headache several days earlier, mainly frontal and at the vertex. Its intensity built up gradually, interspersed with occasional periods of relief for up to an hour but later became continuous. During its early stages, he saw his General Practitioner (GP), who prescribed analgesics and arranged for review but advised C.R.S. to go to the Emergency Department if headaches rapidly worsened. Shortly afterwards, the headaches increased so a neighbour took the patient to the Emergency Department in the late afternoon. After assessment, the doctor increased the analgesics and kept him under observation before discharging him about 4 hours later and advised him to consult his GP again for review.

That evening, C.R.S. noticed difficulty with fine movement, for example, texting messages incomprehensible to his family. Over the next few days,he noticed that his right leg and foot had become 'clumsy', heavy, and difficult to move. He tried to get to his garage to get some items from the freezer but fell a few times on the way.

Findings
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The striking feature now was the marked change in his walking, which was laboured as he had to drag his right leg and with an unusual 'clumsiness' of his right hand and arm. Initially, it was difficult to distinguish between motor weakness of the upper limb and impaired 'spatial awareness', the latter suggesting parietal lobe damage and commonly tested for in terms of 'joint position sense' (JPS). These features were in marked contrast to the clarity of his mind, speech, and recollection. The history and physical signs were compatible with a