Hyaline astrocytic inclusions in pediatric epilepsy: report of two cases
1Service Central d'Anatomie et de Cytologie Pathologiques, Hôpital Lariboisière-Université Paris 7, Paris France.
Insights
Two pediatric epilepsy cases revealed unique astrocytic inclusions. These hyaline bodies, positive for filamin A, highlight potential new insights into astrocyte protein accumulation in epilepsy.
Area of Science:
- Neuroscience
- Cell Biology
- Pathology
Background:
- Intractable partial seizures in children can be linked to specific neuropathological findings.
- Neocortical astrocytes may exhibit distinctive cytoplasmic inclusions in certain epilepsy cases.
- Understanding these inclusions can offer insights into epilepsy pathophysiology.
Observation:
- Identified distinctive hyaline inclusion bodies within neocortical astrocytes.
- Patients aged 10 and 16 experienced intractable partial seizures since age 2.
- Inclusions were eosinophilic, refractile, PAS negative, with granular osmiophilic structure on electron microscopy.
Findings:
- Immunohistochemistry showed strong positivity for filamin in one case, weak in another.
- Inclusions variably expressed alpha-B-crystallin, GFAP, S-100 protein, and cytoglobin.
- Clinical outcomes varied: complete recovery in one, seizure reduction in another with mental retardation.
Implications:
- Highlights the potential role of filamin A and other protein aggregates in astrocyte pathology.
- Suggests these inclusions may be a significant finding in specific pediatric epilepsy cases.
- Provides a basis for further research into the pathophysiology of astrocyte inclusions in epilepsy.
Abstract:
Distinctive hyaline inclusion bodies in the cytoplasm of neocortical astrocytes were observed in surgical resection specimens of a frontal epileptic focus, in 2 patients aged 16 and 10 who had suffered intractable partial seizures since the age of 2 years. One case had minimal neurological impairment and no brain malformation on MRI and recovered completely following surgery. The second case had mental retardation and surgery reduced the frequency and generalization of seizures. In both cases, the astrocytic inclusions were strongly eosinophilic, hyaline and refractile. They were PAS negative. Electron microscopy in the first case, confirmed their granular osmiophilic structure. By immunohistochemistry, the inclusions were strongly positive for filamin in the first case, only some were weakly positive in the second case. They also variably expressed other proteins such as alpha-B-crystallin, GFAP, S-100 protein and cytoglobin. We compare our findings with previously reported cases and discuss the clinical significance of the inclusions and the pathophysiologic relevance of filamin A and other proteins accumulation in astrocytes.
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