Yoneda Makoto
Department of Neurology, University of Fukui Hospital, Japan.
Brain Nerve. 2013 Apr;65(4):365-76.
Encephalopathy occasionally occurs in association with thyroid disorders, but most of these are treatable. These encephalopathies include a neuropsychiatric disorder associated with hypothyroidism, called myxedema encephalopathy. Moreover, Hashimoto's encephalopathy (HE) has been recognized as a new clinical disease based on an autoimmune mechanism associated with Hashimoto's thyroiditis. Steroid treatment was successfully administered to these patients. Recently, we discovered that the serum autoantibodies against the NH2-terminal of α-enolase (NAE) are highly specific diagnostic biomarkers for HE. Further, we analyzed serum anti-NAE autoantibodies and the clinical features in many cases of HE from institutions throughout Japan and other countries. Approximately half of assessed HE patients carry anti-NAE antibodies. The age was widely distributed with 2 peaks (20-30 years and 50-70 years). Most HE patients were in euthyroid states, and all patients had anti-thyroid (TG) antibodies and anti-thyroid peroxidase (TPO) antibodies. Anti-TSH receptor (TSH-R) antibodies were observed in some cases. The common neuropsychiatry features are consciousness disturbance and psychosis, followed by cognitive dysfunction, involuntary movements, seizures, and ataxia. Abnormalities on electroencephalography (EEG) and decreased cerebral blood flow on brain SPECT were common findings, whereas abnormal findings on brain magnetic resonance imaging (MRI) were rare. HE patients have various clinical phenotypes such as the acute encephalopathy form, the chronic psychiatric form, and other particular clinical forms, including limbic encephalitis, progressive cerebellar ataxia, and Creutzfeldt-Jakob disease (CJD)-like form. The cerebellar ataxic form of HE clinically mimics spinocerebellar degeneration (SCD) and is characterized by the absence of nystagmus, absent or mild cerebellar atrophy, and lazy background activities on EEG. Taken together, these data suggest that the possibility of encephalopathy associated with thyroid disorders must be considered.
脑病偶尔会与甲状腺疾病相关联出现，但其中大多数是可治疗的。这些脑病包括一种与甲状腺功能减退相关的神经精神障碍，称为黏液性水肿性脑病。此外，桥本脑病（HE）已被确认为一种基于与桥本甲状腺炎相关的自身免疫机制的新临床疾病。这些患者接受类固醇治疗取得了成功。最近，我们发现针对α-烯醇化酶（NAE）氨基末端的血清自身抗体是HE的高度特异性诊断生物标志物。此外，我们分析了来自日本和其他国家各机构的许多HE病例的血清抗NAE自身抗体和临床特征。大约一半接受评估的HE患者携带抗NAE抗体。年龄分布广泛，有两个高峰（20 - 30岁和50 - 70岁）。大多数HE患者处于甲状腺功能正常状态，所有患者均有抗甲状腺球蛋白（TG）抗体和抗甲状腺过氧化物酶（TPO）抗体。部分病例中观察到抗促甲状腺激素受体（TSH - R）抗体。常见的神经精神特征是意识障碍和精神病，其次是认知功能障碍、不自主运动、癫痫发作和共济失调。脑电图（EEG）异常和脑单光子发射计算机断层扫描（SPECT）显示脑血流量减少是常见表现，而脑磁共振成像（MRI）异常表现罕见。HE患者有多种临床表型，如急性脑病形式、慢性精神形式以及其他特殊临床形式，包括边缘性脑炎、进行性小脑共济失调和克雅氏病（CJD）样形式。HE的小脑共济失调形式在临床上类似于脊髓小脑变性（SCD），其特征为无眼球震颤、无或轻度小脑萎缩以及脑电图背景活动减弱。综上所述，这些数据表明必须考虑与甲状腺疾病相关的脑病的可能性。
