The story

A 66-year-old man was referred by his general practitioner following an event in October 2009. During his weekly trip into town he had attempted to drive his car but found that he was unable to operate the controls. Nor could he work the gear stick, or apply or release the handbrake. His wife, who witnessed this episode, added that he was unable to navigate and to follow the route when a passenger in the car took over driving. His power, movements and speech were not affected. One hour later, after he had returned home, he was oriented in space and time but was still not felt to be back to normal in terms of speed and clarity of thought.

For several weeks before this episode his wife had noticed that his concentration and ability with daily activities and domestic tasks had deteriorated. On one occasion he had forgotten to put out the recycling bin on the appointed day of the week and he forgot the usual cleaning routine at home, behaviour that was uncharacteristic. Several days before the event he had complained of a mild headache, described as an ache behind the eyes, which had been worse in the mornings. There was no history of fever, sweats, weight loss or other systemic symptoms. There was a past history of hypertension and hypercholesterolaemia. He was an ex-smoker with a 40 pack-year history.

Initial examination revealed a blood pressure of 171/100 mm Hg but otherwise systemically he was normal. He was alert and oriented in time and place. He had normal visual acuity and eye movements. There was a left lower quadrantanopia, left-sided visual neglect and cortical sensory loss in the left hand (agraphaesthesia and astereognosis). There was no evidence of constructional or dressing apraxia or of visual agnosia. Language and other …