Atypical Case of VV1 Creutzfeldt-Jakob Disease Subtype: Case Report.

Creutzfeldt–Jakob disease (CJD) is a rare form of rapidly progressive, neurodegenerative disease that results from the misfolding and accumulation of an aberrant, disease-associated prion protein (PrPD). CJD affects 1–1.5 cases per million per year with the sporadic-type accounting for an estimated 85% of these cases. Sporadic CJD (sCJD) is further subdivided into five subtypes based on genetic polymorphisms; the rarest subtype, sCJDVV1, occurs at a rate of 1 case per one-hundredth million population per year. Clinical characteristics of the sCJDVV1 subtype have been reported to show, early age of onset (44 years), average disease duration of 21 months, absent PSWCs on electroencephalography (EEG), and MRI hyperintensities in the cerebral cortex with usual negative signal in the basal ganglia or thalamus. We present a case of the sCJDVV1 subtype with uncommon features. Contrary to current data on sCJDVV1, our patient presented with an unusual age at onset (61 years) and longer disease duration (32 months). The highly sensitive and specific real-time quaking-induced conversion (RT-QuIC) assay was negative. Presenting clinical symptoms included paranoid thoughts and agitation, rapidly progressive memory decline, prosopagnosia, and late development of myoclonus and mutism. Other findings showed positive antithyroid peroxidase antibodies (anti-TPO), and absent PSWCs on EEG. High-dose steroid therapy treatment was administered based on positive anti-TPO findings, which failed to elicit any improvement and the patient continued to decline. To our knowledge, only four cases with the sCJDVV1 subtype, including our patient, have been reported to have a negative result on RT-QuIC. This may suggest varied sensitivity across sCJD subtypes. However, given the rarity of our patient's subtype, and the relatively novel RT-QuIC, current data are based on a small number of cases and larger cohorts of confirmed VV1 cases with RT-QuIC testing need to be reported.

克雅氏病（CJD）是一种罕见的快速进展性神经退行性疾病，由一种异常的、与疾病相关的朊蛋白（PrPᴰ）错误折叠和积聚所致。克雅氏病每年每百万人中有1 - 1.5例发病，其中散发型估计占这些病例的85%。散发型克雅氏病（sCJD）根据基因多态性进一步细分为五种亚型；最罕见的亚型sCJDVV1每年每亿人口中有1例发病。据报道，sCJDVV1亚型的临床特征为发病年龄早（44岁）、平均病程21个月、脑电图（EEG）无周期性同步放电（PSWCs），大脑皮层磁共振成像（MRI）呈高信号，基底神经节或丘脑通常为阴性信号。我们报告一例具有不常见特征的sCJDVV1亚型病例。与目前关于sCJDVV1的资料相反，我们的患者发病年龄不寻常（61岁）且病程更长（32个月）。高灵敏度和特异性的实时震颤诱导转化（RT - QuIC）检测呈阴性。临床表现的症状包括偏执想法和躁动、快速进展性记忆力下降、面容失认症以及后期出现肌阵挛和缄默症。其他发现包括抗甲状腺过氧化物酶抗体（抗 - TPO）阳性，脑电图无周期性同步放电。基于抗 - TPO阳性结果给予了大剂量类固醇治疗，但未引起任何改善，患者病情继续恶化。据我们所知，包括我们的患者在内，只有4例sCJDVV1亚型病例在RT - QuIC检测中呈阴性结果。这可能表明sCJD各亚型的敏感性不同。然而，鉴于我们患者的亚型罕见，且RT - QuIC相对较新，目前的数据基于少数病例，需要报告更多经RT - QuIC检测确诊的VV1病例队列。