We performed a neuropathological analysis, including in situ nick end labeling (ISEL) and immunohistochemistry, of two cases of clinicogenetically confirmed infantile spinal muscular atrophy (SMA) type II. Both cases showed severe reduction of the motor neurons and gliosis in the spinal cord and brain stem, although the occurrences of central chromatolysis and ballooned neurons were not frequent. Clark's and lateral thalamic nuclei, which are usually altered in SMA type I, were spared, whereas Betz cells in the precentral gyrus and large myelinated fibers in the lateral funiculus were reduced in number. Regarding apoptosis, only the younger case demonstrated a few ISEL-positive nuclei in the dorsal horn, with reduced Bcl-x expression level in the Purkinje cells. Unlike SMA type I, the expression of neurofilaments was not disturbed and the reduction in synaptophysin expression level in the anterior horn was mild. An oxidative stress-related product was deposited in atrophic motor neurons in the spinal cord, and neurons with nuclei immunoreactive for 8-hydroxy-2'-deoxyguanosine were found in the lateral thalamus. In contrast, the expression of glial glutamate transporters was not altered. These data suggest that oxidative stress and, to a lesser extent, apoptotic cell death, but not disturbed neurofilament metabolism or excitotoxicity, may be involved in neurodegeneration in SMA type II.

No abstract

Subacute sclerosing panencephalitis is caused by persistent brain infection of mutated measles virus, showing inflammation, neuronal loss, and demyelination. We neuropathologically examined six autopsy cases of subacute sclerosing panencephalitis, using in situ nick end-labeling and immunohistochemistry. Both the neurons and glial cells in the cerebral cortex showed immunoreactive nuclei in the nick end-labeling in two cases with disease duration within 2 years, whereas they were confined to the glial cells in the demyelinated cerebral white matter in three cases with disease duration ranging from 2 to 10 years. The nuclei and cytoplasm were immunoreactive for 8-hydroxy-2'-deoxyguanosine and 8-hydroxyguanosine, markers of oxidative damage to DNA and ribonucleic acid, respectively, in the cerebral cortex in three cases with disease duration within 9 years. In contrast, 4-hydroxy-2-nonenal-modified proteins, products of lipid peroxidation, were deposited in the demyelinated white matters in four cases with disease duration longer than 9 years. In three cases with long survival, the expression of glial glutamate transporters was reduced in the cerebral cortex. It is speculated in subacute sclerosing panencephalitis that apoptosis and oxidative stress to DNA can contribute to the early neuronal damage, whereas lipid peroxidation and disturbed glutamate transport may be related to the subsequent neurodegeneration.

No abstract

No abstract