Lydia Abdul Latif

Neurophysiological and Behavioral Effects of tDCS Combined With Constraint-Induced Movement Therapy in Poststroke Patients

Background. Recovery of motor function after stroke may depend on a balance of activity in the neural network involving the affected and the unaffected motor cortices. Objective. To assess whether transcranial direct current stimulation (tDCS) can increase the training-induced recovery of motor functions. Methods. In an exploratory study, 14 patients with chronic stroke and mean Fugl-Meyer Upper Extremity Motor Assessment of 29 (range = 8-50) entered a double-blind sham-controlled study, aimed to investigate neurophysiological and behavioral effects of bihemispheric tDCS (cathodal stimulation of the unaffected motor cortex and anodal stimulation of the affected motor cortex), combined with constraint-induced movement therapy (CIMT). Results. Patients in both groups demonstrated gains on primary outcome measures, that is, Jebsen Taylor Hand Function Test, Handgrip Strength, Motor Activity Log Scale, and Fugl-Meyer Motor Score. Gains were larger in the active tDCS group. Neurophysiological measurements showed a reduction in transcallosal inhibition from the intact to the affected hemisphere and increased corticospinal excitability in the affected hemisphere only in the active tDCS/CIMT group. Such neurophysiological changes correlated with the magnitude of the behavioral gains. Both groups showed a reduction in corticospinal excitability of the unaffected hemisphere. Conclusions. CIMT alone appears effective in modulating local excitability but not in removing the imbalance in transcallosal inhibition. Bihemispheric tDCS may achieve this goal and foster greater functional recovery.

Effects of motor cortex modulation and descending inhibitory systems on pain thresholds in healthy subjects.

UNLABELLED Pain modulation can be achieved using neuromodulatory tools that influence various levels of the nervous system. Transcranial direct current stimulation (tDCS), for instance, has been shown to reduce chronic pain when applied to the primary motor cortex. In contrast to this central neuromodulatory technique, diffuse noxious inhibitory controls (DNIC) refers to endogenous analgesic mechanisms that decrease pain following the introduction of heterotopic noxious stimuli. We examined whether combining top-down motor cortex modulation using anodal tDCS with a bottom-up DNIC induction paradigm synergistically increases the threshold at which pain is perceived. The pain thresholds of 15 healthy subjects were assessed before and after administration of active tDCS, sham tDCS, cold-water-induced DNIC, and combined tDCS and DNIC. We found that both tDCS and the DNIC paradigm significantly increased pain thresholds and that these approaches appeared to have additive effects. Increase in pain threshold following active tDCS was positively correlated with baseline N-acetylaspartate in the cingulate cortex and negatively correlated with baseline glutamine levels in the thalamus as measured by magnetic resonance spectroscopy. These results suggest that motor cortex modulation may have a greater analgesic effect when combined with bottom-up neuromodulatory mechanisms, presenting new avenues for modulation of pain using noninvasive neuromodulatory approaches. PERSPECTIVE This article demonstrates that both noninvasive motor cortex modulation and a descending noxious inhibitory controls paradigm significantly increase pain thresholds in healthy subjects and appear to have an additive effect when combined. These results suggest that existing pain therapies involving DNIC may be enhanced through combination with noninvasive brain stimulation.

Effect of a reminder system using an automated short message service on medication adherence following acute coronary syndrome.

Background: Medication non-adherence leads to a vast range of negative outcomes in patients with coronary artery disease. An automated web-based system managing short message service (SMS) reminders is a telemedicine approach to optimise adherence among patients who frequently forget to take their medications or miss the timing. Aim: This paper sought to investigate the effect of automated SMS-based reminders on medication adherence in patients after hospital discharge following acute coronary syndrome (ACS). Methods: An interventional study was conducted at a tertiary teaching hospital in Malaysia. A total of 62 patients with ACS were equally randomised to receive either automated SMS reminders before every intake of cardiac medications or only usual care within eight weeks after discharge. The primary outcome was adherence to cardiac medications. Secondary outcomes were the heart functional status, and ACS-related hospital readmission and death rates. Results: There was a higher medication adherence level in the intervention group rather than the usual care group, (χ2 (2)=18.614, p<0.001). The risk of being low adherent among the control group was 4.09 times greater than the intervention group (relative risk =4.09, 95% confidence interval (CI) 1.82–9.18). A meaningful difference was found in heart functional status between the two study groups with better results among patients who received SMS reminders, (χ2 (1) = 16.957, p<0.001). Conclusion: An automated SMS-based reminder system can potentially enhance medication adherence in ACS patients during the early post-discharge period.

Sample Size Calculation in Physical Medicine and Rehabilitation: A Systematic Review of Reporting, Characteristics, and Results in Randomized Controlled Trials

OBJECTIVE To assess systematically the reporting of sample size calculation in randomized controlled trials (RCTs) in 5 leading journals in the field of physical medicine and rehabilitation (PM&R). DATA SOURCES The data source was full reports of RCTs in 5 leading PM&R journals (Journal of Rehabilitation Medicine, Archives of Physical Medicine and Rehabilitation, American Journal of Physical Medicine and Rehabilitation, Clinical Rehabilitation, and Disability and Rehabilitation) between January and December of 1998 and 2008. Articles were identified in Medline. STUDY SELECTION A total of 111 articles met our inclusion criteria, which include RCTs of human studies in the 5 selected journals. DATA EXTRACTION Sample size calculation reporting and trial characteristics were collected for each trial by independent investigators. DATA SYNTHESIS In 2008, 57.3% of articles reported sample size calculation as compared with only 3.4% in 1998. The parameters that were commonly used were a power of 80% and alpha of 5%. Articles often failed to report effect size or effect estimates for sample size calculation. Studies reporting sample size calculation were more likely to describe the main outcome and to have a sample size greater than 50 subjects. The study outcome (positive vs negative) was not associated with the likelihood of sample size reporting. Trial characteristics of the 2 periods (1998 vs 2008) were similar except that in 1998 there were more negative studies compared with 2008. CONCLUSIONS Although sample size calculation reporting has improved dramatically in 10 years and is comparable with other fields in medicine, it is still not adequate given current publication guidelines.

A cardiovascular mathematical model of graded head-up tilt.

A lumped parameter model of the cardiovascular system has been developed and optimized using experimental data obtained from 13 healthy subjects during graded head-up tilt (HUT) from the supine position to . The model includes descriptions of the left and right heart, direct ventricular interaction through the septum and pericardium, the systemic and pulmonary circulations, nonlinear pressure volume relationship of the lower body compartment, arterial and cardiopulmonary baroreceptors, as well as autoregulatory mechanisms. A number of important features, including the separate effects of arterial and cardiopulmonary baroreflexes, and autoregulation in the lower body, as well as diastolic ventricular interaction through the pericardium have been included and tested for their significance. Furthermore, the individual effect of parameter associated with heart failure, including LV and RV contractility, baseline systemic vascular resistance, pulmonary vascular resistance, total blood volume, LV diastolic stiffness and reflex gain on HUT response have also been investigated. Our fitted model compares favorably with our experimental measurements and published literature at a range of tilt angles, in terms of both global and regional hemodynamic variables. Compared to the normal condition, a simulated congestive heart failure condition produced a blunted response to HUT with regards to the percentage changes in cardiac output, stroke volume, end diastolic volume and effector response (i.e., heart contractility, venous unstressed volume, systemic vascular resistance and heart rate) with progressive tilting.

Early AbobotulinumtoxinA (Dysport®) in Post-Stroke Adult Upper Limb Spasticity: ONTIME Pilot Study

The ONTIME study investigated whether early post-stroke abobotulinumtoxinA injection delays appearance or progression of upper limb spasticity (ULS) symptoms. ONTIME (NCT02321436) was a 28-week, exploratory, double-blind, randomized, placebo-controlled study of abobotulinumtoxinA 500U in patients with ULS (Modified Ashworth Scale [MAS] score ≥ 2) 2–12 weeks post-stroke. Patients were either symptomatic or asymptomatic (only increased MAS) at baseline. Primary efficacy outcome measure: time between injection and visit at which re-injection criteria were met (MAS ≥ 2 and ≥1, sign of symptomatic spasticity: pain, involuntary movements, impaired active or passive function). Forty-two patients were randomized (abobotulinumtoxinA 500U: n = 28; placebo: n = 14) with median 5.86 weeks since stroke. Median time to reach re-injection criteria was significantly longer for abobotulinumtoxinA (156 days) than placebo (32 days; log-rank: p = 0.0176; Wilcoxon: p = 0.0480). Eleven (39.3%) patients receiving abobotulinumtoxinA did not require re-injection for ≥28 weeks versus two (14.3%) in placebo group. In this exploratory study, early abobotulinumtoxinA treatment significantly delayed time to reach re-injection criteria compared with placebo in patients with post-stroke ULS. These findings suggest an optimal time for post-stroke spasticity management and help determine the design and sample sizes for larger confirmatory studies.

Predicting return to work following a cardiac event in Malaysia

BACKGROUND Return to work is an important aspect for cardiac rehabilitation following a major cardiac event. OBJECTIVE The aim was to understand the local prevalence and factors associated with returning to work in Malaysia after a cardiac event. METHODS A cross sectional design was used. All patients attending the cardiac rehabilitation program after major cardiac event during an 11-months period (2011-2012) were included. Data relating to socio-demographic, work-related, risk factors and acute myocardial infarction were collected. The SF-36 questionnaire was used to assess quality of life. Regression analysis was used to determine the predicting factors to return to work. RESULTS A total of 398 files were screened, 112 respondents agreed to participate giving a response rate of 47.3%. The prevalence of returned to work (RTW) was 66.1% [95% CI: 57.2-75.0]. Factors associated with work resumption were age (Adj. OR: 0.92 (95% CI: 0.84-0.99), diabetes mellitus (Adj. OR: 3.70, 95% CI: 1.35-10.12), Mental Component Summary (MCS) score (Adj. OR: 1.05 (95% CI: 1.01-1.09) and baseline angiography findings. Patients with single vessel and two vessel disease were 8.9 times and 3.78 times more likely to return to work compared to those with 3 vessels (Adj. OR: 8.90 (95% CI: 2.29-34.64) and Adj. OR: 3.78, (95% CI: 1.12, 12.74). CONCLUSIONS We proposed a cardiac rehabilitation program to emphasize mental health as it may improve successful return to work after cardiac event.

The Effect of Repetitive Transcranial Magnetic Stimulation on Postural Stability After Acute Stroke: A Clinical Trial

Introduction: Balance impairment is a common problem and a major cause of motor disability after stroke. Therefore, this study aimed to investigate whether low-frequency repetitive Transcranial Magnetic Stimulation (rTMS) improves the postural balance problems in stroke patients. Methods: This randomized double blind clinical trial with 12 weeks follow-up was conducted on stroke patients. Treatment was carried with 1 Hz rTMS in contralateral brain hemisphere over the primary motor area for 20 minutes (1200 pulses) for 5 consecutive days. Static postural stability, Medical Research Council (MRC), Berg Balance Scale (BBS), and Fugl-Meyer assessments were evaluated immediately, 3 weeks and 12 weeks after intervention. Results: A total of 26 patients were enrolled (age range=53 to 79 years; 61.5% were male) in this study. Administering rTMS produced a significant recovery based on BBS (df=86, 7; F=7.4; P=0.01), Fugl-Meyer Scale (df=86, 7; F=8.7; P<0.001), MRC score (df=87, 7; F=2.9; P=0.01), and static postural stability (df=87, 7; F=9.8; P<0.001) during the 12 weeks follow-up. Conclusion: According to the findings, rTMS as an adjuvant therapy may improve the static postural stability, falling risk, coordination, motor recovery, and muscle strength in patients with stroke.