Effect of Mental Practice on the Improvement of Function and Daily Activity Performance of the Upper Extremity in Patients With Subacute Stroke: A Randomized Clinical Trial

ObjectivesMore than 50% of patients with upper limb paresis after stroke face long-term impaired arm function and ensuing disability in daily life. This study aims to evaluate the effectiveness of a task-oriented mental practice (MP) approach as an addition to regular arm–hand therapy in patients with subacute stroke.MethodsA multicenter, prospective, single-blind, randomized clinical trial was performed. Patients trained for 6 weeks, at least 3 times per day. In the experimental group, patients performed video-instructed MP. In the control group, patients performed neurodevelopmental therapy–based exercise therapy. The primary outcome measures are Fugl-Meyer test, Frenchay arm test, Wolf motor function test, and accelerometry.ResultsThe patients did improve over time on Fugl-Meyer test and Wolf motor function test in both the control and the experimental group. A significant improvement on the Frenchay arm test was found after training (which was maintained at 12-month follow-up) only in the experimental group. However, no difference in training effects between groups was demonstrated.ConclusionsTraining effects were demonstrated after MP training in patients with subacute stroke. However, the results of this study do not corroborate the hypothesis that the use of MP in addition to therapy as usual in patients with subacute stroke has an additional effect over neurodevelopmental therapy in addition to therapy as usual.     

Assessment of arm activity using triaxial accelerometry in patients with a stroke

van der Pas SC, Verbunt JA, Breukelaar DE, van Woerden R, Seelen HA. Assessment of arm activity using triaxial accelerometry in patients with a stroke.

Objective

To study the validity of accelerometry in the assessment of arm activity of patients with impaired arm function after stroke.

Design

Cross-sectional concurrent validity study.

Setting

Rehabilitation center.

Participants

Patients (N=45) at different stages after stroke.

Interventions

Not applicable.

Main Outcome Measures

All patients wore 2 triaxial accelerometers around their wrists during 3 consecutive days. Arm activity was assessed, based on unilateral (activity of the affected arm) and bilateral accelerometry (ratio between the activity of the affected and nonaffected arm). The Motor Activity Log-26 (MAL-26) Amount of Use (AOU) scale was used as the main external criterion to test the concurrent validity of arm accelerometry. In addition, the MAL-26 Quality of Movement (QOM) scale and the Stroke Impact Scale (SIS) subscale Hand Function were used. To test the divergent validity, the SIS subscale Mobility was used. Spearman correlation coefficients were calculated. In an additional regression analysis, the hypothesized confounding influence of spasm, therapy intensity, and interobserver differences was studied.

Results

Both unilateral (ρ=.58, P<.001) and bilateral (ρ=.60, P<.001) accelerometry were significantly related to the MAL-AOU scale. Associations of both unilateral and bilateral accelerometry with the MAL-QOM and SIS subscale Hand Function corroborated these findings. The SIS subscale Mobility was not significantly associated with unilateral accelerometry (ρ=.41, P=.01) or bilateral accelerometry (ρ=.23, P=.11). None of the hypothesized confounders influenced these associations significantly.

Conclusions

Based on the results, both the concurrent and divergent validity of unilateral and bilateral arm accelerometry for measuring arm activity after stroke are good.     

Pain-related factors contributing to muscle inhibition in patients with chronic low back pain: an experimental investigation based on superimposed electrical stimulation

OBJECTIVE: To evaluate muscle strength, as a component of physical deconditioning, and central activation ratio, representing the performance level during testing, in patients with chronic low back pain as compared to healthy controls, and to evaluate the contribution of cognitive-behavioral and pain-related factors to the central activation ration of patients with chronic low back pain. METHODS: Twenty-five patients with chronic low back pain and 25 age and gender-matched controls participated. Muscle strength, that is, peak torque of the quadriceps muscle, was measured on a Cybex dynamometer. During peak torque, the quadriceps muscle was percutaneously stimulated using superimposed electrical stimulation, generating an additional twitch torque in case of submaximal performance. The central activation ratio was calculated as peak torque/(peak torque + additional twitch torque). To evaluate cognitive-behavioral and pain-related factors influencing the central activation ratio, measures of fear of injury, pain catastrophizing, psychologic distress, and pain intensity were used. Differences between groups were tested using either T tests or Mann-Whitney U tests. Associations were tested by partial correlation coefficients controlling for gender. RESULTS: The male:female ratio was 15:10. Mean age and chronic low back pain duration were 42.7 (+/-9.5) and 9.9 (+/-8.3) years, respectively. Mean muscle torque (per kg lean body mass) in patients (1.95 Nm/kg +/-0.8) was less than in controls (3.16 Nm/kg +/-0.7) (P < 0.01). Median central activation ratio was lower in patients (P < 0.05). Patients experiencing increased psychologic distress and patients with a higher current pain level showed a lower central activation ratio (P < 0.05). CONCLUSIONS: When interpreting decreased muscle strength in terms of physical deconditioning in patients with chronic low back pain, submaximal performance has to be taken into account. The results suggest that patients with chronic low back pain who report increased psychologic distress and a higher level of current pain tend to show increased inhibition of muscle activity, leading to submaximal performance.     

Role of complement in innate and autoimmunity

The complement system is a major driver of our innate immune response and plays an important role in defence against foreign pathogens. It is composed of a large number of proteins that are found in the circulation, in tissues and other body fluids in pro-enzymatic form. The many biologic activities of the complement system are uncovered following activation by three known pathways. Together with phagocytic cells the complement system is a powerful tool to defend the host against foreign attack. However the complement system, under certain conditions, can be unfavorable to the host namely in diseases such as IgA nephropathy, systemic lupus erythematosus and in diseases where minor changes have occurred in the integrity of tissue such as in ischemia reperfusion. This review describes the many faces of complement in the field of innate and acquired immunity and takes the reader on a journey of the role of complement in health and disease.