A preliminary functional MRI study with temporal clustering analysis for localization of epileptic activity

Objective: To study the potential of using temporal clustering analysis (TCA) technique in localizing an epileptogenic zone. Methods: Twelve patients with epilepsy were examined using resting functional MRI (fMRI). The patients had detectable focal lesions on cranial MRI. TCA was performed to analyze resting fMRI data in order to identify the timing of interictal epileptiform discharges (IEDs). Standard event-related fMRI analysis in SPM99 was used to generate maps of the activation induced by epileptic brain activities. Comparisons were made between TCA results and SPM motion trochoid. Results Eight of the twelve subjects showed activations in the brain regions that were consistent with those lesions determined on anatomic MRI. The remaining four subjects showed no clear activation in the areas of detectable lesions. In addition, correlation was found between TCA results and motion trochoids. Conclusions: Temporal cluster analysis, an exploratory data-driven technique, may provide the timing information about interictal epileptiform discharges. However, the results from this novel fMRI analytical technique need to be interpreted with caution as it is vulnerable to motion artifact. (authors)