Neuropathologic Findings and Electrolyte Abnormalities in a Case of Lennox-Gastaut Syndrome (SCN2a- related) Encountered at Autopsy

Abstract Introduction/Objective Lennox-Gastaut syndrome is a severe form of childhood epilepsy which may be due to several conditions, including sodium channelopathies which alter neuronal firing patterns. We present a case of a 6-year-old female with Lennox-Gastaut syndrome (SCN2A-related) complicated by developmental delay, spastic quadriplegia, and gastrojejunostomy tube dependence who was referred for medicolegal autopsy due to death subsequent to becoming unresponsive during a supervised bath. Methods/Case Report A complete autopsy was performed, including gross and microscopic examination of all primary organ systems, formal neuropathologic examination, and postmortem microbiology, toxicology, and vitreous electrolyte studies. The decedent showed evidence of developmental delay and flexion contractures of the extremities. No significant traumatic injuries were identified. A postmortem nasopharyngeal swab was positive for Rhinovirus/Enterovirus and Influenza A H3. A postmortem vitreous electrolyte panel demonstrated a dehydration pattern, including markedly elevated sodium and chloride and elevated urea nitrogen. Gross examination of the brain showed a thin corpus callosum, small hippocampi, as well as abnormal cerebellar dentate and inferior olivary nuclei. Microscopic examination of the brain tissue supported the gross findings, including dentato-olivary dysplasia. The cause of death was certified as dehydration complicating Lennox-Gastaut syndrome (SCN2a-related). Rhinovirus/Enterovirus and Influenza A H3 infections were considered contributory to death. The manner of death remained undetermined, since it was unknown if the decedent’s natural diseases, issues following a scheduled gastrojejunostomy feeding regimen, neglect, or some combination thereof caused the dehydration. Results (if a Case Study enter NA) NA Conclusion This case highlights unique and rarely documented neuropathologic findings and electrolyte abnormalities that may be seen in Lennox-Gastaut syndrome associated with an SCN2A mutation in addition to demonstrating the challenges of cause and manner death certification in cases of severe developmental disorders of childhood related to sodium channelopathies.