Reduced cerebellar vermis activation during urinary storage and micturition in multiple system atrophy: 99mTc-labelled ECD SPECT study.

Single-photon emission computed tomography brain imaging with special reference of bladder function was performed in eight multiple system atrophy (MSA) patients (two men, six women; mean age, 61 years) and age-matched five normal control subjects (three men, two women; 62 years). In both groups imagings were obtained in three conditions; empty bladder, storage, and micturition. [99mTc]-labelled ECD (555 MBq) was intravenously injected, which was immediately trapped and stabilized within the brain. Using NEUROSTAT software, which could also cancel morphologic differences between MSA and canonical brain, statistical difference between normalized mean tracer counts of both groups in each phase was calculated and visualized. In the storage phase, there was a significant decrease in tracer activity in bilateral cerebellar vermis, particularly of the right side in the MSA group (P < 0.05), which is also known to be involved in the neural control of micturition. In the micturition phase, the area of decrease in tracer activity in the cerebellar vermis became wider in the MSA group. In the resting state, no statistically significance was seen between both groups. In conclusion, it is suggested that the decrease in tracer activity in the cerebellar vermis during urinary storage and micturition is contributing to the micturitional disturbance in this disorder.