Background
Over the recent years there has been a growing debate regarding the extent and nature of the overlap in neuropathology between schizophrenia (SZ) and autism spectrum disorder (ASD). Dynamic functional network connectivity (dFNC) is a recent analysis method that explores temporal patterns of functional connectivity (FC). We compared resting-state dFNC in SZ, ASD and healthy controls (HC), characterized the associations between temporal patterns and symptoms, and performed a three-way classification analysis based on dFNC indices.
Methods
Resting-state fMRI was collected from 100 young adults: 33 SZ, 33 ASD, 34 HC. Independent component analysis (ICA) was performed, followed by dFNC analysis (window = 33 s, step = 1TR, k-means clustering). Temporal patterns were compared between groups, correlated with symptoms, and classified via cross-validated three-way discriminant analysis.
Results
Both clinical groups displayed an increased fraction of time (FT) spent in a state of weak, intra-network connectivity [
p
< .001] and decreased FT in a highly-connected state [
p
< .001]. SZ further showed decreased number of transitions between states [p < .001], decreased FT in a widely-connected state [p < .001], increased dwell time (DT) in the weakly-connected state [p < .001], and decreased DT in the highly-connected state [
p
= .001]. Social behavior scores correlated with DT in the widely-connected state in SZ [
r
= 0.416,
p
= .043], but not ASD. Classification correctly identified SZ at high rates (81.8%), while ASD and HC at lower rates.
Conclusions
Results indicate a severe and pervasive pattern of temporal aberrations in SZ (specifically, being “stuck” in a state of weak connectivity), that distinguishes SZ participants from both ASD and HC, and is associated with clinical symptoms.
The results suggest that H-coil deep-TMS administered continuation treatment can help maintain an antidepressant effect for 18 weeks, following 4 weeks of acute treatment.
Treatment for negative symptoms and cognitive deficits, core elements of schizophrenia, remains inadequate. Stimulation of the prefrontal cortex via transcranial magnetic stimulation (TMS) yields only moderate results, possibly due to limited stimulation depth. Deep-TMS enables deeper and wider stimulation than before. This preliminary study is the first to examine deep-TMS as a possible add-on treatment for negative symptoms and cognitive deficits of schizophrenia. The effect of 20 daily deep-TMS sessions (20 Hz, 120% motor threshold) over the prefrontal cortex of 15 patients indicated improvement in cognition and negative symptoms that was maintained at 2-wk post-treatment follow-up.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.