Grip force control of predictable external loads.

The grip force used to grasp and hold an object is modulated synchronously and precisely with a self-produced load indicating predictive feedforward control. It is unclear whether an externally produced load can be anticipated with similar feedforward-timing and precision if it can be predicted, e.g., because it has a periodic time course. In the present study we tested eight healthy subjects during the compensation of an externally produced sinusoidal load with cycle duration 1.5 s and more than 700 repetitions during two successive sessions. Performance parameters characterizing the timing and precision of the grip force-load coupling were analyzed across the sessions and compared with a retention measurement on the following day and with an experimental condition when the same loads were self-produced. The time lag between the grip force and the load decreased from values greater than zero to values close to zero during the practice sessions indicating a change from a more reactive to a predictive response. In contrast, the precision and economy of the coupling showed no improvement. Performance on the second day was similar to initial performance, only some retention of feedforward timing was obvious. Precision and economy of grip force control during self-produced loading was clearly superior to external loading even after extended practice. Our findings confirm that periodic external loads are controlled by predictive feedforward mechanism after sufficient experience. However, performance was not stable and did not reach the level of self-generated loading. These results are interpreted as reflecting the significance of an efferent copy of the motor command in sensorimotor processing that may be associated with a distinct neuronal representation.

Comparison of insulin glargine versus NPH insulin in people with Type 2 diabetes mellitus under outpatient-clinic conditions for 18 months using a basal-bolus regimen with a rapid-acting insulin analogue as mealtime insulin.

AIMS: To assess the effects of a structured in-patient diabetes training programme in people with Type 2 diabetes mellitus on a basal-bolus regimen using insulin glargine or NPH insulin and rapid-acting insulin analogues with respect to glycaemic control, weight development and incidence of hypoglycaemia in an outpatient-clinic setting. PATIENTS AND METHODS: This was a prospective, non-randomized, single centre, comparative observational study including 119 subjects. Pre-study treatment was a basal-bolus regimen with NPH insulin and a rapid-acting insulin analogue. Subjects either continued with NPH insulin (n=56) or were switched over to insulin glargine (n=63) at the discretion of the investigator (aiming at equal numbers in each group). Patients then attended routine out-patient follow up visits for 18 months. RESULTS: HbA1c in the insulin glargine group improved statistically significant by -0.49%; [95%CI, -0.26, -0.71; p<0.001; HbA1c at endpoint 6.95+/-0.71%], whereas in the NPH group the reduction by -0.12% [95%CI, -0.31, 0.06; p=0.189; HbA1c at endpoint 7.22+/-0.74%] was statistically not significant. After 18 months of treatment the difference between treatment groups was 0.37% (p<0.015). Mean weight gain was significantly higher in the NPH group than in the glargine group (2.1 vs. 0.25 kg; p=0.025). A lower risk of hypoglycaemia in the glargine group (0.50 vs. 0.71 episodes/patient/month) did not reach statistical significance (p=0.081). CONCLUSIONS: Following a structured in-patient diabetes training programme glycaemic control in people with Type 2 diabetes mellitus on a basal-bolus regimen improved significantly only with insulin glargine suggesting that training alone may not be sufficient to further improve metabolic control in relatively well controlled patients on NPH insulin. Therefore, in addition to a structured training programme also the insulin regimen should be optimized, e.g. by introduction of an insulin analogue.

[How much do inpatient treated diabetics know about their disease?]. / Wie viel wissen stationär behandelte Diabetiker über ihre Erkrankung? Eine empirische Untersuchung in einem städtischen Klinikum in München.

AIM OF STUDY: The aim of the study was to find to find out which factors are able to predict the disease-specific knowledge of in-patient diabetic patients and to characterize this group of patients. METHODS: The disease-specific knowledge of diabetic patients of a Hospital in Munich, Germany (department of diabetology) was tested using a general questionnaire and a specific diabetes knowledge test. All data manipulation and statistical calculations were conducted with the statistical software package SAS (version 9.1). RESULTS: On average type-1-diabetics achieved 73% of the possible points in the knowledge test, type-2-diabetics achieved 68% of total points. In bivariate analyses, using logistic regression, existence of diabetes related complications was a significant predictor of poor knowledge (OR = 4.36; 95%-KI: 1.38-13.77) in type-1-diabetics. Other factors, e. g. lack of diabetes education were associated with low test results but reached no statistical significance (OR = 6.13; 95%-KI: 0.67-56.42). In multivariate logistic regression (female) gender was a significant risk factor for low test results (OR = 7.66; 95%-KI: 1.18-49.8). In type-2-diabetics lack of diabetes education (OR = 3.86; 95%-KI: 1.51-9.84), low self-assessment of information about diabetes (OR = 3.90; 95%-KI: 1.36-11.21) and lack of knowledge about diabetes diet (OR = 4.06; 95%-KI: 1.60-10.28) were predictors of poor test results. The existence of diabetes related complications was associated with poor test results but showed no statistical significance in multivariate analysis (OR = 2.99; 95%-KI: 0.85-10.43). CONCLUSIONS: There is a group of diabetic inward-patients that is less informed about diabetes and shows knowledge deficits in testing. These patients often lack diabetes education and show an unfavourable course of the disease, already having diabetes related complications. Type-2-diabetes patients who feel that they have poor information about their disease actually achieve lower results in knowledge testing. Efforts to assure diabetes education for these patients are essentially necessary.

The dependence of ipsilesional aiming deficits on task demands, lesioned hemisphere, and apraxia.

Neuroimaging studies as well as neurophysiological and lesion data indicate that the ipsilateral hemisphere plays a role in controlling the active limb. However, the nature and the conditions of this ipsilateral control are not well understood. We measured aiming movements with the ipsilesional limb toward targets with different characteristics which were made by patients with unilateral left brain damage (LBD) or right brain damage (RBD). The movement kinematics were analysed. Performance measures of the pointing movements were impaired in LBD patients, whereas RBD patients performed normally. LBD patients had obvious deficits during all tasks; however, they were exacerbated when high accuracy was required, and when an exocentric target had to be reached without visual feedback. Thus, the motor-dominant hemisphere plays a specific role in the programming and execution of ipsilateral aiming movements, and the importance of ipsilateral control increases with increasing task demands. To assess the relationship between pointing deficits and apraxia in LBD patients, the imitation of meaning gestures was tested. We replicated a recent study, showing that deviations of the final hand position from the demonstration were not correlated with abnormal kinematics of the corresponding arm movement when LBD patients performed this test. However, there were correlations between related kinematic measures during pointing and gesture imitation. These findings suggest a deficit of motor programming and execution after damage to the motor-dominant brain which is unrelated to the spatial errors characteristic of apraxia. This deficit affects different types of goal-directed aiming movements and its severity depends on task demands.