Alien hand syndrome (AHS) is characterised by abnormal motor behaviour of the contralateral upper limb, which is subjectively experienced as involuntary or alien induced.¹ The affected hand often shows a grasp reflex and an instinctive grasp reaction, as well as elements of “magnetic apraxia” associated with frontal lobe damage. The most common frontal type of AHS is repeatedly observed in patients with lesions in the supplementary motor area, anterior cingulate gyrus, medial prefrontal cortex, and anterior corpus callosum. Involuntary uncontrolled movements in AHS usually remain unchanged or improve gradually over periods of varying length. A paroxysmal form of alien hand syndrome has been described very rarely. In these exceptional cases, focal epileptic seizures were suspected to be the pathophysiological substrate for paroxysmal alien limb phenomena.^2,3

Case report

We report a 61 year old right handed man with a paroxysmal form of alien hand syndrome resulting from an ischaemic lesion within the rostral part of the right cingulate motor area (CMA) (fig 1A). Short episodes with typical spontaneous involuntary movements of his left hand (groping, scratching, grasping) developed suddenly four days before patient’s admission to our ward. At that time, normal glycaemia and a transient increase in blood …