Minimal Detectable Change and Clinically Important Difference of the Wolf Motor Function Test in Stroke Patients

Objectives. This study aimed to establish the minimal detectable change (MDC) and clinically important differences (CID) of the Wolf Motor Function Test (WMFT) in patients with stroke, and to assess the proportions of patients' change scores exceeding the MDC and CID after stroke rehabilitation. Methods. A total of 57 patients received 1 of the 3 treatments for 3 weeks and underwent clinical assessments before and after treatment. The MDC, at 90% confidence (MDC 90), was calculated from the standard error of measurement to indicate a real change for individual patients. Anchor-based and distribution-based approaches were used to triangulate the values of minimal CID. The percentages of patients exceeding the MDC and minimal CID were also examined. Results. The MDC90 of the WMFT was 4.36 for the performance time (WMFT time) and 0.37 for the functional ability scale (WMFT FAS). The minimal CID ranged from 1.5 to 2 seconds on the WMFT time and from 0.2 to 0.4 points on the WMFT FAS. The MDC and CID proportions ranged from 14% to 30% on the WMFT time and from 39% to 65% on the WMFT FAS, respectively. Conclusions. The change score of an individual patient has to reach 4.36 and 0.37 on the WMFT time and WMFT FAS to indicate a real change. The mean change scores of a stroke group on the WMFT time and WMFT FAS should achieve 1.5 to 2 seconds and 0.2 to 0.4 points to be regarded as clinically important changes. Furthermore, the WMFT FAS may be more responsive than the WMFT time based on the results of proportions exceeding the threshold criteria.

[Ultrasound guidance in pediatric regional anesthesia]

Ultrasound imaging is being used to guide pediatric nerve block procedures. Difficulties that arise because of the smaller anatomical structures in children can be compensated for by the greater aqueous consistency and reduced calcification. Given the shorter distance between the surface of the skin and nerves, it is advisable to use a linear array transducer working at a high frequency (7-10 MHz). Like adults, children benefit when ultrasound guidance is used in the performance of neuraxial nerve trunk blocks, particularly of the umbilical and ilioinguinal nerves, and in greater measure in spinal blocks. Ultrasound guidance enhances efficacy and also affords the important advantage of greater safety. The main disadvantages are the cost of equipment and the necessary learning curve.

[Pediatric complex regional pain syndrome affecting an upper limb: 7 cases and a brief review of the literature]

OBJECTIVES

To review the clinical, psychiatric, and social characteristics of complex regional pain syndrome in children and adolescents treated in the last 4 years at our pediatric pain clinic.

MATERIAL AND METHODS

We analyzed the specialty of the initial treating physician, age, sex, initial diagnosis, pain intensity, degree of disability, fear of movement, clinical stage, history of trauma, time between onset and diagnosis, psychiatric illness, family support and behavior, chronic pain in near relatives, school grades and attendance, treatment given at the pediatric pain clinic, recurrences, and course of disease.

RESULTS

The cases of 7 patients (4 female, 3 male) between the ages of 8 and 15 years were analyzed. Four had been referred by the child psychiatry department. The initial diagnosis was erroneous in all but 1 case. Pain intensity and associated disability were severe in 5 patients and 4 expressed intense fear of moving the limb. Five patients had initial stage I disease, 5 had a history of trauma, and 5 had been previously treated by immobilization of the limb and prescription of nonsteroidal anti-inflammatory drugs. The time between onset and diagnosis ranged from 2 to 18 months (mean [SD], 6.4 [3.5] months). In most cases psychiatric disease and concomitant social disability were present. Treatment prescribed at the pediatric pain clinic consisted of a combination of oral medication, psychologic and psychiatric counseling, and intensive physiotherapy for all but 2 children, who required regional nerve blocks.

CONCLUSION

The clinical course was satisfactory for all but 1 patient, who developed severe disability. Complex regional pain syndrome affecting an upper limb is uncommon in children but not rare.

Upper extremity regional anesthesia: essentials of our current understanding, 2008

Brachial plexus blockade is the cornerstone of the peripheral nerve regional anesthesia practice of most anesthesiologists. As part of the American Society of Regional Anesthesia and Pain Medicine's commitment to providing intensive evidence-based education related to regional anesthesia and analgesia, this article is a complete update of our 2002 comprehensive review of upper extremity anesthesia. The text of the review focuses on (1) pertinent anatomy, (2) approaches to the brachial plexus and techniques that optimize block quality, (4) local anesthetic and adjuvant pharmacology, (5) complications, (6) perioperative issues, and (6) challenges for future research.

Targeted muscle reinnervation for real-time myoelectric control of multifunction artificial arms

CONTEXT

Improving the function of prosthetic arms remains a challenge, because access to the neural-control information for the arm is lost during amputation. A surgical technique called targeted muscle reinnervation (TMR) transfers residual arm nerves to alternative muscle sites. After reinnervation, these target muscles produce electromyogram (EMG) signals on the surface of the skin that can be measured and used to control prosthetic arms.

OBJECTIVE

To assess the performance of patients with upper-limb amputation who had undergone TMR surgery, using a pattern-recognition algorithm to decode EMG signals and control prosthetic-arm motions.

DESIGN, SETTING, AND PARTICIPANTS

Study conducted between January 2007 and January 2008 at the Rehabilitation Institute of Chicago among 5 patients with shoulder-disarticulation or transhumeral amputations who underwent TMR surgery between February 2002 and October 2006 and 5 control participants without amputation. Surface EMG signals were recorded from all participants and decoded using a pattern-recognition algorithm. The decoding program controlled the movement of a virtual prosthetic arm. All participants were instructed to perform various arm movements, and their abilities to control the virtual prosthetic arm were measured. In addition, TMR patients used the same control system to operate advanced arm prosthesis prototypes.

MAIN OUTCOME MEASURE

Performance metrics measured during virtual arm movements included motion selection time, motion completion time, and motion completion ("success") rate.

RESULTS

The TMR patients were able to repeatedly perform 10 different elbow, wrist, and hand motions with the virtual prosthetic arm. For these patients, the mean motion selection and motion completion times for elbow and wrist movements were 0.22 seconds (SD, 0.06) and 1.29 seconds (SD, 0.15), respectively. These times were 0.06 seconds and 0.21 seconds longer than the mean times for control participants. For TMR patients, the mean motion selection and motion completion times for hand-grasp patterns were 0.38 seconds (SD, 0.12) and 1.54 seconds (SD, 0.27), respectively. These patients successfully completed a mean of 96.3% (SD, 3.8) of elbow and wrist movements and 86.9% (SD, 13.9) of hand movements within 5 seconds, compared with 100% (SD, 0) and 96.7% (SD, 4.7) completed by controls. Three of the patients were able to demonstrate the use of this control system in advanced prostheses, including motorized shoulders, elbows, wrists, and hands.

CONCLUSION

These results suggest that reinnervated muscles can produce sufficient EMG information for real-time control of advanced artificial arms.

[Positioning injuries among patients undergoing spine surgery]

INTRODUCTION

The aim of this study was to answer the questions: Which kind of positioning injuries occurred in anaesthetized orthopaedic patients undergoing spine surgery who were prone-positioned for more than two hours? What was the incidence of positioning injuries? Which patients were at particular risk of developing positioning-related injuries?

MATERIAL AND METHODS

Follow-up study comprising 299 patients. A patient record followed the patient from the day of surgery until discharge. Selected pre-disposing factors related to positioning injuries as well as positioning-related injuries were registered. One year after surgery, localisation, duration and treatment of positioning-related injuries were registered. A total of 299 patients were included. Among these, 60 patients died within the first year, and 52 could not be reached. The remaining 187 patients were interviewed by telephone one year after surgery using a structured guide

RESULTS

In all, 33 patients had nerve injuries one year after surgery, among these 18 patients had nerve injuries located to the upper extremities.

CONCLUSION

A possible association between the duration of the prone position and positioning injuries emerged, but there was no connection between nerve injuries located to the upper extremities and the predisposing factors. Nerve injuries in arms/hands influence daily living. Future studies are needed to investigate predisposing factors such as high body mass index and body build, and guidelines for positioning are recommended.

Effect of grip location, arm support, and muscle stretch on sustained finger flexor activity following stroke

After gripping an object with the affected hand, stroke survivors may experience difficulty in relaxing the hand to release the object. The goals of this study were: 1) to quantify the severity of this problem by measuring the time needed to terminate a grip activity (grip termination time) and 2) to examine the effect of factors such as grip location, external arm support, and muscle stretch on grip termination time for the affected hand. Ten subjects with chronic hemiparesis subsequent to stroke grasped a cylinder with maximum effort for 5 seconds and then attempted to relax the fingers as quickly as possible. Finger flexor muscle activity was recorded. Grip termination time was defined as the time required for the finger flexor activity to drop to the initial (pre-exertion) level. Grip termination time for the affected hand (6.1 seconds) was three times greater than that for the unaffected hand (2.1 seconds). Reduction of required activation of proximal arm muscles through use of a gravity-compensating arm orthosis decreased the grip termination time for the affected hand (p0.05). Conversely, active muscle stretch increased grip termination time. Therapies and treatment methods which reduce the delay in terminating finger flexor muscle activity may increase functional independence for stroke survivors.

The pain response of infants in Turkey to vaccination in different injection sites

This study was carried out with the aim of comparing pain responses of children who receive intramuscular (IM) vaccination in deltoid muscle versus the pain responses of those who receive IM vaccination in the vastus lateralis. A total of 185 infants were randomly assigned to one of the two study groups. The deltoid group and the vastus lateralis group were vaccinated respectively in the deltoid muscle and the vastus lateralis. Our results indicated that pain response of infants was similar in each group. However, crying duration of the children who received the vastus lateralis vaccination was shorter than that of the deltoid group after the procedure.

A man in the barrel with neck pain

A 38-year-old man presented with an abrupt onset of occipital and neck pain, radiating to both shoulders. The pain was accompanied by inability to lift his arms against gravity (the "man-in-the-barrel" syndrome). These symptoms were associated with bilateral hand paresthesias, right-sided throbbing headache, vertigo, nausea, and vomiting. All symptoms resolved within 30 minutes, but arm weakness recurred. The differential diagnosis and historical origins of the "man-in-the-barrel" syndrome are reviewed.

Differential effects of startle on reaction time for finger and arm movements

Recent studies using a reaction time (RT) task have reported that a preprogrammed response could be triggered directly by a startling acoustic stimulus (115-124 dB) presented along with the usual "go" signal. It has been suggested that details of the upcoming response could be stored subcortically and are accessible by the startle volley, directly eliciting the correct movement. However, certain muscles (e.g., intrinsic hand) are heavily dependent on cortico-motoneuronal connections and thus would not be directly subject to the subcortical startle volley in a similar way to muscles whose innervations include extensive reticular connections. In this study, 14 participants performed 75 trials in each of two tasks within a RT paradigm: an arm extension task and an index finger abduction task. In 12 trials within each task, the regular go stimulus (82 dB) was replaced with a 115-dB startling stimulus. Results showed that, in the arm task, the presence of a startle reaction led to significantly shorter latency arm movements compared with the effect of the increased stimulus intensity alone. In contrast, for the finger task, no additional decrease in RT caused by startle was observed. Taken together, these results suggest that only movements that involve muscles more strongly innervated by subcortical pathways are susceptible to response advancement by startle.

Wireless wearable controller for upper-limb neuroprosthesis

The objective of this project was to develop a wireless, wearable joint angle transducer to enable proportional control of an upper-limb neuroprosthesis by wrist position. Implanted neuroprostheses use functional electrical stimulation to provide hand grasp to individuals with tetraplegia. Wrist position is advantageous for control because it augments the tenodesis grasp and can be implemented bilaterally. Recently developed, fully implantable multichannel stimulators are battery-powered and use wireless telemetry to control stimulator outputs. An external wrist controller was designed for command signal acquisition for people with cervical-level spinal cord injury to control this implantable stimulator. The wearable controller, which uses gigantic magnetoresistive sensing techniques to measure wrist position, is worn on the forearm. A small dime-sized magnet is fixed to the back of the hand. Results indicate that the device is a feasible control method for an upper-limb neuroprosthesis and could be reduced to a small "wristwatch" size for cosmesis and easy donning.

Bilateral upper limb training with functional electric stimulation in patients with chronic stroke

BACKGROUND

The recovery rate of upper limb function after stroke is poor when compared with independent walking. Therefore, effective methods are warranted for upper limb rehabilitation.

OBJECTIVE

The aim of this study was to investigate the effectiveness of functional electric stimulation (FES) with bilateral activities training on upper limb function.

METHODS

This study was a double-blinded randomized controlled trial. Twenty patients were recruited 6 months after the onset of stroke and completed 15 training sessions. Participants were randomly assigned to the FES group or to the control group. Each session consisted of stretching activities (10 minutes), FES with bilateral tasks (20 minutes), and occupational therapy treatment (60 minutes). The participants used a self-trigger mechanism, with an accelerometer as a motion detector, for generating an electric stimulation pattern that was synchronized with the bilateral upper limb activities during the training. The participants in the control group received the same duration of stretching and occupational therapy training except that they just received placebo stimulation with the bilateral tasks. The outcome measures included Functional Test for the Hemiplegic Upper Extremity (FTHUE), Fugl-Meyer Assessment (FMA), grip power, forward reaching distance, active range of motion of wrist extension, Functional Independence Measure, and Modified Ashworth Scale.

RESULTS

At baseline comparison, there was no significant difference in both groups. After 15 training sessions, the FES group had significant improvement in FMA (P = .039), FTHUE (P = .001), and active range of motion of wrist extension (P = .020) when compared with the control group.

CONCLUSIONS

Bilateral upper limb training with FES could be an effective method for upper limb rehabilitation of stroke patients after 15 training sessions.

Longitudinal sliding of the median nerve in patients with non-specific arm pain

In patients with non-specific arm pain (NSAP; also known as repetitive strain injury), there are clinical signs of altered median nerve sliding. It is possible that a restriction along the nerve course will lead to abnormal increases in local strain during limb movements, possibly contributing to symptoms. The present study uses ultrasound imaging to examine median nerve sliding through the proximal and distal nerve segments in 18 NSAP patients. Longitudinal nerve sliding was measured during metacarpophalangeal, wrist and elbow movements. During elbow movements, the angle of elbow extension at which the nerve begins to move was determined, since this was expected to decrease with a restriction through the shoulder. The results from this study were compared with previously reported data. Nerve movements ranged from 1.26 to 4.73 mm in patients compared with 1.43-5.57 mm in controls. There was no significant difference in nerve sliding (p>0.05) or in the angle of elbow extension at which the nerve began to move (mean=53.4 degrees in patients, 52.0 degrees in controls; p>0.05). In summary, restriction of median nerve sliding is unlikely to play a major role in NSAP. Therefore, painful responses during limb movements which tension the nerve are unlikely to result from abnormal increases in nerve strain.

Bilateral capacity for speech sound processing in auditory comprehension: evidence from Wada procedures

Data from lesion studies suggest that the ability to perceive speech sounds, as measured by auditory comprehension tasks, is supported by temporal lobe systems in both the left and right hemisphere. For example, patients with left temporal lobe damage and auditory comprehension deficits (i.e., Wernicke's aphasics), nonetheless comprehend isolated words better than one would expect if their speech perception system had been largely destroyed (70-80% accuracy). Further, when comprehension fails in such patients their errors are more often semantically-based, than-phonemically based. The question addressed by the present study is whether this ability of the right hemisphere to process speech sounds is a result of plastic reorganization following chronic left hemisphere damage, or whether the ability exists in undamaged language systems. We sought to test these possibilities by studying auditory comprehension in acute left versus right hemisphere deactivation during Wada procedures. A series of 20 patients undergoing clinically indicated Wada procedures were asked to listen to an auditorily presented stimulus word, and then point to its matching picture on a card that contained the target picture, a semantic foil, a phonemic foil, and an unrelated foil. This task was performed under three conditions, baseline, during left carotid injection of sodium amytal, and during right carotid injection of sodium amytal. Overall, left hemisphere injection led to a significantly higher error rate than right hemisphere injection. However, consistent with lesion work, the majority (75%) of these errors were semantic in nature. These findings suggest that auditory comprehension deficits are predominantly semantic in nature, even following acute left hemisphere disruption. This, in turn, supports the hypothesis that the right hemisphere is capable of speech sound processing in the intact brain.

Safety and behavioral effects of high-frequency repetitive transcranial magnetic stimulation in stroke

BACKGROUND AND PURPOSE

Electromagnetic brain stimulation might have value to reduce motor deficits after stroke. Safety and behavioral effects of higher frequencies of repetitive transcranial magnetic stimulation (rTMS) require detailed assessment.

METHODS

Using an active treatment-only, unblinded, 2-center study design, patients with chronic stroke received 20 minutes of 20 Hz rTMS to the ipsilesional primary motor cortex hand area. Patients were assessed before, during the hour after, and 1 week after rTMS.

RESULTS

The 12 patients were 4.7+/-4.9 years poststroke (mean+/-SD) with moderate-severe arm motor deficits. In terms of safety, rTMS was well tolerated and did not cause new symptoms; systolic blood pressure increased from pre- to immediately post-rTMS by 7 mm Hg (P=0.043); and none of the behavioral measures showed a decrement. In terms of behavioral effects, modest improvements were seen, for example, in grip strength, range of motion, and pegboard performance, up to 1 week after rTMS. The strongest predictor of these motor gains was lower patient age.

CONCLUSIONS

A single session of high-frequency rTMS to the motor cortex was safe. These results require verification with addition of a placebo group and thus blinded assessments across a wide spectrum of poststroke deficits and with larger doses of 20 Hz rTMS.

Multiple accessory structures in the upper limb of a single cadaver

The arterial and muscular variations of the upper limbs are common but important with regard to surgical approaches. Even though anomalies of the coracobrachialis muscle are rare, anatomical variations of the biceps brachii, existence of the accessory muscles in the forearm and persistent median artery are known and well documented. During routine dissection, we observed some important anatomical variations in a 50-year-old male cadaver. The variations were unilateral. The anomalies were: third head for biceps brachii muscle, an accessory belly for coracobrachialis muscle crossing the median nerve and brachial vessels and continuing with the medial head of triceps brachii muscle to be inserted to the olecranon process (coracoulnaris), a persistent median artery and an additional muscle in the anterior compartment of forearm. Although there are individual reports about these variations, the combination of these variations in one cadaver has not previously been described in the literature. Awareness of these variations is necessary to avoid complications during radiodiagnostic procedures or surgeries in the upper limb.

Stroke rehabilitation reaches a threshold

Motor training with the upper limb affected by stroke partially reverses the loss of cortical representation after lesion and has been proposed to increase spontaneous arm use. Moreover, repeated attempts to use the affected hand in daily activities create a form of practice that can potentially lead to further improvement in motor performance. We thus hypothesized that if motor retraining after stroke increases spontaneous arm use sufficiently, then the patient will enter a virtuous circle in which spontaneous arm use and motor performance reinforce each other. In contrast, if the dose of therapy is not sufficient to bring spontaneous use above threshold, then performance will not increase and the patient will further develop compensatory strategies with the less affected hand. To refine this hypothesis, we developed a computational model of bilateral hand use in arm reaching to study the interactions between adaptive decision making and motor relearning after motor cortex lesion. The model contains a left and a right motor cortex, each controlling the opposite arm, and a single action choice module. The action choice module learns, via reinforcement learning, the value of using each arm for reaching in specific directions. Each motor cortex uses a neural population code to specify the initial direction along which the contralateral hand moves towards a target. The motor cortex learns to minimize directional errors and to maximize neuronal activity for each movement. The derived learning rule accounts for the reversal of the loss of cortical representation after rehabilitation and the increase of this loss after stroke with insufficient rehabilitation. Further, our model exhibits nonlinear and bistable behavior: if natural recovery, motor training, or both, brings performance above a certain threshold, then training can be stopped, as the repeated spontaneous arm use provides a form of motor learning that further bootstraps performance and spontaneous use. Below this threshold, motor training is “in vain”: there is little spontaneous arm use after training, the model exhibits learned nonuse, and compensatory movements with the less affected hand are reinforced. By exploring the nonlinear dynamics of stroke recovery using a biologically plausible neural model that accounts for reversal of the loss of motor cortex representation following rehabilitation or the lack thereof, respectively, we can explain previously hard to reconcile data on spontaneous arm use in stroke recovery. Further, our threshold prediction could be tested with an adaptive train–wait–train paradigm: if spontaneous arm use has increased in the “wait” period, then the threshold has been reached, and rehabilitation can be stopped. If spontaneous arm use is still low or has decreased, then another bout of rehabilitation is to be provided.

Stroke often leaves patients with predominantly unilateral functional limitations of the arm and hand. Although recovery of function after stroke is often achieved by compensatory use of the less affected limb, improving use of the more affected limb has been associated with increased quality of life. Here, we developed a biologically plausible model of bilateral reaching movements to investigate the mechanisms and conditions leading to effective rehabilitation. Our motor cortex model accounts for the experimental observation that motor training can reverse the loss of cortical representation due to lesion. Further, our model predicts that if spontaneous arm use is above a certain threshold, then training can be stopped, as the repeated spontaneous use provides a form of motor learning that further improves performance and spontaneous use. Below this threshold, training is “in vain,” and compensatory movements with the less affected hand are reinforced. Our model is a first step in the development of adaptive and cost-effective rehabilitation methods tailored to individuals poststroke.

Perceptual influences on Fitts' law

The linear relationship between movement time (MT) and index of difficulty (ID) for Fitts' type tasks has proven ubiquitous over the last 50+ years. A reciprocal aiming task (IDs 3, 4.5, 6) was used to determine if an enlarged visual display (visual angle 5.1 degrees , 7.4 degrees , or 13.3 degrees) would alter this relationship. With ID = 6, a condition typically associated with discrete action control, the largest visual display (13.3 degrees) allowed the motor system to exploit features of cyclical action control, e.g., shorter dwell times, more harmonic motion, less time decelerating the limb. The large visual display resulted in a quadratic relationship between MT and ID. For the IDs of 3 and 4.5, the visual displays did not alter the underlying control processes. The results are discussed in terms of the preference of the motor system to assemble movements from harmonic basis functions when salient visual information is provided.

Surgical anatomy of the radial nerve and profunda brachii artery within the triangular interval

INTRODUCTION

To date, only scant data has been reported regarding the anatomy of the radial nerve and profunda brachii artery and their relationships while within the triangular interval of the posterior arm. As this area has recently gained attention for using motor branches of the triceps muscle for nerve transfers, the present study was conducted.

MATERIALS AND METHODS

Fifteen adult cadavers (30 sides) underwent dissection, observation and quantitation of their triangular intervals and its contents. The relationship between the profunda brachii and radial nerve in the proximal one half and distal one half of this area was documented.

RESULTS

The length of the triangular interval had a mean of 6 cm and the width of this area was on average 2.5 cm. Within the triangular interval, we identified on average, 2.5 arterial branches and 2.3 nerve branches from the profunda brachii and radial nerve, respectively. The maximal number of branches of either the artery or nerve within this geometric region was five. In the proximal one half of this area, 75% of the arteries were found anterior to the radial nerve whereas in the distal one half of the interval most nerves were flanked by arterial branches on both medial and lateral sides. Not all branches of the profunda brachii artery were muscular in this region as some were found to supply the adjacent radial nerve. Communication between the profundi brachii artery in the triangular interval and the posterior humeral circumflex artery was found on two left sides (6.7%).

CONCLUSIONS

We hope that these anatomical data may be useful to the surgeon who utilizes branches of the proximal radial nerve for neurotization procedures or branches of the profunda brachii for flap procedures.

Arterial access through the right subclavian artery in surgery of the aortic arch improves neurologic outcome and mid-term quality of life

BACKGROUND

We have shown that selective antegrade cerebral perfusion improves mid-term quality of life in patients undergoing surgical repair for acute type A aortic dissection and aortic aneurysms. The aim of the study was to assess the impact of continuous cerebral perfusion through the right subclavian artery on immediate outcome and quality of life.

METHODS

Perioperative data of 567 consecutive patients who underwent surgery of the aortic arch using deep hypothermic circulatory arrest have been analyzed. Patients were divided into three groups, according to the management of cerebral protection. Three hundred eighty-seven patients (68.3%) had deep hypothermic circulatory arrest with pharmacologic protection with pentothal only, 91 (16.0%) had selective antegrade cerebral perfusion and pentothal, and 89 (15.7%) had continuous cerebral perfusion through the right subclavian artery and pentothal. All in-hospital data were assessed, and quality of life was analyzed prospectively 2.4 +/- 1.2 years after surgery with the Short Form-36 Health Survey Questionnaire.

RESULTS

Major perioperative cerebrovascular injuries were observed in 1.1% of the patients with continuous cerebral perfusion through the right subclavian artery, compared with 9.8% with selective antegrade cerebral perfusion (p < 0.001) and 6.5% in the group with no antegrade cerebral perfusion (p = 0.007). Average quality of life after an arrest time between 30 and 50 minutes with continuous cerebral perfusion through the right subclavian artery was significantly better than selective antegrade cerebral perfusion (90.2 +/- 12.1 versus 74.4 +/- 40.7; p = 0.015).

CONCLUSIONS

Continuous cerebral perfusion through the right subclavian artery improves considerably perioperative brain protection during deep hypothermic circulatory arrest. Irreversible perioperative neurologic complications can be significantly reduced and duration of deep hypothermic circulatory arrest can be extended up to 50 minutes without impairment in quality of life.

[Optimization of the components of regulation of vascular tone and microcirculatory hemostasis during prolonged regional block in local cold injury]

The impact of prolonged conduction block of the brachial plexus on the regulatory components of vascular tone, the state of vascular platelet hemostasis, and the activity of an inflammatory process was studied in patients with second-to-fourth degree local arm frostbites. The block alleviated arterial spasm, indirectly lowered myogenic tone, and decreased shunt blood flow. Nutritive circulation increased in the presence of a total increase in blood flow to the arm. There were increases in the intensity, rate, and potential of platelet aggregation. The concentration of proinflammatory cytokines reduced. This resulted in more efficient treatment.

[Portable ultrasound devices in regional anesthesia: the brachial plexus block]

Ultrasonography has received increasing attention in regional anesthesia in recent years because it allows visualization of the nerves, the needle, and the surrounding structures and makes it possible to monitor distribution of the local anesthetic. Ultrasound technology is unfamiliar to most anesthesiologists, unless they work with transesophageal echocardiography. Ultrasound-guided regional anesthesia relies entirely on the expertise of the person performing the technique and how that person interprets the images, though the latest portable ultrasound devices are ergonomically designed for fast, easy use, even by less experienced personnel. The high-frequency probes can identify the brachial plexus and produce excellent images of considerable educational value that differ only slightly from those provided by larger, more expensive equipment. Ultrasonography makes it possible to identify the brachial plexus, from the roots to the peripheral nerves of the arm. We describe the main approaches used in providing an ultrasound-guided brachial plexus block and explain the basic principles of ultrasound imaging.

Electrophysiological patterns of diabetic polyneuropathy

OBJECTIVE

This study evaluates the pattern of electrodiagnostic (EDX) abnormalities in diabetic sensorimotor polyneuropathies.

METHODS

EDX data from 112 consecutive patients with type 2 diabetes mellitus with distal, predominantly sensory, polyneuropathies were reviewed. Motor conduction velocities (CV), distal motor latencies (DML), compound muscle action potential (CMAP) amplitudes, distal to proximal amplitude ratios (PID), and F-wave latencies (FWL) were analyzed. Data were normalized based on normative reference values, and the proportion of nerves with abnormal values in the lower and upper limbs were evaluated. These data were also analyzed in relation to whether there was possible demyelinating versus axonal injury. Statistical analyses included comparison of the proportions of abnormal nerves in upper versus lower limbs as well as using Generalized Estimating Equations (GEE) to account for correlated observations for each patient between lower and upper limbs and adjusting for patient age effect.

RESULTS

CVs were significantly more abnormal in the legs than the arms (p < 0.0006) and decreased CMAP amplitudes meeting criteria for axonal injury were also more frequent in the legs (p < 0.0001). Using the GEE model, axonal injury was more common in the legs while demyelinating injury was more common in the arms based on FWLs, especially in younger persons (e.g., 40 years old vs. 50 years old). These differences are not readily explained by the duration of the diabetes.

CONCLUSION

Since in diabetics "axonal" type injury may be more common in the legs while "demyelinating" injury more frequent in the arms, this study emphasizes the limitation of this type of classification, and supports the idea that the pattern of EDX abnormalities in different types of neuropathies may be more helpful.

Accessory brachialis muscle: a case report

Variations of arm flexors are not uncommon with the exception of brachialis muscle. The role of brachialis is critical as it is the primary flexor of the elbow joint. Variations of brachialis are rare in literature. We present a case of an accessory-brachialis muscle (AcBr), found during routine cadaveric dissection. The AcBr originated from the lateral aspect of the brachialis muscle and lateral intermuscular septum. During its course towards the elbow, it crossed over the radial nerve and the distal tendon splits into two. The medial slip ran over the ulnar artery and merged with the deep fascia covering the pronator teres muscle, whereas lateral slip was inserted to the fascia covering the supinator. In the ipsilateral arm, an additional lateral cutaneous nerve of forearm (LCNF) was found coursing over the brachialis muscle medial to the LCNF. Clinical consideration of the present variations has been discussed. The present variation should be considered in the etiology of radial-tunnel syndrome (RTS).

[Peripheral nerve entrapment syndrome of the upper extremities in cases of inflammatory, rheumatic joint diseases]

Entrapment neuropathy of the upper extremities could be detected by electroneurophysiological investigations in one third of our patients with rheumatoid arthritis. These neuropathies are often overlooked and therefore not treated appropriately. The functional impairment of arms and hands should not be neglected. In this report, we summarize the symptoms, the diagnostic tools and the surgical treatment of entrapment neuropathies according to their topography. Typical cases are presented.

Altered multijoint reflex coordination is indicative of motor impairment level following stroke

Following stroke, individuals often are unable to activate their elbow and shoulder muscles independently. There is growing evidence that altered reflex pathways may contribute to these abnormal patterns of activation or muscle synergies. Most studies investigating reflex function following stroke have examined only individual joints at rest. Thus, the purpose of this study was to quantify multijoint reflex contributions to the stereotyped muscle synergies commonly observed following stroke. We hypothesized that the patterns of reflex coordination mirror the abnormal muscle coactivity patterns previously reported for voluntary activation. 10 chronic stroke and 8 age-matched control subjects participated. Reflexes were elicited by perturbing the arm with a 3 degree of freedom robot while subjects exerted voluntary forces at the elbow and shoulder. The force conditions tested were selected to assess the influence of gravity and the influence of joint torque generation without gravity on reflex coordination. Reflex magnitude was quantified by the average rectified electromyogram, recorded from 8 muscles that span the elbow and shoulder. Patterns of reflex coordination were quantified using independent components analysis. Results show significant reflex coupling between elbow flexor and shoulder abductor-extensor muscles in stroke patients during isolated elbow and shoulder torque generation and during active arm support against gravity. Identified patterns of stretch reflex coordination were consistent with the stereotyped voluntary flexion synergy, suggesting reflex pathways contribute to abnormal muscle coordination following stroke.

Arm-cranking exercise assisted by Functional Electrical Stimulation in C6 tetraplegia: a pilot study

Tetraplegic volunteers undertook progressive exercise training, using novel systems for arm-cranking exercise assisted by Functional Electrical Stimulation (FES). The main aim was to determine potential training effects of FES-assisted arm-crank ergometry (FES-ACE) on upper limb strength and cardiopulmonary (fitness) in tetraplegia. Surface FES was applied to the biceps and triceps during exercise on an instrumented ergometer. Two tetraplegic volunteers with C6 Spinal Cord Injury (SCI) went through muscle strengthening, baseline exercise testing and three months of progressive FES-ACE training. Repeat exercise tests were carried out every four weeks during training, and post-training, to monitor upper-limb strength and cardiopulmonary fitness. At each test point, an incremental test was carried out to determine peak work rate, peak oxygen uptake, gas exchange threshold and oxygen uptake-work rate relationship during FES-ACE. Peak oxygen uptake for Subject A increased from 0.7 l/min to 1.1 l/min, and peak power output increased from 7 W to 38 W after FES-ACE training. For Subject B, peak oxygen uptake was unchanged, but peak power output increased from 3 W to 8 W. These case studies illustrate potential benefits of FES-ACE in tetraplegia, but also the differences in exercise responses between individuals.

Reflex modulation is linked to the orientation of arm mechanics relative to the environment

To successfully complete a motor task, it is necessary to control not only the kinematics and dynamics of a limb, but also its mechanical properties. In a multijoint task such as the control of arm posture, limb mechanics are directional, resisting external disturbances more effectively in certain directions than others. It has been demonstrated that feedforward neuromotor pathways can regulate these directional characteristics of the arm to compensate for changes in the mechanical properties of the environment. However, it is unclear if spinal reflex pathways exhibit a similar specificity. The present results suggest that the sensitivity of the human stretch reflex also can be tuned to adapt the mechanical properties of the arm in a task appropriate manner. We hypothesized that the orientation of arm mechanics relative to the mechanical properties of the environment would influence reflex adaptation. Two destabilizing environments, oriented relative to the mechanical properties of the arm, were used to test this hypothesis. These environments were simulated using a 3 degrees of freedom (DOF) robot, which also was used to perturb arm posture. The resulting reflexes, assessed by electromyograms recorded from 8 muscles, were found to modulate in accordance with how the environmental instability was oriented relative to the mechanical properties of the arm. Our results suggest that stretch sensitive reflexes throughout the arm are modulated in a coordinated manner corresponding to the orientation of arm mechanics relative to the environment.

[New facilities in management of complex regional pain upper limb syndrome with thoracoscopic sympathectomy]

26 patients (21 females and 5 males, aged from 40 to 70 years) with complex regional pain syndrome (CRPS) who underwent thoracic sympathectomy at the Th3-4 level on the damaged side, were examined 1,5-2 months since trauma. After an operation all patients showed pain management, improvement of motor and trophic functions, positive dynamics of laser Doppler flowmetry and computer thermography. The given method was demonstrated to be effective and mostly successful at the early stages of CRPS.

Microsurgical treatment of injury to peripheral nerves in upper and lower limbs: a critical review of the last 8 years

Nerve injuries to the upper and inferior limbs represent a common event due both to home and working accidents. Minor traumas can lead to severe disabilities if a wrong treatment is carried out. From 1997 to 2005, 920 patients were observed with a total of 1,200 major or minor nerves injuries operated. In 852 cases acute lesions treated. In 68 patients we reviewed old injuries. In 707 patients direct nerve suture and in 145 patients nerve grafts were carried out. One to 8 years follow up observed. Different protocols were adopted according to the injury: simple cut, complex lesion or surgical revision. Results were evaluated during the follow up period with different models: motor evaluation in six levels (BMRC), sensitive evaluation in five levels (HIGHET), and global evaluation with four grades (from the worst to the best result). Nerve healing is a complex biological phenomenon influenced by many parameters related both to the patient characteristics and nerve lesion. Functional and esthetical outcomes vary also according to: age, cultural and economic condition, health status, and smoking. Post operative rehabilitation is mandatory to obtain an acceptable functional result. Nerve injuries to the upper and inferior limbs represent a challenge for the microsurgeon. Ultimate success in nerve surgery is judged by functional as well as cosmetic parameters. Only patients with the appropriate indication should be operated and always by a skilled surgeon.

Localization of arm representation in the cerebral peduncle of the non-human primate

Motor deficit severity and the potential for recovery in patients with brain injury depend on the integrity of descending corticofugal projections. Clinical assessment of these conditions following subtotal brain trauma requires a comprehensive understanding of the anatomical structures involved in the lesion as well as those structures that are spared. To assist in this endeavor, we investigated motor fiber organization in the crus cerebri of the cerebral peduncle (ccCP) in the rhesus monkey. Fibers originating from the arm representations of the primary (M1), supplementary (M2), rostral cingulate (M3), caudal cingulate (M4), dorsolateral pre- (LPMCd) and ventrolateral pre- (LPMCv) motor cortices were studied. The projections from the frontal and cingulate motor cortices formed descending longitudinal bundles that occupied the medial three-fifths of the ccCP at superior and middle levels. Although considerable overlap characterized these corticofugal projections, a general topography was discernable. Fibers from M1 and M4 occupied the central subsector of the ccCP, and fibers from M3 resided medially. The main distribution of LPMCd, LPMCv, and M2 fibers occupied the centromedial region and overlapped extensively. Progressing inferiorly, all fiber bundles in the central and centromedial sectors gradually extended medially, and overlap increased. A common location of fiber passage occurred at the midbrain-pontine isthmus where all of the fiber bundles overlapped. Our findings indicate that the widespread distribution of corticofugal motor projections may account for the favorable levels of motor recovery that accompany subtotal midbrain injury. At superior and mid-levels of the ccCP anteromedial lesions may disrupt projections from M3, whereas anterolateral lesions may disrupt projections from M1 and M4. Fibers from M2, LPMCv, and LPMCd may be compromised to some degree in both situations. The compact and commixed nature of motor fiber organization at inferior levels and the midbrain-pontine isthmus suggests a vulnerable region of passage for comprehensive disruption of frontal and cingulate corticofugal projection fibers.

Ipsilateral versus contralateral cortical motor projections to a shoulder adductor in chronic hemiparetic stroke: implications for the expression of arm synergies

An increase in ipsilateral descending motor pathway activity has been reported following hemiparetic stroke. In axial muscles, increased ipsilateral cortical activity has been correlated with good recovery whereas in distal arm muscles it is correlated with poor recovery. Currently, little is known about the control of proximal upper limb muscles following stroke. This muscle group is less impaired than the distal arm muscles following stroke, yet contributes to the abnormal motor coordination patterns associated with movements of the arm which can severely impair reaching ability. This study used transcranial magnetic stimulation (TMS) to evaluate the presence and magnitude of ipsilateral and contralateral projections to the pectoralis major (PMJ) muscle in stroke survivors. A laterality index (LI) was used to investigate the relationship between ipsilateral and contralateral projections and strength, clinical impairment level, and the degree of abnormal coordination expressed in the arm. The ipsilateral and contralateral hemispheres were stimulated using 90% TMS intensity while the subject generated shoulder adduction torques in both arms. Motor evoked potentials (MEPs) were measured in the paretic and non-paretic PMJ. The secondary torque at the elbow was measured during maximal adduction as an indicator of the degree of extensor synergy. Ipsilateral MEPs were most common in stroke survivors with moderate to severe motor deficits. The LI was correlated with clinical impairment level (P = 0.05) and the degree of extension synergy expressed in the arm (P = 0.03). The LI was not correlated with strength. These results suggest that increased excitability of ipsilateral pathways projecting to the proximal upper arm may contribute to the expression of the extension synergy following stroke. These findings are discussed in relation to a possible unmasking or upregulation of oligosynaptic cortico-bulbospinal pathways following stroke.

Vibrotactile threshold measurement for detecting peripheral neuropathy: defining variability and a normal range for clinical and research use

AIMS/HYPOTHESIS

We aimed to define normal ranges for vibration sense as measured by vibratory perception thresholds (VPTs) using biothesiometry.

METHODS

We performed biothesiometry in a community-dwelling sample of 901 people aged 55 to 85 years who did not have diabetes. We quantitated the variation between repeat measures using analysis of variance and Bland-Altman plots. We also plotted the age- and sex-specific reference ranges.

RESULTS

We found small but statistically significant differences between repeat measures using the ascending and descending method of limits. Statistically higher vibration thresholds were noted on the right arm and leg compared with the left. Significantly higher vibration thresholds were also seen in men vs women for both lower limbs. We also defined sex-specific reference intervals (normal ranges) for biothesiometry for older persons and quantitated the increase in vibration threshold with increasing age.

CONCLUSIONS/INTERPRETATION

For reliability, it may be sufficient to obtain the average of two ascending measures separated by at least 1 min in just the right hand or right foot, since this is usually the one with the higher threshold. Although identical reference ranges can be used for men and women for the upper limb, there are significant differences in the lower limbs. The major determinant of VPT is age: we have established age-specific norms for VPT testing for adults between 55 and 85 years of age.

An unusual union of the intercostobrachial nerve and the medial pectoral nerve

Variations in the branching pattern of the intercostobrachial nerve have been known to complicate dissection during mastectomy and other procedures involving the axilla. We present the case of an 87-year-old Caucasian female, in whom the intercostobrachial nerve joined with a separate branch from the medial pectoral nerve. The clinical consequences of such a variation may include pectoral muscle motor loss, in addition to the commonly reported sensory loss resulting from the accidental injury or intentional sacrifice of the intercostobrachial nerve during axillary dissection.

Activation of parieto-frontal stream during reaching and grasping studied by positron emission tomography in monkeys

The whole brain activation during visually guided reaching and grasping behaviors was investigated in three macaque monkeys using positron emission tomography (PET) scanning with [(15)O]H(2)O. Activation was consistently observed in the parietal regions such as PO, MIP, VIP, LIP and AIP, frontal regions such as PMd, M1 and S1 on the contralateral hemisphere and in the ipsilateral intermediate and lateral deep cerebellar nuclei. Activation was also observed in the areas representing the central and peripheral visual field in the early visual cortices. Thus, the visuo-motor processing, including parieto-frontal stream, involved in the control of visually guided reaching and grasping behaviors could be visualized for the first time in macaque monkeys.

Recovery of upper extremity sensorimotor system acuity in baseball athletes after a throwing-fatigue protocol

CONTEXT

Research indicates that upper extremity fatigue hampers sensorimotor system acuity. However, no investigators have observed recovery of upper extremity acuity after fatigue.

OBJECTIVE

To observe recovery of active position reproduction acuity in overhead throwers after a throwing-fatigue protocol.

DESIGN

Single-session, repeated-measures design.

SETTING

University musculoskeletal laboratory.

PATIENTS OR OTHER PARTICIPANTS

Sixteen healthy collegiate baseball players (age = 21.0 +/- 1.6 years, height = 175.8 +/- 10.2 cm, mass = 82.8 +/- 4.3 kg).

INTERVENTION(S)

Subjects threw a baseball with maximum velocity (every 5 seconds) from a single knee. Every 20 throws, subjects rated their upper extremity exertion on a Borg scale until reporting a level of more than 14.

MAIN OUTCOME MEASURE(S)

We used an electromagnetic tracking system to measure active multijoint position reproduction acuity at 5 intervals: prefatigue; immediately postfatigue; and after 4, 7, and 10 minutes of recovery. Blindfolded subjects reproduced their arm-cocked and ball-release positions. Dependent variables were 3-dimensional variable errors of scapulothoracic, glenohumeral, elbow, and wrist joints; endpoint (ie, hand) position error represented overall upper extremity acuity. The independent variable was time (measured prefatigue and at 4 postfatigue intervals).

RESULTS

Fatigue significantly affected acuity of scapulothoracic, glenohumeral, and elbow joints and endpoint error for both positions (P < .001). Fatigue significantly affected wrist acuity only for ball release (P < .001). For arm-cocked reproduction, each measure of acuity, except that of the glenohumeral joint, recovered by 7 minutes; for ball release, each measure of acuity recovered within 4 minutes (P > .05).

CONCLUSIONS

The sensorimotor system deficits that we observed after fatigue recovered within 7 minutes in most upper extremity joints. Glenohumeral arm-cocked position reproduction acuity failed to recover within 10 minutes. Research indicates that overhead throwers are vulnerable in this position to the capsulolabral injuries commonly observed in throwing athletes. Future researchers should explore this relationship and the effectiveness of exercises aimed at enhancing sensorimotor system acuity and endurance.

Does the location of the touch from the contralateral finger application affect grip force control while lifting an object?

It was recently shown that the magnitude of grip force used to lift and transport a hand-held object decreased if a light finger touch from the contralateral arm was provided to the wrist of the target arm [A.S. Aruin, Support-specific modulation of grip force in individuals with hemiparesis, Arch. Phys. Med. Rehabil. 86 (2005) 768-775]. In this study, we investigated whether the location of the finger touch along the target arm affects the way grip force is reduced. Subjects performed the same task of lifting and transporting an instrumented object with no involvement of the contralateral arm and when an index finger touch of the contralateral arm was provided to the wrist, thumb, mid-forearm, and the hand-held object. Grip force was reduced by approximately the same amount in all conditions with the finger touch compared to the no touch condition suggesting that its reduction was not associated with a particular point of contact of the finger with the target arm. The results of the study provide additional evidence to support of the use of a second arm in the performance of activities of daily living and stress the importance of future studies investigating contralateral arm sensory input on grip force control.

[Vascular and neurological complications of supracondylar humeral fractures in children]

The author reports two cases of pediatric patients with supracondylar humeral fractures complicated by concomitant vascular injury. One of the patients also presented with neurological symptoms from compression of the ulnar and median nerves. In the case of vascular injury only, it was necessary to resect a 1-cm segment of the brachial artery which was thrombosed due to intimal disruption. In the other case, surgery was not indicated immediately; however, liberation of the nervus ulnaris and nervus medianus was later required because of nerve compression by the scar and bone. The author considers the exact diagnosis, precise reduction and stable fixation of a fracture to be most important for a good outcome of treatment. Any associated vascular injury is indicated for surgery only after a thorough diagnostic consideration, and may not be needed in every case. The most decisive factor is the clinical presentation. Injury to the nerve system is indicated for surgical treatment at a later period, at 3 months post-injury at the earliest.

Proximal pain in patients with carpal tunnel syndrome: a clinical-neurophysiological study

Patients with carpal tunnel syndrome (CTS) usually complain of pain and paresthesia in the hand or wrist, but pain proximally to the wrist has been frequently reported in this condition. This study was aimed at understanding which clinical features are associated with the presence of proximal pain (PP) in the upper limb of CTS patients. We recruited 250 patients with clinical and neurophysiological evidence of CTS. After thorough selection to rule out concomitant upper limb painful conditions, 112 patients (175 hands) were included. PP was defined as the presence of pain in the upper limb proximally to the wrist (neck excluded) in association with sensory complaints in the hand. Patients were asked about the presence and severity of proximal sensory complaints, the distribution of sensory complaints in the hand, and underwent an objective evaluation and neurographic study. Thenar muscle strength was significantly larger, the neurophysiological measures were significantly less severe, and hand paresthesia was significantly greater in patients with PP. The neurographic score and the measures of median nerve damage were inversely correlated with the severity of PP. PP was related to extramedian spread of symptoms in the hand. None of the objective/neurographic variables was related to severity of sensory complaints restricted to the hand. PP may be found in a consistent number of CTS patients. PP may represent a clinical marker of mild median nerve damage. The presence of proximal complaints might be related to peripheral or central nervous system mechanisms.

Incorporating voluntary knee flexion into nonanticipatory balance corrections

Knee movements play a critical role in most balance corrections. Loss of knee flexibility may cause postural instability. Conversely, trained voluntary knee flexions executed during balance corrections might help to overcome balance deficits. We examined whether bilateral knee flexion could be added to automatic balance corrections generated by sudden balance perturbations. We investigated how this could be achieved and whether it improved or worsened balance control. Twenty-four healthy subjects participated in three different test conditions, in which they had to flex their knees following an auditory cue (VOLUNTARY condition), had to restore their balance in response to multidirectional rotations of a support surface (REACTIVE condition), or the combination of these two (COMBINED condition). A new variable set (PREDICTED), calculated as the mathematical sum of VOLUNTARY and REACTIVE, was compared with the COMBINED variable set. COMBINED responses following forward rotations were close to PREDICTED, or greater, suggesting adequate integration of knee flexion into the automatic balance reactions. For backward rotations, the COMBINED condition resulted in several near-falls, and this was generally associated with smaller knee flexion and smaller EMG responses. Subjects compensated by using greater trunk flexion and arm movements. Activity in several muscles displayed earlier onsets for the COMBINED condition following backward rotations. We conclude that healthy adults can incorporate voluntary knee flexion into their automatic balance corrections and that this depends on the direction of the postural perturbation. These findings highlight the flexibility of the human balance repertoire and underscore both the advantages and limitations of using trained voluntary movements to aid balance corrections in man.

MRI of the distal biceps femoris muscle: normal anatomy, variants, and association with common peroneal entrapment neuropathy

OBJECTIVE

The objectives of our study were to describe the previously unreported normal MR anatomy of the distal biceps femoris muscle and its relationship with the common peroneal nerve and to present a case in which previously unreported MR evidence of an anatomic variation in the distal biceps femoris muscle was associated with common peroneal entrapment neuropathy.

MATERIALS AND METHODS

One hundred consecutive 1.5-T knee MR studies of 97 asymptomatic patients were retrospectively reviewed by two observers in consensus for, first, normal anatomy of the distal biceps femoris muscle; second, anatomic variations of the muscle; and, third, the relationship of the muscle to the common peroneal nerve. Measurements of the distal and posterior extents of the short and long heads of the biceps femoris were performed. An MR study of a symptomatic patient with clinical evidence of common peroneal neuropathy associated with a surgically proven anatomic variation of the distal biceps femoris was reviewed.

RESULTS

Two MR anatomic patterns were seen in the asymptomatic patient group: First, in 77 knees (77%), the common peroneal nerve was located within abundant fat posterolateral to the biceps femoris; and, second, in 23 cases (23%), the common peroneal nerve traversed within a narrow fatty tunnel between the biceps femoris and lateral head of the gastrocnemius muscles. There was a positive correlation between the distal and posterior extents of the short head of the biceps femoris muscle and the presence of the tunnel.

CONCLUSION

Variations in the posterior and distal extents of the biceps femoris muscle can produce a tunnel in which the common peroneal nerve travels. We also described a case of common peroneal neuropathy secondary to tunnel formation.

Time Course of Trunk, Arm, Leg, and Functional Recovery After Ischemic Stroke

Background. Patterns of recovery provide useful information concerning the potential of physical recovery over time and therefore the setting of realistic goals for rehabilitation programs. Objective. To compare the time course of trunk recovery with the patterns of recovery of arm, leg, and functional ability. Methods . Consecutive stroke patients were recruited in 2 acute neurology wards. Participants were evaluated at 1 week, 1 month, and 3 and 6 months after stroke. Patients were assessed with the Trunk Impairment Scale, Fugl-Meyer arm and leg test, and Barthel Index. Results. Thirty-two patients were included in the study. There were no dropouts. Repeated measures analysis of the recovery patterns of motor and functional performance revealed the most striking improvement for all measures from 1 week to 1 month ( P value between .0021 and <.0001) and a significant improvement from 1 month to 3 months after stroke ( P value ranges from .0008 to <.0001). No significant improvement was found between 3 and 6 months after stroke for any of the measures. Statistical analysis revealed no significant difference between time course of trunk, arm, leg, and functional recovery ( P = .2565). No significant differences in level of motor and functional recovery were found at the different time points. Conclusions. Separate analyses of motor and functional recovery patterns after stroke confirm the importance of the first month for recovery. Contrary to common belief, the time course of recovery of the trunk is similar to the recovery of arm, leg, and functional ability.

Bilateral Arm Training With Rhythmic Auditory Cueing in Chronic Stroke: Not Always Efficacious

Objective. Bilateral arm training with rhythmic auditory cueing (BATRAC) has been reported to be efficacious in promoting upper-extremity (UE) recovery in chronic stroke. We tested a modified form of BATRAC (modBATRAC) in a new group of participants with a condensed treatment regime to determine whether we could replicate these reported results. Methods. Fourteen subjects with chronic stroke completed 2 weeks of 2.25 hours per session, 4 sessions per week of modBATRAC. Results. No significant changes were observed in UE Fugl-Meyer or Wolf Motor Function Test scores. Subjects did report increased paretic UE use on the Motor Activity Log (mean change, 0.50; SD = 0.70). Conclusions. The results of this study offer only partial support for the efficacy of modBATRAC. As in previous trials, modBATRAC facilitated increased use of the paretic arm, but unlike previous trials, it did not increase motor performance. These differences may reflect a more temporally condensed training schedule and less impaired patients.

Effects of robot-assisted therapy on upper limb recovery after stroke: a systematic review

OBJECTIVE

The aim of the study was to present a systematic review of studies that investigate the effects of robot-assisted therapy on motor and functional recovery in patients with stroke.

METHODS

A database of articles published up to October 2006 was compiled using the following Medline key words: cerebral vascular accident, cerebral vascular disorders, stroke, paresis, hemiplegia, upper extremity, arm, and robot. References listed in relevant publications were also screened. Studies that satisfied the following selection criteria were included: (1) patients were diagnosed with cerebral vascular accident; (2) effects of robot-assisted therapy for the upper limb were investigated; (3) the outcome was measured in terms of motor and/or functional recovery of the upper paretic limb; and (4) the study was a randomized clinical trial (RCT). For each outcome measure, the estimated effect size (ES) and the summary effect size (SES) expressed in standard deviation units (SDU) were calculated for motor recovery and functional ability (activities of daily living [ADLs]) using fixed and random effect models. Ten studies, involving 218 patients, were included in the synthesis. Their methodological quality ranged from 4 to 8 on a (maximum) 10-point scale.

RESULTS

Meta-analysis showed a nonsignificant heterogeneous SES in terms of upper limb motor recovery. Sensitivity analysis of studies involving only shoulder-elbow robotics subsequently demonstrated a significant homogeneous SES for motor recovery of the upper paretic limb. No significant SES was observed for functional ability (ADL).

CONCLUSION

As a result of marked heterogeneity in studies between distal and proximal arm robotics, no overall significant effect in favor of robot-assisted therapy was found in the present meta-analysis. However, subsequent sensitivity analysis showed a significant improvement in upper limb motor function after stroke for upper arm robotics. No significant improvement was found in ADL function. However, the administered ADL scales in the reviewed studies fail to adequately reflect recovery of the paretic upper limb, whereas valid instruments that measure outcome of dexterity of the paretic arm and hand are mostly absent in selected studies. Future research into the effects of robot-assisted therapy should therefore distinguish between upper and lower robotics arm training and concentrate on kinematical analysis to differentiate between genuine upper limb motor recovery and functional recovery due to compensation strategies by proximal control of the trunk and upper limb.

A biologically inspired neural network controller for ballistic arm movements

BACKGROUND

In humans, the implementation of multijoint tasks of the arm implies a highly complex integration of sensory information, sensorimotor transformations and motor planning. Computational models can be profitably used to better understand the mechanisms sub-serving motor control, thus providing useful perspectives and investigating different control hypotheses. To this purpose, the use of Artificial Neural Networks has been proposed to represent and interpret the movement of upper limb. In this paper, a neural network approach to the modelling of the motor control of a human arm during planar ballistic movements is presented.

METHODS

The developed system is composed of three main computational blocks: 1) a parallel distributed learning scheme that aims at simulating the internal inverse model in the trajectory formation process; 2) a pulse generator, which is responsible for the creation of muscular synergies; and 3) a limb model based on two joints (two degrees of freedom) and six muscle-like actuators, that can accommodate for the biomechanical parameters of the arm. The learning paradigm of the neural controller is based on a pure exploration of the working space with no feedback signal. Kinematics provided by the system have been compared with those obtained in literature from experimental data of humans.

RESULTS

The model reproduces kinematics of arm movements, with bell-shaped wrist velocity profiles and approximately straight trajectories, and gives rise to the generation of synergies for the execution of movements. The model allows achieving amplitude and direction errors of respectively 0.52 cm and 0.2 radians. Curvature values are similar to those encountered in experimental measures with humans. The neural controller also manages environmental modifications such as the insertion of different force fields acting on the end-effector.

CONCLUSION

The proposed system has been shown to properly simulate the development of internal models and to control the generation and execution of ballistic planar arm movements. Since the neural controller learns to manage movements on the basis of kinematic information and arm characteristics, it could in perspective command a neuroprosthesis instead of a biomechanical model of a human upper limb, and it could thus give rise to novel rehabilitation techniques.