認知症を伴う筋萎縮性側索硬化症の臨床像を呈したglobular glial tauopathyの1剖検例

An Autopsy Case of Globular Glial Tauopathy Presenting with Amyotrophic Lateral Sclerosis with Dementia

認知症を伴う筋萎縮性側索硬化症（ALS-D）の臨床像を呈したglobular glial tauopathy（GGT）の剖検例を報告した。上位優位の運動ニューロン徴候と認知症という臨床像からALS-Dと診断したが，病理学的に左優位の前頭葉萎縮と神経細胞脱落，グリアに小球状の4リピートタウ封入体を認め，GGTの病理像であった。中心前回と錐体路の変性が高度で，ベッツ細胞と脊髄前角細胞にタウ封入体を認めた。

Abstract

We report an autopsy case of globular glial tauopathy (GGT) presenting clinically with amyotrophic lateral sclerosis (ALS) with dementia. A 79-year-old female developed weakness in the right upper limb, which progressed gradually. She developed apathy and speech disorder at 80 years of age. On neurological examination, she showed signs of upper and lower motor neuron disorder and dementia, but no extrapyramidal signs. The clinical diagnosis was ALS with dementia. The autopsy revealed left predominant marked atrophy of the frontal lobe due to severe neuronal loss and Gliosis. Immunohistochemistry using anti-4-repeat tau antibody revealed numerous globular glial inclusions. Severe neurodegeneration in the primary motor cortex and corticospinal tract was observed. There were distinctive tau-positive inclusions in both Betz and anterior horn cells. TDP-43-positive inclusions in motor neurons were not detected. Sequence analysis of the tau gene revealed no mutations in exons 1-5, 7, 9-13, or the adjacent intronic sequences. GGT can cause a clinical phenotype of ALS with dementia.

(Received December 28, 2015; Accepted February 23, 2016; Published August 1, 2016)