Sensory alien hand syndrome in corticobasal degeneration: a cerebral blood flow study.

The presence of alien hand syndrome (AHS) is suggestive of the diagnosis of corticobasal degeneration when it develops in a progressive way. Sensory AHS (sAHS) should be distinguished from the motor form described more commonly. The physiopathology of sAHS remains unclear. The aim of this study is to determine cerebral regions involved in sAHS. We compared perfusion single photon emission computer tomography scans of patients with sAHS (n = 3) and without (n = 4). We observed significant decrease of regional cerebral blood flow over the nondominant thalamus in sAHS+ compared to sAHS- patients. This result suggests the involvement of the nondominant thalamus in sAHS.