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08.10.2009
הדפס  
A 6 year-old right-handed male.
Right-sided simple partial seizures with secondary generalization.
The MRI showed left parietal cyst.

Surgical Planning, Cyst/Epilepsy

CASE STUDY: SURGICAL PLANNING Cyst/Epilepsy

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

Case Study:

A 6 year-old right-handed male.

Right-sided simple partial seizures with secondary generalization.

The MRI showed left parietal cyst.

An MEG study was performed using a Magnes II 74-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.

Two clusters of interictal spike source localizations were seen on the medial and lateral walls of the cyst.
Somatosensory evoked fields were recorded using a non-magnetic tactile stimulator applied to the right thumb (RD1), index finger (RD2) and little finger (RD5), and left thumb (LD1) and little finger (LD5). The source locations of the somatosensory cortex were used to define the location of the central sulcus, indicating that the cyst was located safely posterior to motor cortex. 
 
A lesionectomy with multiple subpial transections over the posterior lateral and medial borders of the cyst was performed. The patient has been seizure free for 25 months. 

Conclusion:
Non-invasive MEG recordings over a 2hour period were sufficient to localize the epileptogenic areas and somatosensory cortex for surgical planning. The results of the MEG study were confirmed at surgery by corticography and a surgical procedure that eliminated the patient’s seizures.