Three-dimensional surface display using 123I-IMP in a case of motor neuron disease with dementia.

A case of motor neuron disease with dementia is presented. A brain CT showed atrophic changes mainly in the left frontal cortex, and 123I-IMP SPECT disclosed a decrease in 123I-IMP uptake in the frontal regions. To distinguish a subregion related to dementia from that related to motor system disorders, a three-dimensional surface display with 123I-IMP was reconstructed. The imaging method clearly demonstrated cortical hypoperfusion in the inferomedial frontal cortex and the motor-sensory cortex. These findings suggest that dementia may be due to the former lesion and motor system disorders due to the latter lesion, respectively.