Spreading depolarization/depression

A 56 yo patient with a left parietal ICH has aphasia – no surprise there. One residents comes out of her room and notes that she has severe difficulty formulating sentences yet her understanding is quite okay. 10 minutes later the SLT pathologists reports severe restriction in understanding: she can follow commands only when underscored by gestures and mimic. The two professionals discuss these findings and call the attending to obtain a final verdict. All three enter the room and find a severely aphasic patient, barely able to form single words and no understanding at all. 5 minutes in the exam, a first complete sentence is formed and she seems to understand everything, talking about her job and family when questioned.

There are at least 3 good explanations for these short-lived neurological changes in stroke, SAH, tumour and ICH patients:

  • seizures
  • hemodynamic instability
  • spreading depression (CSD)
In the past, I tended to fill them up with Levetiracetam all the time and run an EEG and an ultrasound to make sure, but most of the time nothing changed.
Now, in the past 10 years CSD has been proven to occur in all these settings and might (mark that this itself has not been shown) explain such waves of differing performance. We discuss the concepts, data and prospects of CSD, using the following references: