Abstract

Saccadic eye movement measurement is reported as potential sensitive biomarker of Huntington's disease (HD), in both pre-manifest and manifest stages. While definitely less specific than imagining techniques, it possess potential for quick, low cost and non invasive quantitative assessment of brain functional status. It is also less prone to neuronal compensation mechanism which continues to conceal the evidence of functional motor impairment, especially when voluntary component is involved in saccadic test paradigm (antisaccade-peripherial-conflict). According to recent findings, the changes of saccadic metrics accompany HD progression and they can be considered as a means of tracking the current patient condition and outcome of new therapeutic interventions. Authors present portable, integrated diagnostic environment, Saccadometer Clinical. The system is designed as minimal-setup for evaluation of saccadic metrics, allowing to establish subjects functional deterioration profile based on the repetitive measurements (status samples) accumulated over the time. The key component is small factor, battery powered, head-mounted intelligent sensor, capable of generating laser dot stimuli for both reflex and volitional decision based saccadic tests, and performing automated eye movement acquisition and classification. Due to portability, ease of use, and build-in telemetry link for wireless communication, the measurement can be carried by patient her/himself in home environment, providing facility for continuous, remote monitoring of patient's functional status. In order to broaden the spectrum of measured parameters, current development efforts aim to include the smooth pursuit and the vestibule-ocular (postural sway) tests within the same miniaturised system, serving as complementary biomarkers of HD.