Protocol for mapping of the supplementary motor area using repetitive navigated transcranial magnetic stimulation.

Background: Damage to the supplementary motor area (SMA) can lead to impairments of motor and language function. A detailed preoperative mapping of functional boarders of the SMA could therefore aid preoperative diagnostics in these patients.

Objective: The aim of this study was the development of a repetitive nTMS protocol for non-invasive functional mapping of the SMA while assuring effects are caused by SMA rather than M1 activation.

Brain Response Induced with Paired Associative Stimulation Is Related to Repetition Suppression of Motor Evoked Potential.

Repetition suppression (RS), i.e., the reduction of neuronal activity upon repetition of an external stimulus, can be demonstrated in the motor system using transcranial magnetic stimulation (TMS).

Thalamic Atrophy Predicts 5-Year Disability Progression in Multiple Sclerosis.

Thalamus is among the first brain regions to become atrophic in multiple sclerosis (MS). We studied whether thalamic atrophy predicts disability progression at 5 years in a cohort of Finnish MS patients. Global and regional brain volumes were measured from 24 newly diagnosed relapsing MS (RMS) patients 6 months after initiation of therapy and from 36 secondary progressive MS (SPMS) patients.

Interaction between repetition suppression in motor activation and long-interval intracortical inhibition.

Repetition suppression (RS) is the adaptation of the neural activity in response to a repeated external stimulus. It has been proposed that RS occurs at the thalamo-cortical level, hence activating a feedback loop to the cortex in order to counteract with the repeated motor cortical activation. In this study, to elucidate the common modulators between the RS and the inhibitory/facilitatory cortical networks, two TMS paradigms were applied, i.

Thalamic Atrophy Without Whole Brain Atrophy Is Associated With Absence of 2-Year NEDA in Multiple Sclerosis.

To study which brain volume measures best differentiate early relapsing MS (RMS) and secondary progressive MS (SPMS) patients and correlate with disability and cognition. To test whether isolated thalamic atrophy at study baseline correlates with NEDA (no evidence of disease activity) at 2 years. Total and regional brain volumes were measured from 24 newly diagnosed RMS patients 6 months after initiation of therapy and 2 years thereafter, and in 36 SPMS patients.

Cortical Inhibition of Face and Jaw Muscle Activity and Discomfort Induced by Repetitive and Paired-Pulse TMS During an Overt Object Naming Task.

Modulatory effects of transcranial magnetic stimulation (TMS) strongly depend on the stimulation parameters. Here, we compared the immediate, task-locked inhibitory effects on speech-related muscles and the tolerability of different TMS protocols during a language production task. Repetitive TMS (rTMS) and paired-pulse TMS (PP) were applied in 13 healthy subjects over the primary motor cortex (M1) during a finger-tapping/tongue-twisting tasks.

Individual characterization of fast intracortical facilitation with paired biphasic-wave transcranial magnetic stimulation.

We characterized the short-interval intracortical facilitation (SICF) via modulation of transcranial magnetic stimulation (TMS) induced motor evoked potentials (MEPs) using paired-pulse stimulation, and analyzed the interactions with known SICF I-wave behavior. The objective was to optimize individual SICF to enhance TMS effects in motor mapping and therapeutic stimulations. We applied navigated TMS in nine healthy volunteers to study SICF.

Efficient Mapping of the Motor Cortex with Navigated Biphasic Paired-Pulse Transcranial Magnetic Stimulation.

Navigated transcranial magnetic stimulation (nTMS) can be applied to locate cortical muscle representations. Usually, single TMS pulses are targeted to the motor cortex with the help of neuronavigation and by measuring motor evoked potential (MEP) amplitudes from the peripheral muscles. The efficacy of single-pulse TMS to induce MEPs has been shown to increase by applying facilitatory paired-pulse TMS (ppTMS).

Modulation of motor cortical excitability with auditory stimulation.

Loud sounds have been demonstrated to increase motor cortex excitability when transcranial magnetic stimulation (TMS) is synchronized with auditory evoked N100 potential measured from electroencephalography (EEG). The N100 potential is generated by an afferent response to sound onset and feature analysis, and upon novel sound it is also related to the arousal reaction. The arousal reaction is known to originate from the ascending reticular activating system of the brain stem and to modulate neuronal activity throughout the central nervous system.

Transcranial magnetic stimulation modulation of corticospinal excitability by targeting cortical I-waves with biphasic paired-pulses.

Background: Transcranial magnetic stimulation (TMS) induced I-wave behavior can be demonstrated at neuronal population level using paired-pulses and by observing short-interval cortical facilitation (SICF). Advancements in stimulator technology have made it possible to apply biphasic paired-pulses to induce SICF.

Objective: Our aim was to characterize the SICF I-wave interaction by biphasic paired-pulses with the ultimate objective to enhance TMS effects via SICF in various TMS-applications.

Infrared thermography reveals effect of working posture on skin temperature in office workers.

Introduction: Musculoskeletal symptoms related to using traditional computer workstations are common. Quantitative methods for measuring muscle stress and strain are needed to improve ergonomics of workstations. We hypothesize that infrared thermography (IRT) is suited for this purpose.

Protocol for motor and language mapping by navigated TMS in patients and healthy volunteers; workshop report.

Introduction: Navigated transcranial magnetic stimulation (nTMS) is increasingly used for preoperative mapping of motor function, and clinical evidence for its benefit for brain tumor patients is accumulating. In respect to language mapping with repetitive nTMS, literature reports have yielded variable results, and it is currently not routinely performed for presurgical language localization. The aim of this project is to define a common protocol for nTMS motor and language mapping to standardize its neurosurgical application and increase its clinical value.

Increased Inhibition in Non-Primary Motor Areas of String-Instrument Players: A Preliminary Study with Paired-Pulse Transcranial Magnetic Stimulation.

The muscle representations in non-primary motor area (NPMA) are located in the dorsal premotor area (PMd) and in the border region between the premotor area and the supplementary motor area (SMA). We characterized the plasticity of intracortical inhibitory and excitatory circuits in muscle representations in primary motor cortex (M1) and in NPMA related to acquired fine motor skills. We compared local cortical inhibition and facilitation balance in M1 and in NPMA between control subjects ( = 6) and right-handed string-instrument players ( = 5).

Motor plasticity after extra-intracranial bypass surgery in occlusive cerebrovascular disease.

Objective: To explore plasticity in patients scheduled for extra-intracranial bypass surgery due to unilateral symptomatic occlusive cerebrovascular disease via navigated transcranial magnetic stimulation.

Methods: In this observational study, patients were allocated to different substudies and examined before and 3 months after operation. (1) Corticospinal excitability was determined via identification of the resting motor threshold.

Facilitatory effect of paired-pulse stimulation by transcranial magnetic stimulation with biphasic wave-form.

Transcranial magnetic stimulation (TMS) is used to probe corticospinal excitability by stimulating the motor cortex. Our aim was to enhance the effects of biphasic TMS by coupling a suprathreshold test pulse and a following subthreshold priming pulse to induce short-interval intracortical facilitation (SICF), which is conventionally produced with monophasic TMS. Biphasic TMS could potentially induce the SICF effect with better energy-efficiency and with lower stimulus intensities.

Longitudinal study on modulated corticospinal excitability throughout recovery in supratentorial stroke.

Corticospinal excitability (CSE) is modulated by stroke-induced lesions affecting the brain. This modulation is known to be dependent on the timing of the evaluation, and strongest abnormalities are often found in the acute stage. Our study aimed to characterize changes in CSE asymmetry between the affected and the unaffected hemisphere (AH and UH) during the first month after stroke onset and at 6 month follow-up.

Midbrain-to-pons ratio in autopsy-confirmed progressive supranuclear palsy: replication in an independent cohort.

Recent neuropathologically confirmed clinical data suggest that the midbrain-to-pons ratio, as calculated from conventional brain MRI, has high specificity and sensitivity for the diagnosis of progressive supranuclear palsy (PSP). Here, we aimed to replicate these findings in an independent autopsy-confirmed cohort of 6 PSP patients and 23 non-PSP patients. Patients with confirmed PSP had clearly lower midbrain-to-pons ratios compared to non-PSP patients (p < 0.

Input-Output Characteristics of Late Corticospinal Silent Period Induced by Transcranial Magnetic Stimulation.

Purpose: Corticospinal silent period (SP) may be interrupted by a burst of muscle activity followed by a second (late) SP, generally assumed to be a continuation from the primary SP. Our objective was to characterize the input-output behavior of the late SP.

Methods: Transcranial magnetic stimulation was applied on the cortical representation area of the right-hand muscles of 12 healthy subjects.

Frontobasilar fractures: proposal for image reviewing algorithm.

Objective: The aim of this study was to develop and test the utility of a novel systematic protocol to analyze CT images of patients with trauma in the anterior cranial base and upper midface.

Material And Methods: The radiological data and primary reports of 27 consecutive patients with a frontal skull base fracture treated in two tertiary care hospitals from 2007 to 2011 were scrutinized. A novel algorithm for systematic image reviewing was used to assess the CT images and the findings were compared with the primary radiological reports.

[Rare causes of progressive paraparesis].

Progressive paraparesis is a neurosurgical and neurological emergency. The patient's neurological outcome relies on the course of the diagnostics and treatment. Physicians having experience in emergency medicine are familiar with the typical etiologies of paraparesis.

Long-term plasticity may be manifested as reduction or expansion of cortical representations of actively used muscles in motor skill specialists.

Our aim was to study long-term plasticity in the organization of cortical muscle representations due to extensive motor training for different skills. We were especially interested in whether skill-specific demands on independent hand muscle movements and synchronous leg muscle movements are reflected differently in the reorganization of muscle representations. We used navigated transcranial magnetic stimulation to estimate the size of cortical representations of opponens pollicis, abductor digiti minimi, and tibialis anterior muscles in five string instrument players, five figure skaters, and five controls.

Nitroglycerin-induced changes in facial skin temperature: 'cold nose' as a predictor of headache?

Nitroglycerin (NTG) often induces headaches when used to treat cardiac diseases. Such property of NTG has been widely used in modelling of migraine-like headaches. However, background reasons, predisposing to the development of NTG-headache, are less studied.

First preoperative functional mapping via navigated transcranial magnetic stimulation in a 3-year-old boy.

Preoperative functional mapping in children younger than 5 years old remains a challenge. Awake functional MRI (fMRI) is usually not an option for these patients. Except for a description of passive fMRI in sedated patients and magnetoencephalography, no other noninvasive mapping method has been reported as a preoperative diagnostic tool in children.

tDCS possibly stimulates glial cells.

Objective: Explore the possibility that transcranial direct current stimulation (tDCS) of the brain affects glial cells.

Methods: Cable theory is used to estimate roughly transmembrane potential in neurons and glial cells. tDCS is additionally compared to neuronal stimulation techniques for which the mechanisms are well known.