The case

A 61-year-old woman gave a 4-month history of abnormal movements of the left arm and of episodic visual disturbance in the right eye. Each symptom would last a few seconds, and would occur when sitting, though at separate times from one another. There were involuntary twisting movements of the left elbow and wrist, followed by immediate return to normal function. There was no altered consciousness. The visual symptoms manifested as a shadow coming across her right eye, with loss of the lower half of the visual field in the right eye only (proven by covering either eye). The symptoms, both ocular and choreiform, though initially infrequent, increased during the first 6 weeks to 12 times per day. Three months after symptom onset, when she first attended the neurology clinic, their frequency had reduced to three times per day.

She had hypertension, chronic obstructive pulmonary disease and she smoked cigarettes. She took simvastatin, indapamide, losartan and Symbicort and Ventolin inhalers but had not taken antiemetic or neuroleptic drugs.

On examination between episodes, the reflexes in the left arm were brisker than on the right with no tremor or abnormal movements. Ophthalmic examination was normal, with no retinal, vascular or optic disc abnormalities. Cardiac examination was normal. She was in sinus rhythm and her blood pressure was 100/66 mm Hg.

Investigations

MR scan of brain (axial fluid-attenuated inversion recovery (FLAIR)) showed a single 9×6 mm area of high signal within the right centrum semiovale posteriorly, probably an infarct (figure 1). The lesion was not bright on diffusion-weighted images and was not seen on apparent diffusion coefficient …