Motor Cortical Excitability Assessed by Transcranial Magnetic Stimulation in Psychiatric Disorders: A Systematic Review

Smoking Restores Impaired LTD-Like Plasticity in Schizophrenia: a Transcranial Direct Current Stimulation Study

“…Interestingly, we found a significant negative correlation between Fagerstroem values and CSP duration in healthy smokers, indicating at least a gradual impact of smoking on CSP duration. Reviewing the literature for motor-cortical excitability in schizophrenia (Bunse et al, 2014), general differences between schizophrenia patients and healthy controls for CSP are subject to a large inter-study variability, possibly influenced by the smoking status of the study subjects, which is usually not reported in these studies. Prolonged, shortened, or unchanged CSP durations in schizophrenia patients were explained by different disease states and different medications (Bunse et al, 2014).…”

“…Reviewing the available literature for cortical excitability and plasticity in schizophrenia using noninvasive brain stimulation, a clear picture emerges. Reduced cortical inhibition (eg, reduced short-interval intracortical inhibition, for review see (Bunse et al, 2014)) might cause enhanced cortical noise, leading to reduced spike-timing-dependent plasticity (as measured by paired-associative stimulation) (Frantseva et al, 2008) and reduced nonfocal plasticity (as measured by anodal and cathodal tDCS) via enhanced asynchronous baseline cortical activity (Hasan et al, 2012b;Hasan et al, 2011) Our observed effect of enhanced LTD-like plasticity associated with nicotine intake through chronic smoking might reduce cortical noise and thus increase the signal-tonoise ratio in schizophrenia patients. This would be in line with the observation that LTD has an important role in hippocampal-based learning and memory functions (Collingridge et al, 2010), suggesting a direct contribution of LTD to information storage (Kemp and ManahanVaughan, 2007).…”

Repeated Transcranial Magnetic Stimulation (rTMS) to improve Electroconvulsive Therapy (ECT) in Treatment-Resistant Depression: A Report of Two Cases

“…However, a single session of ECT does not increase CSP 23 while several ECT increase CSP (24), a finding consistent with GABAergic activity of ECT. Transcranial magnetic stimulation also increases the CSP and depressed patients who responded to the high frequency rTMS (20Hz) of the left DLPFC have an increase of CSP and ICI [25][26][27]. Change of ICI was correlated with improved HAM-D score (Hamilton Rating Scale for Depression) [28].…”

Multimodal Applications of Transcranial Magnetic Stimulation for Circuit-Based Psychiatry

“…8 A number of studies have used motor neurophysiology singleor paired-pulse TMS protocols to identify general mechanisms of disease, biomarkers, and predictors of treatment response in psychiatric populations. 9 Although these results reveal global crosscircuit pathological changes in excitability, inhibition, facilitation, or cortical plasticity, they are generally nonspecific. This is primarily because these measures typically focus on the motor system, which may be affected in psychiatric disorders but is generally not the critically altered circuit.…”