The inferior olivary nucleus (ION) from nine patients with multiple system atrophy was examined with antibodies against alpha-synuclein, ubiquitin, synaptophysin, glial fibrillary acidic protein, the Golgi apparatus (GA)-trans-Golgi network (TGN), and microglia/macrophages. As previously reported, there were neuronal loss, gliosis, and alpha-synuclein-positive cytoplasmic inclusions in neurons and glia. In addition, all neurons with alpha-synuclein-positive cytoplasmic inclusions contained abnormal profiles of the GA and TGN, which were reduced in size and numbers. This finding suggests a relationship between the pathogenetic mechanisms causing inclusion body formation and abnormalities of the GA-TGN. This study is also consistent with the conclusion that lesions of the ION may not always reflect changes of transsynaptic degeneration secondary to Purkinje cell loss.

Semiquantitative morphological analysis of cerebral intraneuronal ubiquitin-positive tau-negative inclusions, a pathologic marker for motor neuron disease with dementia (MND-D), was performed in the dentate gyrus and parahippocampal gyrus of 20 clinicopathologically confirmed patients with MND-D. The forms of the inclusions were tentatively classified into three types: (i) C-type, consisting of relatively large and intensely stained crescent or circular structures; (ii) L-type, showing fine linear structures around the nuclei; and (iii) G-type, showing faintly stained granular structures. The frequencies of the C-type, L-type and G-type was 0.5-9.3%,0.2-6.5% and 0-6.6% of dentate granule cells, respectively. In contrast to the dentate gyrus, almost all inclusions showed either the C-type or L-type form in the parahippocampal gyrus. A positive correlation was noted only between incidences of C-type inclusion of the dentate gyrus and that of the parahippocampal gyrus (r = 0.69, P < 0.05). The morphological differences of the inclusions probably reflect different stages of their formation.

The structure of the central and peripheral nervous systems was studied. in the C57BL/6Akita (Akita) mouse, a non-obese type 2 diabetes model characterized by early onset, autosomal dominant inheritance and a mutation of the insulin 2 gene. Usual neuropathological examinations showed no remarkable abnormalities in the brain, spinal cord or sciatic nerve of Akita mice up to 48 weeks of age. However, immunohistochemical examination revealed that expression of alphaB-crystallin was enhanced in oligodendrocytes in the cerebral white matter, especially in the corpus callosum, after 32 weeks of age. The oligodendrocytes were not positive for ubiquitin and HSP25. It is suggested that long-standing hyperglycemia might stress the CNS and thus enhance the expression of alphaB-crystallin in oligodendrocytes.

We report a 51-year-old Japanese man with chronic alcoholism who complained of mental confusion following respiratory and intestinal infections. The splenium of the corpus callosum showed hyperintensity on both diffusion-weighted MR images and fluid-attenuated inversion recovery images and hypointensity on T1-weighted images. These findings were resolved on MR images obtained 3 days later. He showed complete neurological recovery within 2 months. We suspected that he had mild encephalopathy with a reversible splenial lesion after systemic viral or bacterial infection.

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