We have a patient on our ICU that suffered through 3 weeks of insufficiently effective therapy of epileptic status from a right occipital astrocytoma after finishing his radiation therapy. MRI showed extensive bilateral insular, thalamic and bitemporal T2 bright and DWI dark lesions that even expanded with developing cortical microbleeds.
Before I list some of the relevant publications on this fascinating topic, let me mention a few take home messages:
- Focal status can show up as DWI bright, ADC dark, T2 bright lesions that are potentially reversible.
- Generalized status shows a peculiar distribution of these lesions in the insula, temporoparietal cortex and pulvinar. If advanced and ongoing, the changes can spread from the cortex to the subcortical white matter and even further.
- The changes can mimic tumor progression (as in our case) although the pattern is quite succinct.
- While in status, many patients have hyperperfusion (e.g. in CT-perfusion or MRI perfusion) around their epileptic focus. Afterwards, there may be hypoperfusion and in fact perfusion studies might help in distinguishing the two entities (if EEG is not immediately available) in nonconvulsive or subtle status, but remember that epileptics tend to get too many CTs anyway.
- There is an excellent chapter in Neuroimaging – Clinical Applications.
- A case report on perfusion studies from Jena (my former workplace)
- Wintermark is an excellent source for perfusion CT – he collected some cases on the topic.
- This case report also reviews perfusion imaging and proposes its use to differentiate the postictal state from status.