[Pathology and pathogenesis of secondary epilepsy to hypoxic-ischemic encephalopathies].
The neuropathology of haemorrhagic and hypoxic-ischaemic perinatal encephalopathies and their effect on the post-natal development of the brain, has been studied in children who survived with these lesions (for days, weeks, months and even years). Eventually some children developed neurological sequelae, including epilepsy and cerebral palsy. In this paper it is emphasized that the post-natal development of the grey matter next to these lesions in altered in a specific manner. The post-natal resolution (scarring) of the subpial haemorrhage causes structural changes in the superficial layers of the cortex and permanent leptomeningial heterotopia. The pyramidal cell of layers II and III whose apical dendrites had been partially amputated by haemorrhage became star cells. The grey matter often survived an infarct of the subjacent white matter, since its circulation remained intact. However its post-natal development was altered in a specific way. The post-natal development of this grey matter (partly deprived of sensory information because of the destruction of afferent fibres and with contact lost because on the destruction of efferent fibres) is inevitably different. Projection pyramidal cells (long axon) axotomized by the subjacent lesion, survive the insult and post-natally are changed into intracortical short axon cells. The intrinsic neuropile of the grey matter (partially isolated) increases in an irregular manner which can be seen using immunohistochemical techniques and Golgi's method: areas with a great increase in fibres alternate with areas with few fibres. The presence of large neurones (Golgi's method) with long drendites covered with spines (acquired neuronal hypertrophy) is frequent. In this paper it is suggested that these changes in the grey matter secondary to subpial haemorrhage and hypoxic-ischaemic perinatal infarcts are accompanied by functional changes which may play and important role in the pathogenesis of epilepsy (infantile spasm) and in infantile cerebral palsy.
Marín-Padilla
M
M
Department of Pathology, Dartmouth Medical School, Hanover, NH 03755, USA.
D000293:Adolescent; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D002545:Brain Ischemia / Q000150:complications*; D002543:Cerebral Hemorrhage / Q000150:complications / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D000860:Hypoxia / Q000150:complications*; D007223:Infant; D007231:Infant, Newborn; D009475:Neurons, Afferent / Q000473:pathology; D009476:Neurons, Efferent / Q000473:pathology; D010841:Pia Mater / Q000473:pathology