[I-Iomazenil Single-Photon Emission Computed Tomography Imaging in a Patient with Mild Traumatic Subdural Hematoma Accompanied by Delayed Transient Aphasia].

Early and late images of I-iomazenil(IMZ)single-photon emission computed tomography(SPECT)reflect distributions of cerebral blood flow and those of cortical benzodiazepine receptor binding potential, respectively. Crossed cerebellar diaschisis reflects left-to-right asymmetry of metabolism in the cerebral hemispheres. We present a case of a 67-year-old woman who developed transient aphasia 3 days after the onset of a mild acute subdural hematoma. Computed tomography scan and magnetic resonance imaging during aphasia did not show enlargement of the hematoma or any new lesions. Electroencephalography did not show any abnormalities. Early images of I-IMZ SPECT 3 days after the onset of aphasia revealed a decrease in radioactivity in the right cerebellar hemisphere relative to that in the left cerebellar hemisphere. Late images of the same I-IMZ SPECT displayed a decrease in radioactivity in the left cerebral hemisphere relative to that in the right cerebral hemisphere. Twenty-four days later, the aphasia disappeared and the left-to-right asymmetries of radioactivity in the cerebellar and cerebral hemispheres on the early and late I-IMZ SPECT images also resolved.