Learning, not adaptation, characterizes stroke motor recovery: evidence from kinematic changes induced by robot-assisted therapy in trained and untrained task in the same workspace.

Both the American Heart Association and the VA/DoD endorse upper-extremity robot-mediated rehabilitation therapy for stroke care. However, we do not know yet how to optimize therapy for a particular patient's needs. Here, we explore whether we must train patients for each functional task that they must perform during their activities of daily living or alternatively capacitate patients to perform a class of tasks and have therapists assist them later in translating the observed gains into activities of daily living. The former implies that motor adaptation is a better model for motor recovery. The latter implies that motor learning (which allows for generalization) is a better model for motor recovery. We quantified trained and untrained movements performed by 158 recovering stroke patients via 13 metrics, including movement smoothness and submovements. Improvements were observed both in trained and untrained movements suggesting that generalization occurred. Our findings suggest that, as motor recovery progresses, an internal representation of the task is rebuilt by the brain in a process that better resembles motor learning than motor adaptation. Our findings highlight possible improvements for therapeutic algorithms design, suggesting sparse-activity-set training should suffice over exhaustive sets of task specific training.

Smoking rates and smoking cessation among individuals with multiple sclerosis.

PURPOSE: Adults with physical disabilities tend to smoke at higher rates than smokers in the general population. No study to date, however, has assessed smoking prevalence and cessation among individuals with multiple sclerosis (MS). Such information is critically needed because smoking is more deleterious for individuals with MS than for smokers without MS and increases MS risk. METHOD: Questionnaires were sent to 700 National Multiple Sclerosis Society Rhode Island Chapter members. RESULTS: Based on a 50% response rate, results demonstrated a 15.2% current smoker prevalence rate, which is lower than USA and Rhode Island general adult population averages. Individuals who smoked, however, tended to be heavy smokers, consuming 20 - 30 cigarettes daily, and had been smoking 10 years or longer. Smokers varied in their interest in quitting but seemed confident in their ability to do so. Respondents reported that it was difficult to quit because smoking was pleasurable; smoking was helpful in coping with boredom and with having MS; withdrawal symptoms were unpleasant; and treatment for tobacco dependence was expensive. CONCLUSIONS: Efficacious smoking cessation interventions for smokers with MS should be developed to address a critical health need for a population of highly nicotine-dependent smokers who face numerous obstacles to quitting.

Recovery rates after stroke and their impact on outcome prediction.

Current assessments do not provide reliable factors predictive of outcome from stroke for stroke survivors of intermediate age and severity of deficit. We sought to investigate whether early rate of functional improvement can facilitate prediction of functional outcome, length of stay, and disposition beyond that afforded by age and initial severity of deficit. Prospective study of consecutive admissions to acute rehabilitation (N = 244) with diagnosis of ischemic or hemorrhagic stroke. Independent measures were age, marital status, living situation, social situation, lag from symptom onset to rehabilitation, stroke type, admission score on the Functional Independence Measure (FIM), rate of FIM change (ROFC) as assessed by the best weekly FIM change in the first 3 weeks of rehabilitation. Dependent measures were functional status on discharge as assessed by a modification of Steinman's method, length of stay, and discharge disposition. Logistic regression analyses on each of the dependent measures identified significant factors, and interactions of significant factors were assessed by analysis of variance on continuous dependent variables. Cross-tabulations using significant factors from the logistic regression analyses were performed to identify groups with homogeneous outcomes. Groups with >80% homogeneity were considered likely to have predictive value. Discharge functional status: Admission FIM (AFIM) again fractionated the population into groups with poor outcome (AFIM <50 remained dependent), good outcome (AFIM >70 achieved nondependence), and an intermediate group with unpredictable outcome. In this intermediate group, ROFC had significant effect only for a small number of patients (n = 9) with rapid improvement (ROFC >25) who achieved nondependence. LOS: AFIM >70 had less than average LOS, ROFC = 10-15 FIM/week had longer than average LOS. LOS was significantly prolonged in patients with poor outcomes. Disposition: AFIM >70 and age <60 were strongly associated with home discharge. Patients not living at home before admission were not discharged home. Married patients had a greater tendency to home discharge than did those not married. ROFC had no bearing on disposition. ROFC has an independent influence on outcome but was sufficiently powerful in our sample to identify reliably only a very small subset of patients with otherwise indeterminate prognosis. LOS seems inordinately prolonged in patients with poor outcomes. Both of these results can guide efficient rehabilitation management.

The stokes radius of the CHAPS-solubilized benzodiazepine receptor complex.

The Stokes radii and the apparent molecular weights of the CHAPS or Triton X-100 solubilized benzodiazepine receptors are calculated by gel exclusion chromatography. The results suggest that the molecular receptor complex solubilized by CHAPS is much larger than the complex solubilized by Triton X-100.

Solubilization of brain benzodiazepine receptors with a zwitterionic detergent: optimal preservation of their functional interaction with the GABA receptors.

Rat brain benzodiazepine receptors have been solubilized by means of the zwitterionic detergent CHAPS under conditions in which the GABA stimulation of [3H]flunitrazepam binding to the benzodiazepine receptors is maintained intact. This stimulation is partially or totally abolished when using other conventional detergents.