Prism Adaptation Test (PAT): A Practical and Quantitative Method to Evaluate Cerebellar Function

Among various diseases on the cerebellum, neurodegeneration is the most difficult to be diagnosed and cured. Neurodegenerative diseases usually progress very slowly, and it appears hard to detect small changes in clinical trials. To overcome this problem, we tried to use prism adaptation because it is a popular method to investigate motor learning of the cerebellum. We finally developed a prism adaptation test (PAT) using hand-reach task and a touch panel, which was compact in size and available in outpatient clinics. More importantly, adaptability index (AI) calculated based on data of PAT was quantitative and distinguished cerebellar patients (AI 0.68) almost completely. AI of PAT was also correlated with ataxic scales SARA and 9-hole Peg test. AI of PAT became smaller significantly when disease duration became longer. It is suggested PAT may be a nice quantitative method to evaluate cerebellar functions.