Capsular Genu Infarction Presenting with Confusional Syndrome: An Analysis of Clinical and Neuroradiologic Findings

ABSTRACT

We reviewed 5 patients with infarcts involving the genu of the internal capsule, who revealed behavioral changes and cognitive defects. They developed an acute confusion and/or dementic feature along with other behavioral changes characterized by apathy, hypersomnia, memory impairment, and cognitive impairment, mimicking frontal lobe dysfunction. Brain MRI and/or CT scan localized the lesion to the genu of the internal capsule. Brain perfusion SPECT performed in 3 patients showed hypoperfusion in ipsilateral cerebral hemisphere. Two mechanisms are suggested to explain the development of confusion or dementia after capsular genu infarct. (I) a disconnection or diaschisis of thalamo-cortical interconnection (ii) selective neuronal loss of cerebral cortex due to chronic MCA or ICA occlusion with insufficient collateral blood flow. We suggest that capsular-genu infarction as a cause of acute confusion or dementia must be included in differential diagnosis.