Misra U K, Kalita J
Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
Electromyogr Clin Neurophysiol. 1998 Jan-Feb;38(1):41-6.
The difference in the clinical, electrophysiological and radiological features in 12 patients with Japanese encephalitis (JE) and eight patients with herpes simplex encephalitis (HSE) have been reported in this study. Meningeal signs, seizures and behavioural abnormalities in HSE; and decerebration or decortication and focal neurologic signs in JE were common. Electroencephalogram in JE revealed diffuse delta slowing in 11, whereas in HSE frontotemporal slowing was present in five, periodic lateralising epileptiform discharges in three and focal spikes in two patients. Magnetic resonance imaging in JE patients revealed characteristic bilateral thalamic hyperintense lesions in T2 in all the patients. In HSE, CT scan revealed frontotemporal hypodensity in six patients. MRI was more sensitive than CT scan. It revealed characteristic frontotemporal hyperintense signals in T2 even in two patients who had normal CT scan. Motor evoked potentials were abnormal in eight out of nine JE patients, whereas these were normal in all five HSE patients in whom these studies were carried out. Attention to these clinical, radiological and neurophysiological findings may help in differentiating these encephalitides even before the results of serological studies are available.
本研究报告了12例日本脑炎（JE）患者和8例单纯疱疹病毒性脑炎（HSE）患者在临床、电生理和放射学特征上的差异。HSE常见脑膜刺激征、癫痫发作和行为异常；JE常见去大脑强直或去皮层强直以及局灶性神经体征。JE患者的脑电图显示11例有弥漫性δ波减慢，而HSE患者中5例有额颞叶减慢，3例有周期性一侧性癫痫样放电，2例有局灶性棘波。JE患者的磁共振成像显示所有患者在T2加权像上均有特征性的双侧丘脑高信号病变。在HSE患者中，CT扫描显示6例有额颞叶低密度影。MRI比CT扫描更敏感。即使在2例CT扫描正常的患者中，MRI在T2加权像上也显示出特征性的额颞叶高信号。9例JE患者中有8例运动诱发电位异常，而在进行该项检查的所有5例HSE患者中运动诱发电位均正常。关注这些临床、放射学和神经生理学表现，即使在血清学研究结果出来之前，也可能有助于鉴别这些脑炎。
