A study of visual evoked potential (VEP), brainstem evoked potential (BAEP) and median nerve somatosensory evoked potential (SSEP) in 26 Malaysian patients with clinically definite Multiple Sclerosis (MS). This study showed an overall high rate of abnormality, with 85% of patients for VEP, 31% for BAEP and 65% for median nerve SSEP. The rate of abnormality was particularly high for patients who were symptomatic, reaching 100% of patients for VEP, 50% of patients in BAEP, 83% of nerves for median nerve SSEP. The rate of abnormality among those who were asymptomatic was lower, varying from 32% of eyes in VEP, 27% of patients in BAEP and 31% of nerves in median nerve SSEP. Three out of 10 patients with optic spinal form of MS have abnormal BAEP. These show the usefulness of the evoked potential studies in confirming the clinical lesions as well as demonstrating subclinical involvement. The rate of abnormal evoked responses for the asymptomatic patients in this study is generally lower than that published elsewhere.
This is a study of 13 Malaysian patients with clinically definite Multiple sclerosis (MS) subjected to a hot bath test with VEPs, BAEPs, median nerve SSEPs before and after heating. Five patients (38%) developed neurological changes with the rise in body temperature. There was an average of 0.46 new sign per patient. Four patients had motor disturbances attributed mainly to aggravation of spinal cord dysfunction. Two patients had additional visual deterioration, one patient has associated VEP change. This study shows that though Uhthoff's phenomenon has not been noted in the reports of Asian MS patients, when subjected to rigorous testing, Asian MS patients also show sensitivity to body temperature change. However, the percentage of positivity of the hot bath test is much lower than that reported for Caucasians. Thus this study shows further differences between Asian and Caucasian MS patients.