Torsional Nystagmus Associated with Palatal Tremor in Vertebral Artery Dolichoectasia (.pdf)

A 50 year-old woman presented with three-month history of oscillopsia. This accompanied with gait disturbance. Her previous medical history was significant for right-side hemiparesis for the last year, DM type2 and essential hypertension. She denied any history of drug abuse.On examination, BCVA was 20/20 in both eyes. Anterior segment and fundus exam were unremarkable. Binocular conjugated pure counter-clockwise torsional nystagmus synchronizing with palatal tremor was observed. The amplitude and frequency of nystagmus were similar in all gazes. Null point was absent. Ocular alignment was orthotropic. Extraocular muscles function, saccadic velocity and smooth pursuit eye movement were all within normal limit. Neurological examination showed rightsided hemiparesis and hyper-reflexia. Celebellar functions were impaired on the right-side including wide-base gaits, dysdiadokonesia and impaired Finger-to-Nose test. Thin slice axial T2 weighted MRI with fat suppression and Apparent Diffusion Coefficient(ADC) images show dolichoectatic left vertebral artery, exerting pressure effect to the left medulla. A hypersignal intensity T2 change with increased diffusion on the ADC image at the left medulla is also depicted. 3D Time of Flight (TOF) MRA of the posterior circulation reveals dolichoectatic left vertebral artery with redundancy to the right. Hypoplasia of the right vertebral artery is noted. To our knowledge, this is the first case of torsional nystagmus with palatal tremor in vertebral artery dolichoectasia.