Alien limb following posterior cerebral artery stroke: failure to recognize internally generated movements?
We describe two rare cases of alien limb syndrome following right posterior cerebral artery (PCA) stroke. Both patients present with left hemianopia, visual neglect and proprioceptive loss in addition to their alien limb symptoms. Lesion subtraction from seven control PCA patients revealed that medial parietal-occipital and thalamic areas were selectively damaged in the alien limb patients. We propose that loss of the sense of motor intention and internal model of the current state of the arm, combined with deficient proprioceptive and visual feedback of the moving limb, are critical for genesis of posterior alien limb and discuss how affected regions normally function to ensure awareness of self-generated motor activity.
Coulthard
Elizabeth
E
Institute of Neurology, University College London, London, United Kingdom.|Institute of Cognitive Neuroscience, University College London, London, United Kingdom.
Rudd
Anthony
A
St Thomas' Hospital, London, United Kingdom.|King's College, London, United Kingdom.
Playford
E Diane
ED
Rehabilitation Group, Institute of Neurology, London, United Kingdom.
Husain
Musad
M
Institute of Neurology, University College London, London, United Kingdom.|Institute of Cognitive Neuroscience, University College London, London, United Kingdom.
D000368:Aged; D002539:Cerebral Arterial Diseases / Q000150:complications* / Q000473:pathology; D005121:Extremities / Q000503:physiopathology*; D005260:Female; D006423:Hemianopsia / Q000209:etiology* / Q000473:pathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D020521:Stroke / Q000150:complications* / Q000473:pathology; D013577:Syndrome