ASYMMETRIC PREDOMINANTLY IPSILATERAL BLEPHAROSPASM AND CONTRALATERAL PARKINSONISM IN AN ELDERLY PATIENT WITH A RIGHT MESENCEPHALIC CYST

A 66-year-old woman presented with a 3-year history of predominantly r ight-sided blepharospasm and a 1-year history of progressive predomina ntly left-sided hemiparkinsonism manifested by a left upper extremity resting tremor and left-sided bradykinesia. Magnetic resonance imaging of the brain revealed a large right mesencephalic cyst with mass effe ct. Positron emission tomography revealed bilateral striatal hypometab olism consistent with nigrostriatal dopaminergic dysfunction. The asso ciation of predominantly ipsilateral blepharospasm and predominantly c ontralateral hemiparkinsonism is very rare, and its association with a posterior fossa space-occupying lesion has been reported only once. T his is the second report of such an association and the first descript ion of adult-onset symptomatology.