Case-Based Modules > Case 6

A 37 year-old woman with no medical history presents with her first seizure of life. She was preparing lunch at home when her right hand started twitching, after which she lost consciousness and developed bilateral tonic-clonic activity. This lasted for one minute, then ended spontaneously before EMS could arrive. Her partner witnessed the entire event. She is brought to the ED.

In the ED, initial vitals are BP 112/68, HR 95, RR 10, SpO2 99% on room air. Labs notable for WBC 12.2, Hb 13.0, Plt 150, Na 140, K 3.9, HCO3 22, BUN 20, Cr 0.97, glucose 89. A non-contrast head CT is obtained, and is unrevealing. You go to examine her. She is initially somnolent, but does wake up to verbal stimuli. She answers your questions in very brief sentences and then dozes back to sleep. Strength appears at least antigravity bilaterally. Over the course of the next hour, her mental status continues to improve.

NCHCT

NCHCT
Is cEEG indicated for this patient?

We should start with asking ourselves-- what question are we asking of cEEG? She already had her seizure. She has some postictal somnolence, but it's rapidly improving. The history certainly sounds concerning for a seizure (focal-onset, no less); your pre-test probability for this diagnosis is high. cEEG would be most helpful in capturing a clinical event in question while actively recording; too late for that here. It doesn't definitively tell us if a previous event of concern was a seizure. It would also be helpful if we were concerned that she's having ongoing non-convulsive seizures, whether at the level of status epilepticus or not. However, with her rapidly-improving mental status, our concern for that should be much lower. (Of course, if her improvement plateaus, or if things get worse, then that would warrant cEEG.) A spot 30-minute EEG is also going to be of low yield here (lower than that of cEEG for sure, based on duration of recording). You can get a look at her interictal record and see if she has any baseline abnormalities that indicate a propensity for seizures. However, it's probably just going to be slow and encephalopathic-- based on her clinical exam now-- and unlikely to show much.