Abstracts

This case is typical of Hemiconvulsive-Hemiplegia-Epielpsy (HHE) and the MRI imaging stongly suggests that prolonged status epilepticus can lead to neuronal injury to inhibitory pathways that suppresses the electroconvulsive activity.
A 3 year old girl with a 10 day history of fevers, otitis media, and treatment with amoxilcillin presented with febrile status epilepticus. The patient was found to be feverish with right hand clenched and right hemiconvulsion of 30 minutes or more. Lorezepam at the local hospital (OSH) was used to stop the seizure, then a phenobarbital load was given. Inital EEG found high amplitude delta over the left hemisphere. The patient was encephaloathic day 2 with decreased movement of her right arm and leg and intermitent eye rolling to the right. An MRI of the head was obtained. A right sided seizure recurred Day 5. She was given lorazepam, intubated, and transferred to Children[apos]s Hospital of Wisconsin (CHW) for further cares and evaluation.
Her mother[apos]s pregnancy and delivery were uncomplicated. Walking ocurred at 18 months. At 3 years, she had 3 word sentences, excessive tantrums, and behavior problems.
The patient was in good health. There is no family history of seizures or febrile seizures, developmental delays, or cerebral palsy.
Admission exam was remarkable for an encephalopathy and right hemiparasis. A right sided seizure recurred. Continuous Video/EEG monitoring revealed numerous electrographic seizures over the left hemisphere until the third hospital day. Electrographic and clinical seizures were controlled with phenobarbital and phenytoin.
Infectious evaluation found normal CFS cells, glucose and protein, no evidence of respiratory viruses, a [italic]Bartenella henselae[/italic] IgG of 1/64/Neg IgM, no evidence of a hypercoaguable state or inflamatory condition such as vasculitis.
The MRI done at the OSH revealed the left thalmus with marked increased signal on FLAIR and T2 while the ipsilateral cortex had increased thickness of the grey matter and slightly increased FLAIR and T2. A repeat study at CHW 3 days latter showed increased FLAIR and T2 over the entire left cortical grey matter equal to mid-thalamus and caudate nucleus. Diffusion weighted imaging revealed showed decreased diffusion in the left cortical grey matter, subcortical white matter, and left thalamus.
The patient had febrile status epilepticus, non-convulsive stutus epilepticus, and prolonged electrographic seizures. Febrile status epilepticus has been reported previously to lead to HHE. However, no mechanism has been described.
This patient[apos]s serial MRI findings strongly suggest that in patients with HHE, status epilepticus causes edema and inflamtion to inhibitory pathways. That is, the inhibitory drive from deep subcortical structures is blocked and leads to further cortical neuronal cell death and the sequelae.
The MRI[apos]s and possible mecahnism will be discussed in more detail.