Alertness, level of activity, and purposive movement following somatosensory deafferentation in monkeys

Grade-4/5 motor activity log-Brazil for post-stroke individuals with a severely impaired upper limb: a validity, reliability and measurement error study

PURPOSE

This study examined the clinimetrics of the Brazilian-Portuguese translation of the Grade-4/5 Motor Activity Log (MAL 4/5), which assesses everyday use of the more affected upper-limb (UL) in stroke survivors with moderate/severe or severe motor impairment.

MATERIALS AND METHODS

The translated MAL 4/5 was administered to 47 stroke survivors with moderate/severe or severe UL motor impairment. Accelerometers were worn on participants' wrists for five days on average prior to the first assessment. Test-retest and inter-rater reliabilities were assessed using the intraclass correlation coefficient (ICC), internal consistency using Cronbach's α, and construct validity was tested with correlations with the accelerometry. The measurement error (SEM) and the minimal detectable change (MDC) were calculated.

RESULTS

MAL4/5-Brazil's test-retest reliability (AOU: ICC = 0.84; QOU: ICC = 0.90), inter-rater reliability (AOU: ICC = 0.83; QOU: ICC = 0.91), internal consistency (Cronbach's α = 0.91 and 0.95 for AOU and QOU scales, respectively), the SEM and MDC were 0.3 and 0.8 points for the AOU subscale and 0.2 and 0.5 points for the QOU subscale, respectively. The construct validity (AOU scale: r = 0.67; QOU scale: r = 0.76) was high.

CONCLUSION

Grade-4/5 Motor Activity Log-Brazil is a reliable and valid instrument for assessing the more-affected UL use of stroke patients with moderate/severe or severe UL motor impairments.

Contralesional plasticity following constraint-induced movement therapy benefits outcome: contributions of the intact hemisphere to functional recovery

Stroke is a leading cause of death and disability worldwide. A common, chronic deficit after stroke is upper limb impairment, which can be exacerbated by compensatory use of the nonparetic limb. Resulting in learned nonuse of the paretic limb, compensatory reliance on the nonparetic limb can be discouraged with constraint-induced movement therapy (CIMT). CIMT is a rehabilitative strategy that may promote functional recovery of the paretic limb in both acute and chronic stroke patients through intensive practice of the paretic limb combined with binding, or otherwise preventing activation of, the nonparetic limb during daily living exercises. The neural mechanisms that support CIMT have been described in the lesioned hemisphere, but there is a less thorough understanding of the contralesional changes that support improved functional outcome following CIMT. Using both human and non-human animal studies, the current review explores the role of the contralesional hemisphere in functional recovery of stroke as it relates to CIMT. Current findings point to a need for a better understanding of the functional significance of contralesional changes, which may be determined by lesion size, location, and severity as well stroke chronicity.

Greater Reduction in Contralesional Hand Use After Frontoparietal Than Frontal Motor Cortex Lesions in Macaca mulatta

We previously reported that rhesus monkeys recover spontaneous use of the more impaired (contralesional) hand following neurosurgical lesions to the arm/hand representations of primary motor cortex (M1) and lateral premotor cortex (LPMC) (F2 lesion) when tested for reduced use (RU) in a fine motor task allowing use of either hand. Recovery occurred without constraint of the less impaired hand and with occasional forced use of the more impaired hand, which was the preferred hand for use in fine motor tasks before the lesion. Here, we compared recovery of five F2 lesion cases in the same RU test to recovery after unilateral lesions of M1, LPMC, S1 and anterior portion of parietal cortex (F2P2 lesion - four cases). Average and highest %use of the contralesional hand in the RU task in F2 cases were twice that in F2P2 cases (p < 0.05). Recovery in the RU task was closely associated with volume and percentage of lesion to caudal (new) M1 (M1c) in both F2 and F2P2 lesion cases. One F2P2 case, with the largest M1c lesion and a large rostral somatosensory cortex (S1r) lesion developed severe contralesional hand non-use despite exhibiting some recovery of fine motor function initially. We conclude that the degree of reduced use of the contralesional hand is primarily related to the volume of M1c injury and that severe non-use requires extensive injury to M1c and S1r. Thus, assessing peri-Rolandic injury extent in stroke patients may have prognostic value for predicting susceptibility to RU and non-use in rehabilitation.

Voluntary exercise ameliorates the good limb training effect in a mouse model of stroke

Stroke is the leading cause of long-term disability in the United States, making research on rehabilitation imperative. Stroke rehabilitation typically focuses on recovery of the impaired limb, although this process is tedious. Compensatory use of the intact limb after stroke is more efficient, but it is known to negatively impact the impaired limb. Exercise may help with this problem; research has shown that exercise promotes neuronal growth and prevents cell death. This study used a mouse model to investigate if post-stroke exercise could prevent deterioration of the function of the impaired limb despite compensatory training of the intact limb. Results showed that mice that exercised, in combination with intact limb training, demonstrated improved functional outcome compared to mice that received no training or compensatory limb training only. These findings suggest that exercise can prevent the deterioration of impaired limb functional outcome that is typically seen with intact limb use.

Perceived effort affects choice of limb and reaction time of movements

The decision regarding which arm to use to perform a task reflects a complex process that can be influenced by many factors, including effort requirements of acquiring the goal. In this study, we considered a virtual reality environment in which people reached to a visual target in three-dimensional space. To vary the cost of reaching, we altered the visual feedback associated with motion of one arm but not the other. This altered the extent of motion that was required to reach, thus changing the effort required to acquire the goal. We then measured how that change in effort affected the decision regarding which arm to use, as well as the preparation time for the movement that ensued. As expected, with increased visual amplification of one arm (reduced effort to reach the goal), subjects increased the probability of choosing that arm. Surprisingly, however, the reaction times to start these movements were also reduced: despite constancy of the visual representation of the target, reaction times were shorter for movements with less effort. Thus, as the perceived effort associated with accomplishing a goal was reduced for a given limb, the decision-making process was biased toward use of that limb. Furthermore, movements that were perceived to be less effortful were performed with shorter reaction times. These results suggest that visual amplification can alter the perceived effort associated with using a limb, thus increasing frequency of use. This may provide a useful method to increase use of a limb during rehabilitation.NEW & NOTEWORTHY We report that visual amplification may serve as an effective means to alter the perceived effort associated with use of a limb. This method may provide an effective tool with which use of the affected limb can be encouraged noninvasively after neurological injury.

Targeted Pelvic Constraint Force Induces Enhanced Use of the Paretic Leg During Walking in Persons Post-Stroke

The purpose of this study was to determine whether activation of muscles in the paretic leg, particularly contributing to propulsion, and gait symmetry can be improved by applying a targeted resistance force to the pelvis in the backward direction during stance phase while walking in individuals post-stroke. Thirteen individuals post-stroke participated in two experimental sessions, which consisted of treadmill walking, with either targeted or constant resistances, together with overground walking. For the targeted condition, a resistance force was applied to the pelvis during the stance phase of the paretic leg. For the constant condition, the resistance force was applied throughout the whole gait cycle. Participants showed greater increase in medial hamstring muscle activity in the paretic leg and improved step length symmetry after the removal of targeted resistance force, compared to effects of a constant resistance force (P < 0.03). In addition, treadmill walking with the targeted resistance induced more symmetrical step length during overground walking 10 min after the treadmill walking, compared to the result of the constant resistance force (P = 0.01). Applying a targeted resistance force to the pelvis during the stance phase of the paretic leg may induce an enhanced use of the paretic leg and an improvement in gait symmetry in individuals post-stroke. These results provide evidence showing that applying a targeted resistance to the pelvis may induce a forced use of the paretic leg during walking.

Long-term deficits of the paretic limb follow post-stroke compensatory limb use in C57BL/6 mice

Stroke is a leading cause of long-term disability that most often results in impairment of a single limb, contralateral to the injury (paretic limb). While stroke survivors often receive some type of rehabilitative training, chronic deficits persist. It has been suggested that compensatory use of the nonparetic limb immediately after injury may underlie these long-term consequences. The current study investigated the behavioral effects of early compensatory limb use on behavioral outcome of the paretic limb in a mouse model of stroke. Mice received unilateral stroke after acquiring skilled motor performance on a reaching task. Following injury, mice received either delayed rehabilitation of the paretic limb or compensatory limb training prior to delayed rehabilitative training. After 28 days of focused rehabilitative training of the paretic limb, mice that had previously received compensatory limb training exhibited performance that was similar to their initial deficit after stroke while mice that received delayed rehabilitative training improved to pre-operative performance levels. Our results indicate that even with extensive focused training of the paretic limb, early compensatory limb use has a lasting impact on the behavioral flexibility and ultimate functional outcome of the paretic limb.

Constraint-induced movement therapy for upper extremities in people with stroke

BACKGROUND

In people who have had a stroke, upper limb paresis affects many activities of daily life. Reducing disability is therefore a major aim of rehabilitative interventions. Despite preserving or recovering movement ability after stroke, sometimes people do not fully realise this ability in their everyday activities. Constraint-induced movement therapy (CIMT) is an approach to stroke rehabilitation that involves the forced use and massed practice of the affected arm by restraining the unaffected arm. This has been proposed as a useful tool for recovering abilities in everyday activities.

OBJECTIVES

To assess the efficacy of CIMT, modified CIMT (mCIMT), or forced use (FU) for arm management in people with hemiparesis after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register (last searched June 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library Issue 1, 2015), MEDLINE (1966 to January 2015), EMBASE (1980 to January 2015), CINAHL (1982 to January 2015), and the Physiotherapy Evidence Database (PEDro; January 2015).

SELECTION CRITERIA

Randomised control trials (RCTs) and quasi-RCTs comparing CIMT, mCIMT or FU with other rehabilitative techniques, or none.

DATA COLLECTION AND ANALYSIS

One author identified trials from the results of the electronic searches according to the inclusion and exclusion criteria, three review authors independently assessed methodological quality and risk of bias, and extracted data. The primary outcome was disability.

MAIN RESULTS

We included 42 studies involving 1453 participants. The trials included participants who had some residual motor power of the paretic arm, the potential for further motor recovery and with limited pain or spasticity, but tended to use the limb little, if at all. The majority of studies were underpowered (median number of included participants was 29) and we cannot rule out small-trial bias. Eleven trials (344 participants) assessed disability immediately after the intervention, indicating a non-significant standard mean difference (SMD) 0.24 (95% confidence interval (CI) -0.05 to 0.52) favouring CIMT compared with conventional treatment. For the most frequently reported outcome, arm motor function (28 studies involving 858 participants), the SMD was 0.34 (95% CI 0.12 to 0.55) showing a significant effect (P value 0.004) in favour of CIMT. Three studies involving 125 participants explored disability after a few months of follow-up and found no significant difference, SMD -0.20 (95% CI -0.57 to 0.16) in favour of conventional treatment.

AUTHORS' CONCLUSIONS

CIMT is a multi-faceted intervention where restriction of the less affected limb is accompanied by increased exercise tailored to the person's capacity. We found that CIMT was associated with limited improvements in motor impairment and motor function, but that these benefits did not convincingly reduce disability. This differs from the result of our previous meta-analysis where there was a suggestion that CIMT might be superior to traditional rehabilitation. Information about the long-term effects of CIMT is scarce. Further trials studying the relationship between participant characteristics and improved outcomes are required.

Upper Limb Motor Impairment After Stroke

Understanding poststroke upper limb impairment is essential to planning therapeutic efforts to restore function. However, determining which upper limb impairment to treat and how is complex because the impairments are not static and multiple impairments may be present simultaneously. How impairments contribute to upper limb dysfunction may be understood by examining them from the perspective of their functional consequences. There are 3 main functional consequences of impairments on upper limb function: (1) learned nonuse, (2) learned bad use, and (3) forgetting as determined by behavioral analysis of tasks. The impairments that contribute to each of these functional limitations are described.

The functional significance of cortical reorganization and the parallel development of CI therapy

For the nineteenth and the better part of the twentieth centuries two correlative beliefs were strongly held by almost all neuroscientists and practitioners in the field of neurorehabilitation. The first was that after maturity the adult CNS was hardwired and fixed, and second that in the chronic phase after CNS injury no substantial recovery of function could take place no matter what intervention was employed. However, in the last part of the twentieth century evidence began to accumulate that neither belief was correct. First, in the 1960s and 1970s, in research with primates given a surgical abolition of somatic sensation from a single forelimb, which rendered the extremity useless, it was found that behavioral techniques could convert the limb into an extremity that could be used extensively. Beginning in the late 1980s, the techniques employed with deafferented monkeys were translated into a rehabilitation treatment, termed Constraint Induced Movement therapy or CI therapy, for substantially improving the motor deficit in humans of the upper and lower extremities in the chronic phase after stroke. CI therapy has been applied successfully to other types of damage to the CNS such as traumatic brain injury, cerebral palsy, multiple sclerosis, and spinal cord injury, and it has also been used to improve function in focal hand dystonia and for aphasia after stroke. As this work was proceeding, it was being shown during the 1980s and 1990s that sustained modulation of afferent input could alter the structure of the CNS and that this topographic reorganization could have relevance to the function of the individual. The alteration in these once fundamental beliefs has given rise to important recent developments in neuroscience and neurorehabilitation and holds promise for further increasing our understanding of CNS function and extending the boundaries of what is possible in neurorehabilitation.

Effects of a gait training session combined with a mass on the non-paretic lower limb on locomotion of hemiparetic patients: a randomized controlled clinical trial

BACKGROUND

Results of recent studies have suggested that restraint of non-paretic lower limb movement could improve locomotion in hemiplegic patients. The aim of this study was therefore to determine if a mass applied to the non-paretic lower limb during a single gait training session (GTS) would specifically improve spatio-temporal, kinematic and kinetic gait parameters (GP) of the paretic lower limb.

METHODS

Sixty chronic hemiplegic subjects were included in this randomized study. Each participated in one of four GTS conditions: overground or on a treadmill while wearing or not wearing an ankle mass. All subjects were assessed before, immediately after and 20 min after the end of the GTS using 3D gait analysis.

RESULTS

The results showed that restraining the non-paretic lower limb during a GTS had no specific effect on GP of the paretic limb, whereas it increased braking force of the non-paretic limb.

CONCLUSION

Restraining the non-paretic lower limb of hemiparetic patients with a mass applied to the ankle does not seem to be an effective approach to improve paretic lower limb parameters during a single GTS.

The behavior-analytic origins of constraint-induced movement therapy: an example of behavioral neurorehabilitation

Constraint-induced (CI) therapy is a term given to a family of efficacious neurorehabilitation treatments including to date: upper extremity CI movement therapy, lower extremity CI movement therapy, pediatric CI therapy, and CI aphasia therapy. The purpose of this article is to outline the behavior analysis origins of CI therapy and the ways in which its procedures incorporate behavior analysis methods and principles. The intervention is founded on the concept of learned nonuse, a mechanism now empirically demonstrated to exist, which occurs after many different types of damage to the central nervous system (CNS). It results from the dramatic alteration of the contingencies of reinforcement that results from substantial CNS damage and leads to a greater deficit than is warranted by the actual damage sustained. CI therapy produces a countervailing alteration in the contingencies of reinforcement. The intervention has been used successfully to substantially improve motor deficits after stroke, traumatic brain injury, spinal cord injury, multiple sclerosis, with cerebral palsy in a pediatric population, and for language impairment in poststroke aphasia. The protocol of CI therapy consists primarily of standard behavior-analytic methods. It produces a marked plastic brain change that is correlated with its therapeutic effect, and therefore provides an example of the way in which behavior change can contribute to a profound remodeling of the brain. CI therapy may be viewed as an example of behavioral neurorehabilitation.

Distal forelimb representations in primary motor cortex are redistributed after forelimb restriction: a longitudinal study in adult squirrel monkeys

Primary motor cortex (M1) movement representations reflect acquired motor skills. Representations of muscles and joints used in a skilled task expand. However, it is unknown whether motor restriction in healthy individuals results in complementary reductions in M1 representations. With the use of intracortical microstimulation techniques in squirrel monkeys, detailed maps of movement representations in M1 were derived before and up to 35 wk after restriction of the preferred distal forelimb (DFL) by use of a soft cast. Although total DFL area and movement threshold remained constant, casting resulted in a redistribution of digit and wrist/forearm representations. Digit representations progressively decreased, whereas wrist/forearm representations progressively increased in areal extent. In three of four monkeys, hand preference returned to normal by the end of the postcast recovery period, and postrecovery maps demonstrated reversal of restriction-induced changes. However, in one monkey, a chronic motor impairment occurred in the casted limb. Rehabilitation via a forced-use paradigm resulted in recovery in use and skill of the impaired limb, as well as restoration of normal motor maps. These results demonstrate that plasticity in motor representations can be induced by training or restricting movements of the limb. Physiological changes induced by restriction appear to be reversible, even in the case of adverse motor outcomes. The respective contributions of both disuse and lost motor skills are discussed. These results have relevance for clinical conditions requiring forelimb casting as well as interpreting the differential effects of injury and disuse that are necessarily intertwined after cortical injury, as occurs in stroke.

Barriers to the implementation of constraint-induced movement therapy into practice

BACKGROUND AND PURPOSE

Constraint-induced movement therapy (CIMT) has been studied for many years in the treatment of the hemiplegic upper extremity (UE). However, there has been limited adoption of the protocol in daily practice.

METHODS

In this article, we review the CIMT literature specifically for meta-analysis, randomized controlled trials (RCTs), recent case reports, case series, and pilot studies of CIMT in the adult poststroke population to identify barriers to implementation.

RESULTS

The following barriers have been identified: (a) limited generalizability, (b) resource intensity, (c) therapist factors, (d) patient factors, and (e) uncertainty regarding the emerging debate that the gains seen may be a result of intense, task-specific therapy focused on the use of the more affected UE and not specific to the protocol.

CONCLUSIONS

CIMT has positive outcomes in the treatment of a select group of stroke survivors. Many national guidelines of stroke rehabilitation recommend that CIMT be used when appropriate, however adoption into practice has been limited. The issue of generalizability is being addressed by expanding protocol application to other populations. Resource intensity, with respect to cost and therapist time, is a major concern and has lead to the development of novel modes of service delivery. The benefit seen with CIMT may actually be the result of exposure to intense, task-specific therapy with a focus on the use of the more affected UE, but more research into this area is needed.

Constraint-Induced Movement Therapy (CIMT): Current Perspectives and Future Directions

Constraint-induced movement therapy (CIMT) has gained considerable popularity as a treatment technique for upper extremity rehabilitation among patients with mild-to-moderate stroke. While substantial evidence has emerged to support its applicability, issues remain unanswered regarding the best and most practical approach. Following the establishment of what can be called the "signature" CIMT approach characterized by intense clinic/laboratory-based practice, several distributed forms of training, collectively known as modified constraint therapy (mCIMT), have emerged. There is a need to examine the strengths and limitations of such approaches, and based upon such information, develop the components of a study that would compare the signature approach to the best elements of mCIMT, referred to here as "alternative" CIMT. Based upon a PEDro review of literature, limitations in mCIMT studies for meeting criteria were identified and discussed. A suggestion for a "first effort" at a comparative study that would both address such limitations while taking practical considerations into account is provided.

Plasticity in cortical motor upper-limb representation following stroke and rehabilitation: two longitudinal multi-joint FMRI case-studies

Motor dysfunction and recovery following stroke and rehabilitation are associated with primary motor cortex plasticity. To better track these effects we studied two patients with sub-acute sub-cortical stroke causing hemiparesis, who underwent an effective behavioral treatment termed Constraint Induced Movement Therapy (CIMT). The therapy involves 2 weeks of intensive motor training of the hemiparetic limb coupled with immobilization of the unaffected limb. The study included a longitudinal series of clinical evaluations and fMRI scans, before and after the treatment. The fMRI task included wrist, elbow, or ankle movements. Activity in the M1 upper-limb region of control subjects was stable, strictly contralateral, and similar in amplitude for elbow and wrist movements. These findings reflect the well-known contralateral motor control and support the idea of overlapping representations of adjacent joints in M1. In both patients, pre-CIMT activation patterns in M1 were tested twice and did not change significantly, were contralateral, and included elbow-wrist differences. Following CIMT, the clinical condition of both patients improved and three fMRI-explored prototypes were found: First, cluster position remained constant; Second, ipsilateral activity appeared in the unaffected hemispheres during hemiparetic movements; Third, patient-specific elbow-wrist inter and intra hemispheric differences were modified. All effects were long-lasting. We suggest that overlapping representations of adjacent joints contributed to the cortical plasticity observed following CIMT. Our findings should be confirmed by studying larger groups of homogeneous patients. Nevertheless, this study introduces multi-joint imaging studies and shows that it is both possible and valuable to carry it out in stroke patients.

Forced-use, without therapy, in children with hemiplegia: preliminary study of a new approach for the upper limb

BACKGROUND

Forced use (FU) is an emerging treatment for children with hemiplegic cerebral palsy (CP). It involves constraining the unaffected arm and no additional treatment of the affected arm. Our study examined a new approach to FU in children with hemiplegic CP: that is, restraint of the unaffected limb and no rehabilitation.

METHODS

Ten children with hemiplegic CP aged between 5 and 9 years were compared with 10 control children (aged between 5 and 8 y). All participants were classified as MACS level II.The FU group wore a fixed cast, on the unaffected arm for 21 consecutive days, and, such as the control group, did not receive any physical therapy.All participants were assessed by the Melbourne Assessment of Unilateral Upper Limb Function and the Shriners Hospital Upper Extremity Evaluation.

RESULTS

A statistically significant increase in both the functional scales was already apparent after cast removal and was maintained during follow-ups. The total Melbourne Assessment of Unilateral Upper Limb Function percentage score increased significantly to 9.5% and 12.3% on 3-week and 3-month follow-up examinations, respectively (P<0.05). A statistically significant increase was observed in 2 of the 3 parts of the Shriners Hospital Upper Extremity Evaluation: spontaneous use (P<0.05) and the ability of the involved limb to grasp and release (G/R) (P<0.05).

CONCLUSIONS

These preliminary results suggest that FU without rehabilitation improves the spontaneous use and function of the affected upper limb. In children with hemiplegia, this approach may be an economically viable means of upper limb treatment that has no side effects.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions to Authors for complete description of level of evidence.

Minimal forced use without constraint stimulates spontaneous use of the impaired upper extremity following motor cortex injury

The purpose of this study was to determine if recovery of neurologically impaired hand function following isolated motor cortex injury would occur without constraint of the non-impaired limb, and without daily forced use of the impaired limb. Nine monkeys (Macaca mulatta) received neurosurgical lesions of various extents to arm representations of motor cortex in the hemisphere contralateral to the preferred hand. After the lesion, no physical constraints were placed on the ipsilesional arm/hand and motor testing was carried out weekly with a maximum of 40 attempts in two fine motor tasks that required use of the contralesional hand for successful food acquisition. These motor tests were the only "forced use" of the contralesional hand. We also tested regularly for spontaneous use of the contralesional hand in a fine motor task in which either hand could be used for successful performance. This minimal intervention was sufficient to induce recovery of the contralesional hand to such a functional level that eight of the monkeys chose to use that hand on some trials when either hand could be used. Percentage use of the contralesional hand (in the task when either hand could be used) varied considerably among monkeys and was not related to lesion volume or recovery of motor skill. These data demonstrate a remarkable capacity for recovery of spontaneous use of the impaired hand following localized frontal lobe lesions. Clinically, these observations underscore the importance of therapeutic intervention to inhibit the induction of the learned nonuse phenomenon after neurological injury.

Constraint-induced movement therapy for upper extremities in stroke patients

BACKGROUND

In stroke patients, upper limb paresis affects many activities of daily life. Reducing disability is therefore a major aim of rehabilitation programmes for hemiparetic patients. Constraint-induced movement therapy (CIMT) is a current approach to stroke rehabilitation that implies the forced use and the massed practice of the affected arm by restraining the unaffected arm.

OBJECTIVES

To assess the efficacy of CIMT, modified CIMT (mCIMT), or forced use (FU) for arm management in hemiparetic patients.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched June 2008), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2008), MEDLINE (1966 to June 2008), EMBASE (1980 to June 2008), CINAHL (1982 to June 2008), and the Physiotherapy Evidence Database (PEDro) (June 2008).

SELECTION CRITERIA

Randomised control trials (RCTs) and quasi-RCTs (qRCTs) comparing CIMT, mCIMT or FU with other rehabilitative techniques, or none.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified the identified trials according to the inclusion and exclusion criteria, assessed methodological quality and extracted data. The primary outcome was disability.

MAIN RESULTS

We included 19 studies involving 619 participants. The trials included participants who had some residual motor power of the paretic arm, the potential for further motor recovery and with limited pain or spasticity, but tended to use the limb little if at all. Only five studies had adequate allocation concealment. The majority of studies were underpowered (median number of included patients was 15) and we cannot rule out small-trial bias. Six trials (184 patients) assessed disability immediately after the intervention, indicating a significant standard mean difference (SMD) of 0.36, 95% confidence interval (CI) 0.06 to 0.65. For the most frequently reported outcome, arm motor function (11 studies involving 373 patients), the SMD was 0.72 (95% CI 0.32 to 1.12). There were only two studies that explored disability improvement after a few months of follow up and found no significant difference, SMD -0.07 (95% CI -0.53 to 0.40).

AUTHORS' CONCLUSIONS

CIMT is a multifaceted intervention: the restriction to the normal limb is accompanied by a certain amount of exercise of the appropriate quality. It is associated with a moderate reduction in disability assessed at the end of the treatment period. However, for disability measured some months after the end of treatment, there was no evidence of persisting benefit. Further randomised trials, with larger sample sizes and longer follow up, are justified.

Volumetric effects of motor cortex injury on recovery of dexterous movements

Due to the heterogeneous nature of most brain injuries, the contributions of gray and white matter involvement to motor deficits and recovery potential remain obscure. We tested the hypothesis that duration of hand motor impairment and recovery of skilled arm and hand motor function depends on the volume of gray and white matter damage of the frontal lobe. Lesions of the primary motor cortex (M1), M1 + lateral premotor cortex (LPMC), M1 + LPMC + supplementary motor cortex (M2) or multifocal lesions affecting motor areas and medial prefrontal cortex were evaluated in rhesus monkeys. Fine hand motor function was quantitatively assessed pre-lesion and for 3-12 months post-lesion using two motor tests. White and gray matter lesion volumes were determined using histological and quantitative methods. Regression analyses showed that duration of fine hand motor impairment was strongly correlated (R(2)>0.8) with the volume of gray and white matter lesions, with white matter lesion volume being the primary predictor of impairment duration. Level of recovery of fine hand motor skill was also well correlated (R(2)>0.5) with gray and white matter lesion volume. In some monkeys post-lesion skill exceeded pre-lesion skill in one or both motor tasks demonstrating that continued post-injury task practice can improve motor performance after localized loss of frontal motor cortex. These findings will assist in interpreting acute motor deficits, predicting the time course and expected level of functional recovery, and designing therapeutic strategies in patients with localized frontal lobe injury or neurosurgical resection.

Aphasia therapy on a neuroscience basis

BACKGROUND: Brain research has documented that the cortical mechanisms for language and action are tightly interwoven and, concurrently, new approaches to language therapy in neurological patients are being developed that implement language training in the context of relevant linguistic and non-linguistic actions, therefore taking advantage of the mutual connections of language and action systems in the brain. A further well-known neuroscience principle is that learning at the neuronal level is driven by correlation; consequently, new approaches to language therapy emphasise massed practice in a short time, thus maximising therapy quantity and frequency and, therefore, correlation at the behavioural and neuronal levels. Learned non-use of unsuccessful actions plays a major role in the chronification of neurological deficits, and behavioural approaches to therapy have therefore employed shaping and other learning techniques to counteract such non-use. AIMS: Advances in theoretical and experimental neuroscience have important implications for clinical practice. We exemplify this in the domain of aphasia rehabilitation. MAIN CONTRIBUTION: Whereas classical wisdom had been that aphasia cannot be significantly improved at a chronic stage, we here review evidence that one type of intensive language-action therapy (ILAT)-constraint-induced aphasia therapy-led to significant improvement of language performance in patients with chronic aphasia. We discuss perspectives for further improving speech-language therapy, including drug treatment that may be particularly fruitful when applied in conjunction with behavioural treatment. In a final section we highlight intensive and rapid therapy studies in chronic aphasia as a unique tool for exploring the cortical reorganisation of language. CONCLUSIONS: We conclude that intensive language action therapy is an efficient tool for improving language functions even at chronic stages of aphasia. Therapy studies using this technique can open new perspectives for research into the plasticity of human language circuits.

Visual restoration in cortical blindness: Insights from natural and TMS-induced blindsight

Unilateral damage to visual cortex of the parietal or occipital lobe can cause the patient to be unaware of contralesional visual information due to either hemispatial neglect or hemianopia. It is now known that both neglect and hemianopia result from the disruption of a dynamic interaction between cortical visual pathways and more phylogenetically primitive visual pathways to the midbrain. We consider the therapeutic implications of these cortical-subcortical interactions in the rehabilitation of hemianopia. We start with the pheonmenon of "blindsight", in which patients with hemianopia can be shown, by implicit measures of visual detection or discrimination, to process visual information without conscious awareness. Some variants of blindsight have been postulated to recruit subcortical processes, while others may reflect compensatory optimisation of processing of spared visual cortex. Both mechanisms may offer opportunities for innovative strategies for rehabilitation of visual field defects. We relate the neural mechanisms that have been proposed to underlie blindsight to those that have been suggested to underlie the recovery of visual function after rehabilitation. It is suggested that the similarity and overlap of the neural processes supporting blindsight and recovery of visual function might provide insights for effective rehabilitation strategies for restoring visual functions.

Functional reorganization and recovery after constraint-induced movement therapy in subacute stroke: case reports

Preliminary assessments of the feasibility, safety, and effects on neuronal reorganization measured with transcranial magnetic stimulation (TMS) from Constraint-Induced Movement Therapy (CIMT) of the upper extremity were made in eight cases of subacute stroke. Within fourteen days of their stroke, patients were randomly assigned to two weeks of CIMT or traditional therapy. Baseline motor performance and cortical/subcortical representation for movement with TMS were assessed before treatment. Post-treatment assessments were made at the end of treatment and at three months after the stroke. The TMS mapping showed a larger motor representation in the lesioned hemisphere of the CIMT patients as compared to the controls at the three-month follow-up assessment. The enlarged motor representation in the lesioned hemisphere for hand movement correlated with improved motor function of the affected hand, suggesting a link between movement representation size as measured with TMS and functionality. These results suggest that TMS can be safely and effectively used to assess brain function in subacute stroke and further suggest that CIMT may enhance cortical/subcortical motor reorganization and accelerate motor recovery when started within the first two weeks after stroke.

Constraint-Induced Movement Therapy

Constraint-induced movement therapy improves outcome after chronic stroke, conforms experimental observations of neuronal plasticity, and proves the efficacy of intensive occupational therapy. More acutely instituted constraint-induced movement therapy has both practical and theoretic risks and benefits that deserve further careful evaluation.