Rajput Ali H, Adler Charles H, Shill Holly A, Rajput Alex
Movement Disorders Program, Neurology Division, University of Saskatchewan/Saskatoon Health Region, 103 Hospital Drive, Saskatoon, SK, S7N 0W8, Canada.
Neurodegener Dis Manag. 2012 Jun;2(3):259-268. doi: 10.2217/nmt.12.23.
The pathophysiology of essential tremor (ET) remains unknown. Standard neuropathological studies have reported no consistent changes but a detailed study found neurodegeneration in all ET cases - 24% demonstrated lower brainstem Lewy body (LB) inclusions and 76% experienced a loss of cerebellar Purkinje cells (PCs) and its sequelae. We review the evidence on neurodegeneration in ET. The prevalence of LB inclusions in ET brains is similar to that in the asymptomatic general population. These incidental LB disease cases have evidence for reduced striatal tyrosine hydroxylase levels, as found in Parkinson's disease, but there is no evidence for reduced tyrosine hydroxylase levels in ET patients. Reduced mean PC counts in ET cases compared with the controls reported by some studies could not be replicated by others. Most ET cases have the same number of PCs as controls of a comparable age. Neither the lower brainstem LB inclusions nor the cerebellar PC loss represent the neurodegenerative basis of ET. Further studies are needed to determine the pathophysiology of ET.
特发性震颤（ET）的病理生理学仍然未知。标准神经病理学研究报告未发现一致的变化，但一项详细研究发现，所有ET病例均存在神经退行性变——24%表现为脑桥下部路易小体（LB）包涵体，76%出现小脑浦肯野细胞（PC）丢失及其后遗症。我们回顾了关于ET神经退行性变的证据。ET大脑中LB包涵体的患病率与无症状普通人群相似。这些偶发性LB病病例有证据表明纹状体酪氨酸羟化酶水平降低，这与帕金森病中发现的情况相同，但没有证据表明ET患者的酪氨酸羟化酶水平降低。一些研究报告称，与对照组相比，ET病例的平均PC计数减少，但其他研究无法重复这一结果。大多数ET病例的PC数量与年龄相当的对照组相同。脑桥下部LB包涵体和小脑PC丢失均不代表ET的神经退行性基础。需要进一步研究以确定ET的病理生理学。
