Abstract

1. This patient is young, making an unusual cause of stroke more likely than degerative arterial disease. The differential includes emboli, dissection and clotting disorders, but these have largely been excluded by the normal investigations. This, together with the presence of infarcts in different territories, memory problems, irritability and the pleocytic CSF, make vasculitis the probable diagnosis.

CNS vasculitides may be primary, or secondary to systemic diseases such as SLE, Wegener’s, Behçet’s disease and polyarteritis nodosa. Usually any systemic features begin before CNS involvement. Thus the negative previous history, absence of systemic signs and normal serology, make a primary CNS vasculitis the most likely diagnosis in this case. The diffuse, punctate abnormalities involving both grey and white matter seen on MRI support this.

Given the high rate of negative biopsies and significant risks involved, in this case in which the diagnosis is fairly clear cut, we would favour a therapeutic