our 48 VM patients showed mean VOR normal range gains in both the HIMP and SHIMP paradigms, although there were some VOR impairments in individual semicircular SCCs. VM patients with motion sickness had lower horizontal VOR gain than those without motion sickness, with the HIMP, but not the SHIMP paradigm.
VM patients have normal VOR gain with either vHIT paradigm.
The clinical significance of this observation is that a definitely abnormal vHIT with either method is unlikely to be due to vestibular migraine and an alternative diagnosis should be sought.