Objective:

Alien Hand Syndrome (AHS) is a rare neurological condition characterized by involuntary limb movements without conscious control, most commonly affecting the left hand. We present a unique case of right-sided AHS in a patient with a history of right thalamic bleed resulting in left hemiparesis.

Background:

n/a

Design/Methods:

A 57-year-old patient with a background of systemic hypertension presented with unintentional movements of the right hand for five months. The movements were observed when the patient's left hand was touched, as the right hand seemingly attempted to protect the left forearm. Clinical examination revealed conscious and alert status, with involuntary movements of the right hand and resistance to examination of the left hand. The patient also exhibited residual left-sided hemiparesis and spasticity in both upper and lower limbs, but no sensory loss. MRI brain imaging with tractography demonstrated thinning of the left half of the corpus callosum mid-portion and reduced fractional anisotropy values compared to the normal-appearing splenium on the right side. Tractography further revealed a decrease in fibers across the corpus callosum on the left side.

Results:

The presented case highlights a rare manifestation of right-sided AHS following a right thalamic bleed. The observed disruptions in interhemispheric connectivity, particularly involving the corpus callosum, suggest an underlying mechanism for the emergence of alien hand movements. The absence of simultaneous resting activations between the left inferior frontal lobe and motor cortex, as revealed by functional MRI, further supports this hypothesis.

Conclusions:

: This case contributes to our understanding of AHS and its association with specific neurological lesions. Further research is warranted to explore the exact mechanisms underlying AHS, develop effective management strategies, and address the challenges faced by patients with this intriguing condition.