Serial perfusion brain tomographic scans detect reversible focal ischaemiain Rasmussen's encephalitis

A 39-year-old man with advanced adult-onset Rasmussen's encephalitis was tr eated with prednisolone and long-term, high-dose, human intravenous immunog lobulin. A pretreatment, semiquantitative interictal brain perfusion single photon emission computed tomography (SPECT) scan using Tc-99(m) HMPAO (hex amethylene propylene amine oxime) showed hypoperfusion in the clinically af fected right frontal, parietal and temporal lobes and contralateral perfusi on defects. A second scan 8 months later revealed significant improvements (more than two standard deviations) in perfusion of the right frontal and t emporal lobes despite serial magnetic resonance imaging evidence of permane nt brain damage. This was associated with useful recovery of the patient's physical and cognitive function. We conclude that serial perfusion brain SP ECT scanning is a useful method to demonstrate improvement in patients with Rasmussen's encephalitis in response to therapy.