Subakut sklerozan panensefalitte demiyelinizasyon mekanizmasi: deneysel bir çalişma

Subacute sclerosing panencephalitis (SSPE) is a chronic disease caused by the measles virus. Although its pathogenesis is unclear, the brain tissue shows inflammatory infiltration, neuronal loss, gliosis, and demyelination. The latter can be due to endogenous metabolic toxins, oxidative damage, and antibodyor complement- mediated myelin breakdown. In this study, the presence of demyelinating soluble substances (cytokine, antibody, complement) in the cerebrospinal fluid (CSF) of SSPE patients was investigated experimentally by injection of CSF samples from patients into mice. Adult Swiss albino mice received an intraperitoneal injection of 0.5 ml CSF from three SSPE patients and three control patients for two consecutive days. To disrupt the blood brain barrier, pertussis toxin was given intraperitoneally before the CSF injections. A total of 14 mice were followed for 6 days (n=7) or 21 days (n=7). Daily examinations were done for tail tone, gait, and paralysis. After the followup period, the brain and sciatic nerves were studied histopathologically (hematoxylin-eosin, myelin stainings and TUNEL method) for demyelination and apoptosis. None of the mice developed clinical signs during the follow-up. Histopathological examination revealed no findings of neuronal degeneration, inflammation or demyelination. Rare apoptotic cells were observed in all groups. Sciatic nerves revealed no difference in morphology, myelin thickness or myelin morphology between groups. These results provided no evidence supporting the presence of soluble substances causing demyelination in the CSF. Demyelination might be caused by oligodendrocyte death during disease progression or by other inflammatory mediators released at later phases of the disease in SSPE.