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28.03.2010
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A 15 year-old right-handed female with onset of a medically intractable seizure disorder at 9 years of age.The seizures were nocturnal and consisted of awakening, body jerking and tonic arm extension with left-sided predominance. The MRI was normal

Frontal Lobe Epilepsy

CASE STUDY: Frontal Lobe Epilepsy

Physician: Hiroshi Otsubo, M.D.
Hospital for Sick Children, Toronto,
Ontario, Canada

Case Study:
A 15 year-old right-handed female with onset of a medically intractable seizure disorder at 9 years of age.
The seizures were nocturnal and consisted of awakening, body jerking and tonic arm extension with left-sided predominance.
The MRI was normal.

Scalp VEEG was nonlateralizing.

An MEG study was performed using a Magnes II dual 37-channel 4-D Neuroimaging system at Scripps Clinic in La Jolla, California. Interictal MEG spikes were captured in 6 second epochs by an observer who monitored the spontaneous MEG and simultaneous EEG signals. The MEG study required about 2 hours of recording time. Sources of interictal epileptic  spikes were analyzed with a single equivalent current dipole model.

A cluster of interictal spike source localizations was seen in the right frontal region.


During subsequent invasive VEEG monitoring for 48 hours, 10 seizures were recorded, all of which originated from the right frontal lobe, precisely duplicating where the MEG interictal spike sources were localized.

A right frontal coticectomy was performed in the region delineated by the MEG and invasive VEEG findings. The patient has been seizure free for 30
months.

Conclusion:
Non-invasive MEG recordings over a 2-hour period provided information helpful for localization of epileptic cortex equivalent to that obtained from a 48-hour invasive VEEG monitoring program. The results of the MEG study were confirmed by the invasive VEEG study and a surgical procedure that eliminated the patient’s seizures.