Video head impulse test findings in patients with peripheral myelin protein 22 related neuropathies

Abstract

Objective: Vestibular impairment may be present in and contribute to imbalance in patients with hereditary neuropathies. We examined the vestibulo-ocular reflex (VOR) characteristics in peripheral myelin protein 22 neuropathies using the video head-impulse test (vHIT). Methods: 23 patients with Charcot-Marie-Tooth disease 1A (CMT1A) and 17 with hereditary neuropathy with liability to pressure palsies (HNPP) were recruited. Three-dimensional vHIT was performed. VOR-gain and latency, refixation-saccade prevalence and first-saccade amplitude, onset-latency, peak-velocity and duration were examined and compared against age-matched controls. Results: In CMT1A and HNPP gait imbalance was reported in 78.3 % and 58.8 % of patients, resulting in recurrent falls in 65.2 % and 23.5 %. Reduced VOR-gain affecting the posterior-canals (PCs) was found in 47.8 % of CMT1A and 11.7 % of HNPP patients. First saccade amplitude and peak-velocities higher in horizontal-canal (HC) and PC in the CMT1A group compared to controls (p < 0.05). In HNPP, first saccades were larger in HC and anterior-canal (AC) planes; saccade peak-velocity was higher in AC and PC planes compared to controls (p < 0.05). In CMT1A, VOR-gain impairment was associated with higher Charcot-Marie-Tooth Examination Score, longer disease duration, and higher total Overall Neuropathy Limitation Scale score (p < 0.05) and VOR-gain was lower for PC in patients with a history of recurrent falls (p < 0.05). VOR-latency was significantly longer in HC and PCs in CMT1A compared to controls (p < 0.05). Conclusions: VOR impairment and slowing of the VOR-latency is found in CMT1A but not the HNPP cohort. These findings may relate to demyelinating processes affecting the vestibular nerves and thus the VOR pathways. Significance: VHIT allows detection of VOR impairment which could be an additional contributor to imbalance and falls in patients with CMT1A. © 2025