Intracranial Hemorrhage in the Corpus Callosum Presenting as Callosal Disconnection Syndrome: FDG-PET and Tractography: A Case Report.

We report the findings of 18F-fluorodeoxyglocese positron emission tomography (FDG-PET) and diffusion tensor tractography (DTT) in a right-handed patient presenting with callosal disconnection syndrome, including alien hand syndrome, after an anterior communicating artery aneurysmal rupture. The 49-year-old patient had right hemiparesis and unintended movement of the right hand during action of the left hand. A brain magnetic resonance imaging revealed lesions in the upper part of the genu and body in the corpus callosum as well as hemorrhage in the inter-hemispheric fissure. We observed extensive disruption of corpus callosum fibers in the upper genu and trunk by DTT for the evaluation of inter-hemispheric connection. FDG-PET revealed severe hypometabolism in the left cerebral hemisphere, including basal ganglia and thalamus, and hypermetabolism in the right cerebral hemisphere. Based on findings of FDG-PET and DTT, the callosal disconnection syndrome presented in the patient could be the result of loss of transcallosal inhibition in the contralateral hemisphere.