Dominant parietal lobe ischaemic stroke presenting as alien hand syndrome

Abstract

We describe an unusual case of stroke manifesting as alien hand syndrome (AHS) causing sudden onset of abnormal hand movements. The patient reported his left arm would move outside his control and grab things in his surroundings without his conscious will. He felt his arm did not belong to him. Examination showed left arm brisk reflexes, astereognosis, and agraphesthesia in the left hand. Imaging revealed an established right parietal lobe ischaemic stroke. Lesions of the parietal cortex can cause AHS by disrupting the interpretation of somatosensory feedback when a movement is made and decreasing the ability to consciously monitor motor intentions. A low threshold should be adopted for arranging brain imaging and a thorough neurological examination is needed in any sudden onset movement disorder.