LAUSR

BACKGROUND Few data are available on the prevalence of midbrain lesions among NMOSD patients. The study aimed to address the frequency of midbrain lesions, especially dorsal midbrain involvement, among a group of NMOSD patients. METHODS The medical records of 108 NMOSD patients were reviewed, who were registered at the Al-Zahra MS Clinic, Isfahan, Iran. The patients´ information including sex, age, first recorded chief complaint, and midbrain lesion presence in the first brain MRI was collected. RESULTS Out of the 108 NMOSD patients, eight had midbrain lesions in their first brain MRI (7.4%). Of these patients, 50% were male and 50% were female, with the mean age being 35.25 ± 12.17 years. The most frequent first chief complaints included diplopia due to incomplete third nerve palsy and vertigo. The brain MRIs of the patients showed symmetric dorsal midbrain involvement in all the patients, and enhancement was discovered in only one of the brain MRIs. CONCLUSION Among the patients, 7.4% presented midbrain involvement at onset. Therefore, midbrain lesions should also be considered as a possible core clinical manifestation in the NMOSD diagnostic criteria.