Ocular control characterization of motor disabilities: The cerebral palsy case

Abstract

Global statistics estimate 80% of people with disabilities live in developing countries, i.e., nearly 85 million people in Latin America and the Caribbean, being the most prevalent the motor disability, for instance 13 million cases in Brazil. Cerebral Palsy (CP) is considered as a public health problem and the most common cause of motor illness in children. Between 50–90% of the patients with this condition present visual problems, reason why this population exhibits visual sensory and motor abnormalities at rates exceeding those detected in neu-rologically normal children. This work proposes an automatic estimation of the ocular motion, an evaluation that might be extended to any kind of motor disorder. Visual patterns are quantified when challenging the ocular motor system by smooth and saccadic gaze tasks. The motion field obtained by a customized optical flow is characterized by velocity histograms of magnitude and orientation. The temporal result is accumulated in a histogram and a correlation distance between histograms quantifies the differences between subjects. Evaluation results showed significant differences between two PC and control groups constituted by 16 subjects each. This work introduces actual quantification of a prevalent disease whose evaluation and treatment so far if fully dependent on the examiner expertise.