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Author: Paul B Fitzgerald (316)



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Dec
1969

Electroconvulsive therapy is effective in treatment-resistant schizophrenia (TRS) but use is limited due to stigma and concerns around cognitive adverse effects. Magnetic seizure therapy (MST) is a promising new neuromodulation technique that uses transcranial magnetic stimulation to induce therapeutic seizures. Studies of MST in depression have shown clinical improvement with a favorable adverse effect profile.

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Jan
2018

With an increasing interest in the use of theta burst stimulation (TBS) as a cognitive enhancer and a potential therapeutic tool for psychiatric disorders, there is a need to identify optimal parameters of TBS in the prefrontal cortex.
This study examined the effect of two blocks of prefrontal intermittent TBS (iTBS) on cortical reactivity and working memory performance, compared to one block of iTBS and sham stimulation. We hypothesized that greater cortical effects would be obtained with two blocks of iTBS.

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Jan
2018

Magnetic seizure therapy (MST) is a novel brain stimulation technique that uses a high-powered transcranial magnetic stimulation device to produce therapeutic seizures. Preliminary MST studies have found antidepressant effects in the absence of cognitive side effects but its efficacy compared to electroconvulsive therapy (ECT) remains unclear. The aim of this study was to investigate the therapeutic efficacy and cognitive profile of MST compared to standard right unilateral ECT treatment.

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Dec
2017

Influential hypotheses propose that alterations in emotional state influence decision processes and executive control of behavior. Both music and transcranial direct current stimulation (tDCS) of prefrontal cortex affect emotional state, however interactive effects of music and tDCS on executive functions remain unknown. Learning to inhibit inappropriate responses is an important aspect of executive control which is guided by assessing the decision outcomes such as errors.

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Feb
2018

Intermittent theta burst stimulation (iTBS) is a noninvasive brain stimulation technique capable of increasing cortical excitability beyond the stimulation period. Due to the rapid induction of modulatory effects, prefrontal application of iTBS is gaining popularity as a therapeutic tool for psychiatric disorders such as depression. In an attempt to increase efficacy, higher than conventional intensities are currently being applied.

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Sep
2017

A wide range of neuroimaging and neuromodulation studies have shown that the dorsolateral prefrontal cortex (DLPFC) plays a pivotal role in decision-making. Of particular interest is the question of its role in decision-making when conditions are uncertain and whether manipulating this neural substrate through neuromodulation changes subsequent risk-taking behaviour. Previous work using the Balloon Analogue Risk Task (BART) suggests that bilateral tDCS stimulation of the DLPFC reduces risk-taking behaviour but unilateral stimulation has no effect.

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Jul
2017

Sequential visual isometric pinch task (SVIPT) has been recently used as a visuomotor sequence task in clinical research. The influence of varying intervals between sequenced trials on the acquisition of implicit sequence learning is not yet determined for SVIPT. The aim of this study was to investigate the effects of inter-trial interval (ITI) on implicit motor sequence learning using SVIPT.

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Mar
2018

Chronic low back pain (CLBP) is a major health issue, yet its underlying mechanisms remain unknown. Studies have demonstrated the importance of emotion and cognition in chronic pain; however, the relevant brain physiology in magnetic resonance imaging (MRI) studies are unclear in CLBP populations. Therefore, this review aimed to identify MRI brain changes and examine their potential relationship with emotional and cognitive processes in CLBP.

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Jul
2017

To examine the effects of intermittent TBS (iTBS) and continuous TBS (cTBS) on cortical reactivity in the dorsolateral prefrontal cortex.
10 healthy participants were stimulated with either iTBS, cTBS or sham at F3 electrode. Single- and paired-pulse TMS and concurrent electroencephalography (EEG) were used to assess change in cortical reactivity and long-interval intracortical inhibition (LICI) via TMS-evoked potentials (TEPs) and TMS-evoked oscillations.

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Jan
2017

Transcranial magnetic stimulation (TMS) is a useful tool for assessment of corticospinal excitability (CSE) changes in both healthy individuals and patients with brain disorders. The usefulness of TMS-elicited motor evoked potentials (MEPs) for the assessment of CSE in a clinical context depends on their intra-and inter-session reliability. This study aimed to evaluate if removal of initial MEPs elicited by using two types of TMS techniques influences the reliability scores and whether this effect is different in blocks with variable number of MEPs.

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Dec
1969

Due to the potential of anodal transcranial direct current stimulation (a-tDCS) for enhancement of fine sequenced movements and increasing interest in achieving high level of fine movements in the trained and untrained hands especially at initial stage of learning, we designed this study to investigate whether the application of single-session a-tDCS with small-size stimulating electrodes over FPN sites, such as dorsolateral prefrontal cortex (DLPFC), primary motor cortex (M1) or posterior parietal cortex (PPC) could enhance sequence learning with the trained hand and these effects are transferred into the untrained hand or not. A total of 51 right-handed healthy participants were randomly assigned to one of the four stimulation groups: a-tDCS of left M1, DLPFC, PPC, or sham. Stimulation was applied for 20 min during a sequential visual isometric pinch task (SVIPT).

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Jun
2017

Background Repetitive transcranial magnetic stimulation (rTMS) is a promising augmentation strategy for treatment-refractory OCD. However, a substantial group still fails to respond. Sleep disorders, e.

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Jun
2017

High frequency repetitive transcranial magnetic stimulation (rTMS) elicits plastic effects in excitatory and inhibitory circuits. Inter-train intervals (ITI) were initially incorporated into rTMS paradigms to avoid overheating and for safety considerations. Recent studies have shown that inclusion of ITI, as opposed to continuous stimulation, is essential for eliciting excitatory effects, but the optimal ITI remains unknown.

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May
2017

Transcranial direct current stimulation (tDCS) is a well-recognised neuromodulatory technology which has been shown to induce short-lasting changes in motor-cortical excitability. The recent and rapid expansion of tDCS into the cognitive domain, however, necessitates deeper mechanistic understanding of its neurophysiological effects over non-motor brain regions. The present study utilised transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) to probe the immediate and longer-term effects of both a bipolar (BP-tDCS) and more focal 4×1 High-Definition tDCS (HD-tDCS) montage applied over the left DLPFC on TMS-evoked potentials (TEPs) and oscillations in 19 healthy adult participants.

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Feb
2017

Deficits in GABAergic inhibitory neurotransmission are a reliable finding in schizophrenia (SCZ) patients. Previous studies have reported that unaffected first-degree relatives of patients with SCZ demonstrate neurophysiological abnormalities that are intermediate between probands and healthy controls. In this study, first-degree relatives of patients with SCZ and their related probands were investigated to assess frontal cortical inhibition.

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Dec
1969

Antidepressant medication is the most common treatment for major depressive disorder (MDD), however, the precise working mechanism underlying these treatments remains unclear. Recent neuromodulation treatments demonstrate that direct stimulation of the dorsolateral prefrontal cortex (DLPFC), dorsomedial prefrontal cortex (DMPFC), and subgenual anterior cingulate (sgACC) relate to clinical improvement, suggesting connectivity alterations of the DLPFC-DMPFC-sgACC network to mediate antidepressant response. The international Study to Predict Optimized Treatment in Depression (iSPOT-D) is an international multicentre study that collected EEG data for 1008 MDD patients, randomized to 3 different antidepressant medications (N=447 MDD with complete pre- and post-treatment data and N=336 non-MDD).

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Dec
1969

Alterations to functional connectivity following a traumatic brain injury (TBI) may lead to impaired cognitive performance and major depressive disorder (MDD). In particular, functional gamma band connectivity is thought to reflect information binding important for working memory. The objective of this study was to determine whether altered functional gamma connectivity may be a factor in MDD following TBI (TBI-MDD).

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Dec
2016

Dysfunctional cortical inhibition (CI) is postulated as a key neurophysiological mechanism in major depressive disorder. Electroconvulsive therapy (ECT) is the treatment of choice for resistant depression and ECT has been associated with enhanced CI. The objective of this study was to evaluate the relationship between CI and ECT response in resistant depression.

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Nov
2016

Repetitive transcranial magnetic stimulation (rTMS) is a relatively recent addition to the neurostimulation armamentarium for treating individuals suffering from treatment refractory depression and has demonstrated efficacy in clinical trials. One of the proposed mechanisms of action underlying the therapeutic effects of rTMS for depression involves the modulation of depression-associated dysfunctional activity in distributed brain networks involving frontal cortical and subcortical limbic regions, via changes to aberrant functional and structural connectivity. Although there is currently a paucity of published data, we review changes to functional and structural connectivity following rTMS for depression.

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Feb
2017

The concurrent use of transcranial magnetic stimulation with electroencephalography (TMS-EEG) is growing in popularity as a method for assessing various cortical properties such as excitability, oscillations and connectivity. However, this combination of methods is technically challenging, resulting in artifacts both during recording and following typical EEG analysis methods, which can distort the underlying neural signal. In this article, we review the causes of artifacts in EEG recordings resulting from TMS, as well as artifacts introduced during analysis (e.

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Nov
2016

Huntington's disease (HD) affects GABA-mediated inhibitory circuitry in the cortex. As there is evidence that sex hormones affect GABAergic function, we investigated whether gender modulates GABA-related pathophysiological changes in HD. Fifteen premanifest HD, 11 symptomatic HD and 16 healthy control participants were assessed with paired-pulse transcranial magnetic stimulation applied to the primary motor cortex.

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Dec
1969

Ultrasound (US) at diagnostic frequency and power is known to alter nerve potentials; however, the precise mechanism of action is unknown. We investigated whether US alters resting nerve potential to lower the threshold for magnetic nerve stimulation. Seventeen healthy subjects were recruited.

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Aug
2017

Schizophrenia is characterised by significant episodic memory impairment that is thought to be related to problems with encoding, however the neuro-functional mechanisms underlying these deficits are not well understood. The present study used a subsequent recognition memory paradigm and event-related potentials (ERPs) to investigate temporal aspects of episodic memory encoding deficits in schizophrenia.
Electroencephalographic data was recorded in 24 patients and 19 healthy controls whilst participants categorised single words as pleasant/unpleasant.

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Aug
2016

Episodic memory (EM) impairments in schizophrenia (SZ) are predictive of functional outcome and are a potential endophenotype of the disorder. The current study investigated the neuroanatomical correlates of EM encoding and retrieval in SZ with structural magnetic resonance and diffusion tensor imaging (DTI) measures in 22 patients with SZ and 22 age- and gender-matched healthy controls. Tract-based Spatial Statistics (TBSS) was used to investigate microstructural alterations in white matter (WM), while FreeSurfer surface-based analysis was used to determine abnormalities in grey matter (GM) and WM volumetrics and cortical thickness.

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Jan
2017

Short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) are noninvasive transcranial magnetic stimulation (TMS) measures of GABAreceptor-mediated inhibition and glutamatergic excitatory transmission, respectively. Conventionally these measures have been restricted to the motor cortex. We investigated whether SICI and ICF could be recorded from the dorsolateral prefrontal cortex (DLPFC) using combined TMS and electroencephalography (TMS-EEG).

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Nov
2016

Previous neuroimaging studies have demonstrated structural brain alterations in blind subjects, but most have focused on primary open angle glaucoma or retinopathy of prematurity, used low-field scanners, a limited number of receive channels, or have presented uncorrected results. We recruited 10 blind and 10 age and sex-matched controls to undergo high-resolution MRI using a 3T scanner and a 32-channel receive coil. We evaluated whole-brain morphological differences between the groups as well as manual segmentation of regional hippocampal volumes.

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Sep
2016

Neuroimaging and electrophysiological research have revealed a range of neural abnormalities in autism spectrum disorder (ASD), but a comprehensive understanding remains elusive. We utilized a novel methodology among individuals with ASD and matched controls, combining transcranial magnetic stimulation (TMS) with concurrent electroencephalogram (EEG) recording (TMS-EEG) to explore cortical function and connectivity in three sites implicated in the neuropathophysiology of ASD (dorsolateral prefrontal cortex, primary motor cortex, and temporoparietal junction). As there is evidence for neurobiological gender differences in ASD, we also examined the influence of biological sex.

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Jun
2016

Several factors may mitigate the efficacy of repetitive transcranial magnetic stimulation (rTMS) over sham rTMS in patients with treatment-resistant depression (TRD). These factors include unilateral stimulation (i.e.

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Jun
2016

Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation method, which shows promising therapeutic effects in controlling drug cravings.
In this study, we present cumulative and booster effects of tDCS sessions on methamphetamine cravings, lapse, and cognitive impairment in a methamphetamine dependent subject.
Our study shows cumulative effects of continuous anodal tDCS sessions on right dorsolateral prefrontal cortex (DLPFC) could reduce drug cravings and their consequences.

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Dec
1969

Repetitive transcranial magnetic stimulation (rTMS) has been demonstrated to have efficacy in the treatment of unipolar depression but limited research has explored the efficacy of rTMS in bipolar depression. Therefore, we conducted a comparative clinical trial evaluating clinical responses to prefrontal bilateral and unilateral rTMS in patients suffering from bipolar depression. We hypothesized that, 1) the response to the treatment would be associated with a decrease in the frequency of beta waves, 2) bilateral stimulation of the cortex would bring about more extensive changes in brain activity than unilateral stimulation, and 3) bilateral stimulation is more effective than unilateral.

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Aug
2016

The modulation of brain function via the application of weak direct current was first observed directly in the early 19th century. In the past 3 decades, transcranial magnetic stimulation and deep brain stimulation have undergone clinical translation, offering alternatives to pharmacological treatment of neurological and neuropsychiatric disorders. Further development of novel neuromodulation techniques employing ultrasound, micro-scale magnetic fields and optogenetics is being propelled by a rapidly improving understanding of the clinical and experimental applications of artificially stimulating or depressing brain activity in human health and disease.

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Oct
2016

Working memory impairment in schizophrenia has been strongly associated with abnormalities in gamma oscillations within the dorsolateral prefrontal cortex (DLFPC). We recently published the first ever study showing that anodal transcranial direct current stimulation (tDCS) to the left DLPFC was able to significantly improve working memory in schizophrenia and did so seemingly via restoring normal gamma oscillatory function. Transcranial alternating current stimulation (tACS) is a form of electrical brain stimulation that delivers stimulation at a specific frequency and has been shown to entrain endogenous cortical oscillations.

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Jan
2017

To investigate the prevalence of occipital bending (an occipital lobe crossing or twisting across the midline) in subjects with schizophrenia and matched healthy controls.
Occipital bending prevalence was investigated in 37 patients with schizophrenia and 44 healthy controls.
Ratings showed that prevalence was nearly three times higher among schizophrenia patients (13/37 [35.

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Dec
1969

Considerable research has demonstrated the efficacy of repetitive transcranial magnetic stimulation (rTMS) treatment in patients with depression. However, limited research has described the pattern of response to rTMS treatment or explored possible predictors of the likelihood of treatment response.
Data from 11 clinical trials (n = 1,132) was pooled and we described the pattern of response to rTMS, rate of response, and remission as well as potential clinical and demographic predictors of response.

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Dec
1969

Striatal degeneration in Huntington's disease (HD) causes changes in cortico-subcortical pathways. Transcranial magnetic stimulation (TMS) is a valuable tool for assessing pathophysiology within these pathways, yet has had limited application in HD. As cortico-subcortical pathways are largely mediated by GABA and dopamine receptor genes, understanding how these genes modulate neurophysiology in HD may provide new insights into how underlying pathology maps onto clinical phenotype.

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Jul
2016

To explore the therapeutic benefit of sequential bilateral repetitive transcranial magnetic stimulation (rTMS) in the treatment of bipolar depression.
A 2 arm randomized controlled parallel design trial comparing the use of active sequential bilateral rTMS to a sham form of stimulation in 49 patients with bipolar disorder and treatment resistant depression.
There was no significant difference in mean reduction in depression rating scale scores or response rates between active and sham stimulation.

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May
2016

Transcranial electrical stimulation (tES) techniques are able to induce changes in cortical excitability and plasticity through the administration of weak currents to the brain and are currently being used to manipulate a vast array of cognitive processes. Despite the widespread use of tES technologies within both research and remedial settings, their precise neurophysiological mechanisms of action are not well established outside of the motor cortex. The expanding use of tES within non-motor brain regions highlights the growing need for a more comprehensive understanding of the effects of stimulation across a diversity of cortical locations.

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Dec
1969

tDCS studies typically find that: lowest levels of comfort occur at stimulation-onset; young adult participants experience less comfort than older participants; and participants' blinding seems effective at low current strengths. At 2 mA conflicting results have been reported, questioning the effectiveness of blinding in sham-controlled paradigms using higher current strengths. Investigator blinding is rarely reported.

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Feb
2016

Transcranial magnetic stimulation (TMS) is an increasingly popular tool in treating psychiatric conditions. The dorsal lateral prefrontal cortex (DLPFC) is typically targeted for stimulation, with magnetic field intensity being calibrated by establishing resting motor threshold (RMT) at hand region of primary motor cortex (M1 hand). This presumes that scalp-to-cortex distance (SCD) and cortical thickness is similar at both sites.

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Apr
2016

Noninvasive brain stimulation has been demonstrated to modulate cortical activity in humans. In particular, theta burst stimulation (TBS) has gained notable attention due to its ability to induce lasting physiological changes after short stimulation durations. The present study aimed to provide a comprehensive meta-analytic review of the efficacy of two TBS paradigms; intermittent (iTBS) and continuous (cTBS), on corticospinal excitability in healthy individuals.

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Feb
2016

Previous studies suggest that altered corneal temperature may be a feature of schizophrenia, but the association between major depressive disorder (MDD) and corneal temperature has yet to be assessed. The aim of this study is to investigate whether eye temperature is different among MDD patients than among healthy individuals. We used a thermographic camera to measure and compare the temperature profile across the corneas of 16 patients with MDD and 16 age- and sex-matched healthy subjects.

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Apr
2016

Recent neuroimaging studies have demonstrated that activation of the putative human mirror neuron system (MNS) can be elicited via visuomotor training. This is generally interpreted as supporting an associative learning account of the mirror neuron system (MNS) that argues against the ontogeny of the MNS to be an evolutionary adaptation for social cognition. The current study assessed whether a central component of social cognition, emotion processing, would influence the MNS activity to trained visuomotor associations, which could support a broader role of the MNS in social cognition.

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Dec
1969

While Major Depressive Disorder (MDD) is primarily characterized by mood disturbances, impaired attentional control is increasingly identified as a critical feature of depression. Deep transcranial magnetic stimulation (deepTMS), a noninvasive neuromodulatory technique, can modulate neural activity and induce neuroplasticity changes in brain regions recruited by attentional processes. This study examined whether acute and long-term high-frequency repetitive deepTMS to the dorsolateral prefrontal cortex (DLPFC) can attenuate attentional deficits associated with MDD.

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Feb
2016

A large number of studies have indicated the effect of anodal transcranial direct current stimulation (a-tDCS) on the primary motor cortex (M1) during motor skill training. The effects of a-tDCS on different stages of motor sequence learning are not yet completely understood. The purpose of this meta-analysis was to determine the effects of single and multiple sessions of a-tDCS on two different tasks: the sequential finger tapping task/serial reaction time task (SEQTAP/SRTT) and the sequential visual isometric pinch task (SVIPT).

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Dec
2015

To provide guidance for the management of mood disorders, based on scientific evidence supplemented by expert clinical consensus and formulate recommendations to maximise clinical salience and utility.
Articles and information sourced from search engines including PubMed and EMBASE, MEDLINE, PsycINFO and Google Scholar were supplemented by literature known to the mood disorders committee (MDC) (e.g.

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