Abnormal adaptation in children affected by cerebral palsy to robot generated dynamic environment.

This paper aims to investigate how robotic devices can be used to understand the mechanism of sensorimotor adaptation in pediatric subjects affected by hemiparetic cerebral palsy. Previous studies showed how healthy adults, after training in presence of a systematic structured disturbing force field, show an "after effect" and therefore they highly adapt and compensate the external disturbance. An open issue is whether this adaptive capability is preserved or disrupted in pediatric impaired subjects when they experience a robot generated dynamic environment. Fourteen pediatric Cerebral Palsy subjects (CP group), and age-matched control group were exposed to a robot generated speed-dependant force field; during familiarization (no forces generated by the robot) the movement of the CP subjects were more curved, displaying greater and variable directional error; in the force field phase both the groups showed an after-effect, but the CP group had a non significant adaptation rate. This outcome suggests the CP subjects have reduced ability to learn external force and they make greater aiming error because of an inefficient anticipatory strategy during visuomotor task.

The impact of robotic rehabilitation in children with acquired or congenital movement disorders.

AIM: The aim of this study was to evaluate if the robot-mediated therapy (RMT) can yield positive outcomes in children with acquired or congenital upper extremity movement disorders. METHODS: This was an uncontrolled pilot study with pre-post treatment outcome comparison carried out by the Pediatric Rehabilitation Department of a Children's Hospital. The study enrolled 12 children, aged 5 to 15 years, suffering from acquired (at least 12 months post-onset) or congenital upper limb motor impairment. ETIOLOGY: 4 stroke, 6 traumatic brain injuries, and 2 hemiplegic cerebral palsy. RMT was provided 3 times a week for an hour during 6 weeks for a total of 18 robot therapy sessions. The Melbourne Scale (MS) and the upper-extremity subsection of the Fugl-Meyer Assessment (FMA) were used for measurement of impairment. Secondary outcome measurements were made through the Modified Ashworth Scale (MAS); the Reaching Performance Scale (RPS); Parent's Questionnaire, and robot-based evaluation measurements. Specifically, authors compared the smoothness, as measured by the jerk metric, and average speed of unconstrained reaching movements. RESULTS: Pre-post clinical evaluation revealed statistically significant gains for all primary and secondary metrics. In addition, significant improvement of robot-based metrics was observed. The primary outcome measurement mean (SEM) gains were 6.71 (1.29) for MS and 3.33 (0.80) for the FMA. RMT led to spasticity decreases in chronic cases, as shown by the reduction of MAS. It led to improved trunk-upper extremity postural attitude as demonstrated by improved RPS, and it was well accepted by parents and children as observed in the Parent's Questionnaire. CONCLUSIONS: This study suggests that RMT may hold rehabilitative benefits in children suffering from acquired and congenital hemiparesis.

Entrapment neuropathy in patients with spastic cerebral palsy.

OBJECTIVES: We performed nerve conduction and needle electromyographic tests in 29 patients with spastic cerebral palsy (SCP) and severe limb deformities. Nerve conduction abnormalities were detected in 32 of 400 sensory or motor nerves, while 11 of 29 patients (37.9%) showed abnormal nerve conduction, indicating one or more entrapment neuropathies. Patients with SCP develop severe joint contractures and deformities due to spastic muscle tone and limited muscle and joint use/flexibility; these contractures and deformities can, in turn, cause nerve damage, possibly as a result of the stretching, angulation or compression mechanisms in the anatomic fibro-osseous passages, where nerves are particularly susceptible.

Usefulness of distinct activity thresholds according to baseline regional asynergy for predicting functional recovery in patients with chronic coronary artery disease and left ventricular dysfunction: a study with nitrate-enhanced sestamibi gated SPECT.

BACKGROUND: The role of gated single photon emission computed tomography (SPECT) in improving viability detection with the use of perfusion imaging is uncertain. This study aimed to verify whether the classification of baseline regional dysfunction with gated SPECT helps to predict functional recovery with the use of quantitative perfusion imaging. METHODS AND RESULTS: Resting nitrate-enhanced sestamibi gated SPECT was performed in 31 patients with left ventricular dysfunction, who later underwent coronary revascularization. With the use of a 16-segment model, tracer activity was quantified, and wall motion and thickening were estimated with a 4-point scoring scheme. Reversible dysfunction was assessed with follow-up gated SPECT. According to receiver operating characteristic curve analysis, the best overall cutoff for predicting reversible dysfunction in asynergic segments was 50% of peak activity or greater, with 83% sensitivity, 54% specificity, and 64% accuracy. When the segments were divided according to wall motion in resting gated SPECT, the optimal activity cutoff was greater than 68% for hypokinetic and 50% or greater for adyskinetic segments. With the use of 2 thresholds, the overall sensitivity remained good (76%), whereas specificity increased to 73% (P <.0005) and accuracy to 74% (P <.02). CONCLUSIONS: Regional dysfunction assessment directly on perfusion images permits use of different activity thresholds with an improvement over a single cutoff for all asynergic segments. Therefore combining perfusion and functional data with nitrate-enhanced gated SPECT at rest appears to be a promising approach for viability detection.

Long-term efficacy and safety of propafenone and sotalol for the maintenance of sinus rhythm after conversion of recurrent symptomatic atrial fibrillation.

This study was performed to evaluate, using a randomized double-blind, placebo-controlled protocol, the long-term efficacy and safety of propafenone and sotalol in maintaining sinus rhythm after conversion of recurrent symptomatic atrial fibrillation (AF). The maintenance of sinus rhythm in patients with recurrent AF has several potential benefits, the most important being a reduced risk of thromboembolic events. Three hundred patients with recurrent AF (> or = 4 episodes in the last year) and AF at enrollment lasting < 48 hours were randomized to receive either propafenone (mean daily dose 13 +/- 1.5 mg/kg; 102 patients), sotalol (mean daily dose 3 +/- 0.4 mg/kg; 106 patients), or placebo (92 patients). After 1-year follow-up, Kaplan-Meier estimates of the proportion of patients remaining in sinus rhythm were comparable between propafenone (63%) and sotalol (73%) and superior to placebo (35%; p = 0.001 vs both drugs). Symptomatic recurrences occurred later with propafenone and sotalol than with placebo. Nine patients (9%) in the propafenone group, 11 (10%) in the sotalol group, and 3 (3%) in the placebo group discontinued therapy due to adverse effects. Malignant nonfatal arrhythmias due to proarrhythmic effects were documented with sotalol only, and occurred < 72 hours from the beginning of therapy in 4 patients (4%). During recurrences, the ventricular rate was significantly reduced in patients taking propafenone and sotalol (p = 0.001 for both drugs vs placebo). The likelihood of remaining in sinus rhythm during follow-up was higher in younger patients with smaller left atrial size and without concomitant heart disease. In patients with recurrent symptomatic AF, propafenone and sotalol are not significantly different from each other and are superior to placebo in maintaining sinus rhythm at 1 year. Recurrences occur later and tend to be less symptomatic with propafenone and sotalol compared with placebo.

Prediction of functional recovery in patients with chronic coronary artery disease and left ventricular dysfunction combining the evaluation of myocardial perfusion and of contractile reserve using nitrate-enhanced technetium-99m sestamibi gated single-photon emission computed tomography and dobutamine stress.

This study aimed to assess whether contractile reserve evaluation using dobutamine gated single-photon emission computed tomography (SPECT) improves the capability of quantitative perfusion analysis to predict functional recovery of viable hibernating myocardium. Resting and dobutamine nitrate-enhanced technetium-99m sestamibi (sestamibi) gated SPECT studies were performed in patients with coronary artery disease who had left ventricular dysfunction. Tracer activity was quantified, and wall motion and thickening visually scored. Reversible dysfunction was identified with gated SPECT repeated after coronary revascularization. Using the best activity threshold, perfusion quantification achieved 85% sensitivity and 55% specificity. Contractile reserve detection was significantly less sensitive (64%, p <0.0005), but more specific (88%, p <0.00001) than perfusion quantification. However, in the subgroup of hypokinetic segments, the sensitivity of contractile reserve assessment was just slightly lower than perfusion quantification (72% vs 91%, p = NS), whereas specificity was significantly higher (94% vs 23%, p <0.00001). Conversely, in the adyskinetic segments, perfusion quantification was significantly more sensitive than contractile reserve (82% vs 59%, p <0.005), but similarly specific (76% vs 85%, p = NS). Therefore, the identification of reversible dysfunction based on perfusion quantification in adyskinetic segments and on contractile reserve detection in hypokinetic segments was significantly more specific (83% vs 55%, p <0.00001) than standard quantitative perfusion SPECT, without major loss in sensitivity (78% vs 85%, p = NS). In conclusion, contractile reserve evaluation using dobutamine gated SPECT enhances the reliability of nitrate-enhanced sestamibi SPECT when used to predict reversible dysfunction in hypokinetic segments, whereas perfusion quantification remains superior in adyskinetic segments.

Nitrate-enhanced gated technetium 99m sestamibi SPECT for evaluating regional wall motion at baseline and during low-dose dobutamine infusion in patients with chronic coronary artery disease and left ventricular dysfunction: comparison with two-dimensional echocardiography.

BACKGROUND: The value of gated single photon emission computed tomography (SPECT) in the assessment of wall motion (WM) in patients with severe perfusion defects and in the evaluation of low-dose dobutamine (LDD)-induced changes is not yet established. In patients with chronic coronary artery disease who have left ventricular (LV) dysfunction, the results of nitrate-enhanced technetium 99m sestamibi (sestamibi) gated SPECT for the evaluation of resting and LDD WM were compared with those of baseline and LDD echocardiography (LDDE). METHODS AND RESULTS: Thirty-seven patients underwent echocardiography and nitrate-enhanced sestamibi gated SPECT within 1 week at rest and during LDD infusion. WM was scored from 1 (normal) to 4 (dyskinetic) by using a 16-segment model. Segments with sestamibi uptake less than 30% were considered unsuitable for WM analysis (36 of 592 segments). Echocardiography was technically unreliable in 10 of 592 segments. The precise agreement between echocardiography and gated SPECT for baseline regional WM was 68.4% (kappa = 0.54), without significant differences for the involved coronary artery territory. The agreement for +/- 1 WM scoring was 96.5% (kappa = 0.94). Contractile reserve during LDD was detected by means of echocardiography in 36% and by means of sestamibi gated SPECT in 33% of baseline asynergic segments. Agreement for detection of WM improvement in response to LDD was 74% (kappa = 0.41). The overall and +/-1 WM score agreement for LDD WM was 67.5% (kappa = 0.50) and 94.7% (kappa = 0.91), respectively. A significant correlation between echocardiography and gated SPECT was observed for both baseline (p = 0.78) and LDD (p = 0.74) WM score index. CONCLUSIONS: In patients with coronary artery disease who have LV dysfunction, nitrate-enhanced sestamibi gated SPECT allows a reliable WM evaluation, both at rest and during LDD infusion, in almost all segments and provides results in agreement with LDDE.

Comparison of baseline and low-dose dobutamine technetium-99m sestamibi scintigraphy with low-dose dobutamine echocardiography for predicting functional recovery after revascularization.

Injection of sestamibi during low-dose dobutamine (LDD) infusion might improve tracer ability to detect viable myocardium. This study investigated the potential value of LDD technetium-99m sestamibi (sestamibi) single-photon emission computed tomography (SPECT) in predicting functional recovery after revascularization by comparing its results with those of sestamibi SPECT at rest and of LDD echocardiography. Before revascularization, 23 patients with chronic coronary artery disease and regional left ventricular dysfunction underwent sestamibi SPECT at rest and, on a separate day, LDD echocardiography and sestamibi SPECT with tracer injection during LDD infusion. Echocardiography at rest was repeated after revascularization. Semiquantitative sestamibi uptake results (grading from 0 = normal to 4 = absent) and wall motion (grading from 1 = normal to 4 = dyskinesia) were evaluated with a 16-segment model. The ventricular wall was divided into 3 vascular territories. At follow-up, 20 of 32 asynergic vascular territories showed functional recovery, whereas 12 showed no changes. For prediction of functional recovery, LDD SPECT achieved better accuracy than SPECT at rest (87% vs 65%, p <0.05); positive and negative predictive values of LDD SPECT were 90% and 83%, respectively, which was not significantly different from the related LDD echocardiographic values (84% and 69%). Thus, LDD sestamibi SPECT appears to be a promising method for detecting myocardial viability, which provides better accuracy than sestamibi SPECT at rest, and achieves predictive values comparable to those of LDD echocardiography.