Analysis of Saccadic Eye Movements of Epileptic Patients using Indigenously Designed and Developed Saccadic Diagnostic System

摘要

Aim: The study aimed to record and analyse saccadic eye movements of epileptic patients. The specific purpose was to determine and compare saccadic parameters of normal subjects with those of age-matched epileptic patients. The selected parameters were saccadic duration, latency, peak saccadic velocity and the main sequence relationship. Any possible relationship between these parameters and severity of epilepsy was also examined. Methodology: A microcontroller-based saccadic diagnostic system was indigenously designed and developed for the above purpose. It was used to elicit, record and analyse around 80 saccadic eye movement recordings from 53 normal subjects for a visual angle range of -60° to +60°. These data have been analysed and the saccadic parameters were determined using MATLAB 2007. Saccadic detection was done using amplitude threshold and velocity threshold techniques and the results were compared. Saccadic eye movement data from 14 epileptics have been recorded. Saccadic parameters in respect of these data was calculated. Data collection from some more epileptics is under progress. Salient results: The system was tested successfully on human subjects and its performance was found satisfactory as per the design requirements with a good feedback from the medical personnel who are presently using it. Analysis of data collected revealed that the amplitude threshold technique was more efficient to detect a saccade in 97% determinations. The saccadic parameters and their relationships for normal subjects were found to be in good agreement with those reported in literature. The saccadic parameters showed a change in epileptics. Conclusions and significance: Our saccadic diagnostic system could be of immense help to those working in the field of saccadic studies due to its simplicity, portability, ease of use and user-friendly features. Additional data to be collected from epileptics and similarly treated will provide concrete and meaningful information diagnosis.