Case Study

A 24 year old woman had a simple febrile seizure at 18 months of age. She later developed a nocturnal convulsion at 12 years of age. Seven trials of AEDs were ineffective in controlling "petit mal" seizures where she would stare, ask others to "wait a minute" or "give me a moment", lick her lips repeatedly, and "clamp down" with her left hand for a minute following which she was sleepy. Right mesial temporal sclerosis was noted on brain MRI. EEG revealed "bilateral phase reversals consistent with epileptiform discharges" (below). Following a closed head injury due to a seizure, she was referred for epilepsy surgery. The patient reported that she was told epilepsy surgery as a "last resort" could render her seizure free, but that she would likely need "death electrodes" to exclude seizures coming from both sides of the brain. As a result she delayed surgery for 4 years but is seizure free after right amygdalohippocampectomy.

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Figure: Interictal EEG demonstrating bilateral wicket spikes that represent a benign EEG variant of uncertain significance. The recording parameters included are the longitudinal bipolar montage with a sensitivity 7 uv and filter settings of 1-70 Hz.

What caused the wicket spikes?

Medial temporal lobe epilepsy is the most common form of localization-related epilepsy in adults, is suggested by the history, and is surgically remediable by temporal lobectomy. Bilateral anterior temporal interictal epileptiform discharges are seen in a significant number of patients but yet unifocal TLE is frequently seen. The interictal EEG demonstrates wicket spikes consisting of intermittent bitemporal bursts of monophasic archiform potentials that bear no relationship to epilepsy. Wickets represent a common reason for the misuse of AEDs in patients without epilepsy1. The above case illustrates the ramifications of a misinterpreted interictal EEG in a patient (now seizure free) with a correct diagnosis but incorrect assumption of the surgical implication.

References

  1. Krauss GL, Abdallah A, Lesser R, Thompson RE, Niedermeyer E. Clinical and EEG features of patients with EEG wicket rhythms misdiagnosed with epilepsy. Neurology 2005;64:1879-1883.
Authored By: 
William O. Tatum DO
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Authored Date: 
02/2011