Abstracts

Status epilepticus has been associated with focal neurological deficits, cognitive impairment and transient MRI abnormalities including changes on diffusion weighted imaging (DWI).
Rapid development of sever hippocampal atrophy after status epilepticus is however rare. We report a case of status epilepticus that was associated with development of severe bilateral hippocampal atrophy with profound memory impairment. A case of status epilepticus in a 45 year old woman is reviewed with clinical, EEG, neuropsychological and radiographic correlation. A 45 year old woman with a history of epilepsy was admitted with complex partial status epilepticus after a single prolonged generalized tonic clonic seizure. EEG monitoring showed right temporal electrographic seizures. She was initially given lorazepam and loaded with phenytoin without resolution of the ictal pattern. Propofol infusion resulted in resolution of the seizures with transient appearance of independant right and left temporal periodic epileptiform discharges. High resolution MRI performed initially after stabilization showed bilateral mesial temporal high signal abnormality on DWI and T2 weighted imaging with no evidence of hippocampal atrophy. There was no clinical or laboratory evidence of an underlying infection, hypoxia or other causes of temporal lobe dysfunction. CSF examination was normal with a negative Herpes Simplex Virus (HSV) PCR.
Profound visual and verbal memory impairment was noted both on bedside and formal neuropsychological testing.
Repeat high resolution MRI performed two months after hospitilization showed resolution of changes on DWI but severe bilateral hippocampal atrophy (right greater than left) was noted. This case is important as it demonstrates evidence of hippocampal injury associated with status epilepticus. The early diffusion weighted imaging changes and EEG localized the seizure focus to the mesial temporal region . The acute and severe memory impairment documented by neuropsychological assessment and severe atrophy on repeat MRI also supports the hypothesis that this change was a result of status epilepticus. Previous MRI performed four years earlier and one at the time of status epilepticus did not show any loss of hippocampal volume further supporting our conclusions.
In summary status epilepticus can lead to irreversible hippocampal damage and profound short term memory impairment. This finding may also have implications in development of abnormalities such as mesial temporal sclerosis in patients with epilepsy.