(Myers K et al. 2017) Mortality in Dravet syndrome is recognized at 15-20% by adulthood. Approximately half of those deaths are due to SUDEP, while about 1/4 are due to status epilepticus (SE). This study looked closely at that second group, those who died from SE, examining the characteristics of 5 patients from Australia who experienced fever-related status epilepticus and subsequent fatal cerebral edema (swelling).
The dramatic cerebral and cerebellar edema was more severe than that which is usually seen following SE, suggesting the phenomenon may be specific to Dravet syndrome. Patients were between 0.8 years and 11 years at the time of death and all had de novo SCN1A mutations. SE duration ranged from 90 minutes to 4 hours (in this patient, SE recurred 14 hours after admission). Multi-organ impairment was present in 4/5 cases within 24 hours of SE and all patients developed signs of brain stem dysfunction, typically 3-5 days after SE but only 28 hours after SE in one case. Medical interventions aimed at reducing intracranial pressure including mannitol, hypertonic saline, cooling, hyperventilation, and external drainage were largely unsuccesful. CT scans were performed on day two in 3 patients and were normal or showed only mild swelling, but these scans repeated between 4-7 days showed diffuse edema. The authors offer suggestions for medical teams monitoring patients with DS after SE:
“Profound status-induced brain edema is a severe, previously unrecognized fatal entity in DS. Children with a history suggestive of DS and SCN1A mutation presenting in status epilepticus should be monitored closely for signs of catastrophic cerebral edema in the following days. Failure to awaken in a timely manner after status should not necessarily be attributed to medication effect or infection, when other causes may be present. Neurologic vital signs including brainstem reflexes should be closely monitored and imaging studies done emergently if recovery from status appears atypical. It remains to be proven whether early recognition of cerebral edema with aggressive intervention to counteract increasing intracranial pressure could be life-saving.”