Multimodal longitudinal imaging of focal status epilepticus

Little is understood about the evolution of structural and functional brain changes during the course of uncontrolled focal status epilepticus in humans.

We serially evaluated and treated a nine-year-old girl with refractory focal status epilepticus. Long-term EEG monitoring, MRI, MRA, SPECT, intraoperative visualization of affected cortex, and neuropathological examination of a biopsy specimen were conducted over a three year time span. Imaging changes were correlated with simultaneous treatment and EEG findings.

The EEG monitoring showed almost continuous spike discharges emanating initially from the right frontocentral area. These EEG abnormalities were intermittently suppressed by treatment with anesthetics. Over time, additional brain areas developed epileptiform EEG abnormalities. Serial MRI studies demonstrated an evolution of changes from normal, through increased regional T2 signal to generalized atrophy. An MRA demonstrated dilatation of the middle cerebral artery stem on the right compared to the left with a broad distribution of flow-related enhancement. An 18FDG-PET scan showed a dramatically abnormal metabolic profile in the same right frontocentral areas, which modulated in response to treatment during the course of the illness. A right frontotemporal craniotomy revealed a markedly hyperemic cortical focus including vascular shunting. A sample of resected cortex showed severe gliosis and neuronal death.

The co-registration of structural and functional imaging and its correlation with operative and pathological findings in this case illustrates the relentless progression of regional and generalized abnormalities in intractable focal status epilepticus that were only transiently modified by exhaustive therapeutic interventions. Increased flow through large vessels appeared to be shunted and did not translate into increased microvascular perfusion.