Patient in late 50thies feels one week slight instability from time to time, and describes it as difficulty walking straight and also has a short vertigo spells (discomfort in the head) when moving head, especially quick turns. Also, he complains to have left-sided tinnitus (pulsating hissing) since this instability problems has started. He had no nausea or other symptoms.
This history doesn’t sound like a vestibular neuritis.
He had no spontaneous Ny and head-impulse test was normal, but Fukuda step test showed marked turning to the right.
VHIT showed normal gains in all canals expect left posterior, where gain was markedly reduced. cVEMP showed vestibulo-infraocular reflex bilaterally but significantly lower amplitude at the left side.
Caloric test was normal, no asymmetry at all and audiometry showed bilateral mild hearing loss at high frequencies.
VHIT (6 canals) and cVEMP allowed us to diagnose acute lesion of inferior vestibular nerve branch in this patient.
Link with interesting videos of pt with inferior vestibular neuritis, showing spontaneous torsional nystagmus and positive head impulse test in the plane of the affected posterior canal.