In the evolving modern era of neuromodulation for movement disorders in adults and children, much progress has been made recently characterizing the human motor network (MN) with potentially important treatment implications. Herein is a focused review of relevant resting state fMRI functional and effective connectivity of the human motor network across the lifespan in health and disease. The goal is to examine how the transition from functional connectivity to dynamic effective connectivity may be especially informative of network-targeted movement disorder therapies, with hopeful implications for children.

Resting-state functional magnetic resonance imaging (rs-fMRI) has the potential to investigate abnormalities in brain network structure and connectivity on an individual level in neurodevelopmental disorders, such as autism spectrum disorder (ASD), paving the way toward using this technology for a personalized, precision medicine approach to diagnosis and treatment. Using a case-control design, we compared five patients with severe regressive-type ASD to five patients with temporal lobe epilepsy (TLE) to examine the association between brain network characteristics and diagnosis. All children with ASD and TLE demonstrated intact motor, language, and frontoparietal (FP) networks. However, aberrant networks not usually seen in the typical brain were also found. These aberrant networks were located in the motor (40%), language (80%), and FP (100%) regions in children with ASD, while children with TLE only presented with aberrant networks in the motor (40%) and language (20%) regions, in addition to identified seizure onset zones. Fisher’s exact test indicated a significant relationship between aberrant FP networks and diagnosis (p = 0.008), with ASD and atypical FP networks co-occurring more frequently than expected by chance. Despite severe cognitive delays, children with regressive-type ASD may demonstrate intact typical cortical network activation despite an inability to use these cognitive facilities. The functions of these intact cognitive networks may not be fully expressed, potentially because aberrant networks interfere with their long-range signaling, thus creating a unique “locked-in network” syndrome.

• Directionality differentiates the SOZ and pZ with 88% accuracy, 73% specificity, and 95% sensitivity. • The Boerwinkle Neuroplasticity Index >70% is predictive of good outcomes. • Signal from seizure onset zone to propagation zone is excitatory and signal from propagation zone to seizure onset zone is inhibitory. • Greater inhibition from propagation zone is associated with better surgical outcome. • Pre to post-operative SOZ and pZ modulation was diminished as expected.

Resting-state functional magnetic resonance imaging provides dynamic insight into the functional organization of the brains’ intrinsic activity at rest. The emergence of resting-state functional magnetic resonance imaging in both the clinical and research settings may be attributed to recent advancements in statistical techniques, non-invasiveness and enhanced spatiotemporal resolution compared to other neuroimaging modalities, and the capability to identify and characterize deep brain structures and networks. In this report we describe a 16-year-old female patient with autism spectrum disorder who underwent resting-state functional magnetic resonance imaging due to late regression. Imaging revealed deactivated networks in deep brain structures involved in monoamine synthesis. Monoamine neurotransmitter deficits were confirmed by cerebrospinal fluid analysis. This case suggests that resting-state functional magnetic resonance imaging may have clinical utility as a non-invasive biomarker of central nervous system neurochemical alterations by measuring the function of neurotransmitter-driven networks. Use of this technology can accelerate and increase the accuracy of selecting appropriate therapeutic agents for patients with neurological and neurodevelopmental disorders.

BACKGROUND: Poor cerebrovascular reactivity is associated with a higher risk of cerebrovascular disease. The most common method to study cerebrovascular reactivity in aging adults, transcranial Doppler ultrasound, yields measurements in large intracranial arteries, but not in regional brain parenchyma that may be more impaired in some disease processes. Measurements derived from transcranial Doppler ultrasound suggest that there are sex differences in cerebrovascular reactivity for aging adults. We investigated the association between age and sex on cerebrovascular reactivity using blood oxygen level dependent (BOLD) magnetic resonance imaging in a representative group of aging adults. METHODS: This cross-sectional study investigated BOLD cerebrovascular reactivity to CO ₂ in a representative group of aging adults, 51 to 83 years old. We manipulated end-tidal carbon dioxide with breathing exercises and evaluated changes in 6 brain regions: whole brain, white matter, cortical gray matter, subcortical gray matter, left hippocampus, and right hippocampus. We used 1 linear regression per region to investigate the effects of age, sex, and their interaction on BOLD cerebrovascular reactivity. RESULTS: We report an age-by-sex interaction for all brain regions ( P ≤0.050), except cortical gray matter ( P =0.062). For white matter and subcortical gray matter, female participants trended toward an age-related BOLD cerebrovascular reactivity increase ( P ≤0.058), while male participants did not change with age ( P >0.580). In the whole brain and bilateral hippocampi, the age trends for each sex were in opposite directions but not significant ( P >0.211). We report a main effect of sex (female greater than male participants) for subcortical gray matter and the right hippocampus ( P ≤0.048) and no main effect of age in any model. CONCLUSIONS: We present the first report of age-related BOLD cerebrovascular reactivity increases in older female participants and higher BOLD cerebrovascular reactivity in older female compared with male participants. Sex and age-by-sex-based differences seem to be driven by changes in white matter, subcortical gray matter, and bilateral hippocampi.