背景:脆性X相关震颤/共济失调综合征(FXTAS)是一种由FMR1基因CGG重复扩增引起的神经退行性疾病。FXTAS和神经元核内包涵体病(NIID)都属于多甘氨酸疾病,临床上表现相似,放射学,和病理特征,很难区分这些疾病。在NIID中经常观察到可逆性脑炎样发作。目前尚不清楚它们是否存在于FXTAS中,可用于NIID和FXTAS的鉴别诊断。
方法:一位63岁的中国男性,患有迟发性步态障碍,认知能力下降,和可逆的发烧发作,意识障碍,头晕,呕吐,尿失禁接受了神经系统评估和检查,包括实验室测试,脑电图测试,成像,皮肤活检,和基因测试。头颅MRI显示小脑中段和大脑T2高信号,除了小脑萎缩和沿着皮质髓质交界处的DWI高强度。观察脑干损伤。皮肤活检显示p62阳性核内包涵体。低血糖的可能性,乳酸性酸中毒,癫痫发作,排除脑血管发作。遗传分析显示在FMR1基因中CGG重复扩增,重复数为111。患者最终被诊断为FXTAS。他在住院期间接受了支持治疗以及对症治疗。他的脑炎症状在一周内完全缓解。
结论:这是一例具有可逆性脑炎样发作的FXTAS病例的详细报告。本报告提供了FXTAS可能的和罕见的功能的新信息,强调脑炎样发作在多甘氨酸疾病中很常见,无法用于鉴别诊断。
BACKGROUND: Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder caused by CGG repeat expansion of FMR1 gene. Both FXTAS and neuronal intranuclear inclusion disease (NIID) belong to polyglycine diseases and present similar clinical, radiological, and pathological features, making it difficult to distinguish these diseases. Reversible encephalitis-like attacks are often observed in NIID. It is unclear whether they are presented in FXTAS and can be used for differential diagnosis of NIID and FXTAS.
METHODS: A 63-year-old Chinese male with late-onset gait disturbance, cognitive decline, and reversible attacks of fever, consciousness impairment, dizziness, vomiting, and urinary incontinence underwent neurological assessment and examinations, including laboratory tests, electroencephalogram test, imaging, skin biopsy, and genetic test. Brain MRI showed T2 hyperintensities in middle cerebellar peduncle and cerebrum, in addition to cerebellar atrophy and DWI hyperintensities along the corticomedullary junction. Lesions in the brainstem were observed. Skin biopsy showed p62-positive intranuclear inclusions. The possibilities of hypoglycemia, lactic acidosis, epileptic seizures, and cerebrovascular attacks were excluded. Genetic analysis revealed CGG repeat expansion in FMR1 gene, and the number of repeats was 111. The patient was finally diagnosed as FXTAS. He received supportive treatment as well as symptomatic treatment during hospitalization. His encephalitic symptoms were completely relieved within one week.
CONCLUSIONS: This is a detailed report of a
case of FXTAS with reversible encephalitis-like episodes. This report provides new information for the possible and rare features of FXTAS, highlighting that encephalitis-like episodes are common in polyglycine diseases and unable to be used for differential diagnosis.