Abstract
Background
Electroconvulsive therapy (ECT) is a promising treatment option in Clozapine refractory schizophrenia patients. ECT is known to improve functional connectivity in default mode network (DMN) in depression. We studied the effect of ECT on resting state functional magnetic resonance imaging (rsfMRI) of patients with clozapine refractory/intolerant schizophrenia.
Methods
50 patients [mean age 30.24 ± 10.14 yr, 21 (42%) females] with 48% clozapine refractory schizophrenia rest clozapine intolerant schizophrenia, posted for modified ECT were recruited. We performed clinical symptoms ratings (SAPS, SANS, CGI_SCH) and image acquisition (rsfMRI ~10-minute with eyes open, T1 MPRAGE) prior to and after 8th ECT. 27 healthy controls [mean age = 30.74 ± 7.93, 11 (42%) females] age, sex and years of education matched for cases, underwent imaging (rsfMRI, T1 MPRAGE) once.
Results
With 3-point improvement on CGI SCH severity scale defined as response, 64% responded, and with 50% improvement in SAPS scale defined as response, 76% responded over the course of ECT (average no of ECTs = 7.5 ± 1.2). The rsfMRI of 40 patients who co-operated for pre- and post-ECT MRI-scans were preprocessed using FSL v.5.0.10. We discarded 13 patients scans which had >=5mm movement. We extracted 25 group independent components out of 27 patients’ scans using FSL MELODIC after correcting for motion and other physiological noise with FSL FIX. Dual regression analysis showed significant (TFCE corrected p<0.001) increase in connectivity between angular gyrus and ipsilateral dorsolateral prefrontal cortex (DLPFC) bilaterally following ECT none of which correlated with clinical scores. We found that DMN remains hypo connected in refractory schizophrenia, which was unaltered by ECT in comparison to healthy controls.
Discussion
Following ECT, we observed a strong increase in functional connectivity between angular gyrus and the ipsilateral DLPFC on both sides indicating improved connectivity in DMN and fronto-parietal network, however DMN remains hypo connected in comparison to healthy controls.