Linear response formula for piecewise expanding unimodal maps

The average R(t) of a smooth function with respect to the SRB measure of a smooth one-parameter family f_t of piecewise expanding interval maps is not always Lipschitz. We prove that if f_t is tangent to the topological class of f_0, then R(t) is differentiable at zero, and the derivative coincides with the resummation previously proposed by the first named author of the (a priori divergent) series given by Ruelle's conjecture.Comment: We added Theorem 7.1 which shows that the horizontality condition is necessary. The paper "Smooth deformations..." containing Thm 2.8 is now available on the arxiv; see also Corrigendum arXiv:1205.5468 (to appear Nonlinearity 2012

Health-related quality of life and psychological features in post-stroke patients with chronic pain: A cross-sectional study in the neuro-rehabilitation context of care

This study aims at exploring disability, health-related quality of life (HrQoL), psychological distress, and psychological features in post-stroke patients with chronic pain. An observational cross-sectional study involving 50 post-stroke patients (25 with chronic pain and 25 without pain) was conducted. The primary outcome was the self-reported level of disability and HrQoL which were both assessed through the Stroke Impact Scale 3.0. Both psychological distress and specific psychological features (i.e., self-efficacy, coping strategies, psychological flexibility, perceived social support) were examined. Post-stroke patients with chronic pain reported statistically significant higher levels of disability and worse HrQoL, higher psychological distress and inflexibility, as well as a lower level of self-efficacy and problem-oriented coping strategies than patients without pain (p < 0.001). Finally, correlation analysis in the group of stroke survivors with pain showed that higher levels of disability were significantly related to higher psychological distress. This study con-firms the negative influence of chronic pain on disability and HrQoL in post-stroke patients and presents preliminary insights on the association between chronic pain, disability, HrQoL, psychosocial distress, and the patient’s approach in dealing with personal difficulties and emotions. These findings carry further implications for multidisciplinary management of post-stroke patients with chronic pain

Diagnostic nerve block in prediction of outcome of botulinum toxin treatment for spastic equinovarus foot after stroke: A retrospective observational study

Objective: To evaluate the role of diagnostic nerve block in predicting the outcome of subsequent botulinum toxin type A treatment for spastic equinovarus foot due to chronic stroke. Design: Retrospective observational study. Patients: Fifty chronic stroke patients with spastic equinovarus foot. Methods: Each patient was given diagnostic tibial nerve block (lidocaine 2% perineural injection) assessment followed by botulinum toxin type A inoculation into the same muscles as had been targeted by the nerve block. All patients were evaluated before diagnostic nerve block, after the nerve block, and 4 weeks after botulinum toxin injection. Outcomes were ankle dorsiflexion passive range of motion of the affected side, and calf muscle spasticity, measured with the modified Ashworth scale and the Tardieu Scale. Results: Significant improvements were measured after diagnostic nerve block and botulinum toxin injection compared with the baseline condition. Diagnostic nerve block led to significantly greater improvements in all outcomes than botulinum toxin injection. Conclusion: This study confirmed diagnostic nerve block as a valuable screening tool in deciding whether to treat spastic equinovarus with botulinum toxin. However, the results support the evidence that diagnostic nerve block results in a greater reduction in muscle overactivity than does botulinum toxin type A in patients with spastic equinovarus due to stroke

Four-week trunk-specific exercise program decreases forward trunk flexion in Parkinson's disease: A single-blinded, randomized controlled trial

INTRODUCTION: Pathological forward trunk flexion is a disabling and drug-refractory motor complication of Parkinson's disease (PD) leading to imbalance, pain, and fall-related injuries. Since it might be reversible, early and multidisciplinary management is emphasised. The primary aim was to compare the effects of a four-week trunk-specific rehabilitation program on the severity of the forward trunk flexion. The secondary aim was to compare the training effects on the motor impairments, dynamic and static balance, pain, falls, and quality of life. METHODS: 37 patients with PD (H&Y\u202f 64\u202f4) and forward trunk flexion were randomized in the experimental (n\u202f=\u202f19) or control group (n\u202f=\u202f18). The former consisted of active self-correction exercises with visual and proprioceptive feedback, passive and active trunk stabilization exercises and functional tasks. The latter consisted of joint mobilization, muscle strengthening and stretching, gait and balance exercises. Protocols lasted 4 weeks (60\u202fmin/day, 5 days/week). Before, after, and at 1-month follow-up, a blinded examiner evaluated patients using primary and secondary outcomes. The primary outcome was the forward trunk flexion severity (degree). Secondary outcomes were the UPDRS III, dynamic and static balance, pain falls, and quality of life assessment. RESULTS: The experimental group reported a significantly greater reduction in forward trunk flexion than the control group from T0 to both T1 (p\u202f=\u202f0.003) and T2 (p\u202f=\u202f0.004). The improvements in dynamic and static balance were significantly greater for the experimental group than the control group from T0 to T2 (p\u202f=\u202f0.017 and 0.004, respectively). Comparable effects were reported on the other outcomes. Pre-treatment forward trunk flexion values were highly correlated to post-treatment trunk deviation changes. CONCLUSION: The four-week trunk-specific rehabilitation training decreased the forward trunk flexion severity and increased postural control in patients with PD. NCT03741959

Temporal judgments of actions following unilateral brain damage

Sense of time is a complex construct, and its neural correlates remain to date in most part unknown. To complicate the frame, physical attributes of the stimulus, such as its intensity or movement, influence temporal perception. Although previous studies have shown that time perception can be compromised after a brain lesion, the evidence on the role of the left and right hemispheres are meager. In two experiments, the study explores the ability of temporal estimation of multi-second actions and non-biological movements in 33 patients suffering from unilateral brain lesion. Furthermore, the modulatory role of induced embodiment processes is investigated. The results reveal a joint contribution of the two hemispheres depending not only on different durations but also on the presence of actions. Indeed, the left hemisphere damaged patients find it difficult to estimate 4500 ms or longer durations, while the right hemisphere damaged patients fail in 3000 ms durations. Furthermore, the former fail when a biological action is shown, while the latter fail in non-biological movement. Embodiment processes have a modulatory effect only after right hemisphere lesions. Among neuropsychological variables, only spatial neglect influences estimation of non-biological movement

Accuracy of botulinum toxin type A injection into the forearm muscles of chronic stroke patients with spastic flexed wrist and clenched fist: manual needle placement evaluated using ultrasonography.

Objective: To investigate the accuracy of manual needle placement for injection of botulinum toxin type A into the forearm muscles of adults with spastic flexed wrist and clenched fist as a consequence of stroke. Design: Prospective clinical study. Patients: A total of 41 adults with chronic stroke who were scheduled to receive botulinum toxin type A injection into the following forearm muscles: flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis and flexor digitorum profundus. Methods: According to Huber & Heck's atlas suggestions on treatment of spasticity with botulinum toxin, surface identification of muscles to inject was performed by means of palpation and anatomical landmarks. Accuracy of needle placement and muscle thickness at the site of needle insertion were assessed using ultrasonography. Results: Overall accuracy of manual needle placement evaluated using ultrasonography was 51.2%. Accuracy was significantly higher for the finger flexors than for the wrist flexors (63.4% vs 39.0%). The finger flexors were significantly thicker than the wrist flexors (mean 1.58 vs 0.49 cm). Conclusion: Instrumental guidance should be used in order to achieve an acceptable accuracy of needle placement when performing botulinum toxin type A injections into the forearm muscles of chronic stroke patients with spastic flexed wrist and clenched fist

Effect of eye patching in rehabilitation of hemispatial neglect.

Eye patching (EP; monocular or right hemifield) has been proposed to improve visuospatial attention to the ignored field in patients with hemispatial neglect. The aim of this paper is to review the literature on the effects of EP in hemispatial neglect after stroke in order to convey evidence-based recommendations to clinicians in stroke rehabilitation. Thirteen intervention studies were selected from the Medline, EMBASE, Scopus, Cochrane Library, CINAHL, PsychINFO, EBRSR, and Health Star databases. Methodological quality was defined according to the Physiotherapy Evidence Database. Overall, seven studies used monocular EP, five used right hemifield patching, and one compared right monocular with right hemifield patching. Seven studies compared normal viewing to monocular or hemifield patching conditions. Six studies included a period of treatment. As to the monocular EP, four studies reported positive effects of right monocular patching. One study showed an improvement in hemispatial neglect with left monocular patching. Two studies found no superiority of right vs. left monocular patching. One study found no effects of right monocular patching. As to the right hemifield EP, one study showed improvements in neglect after right hemifield patching. Three studies found that right hemifield patching combined with another rehabilitation technique was more effective than that treatment alone. One study found no differences between right hemifield patching combined with another treatment and that treatment alone. One study found the same effect between right hemifield patching alone and another rehabilitation technique. Our results globally tend to support the usefulness of right hemifield EP in clinical practice. In order to define a level of evidence with the standard rehabilitation evidence rating tools, further properly powered randomized controlled trials or meta-analysis are needed

Effect of eye patching in rehabilitation of hemispatial neglect.

Eye patching (EP; monocular or right hemifield) has been proposed to improve visuospatial attention to the ignored field in patients with hemispatial neglect. The aim of this paper is to review the literature on the effects of EP in hemispatial neglect after stroke in order to convey evidence-based recommendations to clinicians in stroke rehabilitation. Thirteen intervention studies were selected from the Medline, EMBASE, Scopus, Cochrane Library, CINAHL, PsychINFO, EBRSR, and Health Star databases. Methodological quality was defined according to the Physiotherapy Evidence Database. Overall, seven studies used monocular EP, five used right hemifield patching, and one compared right monocular with right hemifield patching. Seven studies compared normal viewing to monocular or hemifield patching conditions. Six studies included a period of treatment. As to the monocular EP, four studies reported positive effects of right monocular patching. One study showed an improvement in hemispatial neglect with left monocular patching. Two studies found no superiority of right vs. left monocular patching. One study found no effects of right monocular patching. As to the right hemifield EP, one study showed improvements in neglect after right hemifield patching. Three studies found that right hemifield patching combined with another rehabilitation technique was more effective than that treatment alone. One study found no differences between right hemifield patching combined with another treatment and that treatment alone. One study found the same effect between right hemifield patching alone and another rehabilitation technique. Our results globally tend to support the usefulness of right hemifield EP in clinical practice. In order to define a level of evidence with the standard rehabilitation evidence rating tools, further properly powered randomized controlled trials or meta-analysis are needed

Robot-assisted arm training in patients with Parkinson's disease: a pilot study.

BACKGROUND: Despite the growing diffusion of robotic devices in neurorehabilitation, no previous study investigated the effects of robotic training on arm impairment due to Parkinson's disease. The aim of this pilot study was to evaluate whether robot-assisted arm training might improve upper limb function in patients with Parkinson's disease.FINDINGS: Ten patients with Parkinson's disease (Hoehn and Yahr stage 2.5-3) received ten, 45-minute, treatment sessions, five days a week, for two consecutive weeks. Robot-assisted arm training was performed with the Bi-Manu-Track (Reha-Stim, Berlin, Germany) that provides a computer-controlled, repetitive, bilateral, mirror-like practice of forearm pronation/supination and wrist extension/flexion. Patients were trained according to the following modalities: passive-passive (both arms moved by the machine) and active-active (both arms actively moving against resistance). The dominant upper limb was evaluated before and immediately after treatment as well as at two weeks of follow-up. Outcomes were the nine-hole peg test, the Fugl-Meyer assessment (upper limb section) and the Unified Parkinson's Disease Rating Scale. After treatment, a significant improvement was found in the nine-hole peg test (P\u2009=\u20090.007) as well as in the upper limb section of the Fugl-Meyer assessment (P\u2009=\u20090.012). Findings were confirmed at the 2-week follow-up evaluation only for the nine-hole peg test (P\u2009=\u20090.007). No significant improvement was found in the Unified Parkinson's Disease Rating Scale at both post-treatment and follow-up evaluations.CONCLUSIONS: Our findings support the hypothesis that robot-assisted arm training might be a promising tool in order to improve upper limb function in patients with Parkinson's disease