Case Study

A 27 year old man had febrile seizures and was diagnosed with epilepsy at 12 years old. Seizures began without warning with an abrupt stare, impaired consciousness and lip-smacking for < 1 minute followed by a brief post-ictal state. Focal seizures with dyscognitive features continued 2-4 times per month despite multiple AEDs prompting pre-surgical evaluation. "Secondarily generalized" seizures began to appear as the primary seizure type 1.5 years prior to admission. A high resolution brain MRI was normal. FDG-PET demonstrated left temporal hypometabolism. Interictal EEG revealed left mid-posterior temporal spikes. He was admitted for video-EEG monitoring for characterization of his seizures. During his hospitalization he experienced 3 seizures with stereotypic semiology. A stare with impaired consciousness x 30-60 seconds was followed by a limp collapse. Within 15-30 seconds slow evolution to a sustained generalized stiffening of the body was then seen. His ictal vEEG is represented below;

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Figure: (A) Demonstrating a left hemispheric electrographic seizure associated with staring and impaired consciousness < 30 seconds from onset. (B) reveals the seizure toward the end with ictal asystole (arrow). Parameters: longitudinal bipolar montage, sensitivity 7 uv, and filters 1-70 Hz.

What was wrong with the patient?

Serious cardiac arrhythmias may occur with focal seizures and result in falls. Bradycardia and ictal asystole (IA) may rarely occur where a seizure has the secondary effect of transient cardiac arrest. Changes in seizure semiology reflect a syncope and often reflect the change or evolution of brain function or expression. Temporal lobe structures appear to be unique in predisposing to IA. Evolution of a seizure to atonia caused by cerebral hypoperfusion occurs about 30-40 seconds following the onset of the seizure in 0.27% of video-EEG monitoring sessions in 1 study1. Anoxia is the presumed mechanism involved in seizure termination. IA may be implicated in sudden unexplained death in epilepsy and seizure control is the treatment of choice. Following cardiology evaluation, a pacemaker was implanted in our patient with elimination of "convulsions" while he awaits epilepsy surgery. Pacemaker implantation may result in reduction in seizure-induced syncope and traumatic injuries due to falls that are associated with IA2.

References

  1. Schuele SU, Bermeo AC, Alexopoulos AV, Locatelli ER, Burgess RC, Dinner DS, Foldvary-Schaeffer N. Video-electrographic and clinical features in patients with ictal asystole. Neurology 2007;69(5):434-441.
  2. Moseley BD, Ghearing GR, Munger TM, Britton JW. The treatment of ictal asystole with cardiac pacing. Epilepsia 2011;52(4):16-19.
Authored By: 
William O. Tatum DO
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Authored Date: 
12/2011