Alien Limb Syndrome Responsive to Amantadine in a Patient with Corticobasal Syndrome

Unilateral neglect or alien hand syndrome? A diagnostic challenge

Alien hand syndrome (AHS) is a rare post-stroke complication. Although the occurrence of AHS after stroke is rare, it can have a disabling impact on the lifestyle and career of the patients post stroke. It is difficult to distinguish AHS from the non-dominant hemispheric infarction with symptoms of hemianopia and left hemineglect, as patients with AHS can also have neglect as well as behaviour symptoms if the frontal lobe is involved. We report the case of a 62-year-old gentleman who was admitted to the rehabilitation ward and was treated for neglect and apraxia following right middle cerebral artery stroke. After further re-evaluation, the patient was diagnosed with AHS. Functionally, he improved and the symptoms disappeared four months after the stroke. In this case report, we highlight the features of AHS and provide a unique management approach.

Alien Hand Syndrome

Alien hand syndrome (AHS) is a rare disorder of involuntary limb movement together with a sense of loss of limb ownership. It most commonly affects the hand, but can occur in the leg. The anterior (frontal, callosal) and posterior variants are recognized, with distinguishing clinical features and anatomical lesions. Initial descriptions were attributed to stroke and neurosurgical operations, but neurodegenerative causes are now recognized as most common. Structural and functional imaging and clinical studies have implicated the supplementary motor area, pre-supplementary motor area, and their network connections in the frontal variant of AHS, and the inferior parietal lobule and connections in the posterior variant. Several theories are proposed to explain the pathophysiology. Herein, we review the literature to update advances in the understanding of the classification, pathophysiology, etiology, and treatment of AHS.

Corticobasal syndrome: A diagnostic conundrum

Corticobasal syndrome (CBS) is an atypical parkinsonian syndrome of great interest to movement disorder specialists and behavioral neurologists. Although originally considered a primary motor disorder, it is now also recognized as a cognitive disorder, usually presenting cognitive deficits before the onset of motor symptoms. The term CBS denotes the clinical phenotype and is associated with a heterogeneous spectrum of pathologies. Given that disease-modifying agents are targeting the pathologic process, new diagnostic methods and biomarkers are being developed to predict the underlying pathology. The heterogeneity of this syndrome in terms of clinical, radiological, neuropsychological and pathological aspects poses the main challenge for evaluation.