Perfusion imaging with arterial spin labeling in acute encephalopathy with reduced subcortical diffusion following secondary generalized status epilepticus

Magnetic resonance perfusion imaging with arterial spin labeling (ASL) can provide valuable information on the circulatory changes associated with status epilepticus (SE). We report a case of a girl with an old brain abscess in the right frontal lobe who developed secondary generalized SE twice (at 3 and 4 years of age). Although she made a full recovery after the first SE, she developed acute encephalopathy with reduced subcortical diffusion (AED) following the second SE with a monophasic clinical course. We compared the ASL findings on day 4 after onset of each SE. After the first SE, ASL revealed postictal hypoperfusion in bilateral anterior circulation territories. By contrast, after the second SE, there was a marked increase in ASL signals of the entire cortex, particularly in the right fronto-parietal lobe, which corresponded to the area of reduced subcortical diffusion. Prolonged cortical hyperperfusion may have caused relative ischemia of the subcortex. As there is growing evidence that oligodendrocytes are selectively vulnerable to ischemia via glutamatemediated excitotoxicity, our findings suggest that white matter ischemia may cause axonal injury in this case. Finding of prolonged cortical ASL hyperperfusion around day 4 after SE onset may be important for the detection of reduced subcortical diffusion.