Search results for "Transcranial"
showing 10 items of 413 documents
Cortical and subcortical visual event-related potentials to oddball stimuli in rabbits
2000
We applied repetitive transcranial magnetic stimulation (rTMS) in order to induce interference on visuo-spatial perception in 11 healthy subjects. Subjects performed a visuo-spatial task requiring judgements about the symmetry of prebisected lines. Visual stimuli consisted of symmetrically or asymmetrically transected lines, tachystoscopically presented for 50 ms on a computer-monitor. Performance was examined in basal condition and during rTMS trains of 10 stimuli at 25 Hz, delivered through a focal coil over right or left posterior parietal cortex (P5 and P6 sites) and triggered synchronously with visual stimulus. Randomly intermixed sham rTMS trains were employed to control for non-speci…
Effects of High Frequency Repetitive Transcranial Magnetic Stimulation (HF-rTMS) on Delay Discounting in Major Depressive Disorder: An Open-Label Unc…
2019
Background: Delay discounting (DD) refers to the decrease of a present subjective value of a future reward as the delay of its delivery increases. Major depressive disorder (MDD), besides core emotional and physical symptoms, involves difficulties in reward processing. Depressed patients often display greater temporal discounting rates than healthy subjects. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique applied in several countries to adult patients with treatment resistant depression. Studies suggest that this technique can be used to modulate DD, but no trial has assessed its effects on depressed patients. Methods: In this open-label unc…
Comparison of TMS-induced arm acticvation and upper limb functional tests in hemiparetic stroke
2013
Stroke has a major impact in the total cost of healthcare in the Western world as stroke is the most common cause of long-term disability [1]. In attempts to enhance motor recovery after stroke effective treatment strategies have been developed in recent years. Appropriate evaluation of the intervention programs requires comprehensive and accurate assessment of the residual abnormal function. In the present study we compare two well-known clinical functional scoring tests developed for the assessment of hemiparetic upper limb function due to stroke and navigated transcranial magnetic stimulation (nTMS), which measures involuntary target muscle response to cortical stimulation. The aim is to…
Multifocal Repetitive Transcranial Magnetic Stimulation—A Novel Paradigm in Migraine Treatment
2019
Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation method used for analyzing structural and functional interactions in brain, assess cortical reactivity, and map functionally relevant brain regions inducing a controlled current pulse in a defined region of the cortex. From a clinical point of view, TMS has shown promising results in the therapeutic approach in a large number of psychiatric and neurological conditions such as anxiety, depression, OCD, headache disorders—migraine being one of the most encountered, etc. In patients with migraine, the pharmacologic therapy can be divided in abortive and preventive treatment of the attack. Usually the treatment is starte…
Implementation of computed tomography angiography (CTA) and computed tomography perfusion (CTP) in Polish guidelines for determination of cerebral ci…
2021
Background: Brain death/death by neurologic criteria (BD/DNC) guidelines are routinely analyzed, compared and updated in the majority of countries and are later implemented as national criteria. At the same time, extensive works have been conducted in order to unify clinical procedures and to validate and implement new technologies into a panel of ancillary tests. Recently evaluated computed tomography angiography and computed tomography perfusion (CTA/CTP) seem to be superior to traditionally used digital subtraction angiography (DSA), transcranial Doppler (TCD) and cerebral perfusion scintigraphy for diagnosis of cerebral circulatory arrest (CCA). In this narrative review, we would like t…
Neuroplasticity in the Adjustment to Blindness
1999
Loss of vision due to injury to the eyes results in deafferentation of very large areas of the human cortex and poses striking demands on other sensory systems to adjust to blindness in a society that heavily relies on vision. Blind subjects need to extract crucial spatial information from touch and hearing. To accomplish this, plastic trans-modal changes appear to take place by which a larger area of the sensorimotor cortex is devoted to the representation of the reading finger in Braille readers, and parts of the former visual cortex are recruited for the processing of tactile and auditory information.
Illusory contours and specific regions of human extrastriate cortex: evidence from rTMS
2003
Functional magnetic resonance imaging studies showed that perception of illusory contours is associated with extrastriate cortex activation prevailing on the right side. 1 Hz repetitive transcranial magnetic stimulation (rTMS) is able to induce lasting inhibition of cortical activity. The objective of the study was to investigate the role of extrastriate cortex in illusory contour perception inducing 1 Hz rTMS interference in healthy subjects. Eight healthy subjects underwent 1 Hz rTMS (600 pulses) through a figure-of-eight coil over right and left occipital cortex (O1 and O2 of 10/20 EEG system); sham magnetic stimulation on the same sites and right motor cortex rTMS (in three subjects) we…
Mapping of the human visual cortex using image-guided transcranial magnetic stimulation
2002
We describe a protocol using transcranial magnetic stimulation (TMS) to systematically map the visual sensations induced by focal and non-invasive stimulation of the human occipital cortex. TMS is applied with a figure of eight coil to 28 positions arranged in a 2x2-cm grid over the occipital area. A digitizing tablet connected to a PC computer running customized software, and audio and video recording are used for detailed and accurate data collection and analysis of evoked phosphenes. A frameless image-guided neuronavigational device is used to describe the position of the actual sites of the stimulation coils relative to the cortical surface. Our results show that TMS is able to elicit p…
Transcranial Direct Current Stimulation over the Right Inferior Parietal Cortex Reduces Transposition Errors in a Syllabic Reordering Task
2021
Evidence derived from functional imaging and brain-lesion studies has shown a strong left lateralization for language, and a complementary right hemisphere dominance for visuospatial abilities. Nevertheless, the symmetrical functional division of the two hemispheres gives no reason for the complexity of the cognitive operations involved in carrying out a linguistic task. In fact, a growing number of neuroimaging and neurostimulation studies suggest a possible right hemisphere involvement in language processing. The objective of this work was to verify the contribution of the left and right parietal areas in a phonological task. We applied anodal transcranial direct current stimulation (tDCS…
Transkranielle Dopplersonographie bei Kopf-Hals-Tumoren*
1991
Transcranial Doppler ultrasound (TCD) recording is a non-invasive diagnostic procedure for the evaluation of the cerebral collateral flow in patients, in whom therapeutic ligation or resection of the common and/or internal carotid artery is planned. Patients are first examined under resting conditions, and then under manual compression of the ipsilateral carotid artery. Since January 1989, 31 ENT and neurosurgical patients have been examined. In all patients an immediate decrease in flow velocity in the middle cerebral artery (mca) of about 25% to 90% was recorded. In 42.8% of the patients the mca flow velocity reached 90% or more of its value under normal conditions within a short period. …