VEMP 所見異常と治療による回復を認めた中枢神経系脱髄疾患の一症例

抄録

　Multiple sclerosis (MS) is characterized by multiple demyelinations within the central nervous system. It has been reported that patients with MS frequently have abnormal findings of cervical vestibular evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP). We report the case of a patient with MS in whom cVEMP and oVEMP testing was useful for assessment of the lesions in the brainstem and their recovery. A 17-year-old woman presented with the feeling of light-headedness and a dull ache in the temple. MRI showed multiple T2-prolonged lesions, suggestive of demyelinated lesions in the left medulla oblongata, left superior cerebellar peduncle and left cerebellar hemisphere. One month after the MRI assessment, the patient's clinical findings worsened. She was diagnosed as having MS. Prior to the start of medical treatment, VEMP testing was performed. Air-conducted cVEMP showed a normal response to right ear stimulation, but decreased p13-n23 amplitudes and prolonged p13 latency in the left ear. Air-conducted oVEMP showed a normal amplitude, but prolonged N1 and P1 latencies in response to right ear stimulation, while there was no response to left ear stimulation. ABRs were normal. The patient was started on steroid pulse treatment, in response to which every T2-prolonged lesion in the MRI improved. Air-conducted cVEMP responses to left ear stimulation were restored to normal. Air-conducted sound oVEMPs showed normal amplitudes, but still slightly prolonged N1 and P1 latencies in response to right ear stimulation. oVEMP responses to left ear stimulation appeared after the treatment. According to the results of the first cVEMP and oVEMP testing, it was considered that lesions existed in the left MLF, vestibular nucleus and intramedullary vestibular nerve, while these structures on the right side were spared. The results of the testing for VEMPs were compatible with the MRI findings and the course of the MS. VEMP testing seems to be useful in the assessment of MS patients.