Continuous and intermittent theta burst stimulation of primary visual cortex do not modulate resting state functional connectivity: A sham-controlled multi-echo fMRI study.

Introduction: Theta burst stimulation (TBS) is a type of rTMS protocol which has the advantage of a shorter delivery time over traditional rTMS. When applied to motor cortex, intermittent TBS (iTBS) has been shown to yield excitatory aftereffects, whereas continuous TBS (cTBS) may lead to inhibitory aftereffects, both lasting from minutes to hours. The majority of TBS research has targeted motor, frontal, and parietal regions, and to date very few studies have examined its efficacy at visual areas.

Modulating intrinsic functional connectivity with visual cortex using low-frequency repetitive transcranial magnetic stimulation.

Introduction: Intrinsic network connectivity becomes altered in pathophysiology. Noninvasive brain stimulation can modulate pathological functional networks in an attempt to restore the inherent response. To determine its usefulness for visual-related disorders, we developed procedures investigating repetitive transcranial magnetic stimulation (rTMS) protocols targeting the visual cortex on modulating connectivity associated with the visual network and default mode network (DMN).

Continuous and intermittent theta burst stimulation to the visual cortex do not alter GABA and glutamate concentrations measured by magnetic resonance spectroscopy.

Background: Theta burst stimulation (TBS), a form of repetitive transcranial magnetic stimulation (rTMS), uses repeated high-frequency bursts to non-invasively modulate neural processes in the brain. An intermittent TBS (iTBS) protocol is generally considered "excitatory," while continuous TBS (cTBS) is considered "inhibitory." However, the majority of work that has led to these effects being associated with the respective protocols has been done in the motor cortex, and it is well established that TMS can have variable effects across the brain.

Reliance on visual feedback from ocular accommodation on motor skills in children with developmental coordination disorder and typically developing controls.

Children with developmental coordination disorder (DCD) present with marked impairments in motor skills, including visual-motor integration. Oculomotor anomalies are more prevalent in children with DCD than typically developing children. Children with DCD further demonstrate altered use of visual feedback compared to typically developing controls.

Assessing differential effects of single and accelerated low-frequency rTMS to the visual cortex on GABA and glutamate concentrations.

Background: The application of repetitive transcranial magnetic stimulation (rTMS) for therapeutic use in visual-related disorders and its underlying mechanisms in the visual cortex is under-investigated. Additionally, there is little examination of rTMS adverse effects particularly with regards to visual and cognitive function. Neural plasticity is key in rehabilitation and recovery of function; thus, effective therapeutic strategies must be capable of modulating plasticity.

Altered white matter structure in auditory tracts following early monocular enucleation.

Purpose: Similar to early blindness, monocular enucleation (the removal of one eye) early in life results in crossmodal behavioral and morphological adaptations. Previously it has been shown that partial visual deprivation from early monocular enucleation results in structural white matter changes throughout the visual system (Wong et al., 2018).

Altered white matter connectivity associated with visual hallucinations following occipital stroke.

Introduction: Visual hallucinations that arise following vision loss stem from aberrant functional activity in visual cortices and an imbalance of activity across associated cortical and subcortical networks subsequent to visual pathway damage. We sought to determine if structural changes in white matter connectivity play a role in cases of chronic visual hallucinations associated with visual cortical damage.

Methods: We performed diffusion tensor imaging (DTI) and probabilistic fiber tractography to assess white matter connectivity in a patient suffering from continuous and disruptive phosphene (simple) visual hallucinations for more than 2 years following right occipital stroke.

Altered white matter structure in the visual system following early monocular enucleation.

Partial visual deprivation from early monocular enucleation (the surgical removal of one eye within the first few years of life) results in a number of long-term morphological adaptations in adult cortical and subcortical visual, auditory, and multisensory brain regions. In this study, we investigated whether early monocular enucleation also results in the altered development of white matter structure. Diffusion tensor imaging and probabilistic tractography were performed to assess potential differences in visual system white matter in adult participants who had undergone early monocular enucleation compared to binocularly intact controls.

Consecutive TMS-fMRI reveals remote effects of neural noise to the "occipital face area".

The human cortical system for face perception comprises a network of connected regions including the middle fusiform gyrus ("fusiform face area" or FFA), the inferior occipital gyrus ("occipital face area" or OFA), and the posterior superior temporal sulcus (pSTS). Here, we sought to investigate how transcranial magnetic stimulation (TMS) to the OFA affects activity within the face processing network. We used offline repetitive TMS to temporarily introduce neural noise in the right OFA in healthy subjects.

rTMS reduces cortical imbalance associated with visual hallucinations after occipital stroke.

Objective: To investigate the efficacy of multiday repetitive transcranial magnetic stimulation (rTMS) to the occipital cortex in a patient with continuous visual phosphene hallucinations for more than 2 years following occipital stroke.

Methods: Low-frequency rTMS (1 Hz) was applied to the lesion site for 30 minutes daily over 5 consecutive days. Functional MRI (fMRI) was performed before and after rTMS treatment.

TMS to object cortex affects both object and scene remote networks while TMS to scene cortex only affects scene networks.

Viewing the world involves many computations across a great number of regions of the brain, all the while appearing seamless and effortless. We sought to determine the connectivity of object and scene processing regions of cortex through the influence of transient focal neural noise in discrete nodes within these networks. We consecutively paired repetitive transcranial magnetic stimulation (rTMS) with functional magnetic resonance-adaptation (fMR-A) to measure the effect of rTMS on functional response properties at the stimulation site and in remote regions.

Relationship of ocular accommodation and motor skills performance in developmental coordination disorder.

Ocular accommodation provides a well-focussed image, feedback for accurate eye movement control, and cues for depth perception. To accurately perform visually guided motor tasks, integration of ocular motor systems is essential. Children with motor coordination impairment are established to be at higher risk of accommodation anomalies.