Ishihara Kenji, Horibe Yuzo, Ohno Hideki, Sugie Masayuki, Shiota Jun'ichi, Nakano Imaharu, Kawamura Mitsuru
Department of Neurology, Showa University School of Medicine, Japan.
Brain Nerve. 2011 Oct;63(10):1117-23.
We retrospectively examined the clinical features and the neuroradiological findings on autopsy of 2 cases of young-onset dementia. The patient in case 1 was a 43-year-old woman who was unable to determine the time on the clock and who made frivolous remarks. Neuropsychological test batteries demonstrated memory impairment and frontal lobe dysfunction. T2-weighted magnetic resonance imaging (MRI) of the head revealed abnormal high-intensity signals around the lateral ventricles and thinning of the corpus callosum. Single photon emission computed tomography (SPECT) revealed patchy reduction in the accumulation of tracers in both the frontal lobes. Her neurological condition gradually deteriorated, and she died 13 years after the onset of the disease. She was clinically diagnosed with atypical Alzheimer's disease on the basis of visual cognitive impairment and memory impairment observed in the initial phase. However, the neuropathological diagnosis was adult-onset leukodystrophy with axonal spheroids. The patient in case 2 was a 43-year-old man who had gradually started behaving selfishly and had become ill-tempered and apathetic. He was admitted to a hospital. He was anosognosic and showed frontal lobe dysfunction. T2-weighted MRI scan of the brain showed abnormal high-intensity signals around the lateral ventricles; atrophy of the frontal and temporal lobes, hippocampus, and brainstem; and thinning of the corpus callosum. SPECT revealed patchy reduction in the accumulation of tracers in both the frontal lobes and the cerebellum. His neurological condition gradually deteriorated, and he died after being clinically ill for 7 years. The patient was clinically diagnosed with frontotemporal dementia on the basis of the clinical features and MRI findings. However, the neuropathological diagnosis was chronic meningoencephalitis. The frequency of neurological metabolic and inflammatory diseases is significantly high although it is not as high as that of degenerative diseases in young-onset dementia. Since such diseases may respond to therapy, they should be considered in the differential diagnosis of young-onset dementia, especially in patients presenting with atypical clinical features. Neuroradiological examination may contribute to the differential diagnosis of atypical dementia at young age.
我们回顾性研究了2例早发性痴呆患者的临床特征及尸检时的神经放射学表现。病例1的患者为一名43岁女性，她无法看钟认时间，说话轻浮。神经心理测试显示存在记忆障碍和额叶功能障碍。头部的T2加权磁共振成像（MRI）显示侧脑室周围有异常高信号，胼胝体变薄。单光子发射计算机断层扫描（SPECT）显示双侧额叶示踪剂摄取呈斑片状减少。她的神经状况逐渐恶化，发病13年后死亡。基于疾病初期出现的视觉认知障碍和记忆障碍，她临床上被诊断为非典型阿尔茨海默病。然而，神经病理学诊断为成人起病的白质营养不良伴轴突球体。病例2的患者为一名43岁男性，他逐渐开始表现得自私，变得脾气暴躁且冷漠。他入院治疗。他存在疾病感缺失，并表现出额叶功能障碍。脑部的T2加权MRI扫描显示侧脑室周围有异常高信号；额叶、颞叶、海马体和脑干萎缩；胼胝体变薄。SPECT显示双侧额叶和小脑示踪剂摄取呈斑片状减少。他的神经状况逐渐恶化，临床患病7年后死亡。基于临床特征和MRI表现，该患者临床上被诊断为额颞叶痴呆。然而，神经病理学诊断为慢性脑膜脑炎。尽管在早发性痴呆中神经代谢和炎症性疾病的发生率不如退行性疾病高，但仍显著偏高。由于这类疾病可能对治疗有反应，因此在早发性痴呆的鉴别诊断中应予以考虑，尤其是对于具有非典型临床特征的患者。神经放射学检查可能有助于年轻患者非典型痴呆的鉴别诊断。
