Differentiate multiple system atrophy of parkinsonian type from multiple system atrophy of cerebellar type by static posturography study.

WANG Yu-zhou; ZHENG Wen-hua; KUANG Zu-ying; CHEN Wen-ming; WANG Zhan-hang; LU Jian-jun; LI Bo; PAN Meng-qiu; XU Yan; YE Jin-long; LI Xiao-di.

Abstract：Objective To investigate the differences between patients with multiple system atrophy of parkinsonian type (MSA-P) and multiple system atrophy of cerebellar type (MSA-C) by static osturography analysis.Methods Static postural analysis was performed by the SYNAPSYS Posturography System (SPS) in 92 subjects, including 29 with MSA-P, 40 with MSA-C and 23 healthy controls.During the study, all subjects were engaged in a Sensory Organization Test (SOT), which consisted of four stance tasks of standing on a normal surface/foam support for 20 seconds with eyes open/closed separately.The amplitude of the postural sway was measured and transformed into energy by Fourier analyzer.SOT scores, the appearance of falls and typical 3-HZ postural tremors during the four tasks were recorded and compared.Energy of the three groups was also compared in different tasks, directions and frequencies.Results Compared with healthy controls, SOT scores were significantly lower in MSA groups (P<0.01).Compared with MSA-P, the vestibular scores were further reduced in MSA-C (P<0.05).Falls were more common in MSA group (especially in the MSA-C group) in the SOT4 task, and the difference between MSA-P and MSA-C was also significant (P<0.05).Typical 3-HZ postural tremor was observed in most MSA-C patients, a few MSA-P patients and none of the healthy controls.Compared with healthy controls, much more energy was consumed in every task, every direction and nearly every energy bands in MSA group.Energy of MSA-P was significantly lower than that of MSA-C mainly in the high frequency band (2 Hz-20 Hz).As the difficulty of the task increased, differences between the two groups were more common in all frequency bands.Conclusion Both MSA-P and MSA-C are characterized by severe postural dysfunction.However, typical postural tremor predominates in MSA-C, and extremely useful in the differential diagnosis of MSA-P and MSA-C.