Herpes simplex encephalomyelitis (HSE) is a rare disease with a high mortality rate. Correct diagnosis is established on the basis of the combination of the clinical and investigative features. Unfortunately, precise diagnosis remains difficult due to several clinical similarities and false negative or inconclusive results of diagnostic tests. Here, we present two cases of HSE together with the morphological and ultrastructural picture. The first case was a 45-year-old man with acute symptoms of encephalitis, and the other one was a 28-year-old woman presenting subacute encephalomyelitis. Both cases had negative serologic and molecular results for Herpes simplex in the blood and cerebrospinal fluid. Brain and spinal cord samples taken from both cases were stained typically with histological and immunohistochemical methods and small tissue fragments were examined with the transmission electron microscope (TEM). Microscopic examination confirmed viral encephalomyelitis in both cases. An electron micrograph showed typical intranuclear viral particles inside of damaged neurons, which together with topography of brain and spinal cord changes suggest HHV-1/HHV-2 in the first case and/or HHV-3 in the other case. Thus, morphological and ultrastructural examinations may be a useful tool to set up correct diagnosis and help to determine the pathogenic factor in patients suspected of viral encephalomyelitis.

中文翻译：

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单纯疱疹性脑脊髓炎的形态学和超微结构变化：试图确定病因。

单纯疱疹性脑脊髓炎（HSE）是一种死亡率很高的罕见疾病。结合临床和研究特征建立正确的诊断。不幸的是，由于几种临床相似性以及诊断测试的假阴性或不确定的结果，精确诊断仍然很困难。在这里，我们介绍了HSE的两种情况以及形态和超微结构图。第一例是一名患有脑炎急性症状的45岁男性，另一例是一名发生亚急性脑脊髓炎的28岁女性。这两例血液和脑脊液中单纯疱疹的血清学和分子学结果均为阴性。通常用组织学和免疫组织化学方法对两种病例的脑和脊髓样品进行染色，并用透射电子显微镜（TEM）检查小组织碎片。镜检确诊均为病毒性脑脊髓炎。电子显微照片显示受损神经元内部的典型核内病毒颗粒，再加上大脑和脊髓的地形变化，在第一种情况下提示为HHV-1 / HHV-2，在另一种情况下提示为HHV-3。因此，形态学和超微结构检查可能是建立正确诊断和帮助确定疑似病毒性脑脊髓炎患者的致病因素的有用工具。电子显微照片显示受损神经元内部的典型核内病毒颗粒，再加上大脑和脊髓的地形变化，在第一种情况下提示为HHV-1 / HHV-2，在另一种情况下提示为HHV-3。因此，形态学和超微结构检查可能是建立正确诊断和帮助确定疑似病毒性脑脊髓炎患者的致病因素的有用工具。电子显微照片显示受损神经元内部的典型核内病毒颗粒，再加上大脑和脊髓的地形变化，在第一种情况下提示为HHV-1 / HHV-2，在另一种情况下提示为HHV-3。因此，形态学和超微结构检查可能是建立正确诊断和帮助确定疑似病毒性脑脊髓炎患者的致病因素的有用工具。