Barriers to patient recruitment in a poststroke neurorehabilitation multicenter trial in Brazil.

There is a high demand for stroke rehabilitation in the Brazilian public health system, but most studies that have addressed rehabilitation for unilateral spatial neglect (USN) after stroke have been performed in high-income countries. Therefore, the aim of this study was to analyze USN patient recruitment in a multicenter noninvasive brain stimulation clinical trial performed in Brazil and to provide study design recommendations for future studies. We evaluated the reasons for exclusion of patients from a multicenter, randomized, double-blinded clinical trial of rehabilitation of USN patients after stroke. Clinical and demographic variables were compared between the included and excluded patients. A descriptive statistical analysis was performed. Only 173 of the 1953 potential neglect patients (8.8%) passed the initial screening. After screening evaluation, 87/173 patients (50.3%) were excluded for clinical reasons. Cognitive impairment led to the exclusion of 21/87 patients (24.1%). Low socioeconomic status led to the exclusion of 37/173 patients (21.4%). Difficulty obtaining transportation to access treatment was the most common reason for their exclusion (16/37 patients, 43.3%). The analyzed Brazilian institutions have potential for conducting studies of USN. The recruitment of stroke survivors with USN was restricted by the study design and limited financial support. A history of cognitive impairment, intracranial stenting or craniectomy, and lack of transportation were the most common barriers to participating in a multicenter noninvasive brain stimulation trial among patients with USN after stroke.

Barriers to patient recruitment in a poststroke neurorehabilitation multicenter trial in Brazil

There is a high demand for stroke rehabilitation in the Brazilian public health system, but most studies that have addressed rehabilitation for unilateral spatial neglect (USN) after stroke have been performed in high-income countries. Therefore, the aim of this study was to analyze USN patient recruitment in a multicenter noninvasive brain stimulation clinical trial performed in Brazil and to provide study design recommendations for future studies. We evaluated the reasons for exclusion of patients from a multicenter, randomized, double-blinded clinical trial of rehabilitation of USN patients after stroke. Clinical and demographic variables were compared between the included and excluded patients. A descriptive statistical analysis was performed. Only 173 of the 1953 potential neglect patients (8.8%) passed the initial screening. After screening evaluation, 87/173 patients (50.3%) were excluded for clinical reasons. Cognitive impairment led to the exclusion of 21/87 patients (24.1%). Low socioeconomic status led to the exclusion of 37/173 patients (21.4%). Difficulty obtaining transportation to access treatment was the most common reason for their exclusion (16/37 patients, 43.3%). The analyzed Brazilian institutions have potential for conducting studies of USN. The recruitment of stroke survivors with USN was restricted by the study design and limited financial support. A history of cognitive impairment, intracranial stenting or craniectomy, and lack of transportation were the most common barriers to participating in a multicenter noninvasive brain stimulation trial among patients with USN after stroke.

Models to Tailor Brain Stimulation Therapies in Stroke.

A great challenge facing stroke rehabilitation is the lack of information on how to derive targeted therapies. As such, techniques once considered promising, such as brain stimulation, have demonstrated mixed efficacy across heterogeneous samples in clinical studies. Here, we explain reasons, citing its one-type-suits-all approach as the primary cause of variable efficacy. We present evidence supporting the role of alternate substrates, which can be targeted instead in patients with greater damage and deficit. Building on this groundwork, this review will also discuss different frameworks on how to tailor brain stimulation therapies. To the best of our knowledge, our report is the first instance that enumerates and compares across theoretical models from upper limb recovery and conditions like aphasia and depression. Here, we explain how different models capture heterogeneity across patients and how they can be used to predict which patients would best respond to what treatments to develop targeted, individualized brain stimulation therapies. Our intent is to weigh pros and cons of testing each type of model so brain stimulation is successfully tailored to maximize upper limb recovery in stroke.

Migraine and motion sickness independently contribute to visual discomfort.

The objective of this study was to evaluate, in patients with migraine and healthy volunteers, with and without a history of motion sickness, the degree of discomfort elicited by drifting striped patterns. Eighteen healthy volunteers (HV) and 30 migraine patients participated in the study. Discomfort was greater in migraine patients than in HV, and in individuals with a history of motion sickness than in those without, but the effect of history of migraine was independent of history of motion sickness. Generalized Estimating Equations models for binary correlated data revealed that these differences did not depend on levels of duty cycle, spatial and temporal frequencies. Visual discomfort in migraine patients was associated with worse performance. There was a significant correlation between median degree of discomfort across conditions and number of migraine attacks in the past month. Discomfort to drifting striped patterns may be related to central sensitization in migraine patients.

Mapping of direction and muscle representation in the human primary motor cortex controlling thumb movements.

Larger body parts are somatotopically represented in the primary motor cortex (M1), while smaller body parts, such as the fingers, have partially overlapping representations. The principles that govern the overlapping organization of M1 remain unclear. We used transcranial magnetic stimulation (TMS) to examine the cortical encoding of thumb movements in M1 of healthy humans. We performed M1 mapping of the probability of inducing a thumb movement in a particular direction and used low intensity TMS to disturb a voluntary thumb movement in the same direction during a reaction time task. With both techniques we found spatially segregated representations of the direction of TMS-induced thumb movements, thumb flexion and extension being best separated. Furthermore, the cortical regions corresponding to activation of a thumb muscle differ, depending on whether the muscle functions as agonist or as antagonist for flexion or extension. In addition, we found in the reaction time experiment that the direction of a movement is processed in M1 before the muscles participating in it are activated. It thus appears that one of the organizing principles for the human corticospinal motor system is based on a spatially segregated representation of movement directions and that the representation of individual somatic structures, such as the hand muscles, overlap.

Intracranial vertebral artery dissection presenting as subarachnoid hemorrhage: successful endovascular treatment.

INTRODUCTION: Intracranial vertebral artery dissection is a rare condition which may present as subarachnoid hemorrhage. In this situation, treatment is controversial. CASE REPORT: A case of intracranial right vertebral artery dissection in a 55-year-old woman presenting with subarachnoid hemorrhage is reported. The patient underwent therapeutic occlusion of the dissected artery through microcatheterization using pushing detachable platinum microcoils and had a good outcome. At this moment, the patient has a normal neurologic examination and a control digital subtraction angiography 1 year after the procedure showed an occluded right vertebral artery at V3; there was retrograde flow in the right intracranial vertebral artery up to the origin of a meningeal branch; the artery was thin and had mural irregularities, without any evidence of aneurismatic dilatation. DISCUSSION: We review the literature and discuss the role of endovascular therapy and other therapeutic options in the treatment of this condition.