Analysis of Brain Activation and Effective Connectivity During Self-paced Unilateral and Bilateral Finger Tapping Using Functional Magnetic Resonance Imaging in Patients with Temporal Lobe Epilepsy

Brain Connectivity in Finger Tapping For Epilepsy Patients

Abstract

Background: Temporal lobe is the most frequent site of origin of partial seizures. Patients with Temporal Lobe Epilepsy (TLE) represent approximately two-thirds of the intractable seizure population. This study aims to explore motor networks in TLE patients.

Methodology: This study involves 12 healthy subjects and 12 TLE patients who have undergone functional magnetic resonance imaging (fMRI) performing self-paced unilateral and bilateral finger tapping. The images were then pre-processed and analysed using Statistical Parametric Mapping (SPM). The activated areas were compared between healthy subjects and TLE patients. The effective connectivity for visual and motor node were performed using Dynamic Causal modelling (DCM).

Results: Comparing the two groups, using two samples t-test, familywise error rate (FWE) p < 0.05, Healthy subjects showed more areas of significant activation. For effective connectivity, in healthy subjects, visual to motor was the dominant model with average value of 0.03Hz bilaterally. In TLE patients, on the right hemisphere, a contrary result was observed whereby motor to visual area was the dominant model. On the left hemisphere, the same model as healthy subjects was the dominant model, visual to motor, but with higher average value of 0.1Hz.

Conclusion: This study found that there was less area of brain that has significant activation in TLE patients during motor activity. TLE brains also exhibit alteration in effective connectivity between visual and motor region.