Updating beliefs beyond the here-and-now: the counter-factual self in anosognosia for hemiplegia.

The syndrome of anosognosia for hemiplegia, or the lack of awareness for one's paralysis following right hemisphere stroke, can provide unique insights into the neurocognitive mechanisms of self-awareness. Yet it remains unclear whether anosognosia for hemiplegia is a modality-specific deficit of sensorimotor monitoring, or whether domain-general processes of attention and belief-updating converge to cause anosognosia for hemiplegia. Using a Bayesian learning framework, we formalized and empirically investigated the hypothesis that failures to update anosognosic beliefs can be explained by abnormalities in the relative uncertainty (i.

Exploratory Randomized Double-Blind Placebo-Controlled Trial of Botulinum Therapy on Grasp Release After Stroke (PrOMBiS).

. OnabotulinumtoxinA injections improve upper-limb spasticity after stroke, but their effect on arm function remains uncertain. .

Theta burst magnetic stimulation over the pre-supplementary motor area improves motor inhibition.

Background: Stopping an ongoing motor response or resolving conflict induced by conflicting stimuli are associated with activation of a right-lateralized network of inferior frontal gyrus (IFG), pre-supplementary motor area (pre-SMA) and subthalamic nucleus (STN). However, the roles of the right IFG and pre-SMA in stopping a movement and in conflict resolution remain unclear. We used continuous theta burst stimulation (cTBS) to examine the involvement of the right IFG and pre-SMA in inhibition and conflict resolution using the conditional stop signal task.

Inhibitory theta burst stimulation of affected hemisphere in chronic stroke: a proof of principle, sham-controlled study.

Non-invasive brain stimulation is presently being tested as a potential therapeutic intervention for stroke rehabilitation. Following a model of competitive interactions between the hemispheres, these interventions aim to increase the plasticity of stroke hemisphere by applying either excitatory protocols to the damaged hemisphere or inhibitory protocols to the non-stroke hemisphere. Here we test the safety and feasibility of using an inhibitory protocol on the stroke hemisphere to improve the response to conventional therapy via a homeostatic increase in learning capacity.

Theta burst stimulation in the rehabilitation of the upper limb: a semirandomized, placebo-controlled trial in chronic stroke patients.

Background: Noninvasive cortical stimulation could represent an add-on treatment to enhance motor recovery after stroke. However, its clinical value, including anticipated size and duration of the treatment effects, remains largely unknown.

Objective: The authors designed a small semi-randomized clinical trial to explore whether long-lasting clinically important gains can be achieved by adding theta burst stimulation (TBS), a form of repetitive transcranial magnetic stimulation (TMS), to a rehabilitation program for the hand.

Age-related changes in causal interactions between cortical motor regions during hand grip.

Brain activity during motor performance becomes more widespread and less lateralized with advancing age in response to ongoing degenerative processes. In this study, we were interested in the mechanism by which this change in the pattern of activity supports motor performance with advancing age. We used both transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to assess age related changes in motor system connectivity during isometric hand grip.

A distinctive pattern of cortical excitability in patients with the syndrome of dystonia and cerebellar ataxia.

Objective: The syndrome of dystonia and cerebellar ataxia (DYTCA) is a recently described condition where cervical dystonia and mild cerebellar ataxia are the major clinical features. Here we attempted to explore the pathophysiology of this condition by comparing measurements of cortical excitability between patients with DYTCA, typical primary dystonia and healthy controls.

Methods: Motor threshold, active MEP recruitment and CSP duration were measured and the excitability of the intracortical inhibitory and excitatory circuits was assessed at rest using a paired pulse protocol.

Standardizing the intensity of upper limb treatment in rehabilitation medicine.

Objective: To describe a treatment protocol for the upper limb that standardizes intensity of therapy input regardless of the severity of presentation.

Design: The protocol is described (Part 1) and feasibility and effect explored (Part 2).

Subjects: Participants (n = 11) had a single ischaemic stroke in the middle cerebral artery territory more than one year previously, and had residual weakness of the hand with some extension present at the wrist and the ability to grasp.

Distinguishing SWEDDs patients with asymmetric resting tremor from Parkinson's disease: a clinical and electrophysiological study.

Approximately 10% of patients diagnosed clinically with early Parkinson's disease (PD) have normal dopaminergic functional imaging (Scans Without Evidence of Dopaminergic Deficit [SWEDDs]). An important subgroup of SWEDDs are those with asymmetric rest tremor resembling parkinsonian tremor. Clinical and pathophysiological features which could help to distinguish SWEDDs from PD have not been explored.

Deficits underlying impaired visually triggered step adjustments in mildly affected stroke patients.

Background: The ability to make step adjustments while walking is often impaired following a stroke, but the basic sensorimotor control deficits responsible have not been established.

Objective: To identify these deficits in Patients who have recovered from stroke leaving only mild lower limb impairment.

Methods: Ten stroke and 10 age-matched control patients stepped onto an illuminated rectangle.

Abnormal motor cortex plasticity in premanifest and very early manifest Huntington disease.

Background: Cognition is affected early in Huntington disease (HD), and in HD animal models there is evidence that this reflects abnormal synaptic plasticity. The authors investigated whether there is any evidence for abnormal synaptic plasticity using the human motor cortex-rTMS model and, if so, if there is any difference between premanifest HD gene carriers and very early manifest HD patients or any relationship with ratings of the severity of motor signs.

Methods: Fifteen HD gene carriers (seven premanifest, eight very early manifest) and 14 control participants were given a continuous train of 100 bursts of theta burst stimulation (cTBS: three pulses at 50 Hz and 80% AMT repeated every 200 ms).

What can man do without basal ganglia motor output? The effect of combined unilateral subthalamotomy and pallidotomy in a patient with Parkinson's disease.

We have studied motor performance in a man with Parkinson's disease (PD) in whom thermolytic lesions of the left subthalamic and left globus pallidus nuclei interrupted the basal ganglia (BG)-thalamo-cortical motor circuit in the left hemisphere. This allowed us to study remaining motor capabilities in the absence of aberrant BG activity typical of PD. Movements of the left arm were slow and parkinsonian whereas movement speed and simple reaction times (RT) of the right (operated) arm were within the normal range with no obvious deficits in a range of daily life activities.

Recurrent stroke: where do we stand with the secondary prevention of noncardioembolic ischaemic strokes?

Strokes recur in 6-20% of the patients, most commonly within the first year; after a TIA or minor stroke; most recurrences will occur within the first 90 days. Our ability to identify patients at high risk is poor and most recurrent strokes cannot be explained by traditional risk factors. In 30-45% of the cases the second stroke will be of a different subtype.

A common polymorphism in the brain-derived neurotrophic factor gene (BDNF) modulates human cortical plasticity and the response to rTMS.

The brain-derived neurotrophic factor gene (BDNF) is one of many genes thought to influence synaptic plasticity in the adult brain and shows a common single nucleotide polymorphism (BDNF Val66Met) in the normal population that is associated with differences in hippocampal volume and episodic memory. It is also thought to influence possible synaptic changes in motor cortex following a simple motor learning task. Here we extend these studies by using new non-invasive transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS) techniques that directly test the excitability and plasticity of neuronal circuits in human motor cortex in subjects at rest.

Motor cortical physiology in patients and asymptomatic carriers of parkin gene mutations.

Autosomal recessive parkin (PARK2) gene-related parkinsonism may be phenotypically and pathophysiologically distinct from idiopathic Parkinson's disease (PD). Furthermore, asymptomatic subjects carrying a single parkin mutation ("parkin carriers") may show striatal dopaminergic dysfunction and increased cortical movement-related activation. Here, we used transcranial magnetic stimulation (TMS) to study corticospinal and intracortical excitability in manifesting parkin patients and asymptomatic carriers.

Clinical applications of transcranial magnetic stimulation in patients with movement disorders.

Transcranial magnetic stimulation (TMS) is a method of non-invasive brain stimulation that affects the cerebral cortex but not deep structures. In patients with movement disorders the most common application of TMS has been to test the excitability of connections within and among motor areas of the cortex, which has provided useful information on pathophysiology; however, inter-individual variability in the responses has resulted in difficulties in translating this method into a clinically applicable diagnostic use. Repeated stimulation (eg, 1 Hz for 20 min) can result in long-term plastic changes in the motor system, which has led to increased interest in possible therapeutic applications.

In-hospital direct cost of acute ischemic and hemorrhagic stroke in Greece.

Objectives: The geographic inequity and the wide variation in the patterns of care of stroke found across Europe together with the lack of health economics evaluation in Greece led to this prospective study, aiming to provide data on in-hospital direct cost of patients with an acute stroke in Greece, and to identify independent prognostic factors.

Methods: Demographic and clinical data were recorded on 429 consecutive patients with an acute ischemic or hemorrhagic stroke admitted to a tertiary care hospital in Greece during a period of 18 months. The costs incurred were estimated using the official financial charts listing in euro (euro), the real expenditure of all hospital departments.

Neural correlates of age-related changes in cortical neurophysiology.

Functional imaging studies of cortical motor systems in humans have demonstrated age-related reorganisation often attributed to anatomical and physiological changes. In this study we investigated whether aspects of brain activity during a motor task were influenced not only by age, but also by neurophysiological parameters of the motor cortex contralateral to the moving hand. Twenty seven right-handed volunteers underwent functional magnetic resonance imaging whilst performing repetitive isometric right hand grips in which the target force was parametrically varied between 15 and 55% of each subject's own maximum grip force.

The effect of age on task-related modulation of interhemispheric balance.

Normal aging is associated with less lateralised task-related activation of the primary motor cortices. It has been hypothesized, but not tested, that this phenomenon is mediated transcallosaly. We have used Transcranial Magnetic Stimulation to look for age-related changes in interhemispheric inhibition (IHI).

Recurrent stroke: the role of common carotid artery intima-media thickness.

The etiology of recurrent stroke is probably multifactorial and many recurrences remain unexplained by conventional risk factors. The purpose of this study is to investigate if common carotid artery intima-media thickness (CCA-IMT), an established vascular risk factor, can predict recurrence in first-ever stroke survivors. Two hundred and eighty-four consecutive patients with a first-ever ischemic stroke were investigated with carotid ultrasonography and were screened for the first recurrent stroke up to 12 months.

Pattern-specific role of the current orientation used to deliver Theta Burst Stimulation.

Objective: To evaluate the role of current direction on the after-effects of Theta Burst Stimulation (TBS) delivered with a biphasic Magstim 200(2) stimulator.

Methods: Inhibitory (cTBS) and excitatory TBS (iTBS) were delivered over the motor cortex of healthy individuals using reversed and standard current orientations (initial current in the antero-posterior direction) at 80% and 100% of their respective active motor thresholds (AMT). The after-effects on the MEP amplitude were measured for 25 min.

Exploring Theta Burst Stimulation as an intervention to improve motor recovery in chronic stroke.

Objective: To explore the effects of a single session of repetitive Transcranial Magnetic Stimulation, given as Theta Burst Stimulation, on behavioural and physiological measures of hand function in chronic stroke patients.

Methods: Six chronic stroke patients with incomplete recovery of the hand were tested under three conditions: excitatory TBS over the stroke hemisphere (iTBS(SH)), inhibitory TBS (cTBS(IH)) over the intact hemisphere and sham stimulation. Behavioural outcomes included simple and choice reaction time paradigms.

Does brain stimulation after stroke have a future?

Purpose Of Review: Transcranial methods of cortical stimulation can induce long-term changes in excitability of the cerebral cortex in humans and may be useful as therapeutic interventions in stroke rehabilitation.

Recent Findings: Two approaches have been tested: (1) increasing excitability of the cortex in the stroke hemisphere and (2) suppression of the non-stroke hemisphere to reduce potential interference with function of the stroke hemisphere. The interventions have been transcranial direct current stimulation, transcranial magnetic stimulation and implanted epidural stimulation.

F wave study in amyotrophic lateral sclerosis: assessment of balance between upper and lower motor neuron involvement.

Objective: We sought to record significant F wave variable changes in ALS patients having no advanced disease. Furthermore, an interpretation of these F wave abnormalities in the context of upper (UMN) and lower motor neuron (LMN) dysfunction was attempted.

Methods: Standard motor and sensory conduction study was performed to the ulnar nerves of 23 patients with ALS (13 males and 10 females with mean age 67.