Head injury and left sided weakness

A 77 year old man fell on an icy pavement on to his left shoulder and cut his head. He did not lose consciousness. Six weeks later while watching television he noticed his left arm shaking. This lasted for about 50 seconds. In the next 10 days he kept dropping things when using his left hand. He also kept veering to the left while driving, coming close to parked cars. He noticed that he had been feeling increasingly drowsy and had some right sided headache.

On examination he had a left hemiparetic gait. His right pupil was larger and less reactive to light. He had a noticeable facial weakness because of the left upper motor neurone; left sided pyramidal weakness; and a left extensor plantar. He had no sensory loss of note. A computed tomogram of the head was arranged.