Abstract

BACKGROUND
Huntington's disease disease (HD) is characterized by motor, cognitive, and neuropsychiatric symptoms. Oculomotor impairments and gait variability have been independently considered as potential markers in HD. But there lacks an integration analysis of eye movement and gait.
OBJECTIVE
We assessed multiple examinations of eye movement and gait variability in HTT mutation carriers, analyzed the consistency between these parameters and clinical severity, then examined the association between oculomotor impairments and gait deficits.
METHODS
Seven pre-HD, 30 HD patients and 30 age-matched controls were included. We collected demographics and assessed the Unified Huntington's Disease Rating Scale (UHDRS). Examinations including saccade, smooth pursuit and optokinetic (OPK) test were performed to evaluate eye movement function. The parameters of gait include stride length, walking velocity, step deviation, step length and gait phase.
RESULTS
There are significant impairments in HD patients in the latency and velocity of saccades, the gain of smooth pursuit as well as the gain and slow phase velocities (SPV) of OPK tests. Only the speed of saccades has significant difference between pre-HD and controls. There are significant impairments of stride length, walking velocity, step length and gait phase in HD patients. Parameters of eye movement and gait variability in HD patients showed consistency with the scores of UHDRS. There were significant correlations between eye movement and gait parameters.
CONCLUSIONS
Our results show that eye movement and gait are impaired in HD patients, and speed of saccades is early impaired in pre-HD. Eye movement and gait abnormalities in HD are significantly correlated with clinical disease severities.

• Keywords: Huntington's disease (HD), eye movement, gait, UHDRS