Simultaneous fMRI, Direct Electrical Stimulation Feasible in Epilepsy

4. Diagnostic Challenges
4. Diagnostic Challenges
fMRI-DES could be used for full-brain volume evaluation of brain connectivity and help lead to the refinement of laser ablative procedures for epilepsy.

PHILADELPHIA — Among patients with extra-temporal medically intractable epilepsy, functional magnetic resonance imaging with simultaneous direct electrical stimulation is feasible and allows for the study of brain connectivity with high resolution and full spatial coverage.

“Non-lesional extra-temporal lobe epilepsies have an additional minimally invasive treatment option: laser therapy,” study investigator Jorge Gonzalez-Martinez, MD, PhD, of the Cleveland Clinic, told Neurology Advisor.

The findings were presented at the 2015 American Society of Epilepsy Annual Meeting in Philadelphia.

According to Dr. Gonzalez-Martinez, the catalyst for the study was the large number of patients with medically intractable epilepsy who do not respond to conventional medical or surgical treatment. The researchers employed a new method of functional magnetic resonance imaging (fMRI) with direct electrical stimulation (DES) followed by resection or focal laser ablation of the epileptic nodes within the epileptic networks.

In all, 15 patients with extra-temporal medically intractable epilepsy received stereoelectroencephalography (SEEG) evaluations.

After the recording periods, patients received fMRI under DES — defined as 25 hertz, 1 to 3 milliamperes and pulse widths of 300 milliseconds — of the ictal onset zones. Dr. Gonzalez-Martinez also performed stimulation of cortical areas not involved with the epileptic activity for the control group.