Analysis Of The Clinical And Electrophysiological Features Of Essential Tremor

Objective:To explore the clinical features of essential tremor(ET)and explore the electrophysiological differences between ET and Parkinson disease(PD)tremor(PD tremor),which is beneficial to the diagnosis of essential tremor.Methods:Seventy ET patients,50 PT patients and 45 age-gender-matched healthy volunteers in Department of Neurology,the Second Affiliated Hospital,Zhejiang University School of Medicine from May 2015 to April 2016 were included.Clinical data and tremor analyses under different postures were obtained.A subgroup of 50 ET patients were included in the study of Non-motor sympotoms.These patients and the other 45 controls were evaluated using the Pittsburgh Sleep Quality Index(PSQI),Hamilton anxiety scale(HAMA),Hamilton’s Depression Scale(HAMD),and(the MOS item short from health survey,SF-36).Cognitive functions were evaluated using the Mini-mental state examination(MMSE).All patients were evaluated with tremor scores and Accelerometry in resting,postural and loading states.The amplitude,frequency and frequency dispersion of rest tremor,postural tremor and the influence of weight on tremor of 35PT patients and 40ET patients were retrospectively analyzed and compared.data of the more and less trembling hands were statistically elaborated.Results:Typical ET patients are characterized by postural or intentional tremor,but in some serious cases can be rest tremor,which is associated with the head,mouth or face tremor.MMSE total score of the ET group(25.60±2.76)were lower than the control group(28.16±1.71)(P<0.001).The incidence of sleep abnormal was higher in ET group(62%)than the control group(15%).Mean PQSI score of the ET group(6.42±2.71)was higher than the control group(3.84±2.13,P<0.05).The percentage of ET patients who had moderate and severe anxiety levels was 78%,this ratio was higher than the control group(22.5%,P<0.05).The percentage of ET patients who had moderate and severe depression levels was 35.5%,this ratio was also higher than the control group(22.5%)(P<0.05).Anxiety and depression had effects on physical and mental health and were also related to the quality of life.The tremor scores and electromyography performance:Both PT tremor scores and ET tremor scores in loading states were higher than those in rest state(P<0.05).PD and ET amplitudes in loading states were larger than those in rest state(P<0.05).The frequencies of all patients in loading states were faster than those in rest state,and there were statistically significant differences in control group,but there were no statistically significant differences in PD group and ET group.Both upper limbs of ET and PD groups were divided into the more affected side and the less affected side in accordance with the tremor score.In rest,postural and loading states,Both PT and ET amplitudes of the more affected hand were larger than the less affected one(P<0.05).the tremor frequencies of PD patients with the more affected hand were faster than the less affected one(P<0.05),but the tremor frequencies of ET with the more affected hand were similar with the less affected one.In resting and loading states,the dispersions of the tremor frequencies of PD with more affected hand were narrower than the less affected one(P<0.05),But In resting,postural and loading states,the dispersions of the tremor frequencies of ET were also similar in both sides.Conclusions:ET patients with motor symptoms,but also non-motor symptoms.If upper limbs of ET and PD groups were divided into the more affected side and the less affected side in accordance with the tremor score,We found that the tremor frequency and frequency dispersion were symmetric in ET but asymmetric in PT.The tremor parameters measured by the Accelerometry can be used to distinguish ET and PD patients.