Objective To investigate the electromyngraphy eharacteristies of Parkinsen's disease (PD) by studying tremor frequency, intensity and drug response. Methods Sixty-six patients with PD hospitalized during March 2005 to May 2006 were re-evaluated and recruited into the study. A ten-channel electromyography recorded the frequency and intensity of the rest tremor and postural tremor. Tremor analysis soft was used to statistically analyze differences between the two types of tremor, correlation between the frequency and intensity, and changes after regular administration of dopaminergic medication. Results The frequencies of rest tremor ((4. 79±0.69 ) Hz) and postural tremor ( (5.54±1.18) Hz ) showed statistical differences (F = 33.5, P<0. 01), but the intensity of rest tremor (0.016-421.700 (rag)2) and postural tremor (0.062-217.900 (mg)2) didn't show statistical differences (F=1.917, P>0.05 ). No regression relation was revealed between the frequency and intensity of tremor (r=0.09, P>0.05). After dopaminergic medication treatment, the intensity declined significantly from 0.016-421.700 (mg)2 to 0.027-82.200 (mg)2(F=5.179,P <0.05), but the difference of frequencies of tremor between before ( (5.09±0.85) Hz) and after treatment ( (5.20 ± 1.08 )Hz) was not significant (F = 0.474, P > 0.05). Conclusions There may be different mechanisms for the rest tremor and postural tremor in PD. There is no correlation identified between the frequency and intensity in PD and this is may be resulted from variability of tremor intensity. Dopaminergic can relieve the symptom of tremor, but it doesn't reduce the frequency of tremor.

Objective To explore the values of electromyography to examine birth injuries.Methods 34 cases of birth injuries were studied,the electromyography and motor nerve conduction of brachial plexcy were recorded.Then,the location and severity of birth injuries were determined.Results Among 34 cases,according to the location of injuries,there were 10 cases of upper trunk injuries,7 cases of upper and middle trunk injuries,5 cases of middle and lower trunk injuries,5 cases of lower trunk injuries,and 7 cases of whole brachialplexus injuries.On the other hand,according to the severity of injuries,there were one case of complete injuries and 33 cases of incomplete injuries which included 2 cases of severe injuries and 31 cases of slight injuries.Conclusion Electromyography is the reliable method to identify the location and severity of brachial plexus injuries,and this examination is necessary to diagnose birth injuries with great clinical values.