Corticobasal degeneration (CBD) is a rare progressive neurodegenerative disorder characterized by asymmetric presentation of cerebral cortex signs, cortical sensory disturbance and extrapyramidal signs. Herein, we report a case of a 66‐year‐old Japanese woman who presented with apraxia of the right hand. She subsequently developed postural instability and cognitive impairments that rapidly worsened. One and a half years later, the patient was wheelchair‐bound and severely demented. Brain magnetic resonance imaging revealed left dominant atrophy of the frontoparietal lobe. There was a hyperintense lesion in the deep white matter expanding toward the subcortical area on fluid‐attenuated inversion recovery (FLAIR) images. In order to rule out the possibility of an intracranial tumor such as an astrocytoma or malignant lymphoma, we performed a brain biopsy of the left frontal middle gyrus. The patient became bedridden and showed akinetic mutism 1 year after biopsy. Pathological examination revealed a large amount of 4‐repeat tau‐immunoreactive neuropil threads scattered predominantly in the corticomedullary junction and tau‐immunoreactive structures, consistent with CBD. Immunostaining for p53 showed no positive cells, and there were very few Ki‐67‐positive cells. On immunoblots of sarkosyl‐insoluble brain extracts, a major doublet of 64 and 68 kDa full‐length tau with two closely related fragments of approximately 37 kDa were detected. Based on these results, the patient was pathologically diagnosed as having CBD, excluding the possibility of tumor. Taken together with previous similar case reports, our findings indicate that a deep white matter hyperintense lesion on FLAIR images may be a useful clue to CBD, predicting rapid clinical progression with severe dementia based on severe white matter degeneration with a large amount of tau accumulation on pathological examination.

No abstract

Leber's hereditary optic neuropathy (LHON) is a mitochondrial disorder characterized by acute or subacute bilateral vision loss. We describe a female who experienced visual impairment at the age of 75 years. Genetic analysis of peripheral blood leukocytes revealed a point mutation (11778G>A) in MTND4 encoded by mitochondrial DNA. The most distinctive feature of our patient was the elevation of serum LA and PA levels and the LA/PA ratio by cycle ergometer exercise without clinical or pathological skeletal muscle involvement. Also, droplet digital PCR (ddPCR) showed that mutation fractions of m.11778G>A in peripheral blood and muscle sample were higher than 99.9%, indicating “homoplasmy”. Although no cases of LHON with clinical impairment of skeletal muscle have been reported, subclinical mitochondrial dysfunction has been reported. We concluded that the ergometer test sensitively detected a subclinical change caused by mitochondrial respiratory chain dysfunction, showing the diversity of genotype and phenotype relationship in LHON.

An 80‐year‐old woman presented with loss of appetite. At age 78, she was diagnosed as familial neuronal intranuclear inclusion disease (NIID) based on (i) leukoencephalopathy with hyperintensities along the corticomedullary junction on diffusion‐weighted imaging (DWI) revealed by brain magnetic resonance imaging (MRI), (ii) skin biopsy samples showing ubiquitin‐positive intranuclear inclusions in adipocytes, and (iii) family history. Her cognitive function was preserved while apathy was apparent. However, on this admission, her cognitive function got worse. Afterward, the patient developed subcortical hemorrhage, and the risk for the hemorrhage was not identified. NIID might be associated with intracranial hemorrhage. In addition, brain MRI after the bleeding showed the rapid expansion of hyperintense lesions on DWI even in the frontal lobe where bleeding was irrelevant. Intracranial hemorrhage might have affected the enlarged hyperintense lesions.

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.