[Factors Modulating Motor Function Changes in Stroke Patients During Inpatient Neurological Rehabilitation]

PURPOSE

To identify factors that have an impact on the degree of functional improvements in stroke patients during inpatient neurological rehabilitation.

METHODS

Retrospective analysis of 398 stroke patients who participated in an inpatient Phase C rehabilitation (Barthel index between 30 and 70 points). We correlated changes in 3 physiotherapeutic assessments (transfer from sitting to standing; transfer from bed to (wheel)chair; climbing stairs) and 3 occupational therapeutic assessments (eating/drinking; dressing of the upper part of the body; object manipulation) with the factors age, gender, Barthel-Index at admission, time since stroke, length of stay in inpatient rehab, number and extent of therapies and ischemic versus hemorrhagic stroke. In addition, a stepwise regression analysis was performed.

RESULTS

The patient group showed significant improvements in all assessments. Length of stay in inpatient rehab and number/extent of therapies correlated with improvements of transfer from sitting to standing, transfer from bed to (wheel)chair, climbing stairs, and dressing of the upper part of the body. Number/extent of therapies also correlated with eating/drinking. Barthel-Index at admission was negatively correlated with transfer from sitting to standing, transfer from bed to (wheel)chair, and dressing of the upper part of the body. No correlation between changes of motor functions and age or gender or type of stroke (ischemic versus hemorrhagic) was found. Patients<3 months after stroke showed stronger improvements of transfer from sitting to standing, transfer from bed to (wheel)chair, climbing stairs, dressing of the upper part of the body, and object manipulation than patients>6 months after stroke. However, patients<3 months after stroke also stayed 10 days longer in inpatient rehab. The stepwise regression analysis identified the number of physiotherapies and Barthel-Index at admission as the most important factors for changes in transfer from sitting to standing and transfer from bed to (wheel)chair, number of physiotherapies and time since stroke for climbing stairs, number of occupational therapies for eating/drinking, number of occupational therapies and time since stroke for dressing the upper part of the body and number of occupational therapies and length of inpatient rehab for object manipulation.

CONCLUSION

In stroke patients, a higher number of therapies is associated with greater improvements of motor functions. Age, gender and type of stroke have no relevant impact on changes of motor functions during inpatient rehabilitation.

Clinical neurophysiology of functional motor disorders: IFCN Handbook Chapter

Functional Motor Disorders are common and disabling. Clinical diagnosis has moved from one of exclusion of other causes for symptoms to one where positive clinical features on history and examination are used to make a "rule in" diagnosis wherever possible. Clinical neurophysiological assessments have developed increasing importance in assisting with this positive diagnosis, not being used simply to demonstrate normal sensory-motor pathways, but instead to demonstrate specific abnormalities that help to positively diagnose these disorders. Here we provide a practical review of these techniques, their application, interpretation and pitfalls. We also highlight particular areas where such tests are currently lacking in sensitivity and specificity, for example in people with functional dystonia and functional tic-like movements.

The Evolution of Hand Proprioceptive and Motor Impairments in the Sub-Acute Phase After Stroke

BACKGROUND

Hand proprioception is essential for fine movements and therefore many activities of daily living. Although frequently impaired after stroke, it is unclear how hand proprioception evolves in the sub-acute phase and whether it follows a similar pattern of changes as motor impairments.

OBJECTIVE

This work investigates whether there is a corresponding pattern of changes over time in hand proprioception and motor function as comprehensively quantified by a combination of robotic, clinical, and neurophysiological assessments.

METHODS

Finger proprioception (position sense) and motor function (force, velocity, range of motion) were evaluated using robotic assessments at baseline (<3 months after stroke) and up to 4 weeks later (discharge). Clinical assessments (among others, Box & Block Test [BBT]) as well as Somatosensory/Motor Evoked Potentials (SSEP/MEP) were additionally performed.

RESULTS

Complete datasets from 45 participants post-stroke were obtained. For 42% of all study participants proprioception and motor function had a dissociated pattern of changes (only 1 function considerably improved). This dissociation was either due to the absence of a measurable impairment in 1 modality at baseline, or due to a severe lesion of central somatosensory or motor tracts (absent SSEP/MEP). Better baseline BBT correlated with proprioceptive gains, while proprioceptive impairment at baseline did not correlate with change in BBT.

CONCLUSIONS

Proprioception and motor function frequently followed a dissociated pattern of changes in sub-acute stroke. This highlights the importance of monitoring both functions, which could help to further personalize therapies.

Recovery of Acute Leukoencephalopathy Documented by Neuroimaging: A Case Report

Objectives

We describe an atypical delayed neurologic recovery from coma and unresponsive wakefulness syndrome (i.e., persistent vegetative state) in a patient with severe drug-induced toxic leukoencephalopathy (presumably due to synthetic cannabinoid intake).

Methods

The patient underwent standardized behavioral and multimodal neuroimaging assessments to monitor clinical evolution and brain function over a 5-month period after presumed intoxication.

Results

A progressive clinical recovery was observed, from an initial state of coma to emergence from a minimally conscious state after 2 months. Despite the stability of extensive white matter lesions documented by CT and structural MRI, fluorodeoxyglucose PET showed partial recovery of cortical metabolism after 5 months.

Discussion

This case report illustrates that the temporal dynamics of recovery from toxic acute leukoencephalopathy may be atypical and delayed. Multimodal monitoring with repeated behavioral and functional neuroimaging assessments tends to improve the prognosis reliability, while early prognosis based on structural damage may result in misleading statements.

The locations of stroke lesions next to the posterior internal capsule may predict the recovery of the related proprioceptive deficits

Background

Somatosensory deficits after stroke correlate with functional disabilities and impact everyday-life. In particular, the interaction of proprioception and motor dysfunctions affects the recovery. While corticospinal tract (CST) damage is linked to poor motor outcome, much less is known on proprioceptive recovery. Identifying a predictor for such a recovery could help to gain insights in the complex functional recovery processes thereby reshaping rehabilitation strategies.

Methods

50 patients with subacute stroke were tested before and after neurological rehabilitation. Proprioceptive and motor impairments were quantified with three clinical assessments and four hand movement and proprioception measures using a robotic device. Somatosensory evoked potentials (SSEP) to median nerve stimulation and structural imaging data (MRI) were also collected. Voxel-based lesion-symptom mapping (VLSM) along with a region of interest (ROI) analysis were performed for the corticospinal tract (CST) and for cortical areas.

Results

Before rehabilitation, the VLSM revealed lesion correlates for all clinical and three robotic measures. The identified voxels were located in the white matter within or near the CST. These regions associated with proprioception were located posterior compared to those associated with motor performance. After rehabilitation the patients showed an improvement of all clinical and three robotic assessments. Improvement in the box and block test was associated with an area in anterior CST. Poor recovery of proprioception was correlated with a high lesion load in fibers towards primary sensorymotor cortex (S1 and M1 tract). Patients with loss of SSEP showed higher lesion loads in these tracts and somewhat poorer recovery of proprioception. The VSLM analysis for SSEP loss revealed a region within and dorsal of internal capsule next to the posterior part of CST, the posterior part of insula and the rolandic operculum.

Conclusion

Lesions dorsal to internal capsule next to the posterior CST were associated with proprioceptive deficits and may have predictive value. Higher lesion load was correlated with poorer restoration of proprioceptive function. Furthermore, patients with SSEP loss trended towards poor recovery of proprioception, the corresponding lesions were also located in the same location. These findings suggest that structural imaging of the internal capsule and CST could serve as a recovery predictor of proprioceptive function.

Functional neurological symptoms are a frequent and relevant comorbidity in patients with multiple sclerosis

Introduction

Functional neurological symptoms (FNS) in multiple sclerosis (MS) have shown to be underinvestigated even though neurological diseases such as MS represent a risk factor for developing FNS. Comorbidity of FNS and MS can produce high personal and social costs since FNS patients have high healthcare utilization costs and a quality of life at least as impaired as in patients with disorders with underlying structural pathology. This study aims to assess comorbid FNS in patients with MS (pwMS) and investigate whether FNS in pwMS are associated with poorer health-related quality of life and work ability.

Methods

Newly admitted patients (234) with MS were studied during their stay at Kliniken Schmieder, a neurological rehabilitation clinic in Konstanz, Germany. The degree to which the overall clinical picture was explained by MS pathology was rated by neurologists and allied health practitioners on a five-point Likert scale. Additionally, neurologists rated each symptom reported by the patients. Health-related quality of life was assessed using a self-report questionnaire and work ability was assessed using the mean number of hours worked per day and information regarding disability pension as reported by patients.

Results

In 55.1% of cases, the clinical picture was completely explained by structural pathology due to MS. 17.1% of pwMS presented an overall clinical picture half or less of which could be explained by underlying structural pathology. PwMS with a higher comorbid FNS burden had a lower health-related quality of life and reported fewer working hours per day than pwMS with symptoms explained by structural pathology. Furthermore, pwMS with a full disability pension had a higher comorbid FNS burden than pwMS with no or partial disability pension.

Discussion

These results show that FNS should be addressed diagnostically and therapeutically since such symptoms are an important comorbidity in MS that is related to poorer health-related quality of life and lower work ability.

Extrinsic feedback facilitates mental chronometry abilities in stroke patients

BACKGROUND

Motor imagery (MI) can serve as a treatment for stroke rehabilitation. MI abilities can be assessed by testing mental chronometry (MC) as the degree of conformity between imagined and real performance of a task. A good MC performance is supposed to indicate good MI capacities.

OBJECTIVE

To explore if MC abilities can be modified by extrinsic feedback in stroke patients.

METHODS

60 subacute stroke patients were randomized into three groups. MC was evaluated by executing a modified version of the Box and Block Test (BBT) mentally and in real before and after a training session. For Groups 1 and 2 the training consisted of repeated performance of the BBT in a mental and then a real version. The time needed to complete each task was measured. Only participants of Group 1 received feedback about how well mental and real performance matched. Group 3 executed the same number of BBTs but without MI.

RESULTS

MC ability only improved in Group 1. The improvement lasted for at least 24 hours. In all groups, BBT real performance was improved post-training.

CONCLUSION

External feedback was able to enhance MC capability which might be an approach for improving MI abilities.

Transcranial direct current stimulation in stroke - Motor excitability and motor function

OBJECTIVE

To characterize motor excitability changes and changes of motor performance induced by a single anodal and cathodal transcranial direct current stimulation (tDCS) session in stroke patients.

METHODS

Twenty subacute stroke patients participated. Motor performance was tested with the Box and Block Test [BBT]. Motor cortex excitability (short interval intracortical inhibition [SICI], intracortical facilitation [ICF], long interval intracortical inhibition [LICI]) was examined by paired pulse transcranial magnetic stimulation before and after a single tDCS session (20 minutes, 1,0 mA). On two different occasions, patients received anodal and cathodal tDCS over the affected hemisphere. TMS recordings were taken from both hands consecutively.

RESULTS

Anodal tDCS significantly reduced SICI without changing ICF or LICI. Cathodal tDCS did not change motor excitability. Both types of tDCS did not alter motor performance. Even prior to anodal tDCS, SICI in the affected hemisphere was lower than in the unaffected hemisphere and was correlated with BBT changes after anodal tDCS.

CONCLUSIONS

Anodal, but not cathodal tDCS specifically modulated intracortical inhibitory circuits, leading to a disinhibition.

SIGNIFICANCE

The results amplify our knowledge on excitability modulations of tDCS in stroke patients.

Design and Preliminary Evaluation of a Robot-assisted Assessment-driven Finger Proprioception Therapy

Neurological injuries such as stroke often lead to motor and somatosensory impairments of the hand. Deficits in somatosensation, especially proprioception, result in difficulties performing activities of daily living involving fine motor tasks. However, it is challenging to accurately detect those impairments due to the limitations of clinical assessments. Hence therapies rarely focus on proprioception specifically, while such training could promote functional benefits. In this work we propose and preliminarily evaluate a robot-assisted, assessment-driven therapy of finger proprioception. We designed and implemented two therapeutic exercises, one targeting passive and the other active position sense. The difficulty level of the therapy exercises was adapted to each patient's proprioceptive impairment. We evaluated the exercises and their usability with 7 stroke participants and 8 clinicians in a 45-minutes protocol. We found that the exercises were feasible for stroke participants, as 5 individuals progressed in difficulty levels over multiple exercise repetitions, indicating adequacy of the adaptation algorithm. Moreover, usability was rated mostly as satisfactory by the patients (System Usability Scale = 73), and they also found the exercises interesting. Clinicians rated the exercises as difficult but clinically meaningful. Overall, these promising preliminary results pave the way for further development and validation of the proposed therapy approach.

Personalized neurorehabilitative precision medicine: from data to therapies (MWKNeuroReha) - a multi-centre prospective observational clinical trial to predict long-term outcome of patients with acute motor stroke

BACKGROUND

Stroke is one of the most frequent diseases, and half of the stroke survivors are left with permanent impairment. Prediction of individual outcome is still difficult. Many but not all patients with stroke improve by approximately 1.7 times the initial impairment, that has been termed proportional recovery rule. The present study aims at identifying factors predicting motor outcome after stroke more accurately than before, and observe associations of rehabilitation treatment with outcome.

METHODS

The study is designed as a multi-centre prospective clinical observational trial. An extensive primary data set of clinical, neuroimaging, electrophysiological, and laboratory data will be collected within 96 h of stroke onset from patients with relevant upper extremity deficit, as indexed by a Fugl-Meyer-Upper Extremity (FM-UE) score ≤ 50. At least 200 patients will be recruited. Clinical scores will include the FM-UE score (range 0-66, unimpaired function is indicated by a score of 66), Action Research Arm Test, modified Rankin Scale, Barthel Index and Stroke-Specific Quality of Life Scale. Follow-up clinical scores and applied types and amount of rehabilitation treatment will be documented in the rehabilitation hospitals. Final follow-up clinical scoring will be performed 90 days after the stroke event. The primary endpoint is the change in FM-UE defined as 90 days FM-UE minus initial FM-UE, divided by initial FM-UE impairment. Changes in the other clinical scores serve as secondary endpoints. Machine learning methods will be employed to analyze the data and predict primary and secondary endpoints based on the primary data set and the different rehabilitation treatments.

DISCUSSION

If successful, outcome and relation to rehabilitation treatment in patients with acute motor stroke will be predictable more reliably than currently possible, leading to personalized neurorehabilitation. An important regulatory aspect of this trial is the first-time implementation of systematic patient data transfer between emergency and rehabilitation hospitals, which are divided institutions in Germany.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov ( NCT04688970 ) on 30 December 2020.

100 years after Liepmann-Lesion correlates of diminished selection and application of familiar versus novel tools

100 years ago, Liepmann highlighted the role of left ventro-dorsal lesions for impairments in conceptual (rather ventral) and motor (more dorsal) related aspects of apraxia. Many studies thereafter attributed to an extended left fronto-temporo-parietal network. Yet, to date there are only few studies that looked at apraxic performance in the selection and application of familiar versus novel tools. In the current study we applied modern voxel-based lesion-symptom mapping (VLSM) to analyze neural correlates of impaired selection and application of familiar versus novel tools. 58 left (LBD) and 51 right brain damaged (RBD) stroke patients participated in the Novel Tools Test (NTT) and the Familiar Tools Test (FTT) of the Diagnostic Instrument for Limb Apraxia (DILA-S). We further assessed performance in control tasks, namely semantic knowledge (BOSU), visuo-spatial working memory (Corsi Block Tapping) and meaningless imitation of gestures (IML). Impaired tool use was most pronounced after LBD. Our VLSM results in the LBD group suggested that selection- versus application-related aspects of praxis and semantics of familiar versus novel tool use can be behaviorally and neuro-anatomically differentiated. For impairments in familiar tool tasks, the major focus of lesion maps was rather ventral while deficiencies in novel tool tasks went along with rather dorsal lesions. Affected selection processes were linked to rather anterior lesions, while impacted application processes went along with rather posterior lesion maps. In our study, particular tool selection processes were rather specific for familiar versus novel tools. Foci for lesion overlaps of experimental and control tasks were noticed ventrally for semantic knowledge and FTT, in fronto-parietal regions for working memory and NTT, and ventro-dorsally for imitation of meaningless gestures and the application of NTT and FTT. We visualized our current interpretation within a neuroanatomical model for apraxia of tool use.

Reliable and valid robot-assisted assessments of hand proprioceptive, motor and sensorimotor impairments after stroke

Background

Neurological injuries such as stroke often differentially impair hand motor and somatosensory function, as well as the interplay between the two, which leads to limitations in performing activities of daily living. However, it is challenging to identify which specific aspects of sensorimotor function are impaired based on conventional clinical assessments that are often insensitive and subjective. In this work we propose and validate a set of robot-assisted assessments aiming at disentangling hand proprioceptive from motor impairments, and capturing their interrelation (sensorimotor impairments).

Methods

A battery of five complementary assessment tasks was implemented on a one degree-of-freedom end-effector robotic platform acting on the index finger metacarpophalangeal joint. Specifically, proprioceptive impairments were assessed using a position matching paradigm. Fast target reaching, range of motion and maximum fingertip force tasks characterized motor function deficits. Finally, sensorimotor impairments were assessed using a dexterous trajectory following task. Clinical feasibility (duration), reliability (intra-class correlation coefficient ICC, smallest real difference SRD) and validity (Kruskal-Wallis test, Spearman correlations \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho$$\end{document}ρ with Fugl-Meyer Upper Limb Motor Assessment, kinesthetic Up-Down Test, Box & Block Test) of robotic tasks were evaluated with 36 sub-acute stroke subjects and 31 age-matched neurologically intact controls.

Results

Eighty-three percent of stroke survivors with varied impairment severity (mild to severe) could complete all robotic tasks (duration: <15 min per tested hand). Further, the study demonstrated good to excellent reliability of the robotic tasks in the stroke population (ICC>0.7, SRD<30%), as well as discriminant validity, as indicated by significant differences (p-value<0.001) between stroke and control subjects. Concurrent validity was shown through moderate to strong correlations (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho$$\end{document}ρ=0.4-0.8) between robotic outcome measures and clinical scales. Finally, robotic tasks targeting different deficits (motor, sensory) were not strongly correlated with each other (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho \le$$\end{document}ρ≤0.32, p-value>0.1), thereby presenting complementary information about a patient’s impairment profile.

Conclusions

The proposed robot-assisted assessments provide a clinically feasible, reliable, and valid approach to distinctly characterize impairments in hand proprioceptive and motor function, along with the interaction between the two. This opens new avenues to help unravel the contributions of unique aspects of sensorimotor function in post-stroke recovery, as well as to contribute to future developments towards personalized, assessment-driven therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00904-5.

Using the Flexor Reflex in a Chronic Stroke Patient for Gait Improvement: A Case Report

The flexor reflex or withdrawal reflex can be elicited by electrical stimulation of the sole of the foot, which serves as a reflex to protect the stimulated limb against tissue damage and consists of flexion movements in the hip, knee, and ankle joint. Triggering this reflex might improve walking abilities in hemiparetic patients. We report the first case of a chronic stroke patient with the most severe impairment of walking. She was examined with and without flexor reflex activation by the Incedo® system. Tests included a 10-m walk and a 2-min walk at baseline, after 3 weeks of training with the Incedo® system and after a follow-up 3 weeks later. Moreover, a kinematic gait analysis was done before and after the training period. At baseline, activation of the flexor reflex induced an improved gait velocity. After the training period, the patient walked twice as fast compared with baseline. Her gait velocity without Incedo® was faster than the gait velocity with Incedo® at baseline. Examination at follow-up indicated that the improvements remained almost unchanged. The kinematic analysis showed an improved stride length and gait velocity during flexor reflex activation. Initially, the foot was elevated higher above the ground during flexor reflex activation. In conclusion, this first case report of a chronic stroke patient demonstrates that flexor reflex activation is feasible and improves gait parameters despite severe impairment of walking abilities.

Behavioral and neurophysiological effects of an intensified robot-assisted therapy in subacute stroke: a case control study

BACKGROUND

Physical training is able to induce changes at neurophysiological and behavioral level associated with performance changes for the trained movements. The current study explores the effects of an additional intense robot-assisted upper extremity training on functional outcome and motor excitability in subacute stroke patients.

METHODS

Thirty moderately to severely affected patients < 3 months after stroke received a conventional inpatient rehabilitation. Based on a case-control principle 15 patients were assigned to receive additional 45 min of robot-assisted therapy (Armeo^®Spring) 5 times per week (n = 15, intervention group, IG). The Fugl-Meyer Assessment for the Upper Extremity (FMA-UE) was chosen as primary outcome parameter. Patients were tested before and after a 3-week treatment period as well as after a follow-up period of 2 weeks. Using transcranial magnetic stimulation motor evoked potentials (MEPs) and cortical silent periods were recorded from the deltoid muscle on both sides before and after the intervention period to study effects at neurophysiological level. Statistical analysis was performed with non-parametric tests. Correlation analysis was done with Spearman´s rank correlation co-efficient.

RESULTS

Both groups showed a significant improvement in FMA-UE from pre to post (IG: + 10.6 points, control group (CG): + 7.3 points) and from post to follow-up (IG: + 3.9 points, CG: + 3.3 points) without a significant difference between them. However, at neurophysiological level post-intervention MEP amplitudes were significantly larger in the IG but not in the CG. The observed MEP amplitudes changes were positively correlated with FMA-UE changes and with the total amount of robot-assisted therapy.

CONCLUSION

The additional robot-assisted therapy induced stronger excitability increases in the intervention group. However, this effect did not transduce to motor performance improvements at behavioral level. Trial registration The trial was registered in German Clinical Trials Register.

CLINICAL TRIAL REGISTRATION NUMBER

DRKS00015083. Registration date: September 4th, 2018. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00015083 . Registration was done retrospectively.

Effects of a single mental chronometry training session in subacute stroke patients - a randomized controlled trial

Background

Motor imagery training might be helpful in stroke rehabilitation. This study explored if a single session of motor imagery (MI) training induces performance changes in mental chronometry (MC), motor execution, or changes of motor excitability.

Methods

Subacute stroke patients (n = 33) participated in two training sessions. The order was randomized. One training consisted of a mental chronometry task, the other training was a hand identification task, each lasting 30 min. Before and after the training session, the Box and Block Test (BBT) was fully executed and also performed as a mental version which served as a measure of MC. A subgroup analysis based on the presence of sensory deficits was performed. Patients were allocated to three groups (no sensory deficits, moderate sensory deficits, severe sensory deficits). Motor excitability was measured by transcranial magnetic stimulation (TMS) pre and post training. Amplitudes of motor evoked potentials at rest and during pre-innervation as well as the duration of cortical silent period were measured in the affected and the non-affected hand.

Results

Pre-post differences of MC showed an improved MC after the MI training, whereas MC was worse after the hand identification training. Motor execution of the BBT was significantly improved after mental chronometry training but not after hand identification task training. Patients with severe sensory deficits performed significantly inferior in BBT execution and MC abilities prior to the training session compared to patients without sensory deficits or with moderate sensory deficits. However, pre-post differences of MC were similar in the 3 groups. TMS results were not different between pre and post training but showed significant differences between affected and unaffected side.

Conclusion

Even a single training session can modulate MC abilities and BBT motor execution in a task-specific way. Severe sensory deficits are associated with poorer motor performance and poorer MC ability, but do not have a negative impact on training-associated changes of mental chronometry. Studies with longer treatment periods should explore if the observed changes can further be expanded.

Trial registration

DRKS, DRKS00020355, registered March 9th, 2020, retrospectively registered

German hospital capacities for prolonged mechanical ventilator weaning in neurorehabilitation - results of a representative survey

A brief survey among members of the German Neurorehabilitation Society aimed to document the hospital capacities (“beds”) for prolonged weaning from a mechanical ventilator for patients with neuro-disabilities that require simultaneous multi-professional neurorehabilitation treatment. Sixty-eight institutions declared to have capacities with a broad distribution across Germany and its federal states. Overall, 1094 “beds” for prolonged weaning (and neurorehabilitation) were reported, 871 together with further information regarding their identification and hence regional location. These units had on average 16.1 beds for prolonged weaning (95% confidence interval 12.6 to 19.6) with a range from 2 to 68 beds per organization. The data indicate substantial capacities for the combined prolonged weaning and neurorehabilitation treatment in Germany. For most “beds” included in this analysis a basic validation was possible. While a reasonable coverage of these specialized service capacities by the survey is likely, the number reported could still be biased by underreporting by non-response. Both the broad variation of number of “beds” for prolonged weaning per unit and their unequal geographical distribution across federal states (per capita rate) warrant a more refined follow-up survey that will provide insights into reasons for the observed pattern of variation for these specialized hospital capacities.

Design and Characterization of a Robotic Device for the Assessment of Hand Proprioceptive, Motor, and Sensorimotor Impairments

Hand function is often impaired after neurological injuries such as stroke. In order to design patient-specific rehabilitation, it is essential to quantitatively assess those deficits. Current clinical scores cannot provide the required level of detail, and most assessment devices have been developed for the proximal joints of the upper limb. This paper presents a new robotic platform for the assessment of proprioceptive, motor, and sensorimotor hand impairments. A detailed technical evaluation demonstrated the capabilities to render different haptic environments required for a comprehensive assessment battery, and showed that the device is suitable for human interaction due to its ergonomic design. A preliminary study on proprioceptive assessment using a gauge position matching task with one healthy, one stroke, and one multiple sclerosis subject showed that the robotic system is able to rapidly and sensitively quantify proprioceptive deficits, and has the potential to be integrated into the clinical settings.

Mental contrasting with implementation intentions (MCII) improves physical activity and weight loss among stroke survivors over one year

OBJECTIVE

Stroke is the most common cause of physical impairment, and having already had a stroke dramatically increases the risk of having another one. Although greater physical activity lowers rates of stroke recurrence, patients often fail to act in line with this recommendation. The present intervention tested whether teaching the self-regulation strategy of mental contrasting (MC) with implementation intentions (II; MCII) improves stroke patients' physical activity and weight loss over 1 year compared with 2 information-only, control interventions.

RESEARCH METHOD

Participants were 183 stroke survivors who were capable of adhering to physical activity recommendations (age: M = 57 years; body mass index (BMI): M = 30). Patients were randomized to 3 conditions: unstructured information (n = 61), structured information (n = 62), and structured information plus MCII (n = 60). Patients' physical activity was assessed 50 weeks after they had left the rehabilitation hospital using the Baecke Inventory (Baecke, Burema, & Frijters, 1982), and by diaries provided at 2 consecutive weekends after 0, 10, 20, 30, 40, and 50 weeks. Diaries were also used to assess weight change.

RESULTS

MCII participants were more physically active after the 50 weeks (Baecke Inventory: 2.74 vs. 2.59, p < .05; diary: 62.45 vs. 54.11, p = .03) and lost more weight (2.15 kg, p = .02) compared with participants in the control conditions.

CONCLUSIONS

Teaching the MCII self-regulation strategy enhanced long-term physical activity in stroke patients relative to health information on its own. MCII thus qualifies as an effective intervention technique to improve secondary stroke prevention. (PsycINFO Database Record

Using an upper extremity exoskeleton for semi-autonomous exercise during inpatient neurological rehabilitation- a pilot study

Background

Motor deficits are the most common symptoms after stroke. There is some evidence that intensity and amount of exercises influence the degree of improvement of functions within the first 6 months after the injury.

The purpose of this pilot study was to evaluate the feasibility and acceptance of semi-autonomous exercises with an upper extremity exoskeleton in addition to an inpatient rehabilitation program. In addition, changes of motor functions were examined.

Methods

Ten stroke patients with a severe upper extremity paresis were included. They were offered to perform a semi-autonomous training with a gravity-supported, computer-enhanced device (Armeo®Spring, Hocoma AG) six times per week for 4 weeks. Feasibility was evaluated by weekly structured interviews with patients and supervisors.

Motor functions were assessed before and after the training period using the Wolf Motor Function Test (WMFT). The Wilcoxon Signed Rank Test was used for assessing pre-post differences. The Pearson correlation co-efficient was used for correlating the number of completed sessions with the change in motor function. Acceptance of the device and the level of satisfaction with the training were determined by a questionnaire based on visual analogue scales.

Results

Neither patients nor supervisors reported side effects. However, one patient had to be excluded from analysis because of transportation difficulties from the ward to the treatment facility. Therefore, analysis was based on nine patients. On average, 13.2 (55%) sessions were realized. WMFT results showed significant improvements of proximal arm functions. The number of sessions correlated with the degree of shoulder force improvement. Patients rated the exercises to be motivating, and enjoyable and would continue using the Armeo®Spring at home if they had the opportunity.

Conclusion

Using an upper extremity exoskeleton for semi-autonomous training in an inpatient setting is feasible without side effects and is positively rated by the patients. It might further support the recovery of upper extremity function.

Trial registration

The trial was retrospectively registered. Registration number ISRCTN42633681.

Assessing Anosognosia in Apraxia of Common Tool-Use With the VATA-NAT

In neurological patients, a lack of insight into their impairments can lead to possibly dangerous situations and non-compliance in rehabilitation therapy with worse rehabilitation outcomes as a result. This so called anosognosia is a multifaceted syndrome that can occur after brain damage affecting different neurological or cognitive functions. To our knowledge no study has investigated anosognosia for apraxia of common tool-use (CTU) so far. CTU-apraxia is a disorder frequently occurring after stroke that affects the use of familiar objects. Here, we introduce a new questionnaire to diagnose anosognosia for CTU-apraxia, the Visual Analogue Test assessing Anosognosia for Naturalistic Action Tasks (VATA-NAT). This assessment is adapted from a series of VATA-questionnaires that evaluate insight into motor (VATA-M) or language (VATA-L) impairment and take known challenges such as aphasia into account. Fifty one subacute stroke patients with left (LBD) or right (RBD) brain damage were investigated including patients with and without CTU-apraxia. Patients were assessed with the VATA-L, -M and -NAT before and after applying a diagnostics session for each function. Interrater reliability, composite reliability as well as convergent and divergent validity were evaluated for the VATA-NAT. Seven percent of the LBD patients with CTU-apraxia demonstrated anosognosia. After tool-use diagnostics this number increased to 20 percent. For the VATA-NAT, psychometric data revealed high interrater-reliability (τ ≥ 0.828), composite reliability (CR ≥ 0.809) and convergent validity (τ = -0.626). When assessing patients with severe aphasia, the possible influence of language comprehension difficulties needs to be taken into account for interpretation. Overall, close monitoring of anosognosia over the course of rehabilitation is recommended. With the VATA-NAT we hereby provide a novel assessment for anosognosia in patients with CTU-apraxia. For diagnosing anosognosia we recommend to combine this new tool with the existing VATA-M and -L subtests, particularly in patients who demonstrate severe functional deficits.

Symptom-specific amygdala hyperactivity modulates motor control network in conversion disorder

Initial historical accounts as well as recent data suggest that emotion processing is dysfunctional in conversion disorder patients and that this alteration may be the pathomechanistic neurocognitive basis for symptoms in conversion disorder. However, to date evidence of direct interaction of altered negative emotion processing with motor control networks in conversion disorder is still lacking. To specifically study the neural correlates of emotion processing interacting with motor networks we used a task combining emotional and sensorimotor stimuli both separately as well as simultaneously during functional magnetic resonance imaging in a well characterized group of 13 conversion disorder patients with functional hemiparesis and 19 demographically matched healthy controls. We performed voxelwise statistical parametrical mapping for a priori regions of interest within emotion processing and motor control networks. Psychophysiological interaction (PPI) was used to test altered functional connectivity of emotion and motor control networks. Only during simultaneous emotional stimulation and passive movement of the affected hand patients displayed left amygdala hyperactivity. PPI revealed increased functional connectivity in patients between the left amygdala and the (pre-)supplemental motor area and the subthalamic nucleus, key regions within the motor control network. These findings suggest a novel mechanistic direct link between dysregulated emotion processing and motor control circuitry in conversion disorder.

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We studied emotion processing effects on motor networks in conversion disorder (CD).

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Simultaneous motor and emotional stimulation resulted in enhanced amygdala activation.

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Left amygdala showed increased functional connectivity with an inhibitory motor loop.

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This suggests a direct link of impaired emotion processing and motor networks in CD.

Age-based model for metacarpophalangeal joint proprioception in elderly

Neurological injuries such as stroke can lead to proprioceptive impairment. For an informed diagnosis, prognosis, and treatment planning, it is essential to be able to distinguish between healthy performance and deficits following the neurological injury. Since there is some evidence that proprioception declines with age and stroke occurs predominantly in the elderly population, it is important to create a healthy reference model in this specific age group. However, most studies investigate age effects by comparing young and elderly subjects and do not provide a model within a target age range. Moreover, despite the functional relevance of the hand in activities of daily living, age-based models of distal proprioception are scarce. Here, we present a proprioception model based on the assessment of the metacarpophalangeal joint angle difference threshold in 30 healthy elderly subjects, aged 55-80 years (median: 63, interquartile range: 58-66), using a robotic tool to apply passive flexion-extension movements to the index finger. A two-alternative forced-choice paradigm combined with an adaptive algorithm to define stimulus magnitude was used. The mixed-effects model analysis revealed that aging has a significant, increasing effect on the difference threshold at the metacarpophalangeal joint, whereas other predictors (eg, tested hand or sex) did not show a significant effect. The adaptive algorithm allowed reaching an average assessment duration <15 minutes, making its clinical applicability realistic. This study provides further evidence for an age-related decline in proprioception at the level of the hand. The established age-based model of proprioception in elderly may serve as a reference model for the proprioceptive performance of stroke patients, or of any other patient group with central or peripheral proprioceptive impairments. Furthermore, it demonstrates the potential of such automated robotic tools as a rapid and quantitative assessment to be used in research and clinical settings.

Motor Imagery Impairment in Postacute Stroke Patients

Not much is known about how well stroke patients are able to perform motor imagery (MI) and which MI abilities are preserved after stroke. We therefore applied three different MI tasks (one mental chronometry task, one mental rotation task, and one EEG-based neurofeedback task) to a sample of postacute stroke patients (n = 20) and age-matched healthy controls (n = 20) for addressing the following questions: First, which of the MI tasks indicate impairment in stroke patients and are impairments restricted to the paretic side? Second, is there a relationship between MI impairment and sensory loss or paresis severity? And third, do the results of the different MI tasks converge? Significant differences between the stroke and control groups were found in all three MI tasks. However, only the mental chronometry task and EEG analysis revealed paresis side-specific effects. Moreover, sensitivity loss contributed to a performance drop in the mental rotation task. The findings indicate that although MI abilities may be impaired after stroke, most patients retain their ability for MI EEG-based neurofeedback. Interestingly, performance in the different MI measures did not strongly correlate, neither in stroke patients nor in healthy controls. We conclude that one MI measure is not sufficient to fully assess an individual's MI abilities.

[Neurofeedback-based motor imagery training for rehabilitation after stroke]

Mental training, including motor observation and motor imagery, has awakened much academic interest. The presumed functional equivalence of motor imagery and motor execution has given hope that mental training could be used for motor rehabilitation after a stroke. Results obtained from randomized controlled trials have shown mixed results. Approximately half of the studies demonstrate positive effects of motor imagery training but the rest do not show an additional benefit. Possible reasons why motor imagery training has so far not become established as a robust therapeutic approach are discussed in detail. Moreover, more recent approaches, such as neurofeedback-based motor imagery or closed-loop systems are presented and the potential importance for motor learning and rehabilitation after a stroke is discussed.

Mental chronometry and mental rotation abilities in stroke patients with different degrees of sensory deficit

BACKGROUND

Motor imagery is used for treatment of motor deficits after stroke. Clinical observations suggested that motor imagery abilities might be reduced in patients with severe sensory deficits. This study investigated the influence of somatosensory deficits on temporal (mental chronometry, MC) and spatial aspects of motor imagery abilities.

METHODS

Stroke patients (n = 70; <6 months after stroke) were subdivided into 3 groups according to their somatosensory functions. Group 1 (n = 31) had no sensory deficits, group 2 (n = 27) had a mild to moderate sensory impairment and group 3 (n = 12) had severe sensory deficits. Patients and a healthy age-matched control group (n = 23) participated in a mental chronometry task (Box and Block Test, BBT) and a mental rotation task (Hand Identification Test, HIT). MC abilities were expressed as a ratio (motor execution time-motor imagery time/motor execution time).

RESULTS

MC for the affected hand was significantly impaired in group 3 in comparison to stroke patients of group 1 (p = 0.006), group 2 (p = 0.005) and healthy controls (p < 0.001). For the non-affected hand MC was similar across all groups. Stroke patients had a slower BBT motor execution than healthy controls (p < 0.001), and group 1 executed the task faster than group 3 (p = 0.002). The percentage of correct responses in the HIT was similar for all groups.

CONCLUSION

Severe sensory deficits impair mental chronometry abilities but have no impact on mental rotation abilities. Future studies should explore whether the presence of severe sensory deficits in stroke patients reduces the benefit from motor imagery therapy.

[Drugs for improvement of motor deficits after stroke]

Randomized controlled trials with a variety of drugs have been performed for approximately 20 years in order to support functional restitution of motor deficits after a stroke. Nowadays, serotonin reuptake inhibitors show the highest level of evidence due to the largest number of positive studies and L‑dopa also seems to be effective; however, much fewer studies have been conducted. In the majority of trials amphetamines provided no additional benefits and D‑cycloserine cannot be recommended either. Future therapeutic approaches, e.g. anti-nogo antibodies and cell therapy are presented.

Complicated spastic paraplegia in patients with AP5Z1 mutations (SPG48)

OBJECTIVE

Biallelic mutations in the AP5Z1 gene encoding the AP-5 ζ subunit have been described in a small number of patients with hereditary spastic paraplegia (HSP) (SPG48); we sought to define genotype-phenotype correlations in patients with homozygous or compound heterozygous sequence variants predicted to be deleterious.

METHODS

We performed clinical, radiologic, and pathologic studies in 6 patients with biallelic mutations in AP5Z1.

RESULTS

In 4 of the 6 patients, there was complete loss of AP-5 ζ protein. Clinical features encompassed not only prominent spastic paraparesis but also sensory and motor neuropathy, ataxia, dystonia, myoclonus, and parkinsonism. Skin fibroblasts from affected patients tested positive for periodic acid Schiff and autofluorescent storage material, while electron microscopic analysis demonstrated lamellar storage material consistent with abnormal storage of lysosomal material.

CONCLUSIONS

Our findings expand the spectrum of AP5Z1-associated neurodegenerative disorders and point to clinical and pathophysiologic overlap between autosomal recessive forms of HSP and lysosomal storage disorders.

Motor cortex excitability and fatigue in multiple sclerosis: a transcranial magnetic stimulation study

We investigated electrophysiological correlates of fatigue in patients with multiple sclerosis (MS). Transcranial magnetic stimulation (TMS) was used to explore motor excitability in three groups of subjects: MS patients with fatigue (MS-F), MS patients without fatigue (MS-NF) and healthy control subjects. All participants had to perform a fatiguing hand-grip exercise. TMS was performed prior to and after the exercise. Prior to the motor task, MS-F patients had less inhibition in the primary motor cortex compared to both other groups. Postexercise, intracortical inhibition was still reduced in the MS-F patients compared to the MS-NF patients. In MS-F patients the postexercise time interval for normalization of the motor threshold was correlated with the fatigue severity. We conclude that MS patients with fatigue have an impairment of inhibitory circuits in their primary motor cortex. The results also indicate that fatigue severity is associated with an exercise-induced reduction of membrane excitability.

Non-Invasive Brain Stimulation in Conversion (Functional) Weakness and Paralysis: A Systematic Review and Future Perspectives

Conversion (functional) limb weakness or paralysis (FW) can be a debilitating condition, and often causes significant distress or impairment in social, occupational, or other important areas of functioning. Most treatment concepts are multi-disciplinary, containing a behavioral approach combined with a motor learning program. Non-invasive brain stimulation (NIBS) methods, such as electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS) have been used in the past few decades to treat FW. In order to identify all published studies that used NIBS methods such as ECT, TMS and transcranial direct current stimulation (tDCS) for treating FW patients a systematic review of the literature was conducted in PubMed and Web of Science. In a second step, narratives were used to retrospectively determine nominal CGI-I (Clinical Global Impression scale–Improvement) scores to describe approximate changes of FW symptoms. We identified two articles (case reports) with ECT used for treatment of FW, five with TMS with a total of 86 patients, and none with tDCS. In 75 out of 86 patients treated with repetitive (r)TMS a nominal CGI-I score could be estimated, showing a satisfactory short-term improvement. Fifty-four out of seventy-five identified patients (72%) had a CGI-I score of 1 (very much improved), 13 (17%) a score of 2 (much improved), 5 (7%) a score of 3 (minimally improved), and 3 (5%) remained unchanged (CGI-I = 4). In no case did patients worsen after rTMS treatment, and no severe adverse effects were reported. At follow-up, symptom improvement was not quantifiable in terms of CGI-I for the majority of the cases. Patients treated with ECT showed a satisfactory short-term response (CGI-I = 2), but deterioration of FW symptoms at follow-up. Despite the predominantly positive results presented in the identified studies and satisfactory levels of efficacy measured with retrospectively calculated nominal CGI-I scores, any assumption of a beneficial effect of NIBS in FW has to be seen with caution, as only few articles could be retrieved and their quality was mostly poor. This article elucidates how NIBS might help in FW and gives recommendations for future study designs using NIBS in this condition.

Temporary deafferentation evoked by cutaneous anesthesia: behavioral and electrophysiological findings in healthy subjects

Motor function and motor excitability can be modulated by changes of somatosensory input. Here, we performed a randomized single-blind trial to investigate behavioral and neurophysiological changes during temporary deafferentation of left upper arm and forearm in 31 right-handed healthy adults. Lidocaine cream was used to anesthetize the skin from wrist to shoulder, sparing the hand. As control condition, on a different day, a neutral cream was applied to the same skin area. The sequence (first Lidocaine, then placebo or vice versa) was randomized. Behavioral measures included the Grating Orientation Task, the Von Frey hair testing and the Nine-hole-peg-test. Transcranial magnetic stimulation was used to investigate short-interval intracortical inhibition, stimulus response curves, motor evoked potential amplitudes during pre-innervation and the cortical silent period (CSP). Recordings were obtained from left first dorsal interosseous muscle and from left flexor carpi radialis muscle. During deafferentation, the threshold of touch measured at the forearm was significantly worse. Other behavioral treatment-related changes were not found. The CSP showed a significant interaction between treatment and time in first dorsal interosseous muscle. CSP duration was longer during Lidocaine application and shorter during placebo exposure. We conclude that, in healthy subjects, temporary cutaneous deafferentation of upper and lower arm may have minor effects on motor inhibition, but not on sensory or motor function for the adjacent non-anesthetized hand.

Motor excitability changes during action observation in stroke patients

OBJECTIVE

To explore whether stroke patients exhibit increases in motor excitability during action observation, whether differences exist between the affected and non-affected sides, and between pure motor strokes and predominantly sensory strokes.

METHODS

In 18 patients (10 pure motor strokes, 8 predominantly sensory strokes, < 6 months after the stroke) transcranial magnetic stimulation was used to test motor excitability while the patients viewed a video showing a hand performing pinch grips. Transcranial magnetic stimulation pulses were applied at 120% of the individual motor threshold at rest, as obtained from the affected hemisphere. Recordings were taken simultaneously from the first dorsal interosseous muscle of both hands. Motor performance was evaluated with the Box and Block Test.

RESULTS

Transcranial magnetic stimulation-evoked muscle responses obtained from the affected and the unaffected sides were significantly higher during action observation than during rest (p = 0.024 and p = 0.004, respectively). This effect was significantly stronger when measuring the same hand as the one viewed in the video (p = 0.019). No difference was found between motor and sensory strokes. In 11 patients there was an action observation-associated increase in the amplitudes of motor evoked potentials in the affected side. In 15 patients there was an action observation-associated increase in motor evoked potentials amplitudes in the unaffected side.

CONCLUSION

The results are potentially relevant for the use of action observation as a treatment strategy.

Catechol-O-Methyltransferase Polymorphism Influences Outcome After Ischemic Stroke

Background. To explore whether a polymorphism in dopamine metabolism influences the effectiveness of neurological rehabilitation and the outcome after ischemic stroke. Methods. The Barthel Index (BI) and the Rivermead Motor Assessment (RMA) were assessed in 78 moderately affected stroke patients (1) after they had entered a neurological inpatient rehabilitation, (2) after 4 weeks of rehabilitation therapy, and (3) 6 months later. Polymorphisms of the gene encoding catechol- O-methyltransferase (COMT) were determined. BI and RMA results were analyzed with respect to the genetic profiles of COMT. Results. Carriers of COMT Val/Val alleles showed better results in BI and RMA than COMT Met/Met carriers at all 3 time points. Val/Met carriers exhibited results in between the homozygotes, suggesting a gene–dose relationship. Altogether, BI and RMA results were highly correlated. Conclusion. Stroke patients with COMT Val/Val alleles had higher motor functions and abilities of activities of daily living even at the beginning of the rehabilitation period. All patient groups improved during the rehabilitation period to a similar degree, suggesting that physical therapy is comparably effective in all polymorphism subtypes.

Motor imagery in stroke patients, or plegic patients with spinal cord or peripheral diseases

OBJECTIVES

When motor imagery (MI) is impaired in stroke patients, it is not clear, whether this is caused by the central lesion with a disruption of networks or this may be due to inactivity/lack of practice following hemiparesis. To answer this question, we investigated MI in two groups of patients: stroke patients and patients with no central lesion, who suffered high-grade tetraparesis caused by myopathy or spinal muscular atrophy.

MATERIALS AND METHODS

The first study measured MI in 31 sub-acute and chronic stroke patients with hand paresis. We used self-assessment questionnaires [Kinaesthetic and Visual Imagery Questionnaire (KVIQ), the Vividness of Motor Imagery Questionnaire (VMIQ)] as well as a new chronometric test (mental version and normal/physical version of Box and Block Test). The second study assessed MI in 10 patients without a central lesion, but with severe tetraparesis of peripheral origin. They were incapable of performing the requested task physically.

RESULTS

MI in patients was better (i) for the third-person (VMIQ(3.P) ) compared to the first-person perspective (VMIQ(1.P) ), (ii) in patients without sensory impairment compared to those with impaired proprioception, (iii) in patients with light paresis compared to severe paresis and (iv) for the non-affected than the affected hand (KVIQ-10). Patients with severe tetraparesis were able to imagine another person's knee bends, but were not capable of imagining themselves performing knee bends.

CONCLUSIONS

MI may be hampered on the affected side in severely paretic patients, particularly in the presence of impaired proprioception. Remarkably, the second study illustrates that motor experiences shape MI. This confirms the close relationship between MI and movement execution. The study advocates the careful use of test batteries for assessment of MI when investigating mental training in clinical trials. Not all patients might benefit to the same extent from MI training. This is possibly contingent on intact proprioception and preserved MI.

Anti-Gal titers in healthy adults and inflammatory bowel disease patients

INTRODUCTION

ALPHA-GAL is a glycoconjugate present on cell membranes of mammals and bacteria but not humans who display anti-Gal antibodies (AB) in high titers provoked by the commensal gut flora. In the present study, we sought to determine the longitudinal course of alpha-Gal specific AB titers of all isotypes over 8 weeks among healthy adult subjects. Furthermore, we hypothesized that inflammatory bowel disease (IBD) patients display increased anti-Gal titers.

MATERIALS AND METHODS

We drew serum from healthy probands (n=20) weekly for 8 weeks and obtained plasma samples of from patients suffering from Crohn's disease (n=20) and ulcerative colitis (n=20). We measured anti-Gal ABs of all isotypes and total immunoglobulin (Ig) content using an enzyme-linked immunosorbent assay technique. For statistical evaluation of the longitudinal titers, we calculated confidence intervals for the slopes of a random intercept model, comparing variances between and within the probands. For group comparisons, we performed paired student t-tests and Pearson correlations.

RESULTS

Alpha-Gal specific IgG, IgM, IgD, and IgA titers remained unvaried within a narrow range upon longitudinal observation. Most probands did not display alpha-Gal specific IgE ABs. Crohn's disease patients showed highly increased alpha-Gal-specific IgA titers compared with control subjects (P<.01).

CONCLUSION

Apart from IgE, alpha-Gal-specific ABs of all isotypes remained constant over longer time periods in healthy subjects. Thus, significant titer changes actually represent increased antigen exposure and a specific anti-alpha-Gal response. Crohn's disease patients display increased anti-Gal IgA titers compared with healthy controls, which reflects a chronically impaired mucosal gut barrier in this patient cohort.

Reduced upper limb sensation impairs mental chronometry for motor imagery after stroke: clinical and electrophysiological findings

BACKGROUND

Motor imagery (MI) is increasingly recognized as a treatment option after stroke, but not all stroke patients are able to perform MI.

OBJECTIVE

To examine if severe somatosensory deficits would affect MI ability.

METHODS

The Box and Block Test (BBT) was used to evaluate mental chronometry as 1 component of MI. Two groups of stroke patients and an age-matched healthy control group (CG) were studied. Patient group 1 (n = 10, PG1) had a severe somatosensory impairment on the affected side and PG2 (n = 10) had pure motor strokes. All subjects first performed the BBT in a mental and in a real version. The time needed to move 15 blocks from 1 side of the box to the other was measured. To compare the groups independently of their performance level, a (real performance--MI)/(real performance) ratio was calculated. Corticospinal excitability was measured by transcranial magnetic stimulation at rest and while the subjects performed an imagined pinch grip.

RESULTS

The CG performed the BBT faster than both patient groups, and PG1 was slower than PG2. MI ability was impaired in PG1 but only for the affected hand. Transcranial magnetic stimulation data showed an abnormally low MI-induced corticospinal excitability increase for the affected hand in PG1, but not in PG2.

CONCLUSIONS

Severe somatosensory deficits impaired mental chronometry. A controlled study is necessary to clarify if these patients benefit at all from MI as an additional treatment.

Motor excitability during movement imagination and movement observation in psychogenic lower limb paresis

BACKGROUND

Patients with a psychogenic paresis have difficulties performing voluntary movements. Typically, diagnostic interventions are normal. We tested whether patients with a psychogenic lower limb paresis exhibit abnormal motor excitability during motor imagery or movement observation.

METHODS

Transcranial magnetic stimulation (TMS) with single and paired pulses was used to explore motor excitability at rest, during imagination of ankle dorsiflexions and during watching another person perform ankle dorsiflexions. Results obtained in ten patients with a flaccid psychogenic leg paresis were compared with a healthy age-matched control group. In addition, results of two patients with a psychogenic fixed dystonia of the leg are presented.

RESULTS

During rest, motor excitability evaluated by motor thresholds, size of motor-evoked potentials (MEP) by single pulse TMS, intracortical inhibition and intracortical facilitation tested by paired-pulse TMS were similar in patients and healthy subjects. MEPs recorded in five patients during movement observation were also comparable across the two groups. During motor imagery, patient MEPs were significantly smaller than in the control group and smaller than during rest, indicating an inhibition.

CONCLUSION

In patients with motor conversion disorder, the imagination of own body movements induces a reduction of corticospinal motor excitability whereas it induces an excitability increase in healthy subjects. This discrepancy might be the electrophysiological substrate of the inability to move voluntarily. Watching another person perform movements induces a normal excitability increase, indicating a crucial role of the perspective and suggesting that focusing the patient's attention on a different person might become a therapeutic approach.

Motor excitability during imagination and observation of foot dorsiflexions

To explore the effects of motor imagery (MI) and action observation (AO) of foot movements on motor excitability. Fifteen healthy subjects were studied at rest, during MI of foot dorsiflexions and during watching a video of foot dorsiflexions. Transcranial magnetic stimulation was used to explore corticospinal and intracortical excitability by comparing amplitudes of motor-evoked potentials during the different conditions. F waves were recorded to test the spinal motoneuronal excitability. MI and AO increased corticospinal excitability, but MI was more effective than AO. During MI, intracortical inhibition was reduced. Intracortical facilitation and spinal motoneuronal excitability remained unchanged. Excitability increases were similar for the right and the left leg when recording from the side the subjects had focused their MI on. However, MI of left foot dorsiflexions did not increase excitability in the right tibial anterior muscle. MI and AO of foot dorsiflexions enhance motor excitability. MI induced a disinhibition in the motor cortex. The lack of excitability increase during MI of contralateral foot movements might be related to the alternating movement pattern during walking. MI and AO effects could support the restitution of motor deficits in neurological diseases with impaired motor excitability.

Comparison of two types of Constraint-Induced Movement Therapy in chronic stroke patients: A pilot study

Several studies showed that Constraint-Induced Movement Therapy (CIMT) leads to a lasting improvement of upper extremity function in chronic stroke patients. The original technique includes an intensive 2-week program with 6 hours of daily physiotherapy. Due to high expenses it is difficult to implement this concept in outpatient care.

PURPOSE

The objective of this study was to evaluate the effects of a 4-week homebased CIMT program among chronic stroke patients and to compare them with a 2-week CIMT program, based on the original technique.

METHODS

Seven adults with chronic stroke completed a newly developed variant of CIMT, performed at patients' homes (group1, CIMThome), supervised by an instructed family member, constraint of unaffected hand for a target of 60% of waking hours. The intervention was analysed with pre-, post-treatment and 6-month follow-up measurements. Effects on improvement in upper extremity function were compared with patients treated according to the original protocol (group2, CIMTclassic), supervised by a physiotherapist, constraint of unaffected hand for a target of 90% of waking hours.

RESULTS

Patients from both groups showed almost identical improvement of their motor function according to scores on the Wolf Motor Function Test (WMFT) and the Motor Activity Log (MAL) immediately after the treatment period as well as at follow-up after 6 months.

CONCLUSIONS

Our study suggests that CIMThome is not only feasible but also as effective as CIMTclassic. This finding should be replicated in a larger prospective randomized trial to perform a non-inferiority analysis.

Electrophysiological correlates of motor conversion disorder

In patients with a functional (psychogenic) paresis, motor conduction tests are, by definition, normal. We investigated whether these patients exhibit an abnormal motor excitability. Four female patients with a functional paresis of the left upper extremity were studied using transcranial magnetic stimulation (TMS). We investigated motor thresholds, intracortical inhibition and intracortical facilitation at rest. Corticospinal excitability was evaluated by single pulse TMS during rest and during imagination of tonic index finger adductions. Data obtained from the affected first dorsal interosseous muscle were compared with the unaffected hand and with a healthy age-matched control group. Three patients demonstrated a flaccid paresis, one patient had a psychogenic dystonia. Motor thresholds, short interval intracortical inhibition and intracortical facilitation recorded from the affected side were normal. In healthy subjects, movement imagination produced an increase of corticospinal excitability. In the patients, motor imagery with the affected index finger resulted in a decrease of corticospinal excitability compared to rest, being significantly different from the unaffected side and from the control group. We suggest that suppression of corticospinal excitability during movement imagination is an electrophysiological correlate of the patients' inability to move voluntarily and provides some insight into the pathophysiology of this disorder.