Orbicularis oculi reflex abnormalities in patients with multiple sclerosis: a clinical, EMG, and MRI investigation.

Abstract

Examination of the orbicularis oculi reflex (OOR) has been used for many years in the diagnostic algorithm of multiple sclerosis (MS) in a few aspects: to define existence and specific location of the lesions and to follow-up dynamic changes in pontine and supranuclear structures of the CNS. Correlation between MRI and electrophysiological data from OOR has not been widely studied in the patients with MS. The aim of the present study is to assess the changes of OOR in patients with MS and their relation to clinical and MRI brainstem findings. Forty-six patients were examined by complex EMG, MRI, and clinical protocol, aged from 21 to 55. Two groups were formed: first group of 40 patients with relapsing remitting MS (RRMS) and second group of six patients with secondary progressive (SPMS). About one third of the patients had neither clinical nor OOR or MRI brainstem abnormal changes. In 22.5% of the cases a clinical, EMG and MRI correlation, showing brainstem lesions, was found We observed different changes in OOR responses in about three fourths of all patients, respectively in 75% of patients with RRMS and in 83.3% of those with SPMS. OOR examination gives us evidence of additional brain lesions in 15% of our patients, whose MRI and clinical findings were unremarkable. Prolonged latency of the first and second component of OOR, additionally with asymmetry or lack of response, was more commonly related to the clinical manifestation.