Journal of Clinical Neuroscience (2005) 12(5), 570 0967-5868/$ - see front matter ª 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2005.03.007 Images in neuroscience Images in neuroscience B. Woon, P.J. Mitchell The Royal Melbourne Hospital, Parkville Victoria, Australia Fig. 1 CT Brain (unenhanced). Fig. 3 MRI Brain, Diffusion Weighted Imaging sequence. CLINICAL BACKGROUND A fifty-two year old man presented with a three day history of confusion and clumsiness. He had two similar presentations 3 years and 6 months ago. Other past history included diet-controlled type 2 diabetes mellitus, hypercholesterolaemia, hypertension and ‘industrial deafness’. On examination he was a short man, alert but disoriented to person, place and time. His speech was incomprehensible and monosyllabic, with inability to follow single stage commands. There was bilateral optic atrophy. All 4 limbs were ataxic, but there were no other long tract signs. The admission was complicated by generalized tonic clonic seizures. He was eventually placed in supportive care. His brain CT (fig. 1) and MRI (figs. 2 and 3) are provided. WHAT IS THE MOST LIKELY DIAGNOSIS: Fig. 2 MRI Brain, Axial FLAIR sequence. (a) (b) (c) (d) (e) Antiphospholipid syndrome Ischaemic stroke Canavan disease MELAS Progressive multifocal leukoencephalopathy Answer at back of issue. 570