Suellen Marinho Andrade

Visual contrast sensitivity in patients with impairment of functional independence after stroke.

BackgroundStroke has been considered a serious public health problem in many countries, accounting for complex disorders involving perception, such as visual, cognitive and functional deficits. The impact of stroke on the visual perception of individuals with impairments in functional independence was investigated.MethodsWe measured changes in functional independence and visual function in 40 patients with stroke (M = 52.3, SD = 0.65) and 10 controls (M = 52.5, SD = 0.66). The patients were divided into four subgroups following the Barthel Index (Group A: 20–35, serious dependence; Group B: 40–55, moderate dependence; Group C: 60–95, mild dependence; and Group D: 100 points, independence). Visual function was evaluated using the Contrast Sensitivity Function (CSF). The contrast threshold was measured using a temporal, two-alternative, forced-choice psychophysical method.ResultsThe results show significant differences in CSF between healthy volunteers and patients with stroke (F (1.56) = 151.2, p < 0.001) for all frequencies (F (2.56) = 125.96, p < 0.001). The results also show that patients with low functional independence had lower contrast sensitivity than those with greater functional independence (F (3.56) = 344.82, p < 0.001).ConclusionsAn association exists between CSF and a worsening in the functional potential for performing daily living activities. Our results suggest that the CSF can be used as a diagnostic tool to analyze visual function associated with deficits in functional independence after stroke. These findings should be considered across the continuum of care for these patients.

Detection of spatial frequency in brain-damaged patients: influence of hemispheric asymmetries and hemineglect

Hemispheric specialization for spatial frequency processing was investigated by measuring the contrast sensitivity curves of sine-wave gratings in 30 left or right brain-damaged patients using different spatial frequencies compared with healthy participants. The results showed that left brain-damaged patients were selectively impaired in processing high frequencies, whereas right brain-damaged patients were more impaired in the processing low frequencies, regardless of the presence of visuo-spatial neglect. These visual processing results can be interpreted in terms of spatial frequency discrimination, with both hemispheres participating in this process in different ways.

Transcranial direct current stimulation over the primary motor vs prefrontal cortex in refractory chronic migraine: A pilot randomized controlled trial

Although transcranial direct current stimulation (tDCS) represents a therapeutic option for the prophylaxis of chronic migraine, the target area for application of the electrical current to the cortex has not yet been well established. Here we sought to determine whether a treatment protocol involving 12 sessions of 2mA, 20min anodal stimulation of the left primary motor (M1) or dorsolateral prefrontal cortex (DLPFC) could offer clinical benefits in the management of pain from migraine. Thirteen participants were assessed before and after treatment, using the Headache Impact Test-6, Visual Analogue Scale and Medical Outcomes Study 36 - Item Short - Form Health Survey. After treatment, group DLPFC exhibited a better performance compared with groups M1 and sham. On intragroup comparison, groups DLPFC and M1 exhibited a greater reduction in headache impact and pain intensity and a higher quality of life after treatment. No significant change was found in group sham. The participants in group M1 exhibited more adverse effects, especially headache, heartburn, and sleepiness, than did those in the other two groups. Transcranial direct current stimulation is a safe and efficacious technique for treating chronic migraine. However, it should be kept in mind that the site of cortical stimulation might modulate the patients response to treatment.

Colour discrimination thresholds in type 1 Bipolar Disorder: a pilot study

Although some studies have reported perceptual changes in psychosis, no definitive conclusions have been drawn about visual disturbances that are related to bipolar disorder (BPD). The purpose of the present study was to evaluate colour vision in BPD patients. Data were recorded from 24 participants: healthy control group (n = 12) and type 1 BPD group (n = 12). The participants were 20–45 years old and they were free from neurological disorders and identifiable ocular disease and had normal or corrected-to-normal visual acuity. Colour discrimination was evaluated using the Lanthony D-15d, Trivector and Ellipse tests, using a psychophysical forced-choice method. The relationship of visual measures to mood state and cognitive function was also investigated. The results showed that BPD patients had higher colour discrimination thresholds in the D15d (p < 0.001), Trivector (p < 0.001) and Ellipse (p < 0.01) tests compared with healthy controls. Linear regression analysis showed that mood state was related to colour discrimination. BPD individuals were not impaired in cognitive tasks. The present study provided new evidence of potential links between type 1 BPD and visual processing impairments. This research suggests a new direction for studies and the need for research in this field of study.

Construção e evidências psicométricas de uma escala de avaliação da percepção visual

Este estudo teve como objetivo construir e conhecer os parâmetros psicometricos de um instrumento para analise da percepcao visual de adultos. Para a construcao da escala participaram 295 adultos saudaveis, sem deficits cognitivos ou perceptivo-visuais. Nesta etapa foi formulada uma escala tetrafatorial constituida por 20 itens que avaliam quatro dimensoes referentes a percepcao visual: constância da forma, figura-fundo, posicao e relacao espacial. Para obter evidencias de validade foi utilizada uma amostra de 183 voluntarios com boa saude fisica e mental e acuidade visual normal ou corrigida. Os dados obtidos relatam a existencia de concordância interjuizes, adequacao semântica e significância no teste-reteste do instrumento. Os coeficientes de fidedignidade variaram de 0,84 a 0,93. Os quatro fatores esperados foram encontrados, cada um contendo 5 itens, e juntos explicaram 57,52% da variância do constructo. O instrumento apresentou parâmetros psicometricos adequados, o que pode justificar sua utilidade em pesquisas basicas e na pratica clinica.

Constraint-Induced Movement Therapy Combined with Transcranial Direct Current Stimulation over Premotor Cortex Improves Motor Function in Severe Stroke: A Pilot Randomized Controlled Trial

Objective. We compared the effects of transcranial direct current stimulation at different cortical sites (premotor and motor primary cortex) combined with constraint-induced movement therapy for treatment of stroke patients. Design. Sixty patients were randomly distributed into 3 groups: Group A, anodal stimulation on premotor cortex and constraint-induced movement therapy; Group B, anodal stimulation on primary motor cortex and constraint-induced movement therapy; Group C, sham stimulation and constraint-induced movement therapy. Evaluations involved analysis of functional independence, motor recovery, spasticity, gross motor function, and muscle strength. Results. A significant improvement in primary outcome (functional independence) after treatment in the premotor group followed by primary motor group and sham group was observed. The same pattern of improvement was highlighted among all secondary outcome measures regarding the superior performance of the premotor group over primary motor and sham groups. Conclusions. Premotor cortex can contribute to motor function in patients with severe functional disabilities in early stages of stroke. This study was registered in ClinicalTrials.gov database (NCT 02628561).

Effects of different montages of transcranial direct current stimulation on the risk of falls and lower limb function after stroke

Abstract Background: Stroke is associated with high rates of falling and severe impairment of lower limb in patients who survive. Objective: The aim of this study was to analyze the effectiveness of different montages of transcranial direct current stimulation (tDCS) on reducing falls and on lower limb function after acute stroke. Methods: Sixty participants with acute stroke were randomly allocated into four groups with different electrode’s setups: anodal, cathodal, bilateral and sham tDCS. Each patient received 10 stimulation sessions (five consecutive days for two weeks). Four Square Step Test, Occurrence of Falling Index, Overall Stability Index, Falls Efficacy Scale – International, Berg Balance Scale, Six-minute walk test and Sit to Stand Test were measured at baseline, post-treatment, and at one- and three-month follow-up. Results: At baseline, no differences between the groups in terms of clinical and demographic characteristics were found. However, after treatment and during follow up, all the groups that received active stimulation showed greater reduction in the risk of falls and improved performance of the lower limb’s motor skills when compared to the sham group. No significant differences were found between the three types of active montages in relation to the risk of falling. In relation to lower limb function, bilateral stimulation provided a higher improvement when compared to anodal and cathodal tDCS. Conclusions: This is the first trial with different setups of tDCS on acute stroke patients. tDCS presents as an effective treatment strategy in reducing the risk of falls and improving lower limb function after a stroke. ClinicalTrials.gov (NCT 02422173).

Stroke Treatment Associated with Rehabilitation Therapy and Transcranial DC Stimulation (START-tDCS): a study protocol for a randomized controlled trial

BackgroundTraditional treatment for motor impairment after stroke includes medication and physical rehabilitation. The transcranial direct current stimulation associated with a standard physical therapy program may be an effective therapeutic alternative for these patients.MethodsThis study is a sham-controlled, double-blind, randomized clinical trial aiming to evaluate the efficacy of transcranial direct current stimulation in activities of daily living and motor function post subacute stroke. In total there will be 40 patients enrolled, diagnosed with subacute, ischemic, unilateral, non-recurring stroke. Participants will be randomized to two groups, one with active stimulation and the other with a placebo current. Patients and investigators will be blinded. Everyone will receive systematic physical therapy, based on constraint-induced movement therapy. The intervention will be applied for 10 consecutive days. Patients will undergo three functional assessments: at baseline, week 2, and week 4. Neuropsychological tests will be performed at baseline and week 4. Adverse effects will be computed at each session. On completion of the baseline measures, randomization will be conducted using random permuted blocks. The randomization will be concealed until group allocation.DiscussionThis study will investigate the combined effects of transcranial direct current stimulation and physical therapy on functional improvement after stroke. We tested whether the combination of these treatments is more effective than physical therapy alone when administered in the early stages after stroke.Trial registrationNCT02156635 - May 30, 2014. Randomization is ongoing (40 participants randomized as of the end of December 2015).

Cognition-enhancing effect of vagus nerve stimulation on refractory epilepsy secondary to lissencephaly: A case report.

A 19-year-old White Brazilian female with epilepsy was evaluated after failing to become seizure free even with the use of antiepileptic drugs. Due to difficulty of communication, a neurocognitive assessment indicated the presence of attenuated delayed psychomotor and cognitive development. In addition to refractory epilepsy, with 30 seizures/day, a clinical diagnosis of lissencephaly was confirmed after MRI and electroencephalography monitoring. The intervention for reducing the seizures consisted of vagus nerve stimulation (VNS). After 30 days, relatives reported significant cognitive and behavioral improvement, such as reduced aggression and impulsivity, which lasted 60 and 90 days (follow-up). Furthermore, there was an improvement in psychomotor and self-care capacity. At this time, there was a significant reduction in seizures from about 30 seizures/month to 5 seizures/month. This case highlights the significant cognitive improvement even before the reduction of seizures in a patient with intractable drug-resistant epilepsy after VNS implant. Even though this is a rare case, the use of VNS in lissencephaly may be a potential tool for cognitive and behavioral improvement.

Adjuvant transcranial direct current stimulation for treating Alzheimer’s disease. A case study

ABSTRACT We report the case of a 73-year-old male patient with Alzheimers disease who underwent 10-daily transcranial direct current stimulation (tDCS) sessions. tDCS was applied over the left dorsolateral prefrontal cortex as an adjuvant to the traditional treatment that the patient was receiving, which consisted of anticholinergic medication and cognitive training. The data were qualitatively analyzed and are presented in an analytic and structured form. The effects on cognitive performance were evaluated using the Alzheimers Disease Assessment Scale-cognitive subscale as the primary outcome. Secondary outcomes were assessed with a set of tests consisting of the Neuropsychiatric Inventory, the Blessed Dementia Scale and the Disability Assessment for Dementia. The data obtained revealed that the application of tDCS had a stabilizing effect on overall patient cognitive function and led to improved performance on all the secondary outcome tests. These preliminary results indicate that tDCS is a potential adjuvant therapeutic tool for cognitive rehabilitation in Alzheimers disease .