Dataset Information

Mapping visuospatial attention: the greyscales task in combination with repetitive navigated transcranial magnetic stimulation.

ABSTRACT:

Background

Visuospatial attention is executed by the frontoparietal cortical areas of the brain. Damage to these areas can result in visual neglect. We therefore aimed to assess a combination of the greyscales task and repetitive navigated transcranial magnetic stimulation (rTMS) to identify cortical regions involved in visuospatial attention processes. This pilot study was designed to evaluate an approach in a cohort of healthy volunteers, with the future aim of using this technique to map brain tumor patients before surgery. Ten healthy, right-handed subjects underwent rTMS mapping of 52 cortical spots in both hemispheres. The greyscales task was presented tachistoscopically and was time-locked to rTMS pulses. The task pictures showed pairs of horizontal rectangles shaded continuously from black at one end to white at the other, mirror-reversed. On each picture the subject was asked to report which of the two greyscales appeared darker overall. The responses were categorized into "leftward" and "rightward," depending on whether the subject had chosen the rectangle with the darker end on the left or the right. rTMS applied to cortical areas involved in visuospatial attention is supposed to affect lateral shifts in spatial bias. These shifts result in an altered performance on the greyscales task compared to the baseline performance without rTMS stimulation.

Results

In baseline conditions, 9/10 subjects showed classic pseudoneglect to the left. Leftward effects also occurred more often in mapping conditions. Yet, calculated rightward deviations were strikingly greater in magnitude (p?ConclusionThe greyscales task, in combination with rTMS, yields encouraging results in the examination of the visuospatial attention function. Future clinical implications should be evaluated.

SUBMITTER: Giglhuber K

PROVIDER: S-EPMC6042394 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mapping visuospatial attention: the greyscales task in combination with repetitive navigated transcranial magnetic stimulation.

Giglhuber Katrin K Maurer Stefanie S Zimmer Claus C Meyer Bernhard B Krieg Sandro M SM

BMC neuroscience 20180711 1

<h4>Background</h4>Visuospatial attention is executed by the frontoparietal cortical areas of the brain. Damage to these areas can result in visual neglect. We therefore aimed to assess a combination of the greyscales task and repetitive navigated transcranial magnetic stimulation (rTMS) to identify cortical regions involved in visuospatial attention processes. This pilot study was designed to evaluate an approach in a cohort of healthy volunteers, with the future aim of using this technique to ...[more]

PMID: 29996777

Similar Datasets

Project description:Purpose:An increase in resting motor threshold (RMT), prolonged cortical silent period duration (CSP), and reduced short-latency afferent inhibition (SAI), confirmed with previous transcranial magnetic stimulation (TMS), suggest decreased cortical excitability in obstructive sleep apnea syndrome (OSAS). The present study included MRI of OSAS patients for navigated TMS assessment of the RMT, as an index of the threshold for corticospinal activation at rest, and SAI as an index of cholinergic neurotransmission. We hypothesize to confirm findings on SAI and RMT with adding precision in the targeting of motor cortex in OSAS. Subjects and Methods:After acquiring head MRIs for 17 severe right-handed OSAS and 12 healthy subjects, the motor cortex was mapped with nTMS to assess the RMT and SAI, with motor evoked potentials (MEPs) recorded from the abductor-pollicis brevis (APB) muscle. The 120%RMT intensity was used for the SAI by a paired-pulse paradigm in which the electrical stimulation to the median nerve is followed by magnetic stimulation of the motor cortex at inter-stimulus intervals (ISIs) of 18-28 ms (ISIs18-28). The SAI control condition included a recording of MEPs without peripheral stimulation. Latency and amplitude of MEP at RMT at 120%RMT for eleven different at ISIs18-28 were analyzed. Results:The study showed a significantly lower percentage deviation of MEP amplitude at ISIs(18-28ms) from the control condition between OSAS and healthy subjects (U=44.0, p=0.01). The intensity of stimulation at RMT was significantly higher in OSAS subjects (U=55.0, p=0.04*). Correlation analysis showed that BMI significantly negatively correlated (?=-0.47) with MEP amplitude percentage deviation in OSAS patients. Conclusion:The nTMS study results in increased RMT, and reduced cortical afferent inhibition in OSAS patients for SAI at ISIs18-28, confirming previous findings of impaired cortical afferent inhibition in OSAS. Future nTMS studies are desirable to elucidate the role of RMT and SAI in diagnostics and treatment of OSAS, and to elucidate the usefulness of nTMS in OSAS research.

Dataset Information

Mapping visuospatial attention: the greyscales task in combination with repetitive navigated transcranial magnetic stimulation.

Background

Results

Publications

Mapping visuospatial attention: the greyscales task in combination with repetitive navigated transcranial magnetic stimulation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure