Herman Kingma

Technology-assisted training of arm-hand skills in stroke: concepts on reacquisition of motor control and therapist guidelines for rehabilitation technology design

BackgroundIt is the purpose of this article to identify and review criteria that rehabilitation technology should meet in order to offer arm-hand training to stroke patients, based on recent principles of motor learning.MethodsA literature search was conducted in PubMed, MEDLINE, CINAHL, and EMBASE (1997–2007).ResultsOne hundred and eighty seven scientific papers/book references were identified as being relevant. Rehabilitation approaches for upper limb training after stroke show to have shifted in the last decade from being analytical towards being focussed on environmentally contextual skill training (task-oriented training). Training programmes for enhancing motor skills use patient and goal-tailored exercise schedules and individual feedback on exercise performance. Therapist criteria for upper limb rehabilitation technology are suggested which are used to evaluate the strengths and weaknesses of a number of current technological systems.ConclusionThis review shows that technology for supporting upper limb training after stroke needs to align with the evolution in rehabilitation training approaches of the last decade. A major challenge for related technological developments is to provide engaging patient-tailored task oriented arm-hand training in natural environments with patient-tailored feedback to support (re) learning of motor skills.

Double-blind clinical trial of thalamic stimulation in patients with Tourette syndrome

Deep brain stimulation of the thalamus has been proposed as a therapeutic option in patients with Tourette syndrome who are refractory to pharmacological and psychotherapeutic treatment. Patients with intractable Tourette syndrome were invited to take part in a double-blind randomized cross-over trial assessing the efficacy and safety of stimulation of the centromedian nucleus-substantia periventricularis-nucleus ventro-oralis internus crosspoint in the thalamus. After surgery, the patients were randomly assigned to 3 months stimulation followed by 3 months OFF stimulation (Group A) or vice versa (Group B). The cross-over period was followed by 6 months ON stimulation. Assessments were performed prior to surgery and at 3, 6 months and 1 year after surgery. The primary outcome was a change in tic severity as measured by the Yale Global Tic Severity Scale and the secondary outcome was a change in associated behavioural disorders and mood. Possible cognitive side effects were studied during stimulation ON at 1 year postoperatively. Interim analysis was performed on a sample of six male patients with only one patient randomized to Group B. Tic severity during ON stimulation was significantly lower than during OFF stimulation, with substantial improvement (37%) on the Yale Global Tic Severity Scale (mean 41.1 ± 5.4 versus 25.6 ± 12.8, P = 0.046). The effect of stimulation 1 year after surgery was sustained with significant improvement (49%) on the Yale Global Tic Severity Scale (mean 42.2 ± 3.1 versus 21.5 ± 11.1, P = 0.028) when compared with preoperative assessments. Secondary outcome measures did not show any effect at a group level, either between ON and OFF stimulation or between preoperative assessment and that at 1 year postoperatively. Cognitive re-assessment at 1 year after surgery showed that patients needed more time to complete the Stroop Colour Word Card test. This test measures selective attention and response inhibition. Serious adverse events included one small haemorrhage ventral to the tip of the electrode, one infection of the pulse generator, subjective gaze disturbances and reduction of energy levels in all patients. The present preliminary findings suggest that stimulation of the centromedian nucleus-substantia periventricularis-nucleus ventro-oralis internus crosspoint may reduce tic severity in refractory Tourette syndrome, but there is the risk of adverse effects related to oculomotor function and energy levels. Further randomized controlled trials on other targets are urgently needed since the search for the optimal one is still ongoing.

Reaction time latencies of eye and hand movements in single- and dual-task conditions

The goal of this study was to investigate whether ocular and hand motor systems operate independently or whether they share processes. Using dualtask methodology, reaction time (RT) latencies of saccadic eye and hand motor responses were measured. In experiment 1, the hand and eye motor systems produced rapid, aimed pointing movements to a visual target, which could occur either to the left or right of a central fixation point. Results showed that RT latencies of the eye response were slower in the dual-task condition than in the single-task condition, whereas the RT latencies of the hand response were virtually the same in both conditions. This interference effect indicated that the ocular and manual motor systems are not operating independently when initiating saccadic eye and goal-directed hand movements. Experiment 2 employed the same experimental paradigm as experiment 1, except for one important modification. Instead of a goal-directed hand movement to the target stimulus, subjects had to make a button-press response with either the index or middle finger of the right hand dependent upon whether the stimulus occurred to the right or left of the control fixation point. The aim of experiment 2 was to investigate the issue whether the observed interference effect in experiment 1 was specific or non-specific (e.g. overhead costs due to coordinating any two responses). The finding that saccadic eye movements and button-press responses in the dual-task condition could be initiated without delay relative to the single-task conditions, supports the specific interference interpretation.

Influence of Task-Oriented Training Content on Skilled Arm-Hand Performance in Stroke: A Systematic Review

Objective. This review evaluates the underlying training components currently used in task-oriented training and assesses the effects of these components on skilled arm—hand performance in patients after a stroke. Methods. A computerized systematic literature search in 5 databases (PubMed, CINAHL, EMBASE, PEDro, and Cochrane) identified randomized clinical trials, published through March 2009, evaluating the effects of task-oriented training. Relevant article references listed in publications included were also screened. The methodological quality of the selected studies was assessed with the Van Tulder Checklist. For each functional outcome measure used, the effect size (bias corrected Hedges’s g) was calculated. Results. The intervention results in 528 patients (16 studies) were studied. From these, 15 components were identified to characterize task-oriented training. An average of 7.8 (standard deviation = 2.1) components were used in the included trials. There was no correlation between the number of task-oriented training components used in a study and the treatment effect size. “Distributed practice” and “feedback” were associated with the largest postintervention effect sizes. “Random practice” and “use of clear functional goals” were associated with the largest follow-up effect sizes. Conclusion. The task-oriented training was operationalized with 15 components. The number of components used in an intervention aimed at improving arm—hand performance after stroke was not associated with the posttreatment effect size. Certain components, which optimize storage of learned motor performance in the long-term memory, occurred more in studies with larger treatment effects.

Control of rapid aimed hand movements : The one-target advantage

A series of 8 experiments examined the phenomenon that a rapid aimed hand movement is executed faster when it is performed as a single, isolated movement than when it is followed by a second movement (the 1-target advantage). Three new accounts of this effect are proposed and tested: the eye movement hypothesis, the target uncertainty hypothesis, and the movement integration hypothesis. Data are reported that corroborate the 3rd hypothesis, but not the first 2 hypotheses. According to the movement integration hypothesis, the first movement in a series is slowed because control of the second movement may overlap with execution of the first. It is shown that manipulations of target size and movement direction mediate this process and determine the presence and absence of the 1-target advantage. Possible neurophysiological mechanisms and implications for motor control theory are discussed.

Interference between saccadic eye and goal-directed hand movements

The aim of the present study was to investigate the nature of the interference effect when the eye is accompanied by a goal-directed hand movement rather than when the eye moves alone. Latencies of eye and hand movements in response to small and large visual target stimuli were measured while employing dual-task methodology. Experiments 1 and 2 were designed to investigate whether the interference effect is related to a specific temporal bottleneck, i.e. the eye and hand motor systems share limited available processes at a specific point in time. The findings of robust interference effects independent of the temporal organization of eye and hand contradicted this notion. The interference effect was not present in experiment 3, where response preparation and target-localization mechanisms were limited by providing subjects with advance information about target position. Experiment 4 employed randomized target positions again and highly salient stimuli, the latter only limiting target-localization processes. The absence of an interference effect adds weight to the argument that visual spatial attentional mechanisms involved in target localization constitute the locus of the interference. Neurophysiological implications of these findings are discussed.

Quality of life of patients with bilateral vestibulopathy

Objectives: Currently, there is no evidence of an effective treatment for patients with bilateral vestibulopathy (BV). Their main complaints are oscillopsia and imbalance. Opinions about the impact of BV on their quality of life are controversial, and their handicap is not always recognized, even among otoneurologists. The aim of this study was to objectively assess the health status of BV patients in order to evaluate the need for pursuing efforts toward the development of new treatments. Methods: The Short-Form Health Survey (SF-36), the Dizziness Handicap Inventory (DHI), the Short Falls Efficacy Scale–International (Short FES-I), and an oscillopsia severity questionnaire were submitted to 39 BV patients. The SF-36 scores were compared to the scores of a general Dutch population. The DHI scores were correlated to the oscillopsia severity scores. The Short FES-I scores were compared to scores in an elderly population. Residual otolithic function was correlated to all scores, and hearing to SF-36 scores. Results: Compared to the general Dutch population, the BV patients scored significantly worse on the “physical functioning,” “role physical,” “general health,” “vitality,” and “social functioning” SF-36 variables (p < 0.05). The DHI scores were strongly correlated with the oscillopsia severity scores (r = 0.75; p < 0.000001). The Short FES-I scores indicated a slight to moderate increase in the patients fear of falling. No significant score differences were found between BV patients with residual otolithic function and patients with complete BV. There was no correlation between hearing status and SF-36 scores. Conclusions: The results correlate with our clinical impression that BV has a strong negative impact on physical and social functioning, leading to a quality-of-life deterioration. There is a clear need for a therapeutic solution. Efforts toward the development of a vestibular implant are justified.

Selective vestibular ablation by intratympanic gentamicin in patients with unilateral active ménière's disease: a prospective, double-blind, placebo-controlled, randomized clinical trial

Objective To establish the efficacy of intratympanic gentamicin treatment in patients with unilateral Ménières disease. Material and Methods This was a prospective, double-blind, randomized clinical trial of intratympanic gentamicin versus intratympanic buffer solution (placebo) in patients with established active Ménières disease in the affected ear. Outcome measures included the number of vertiginous spells, degree of sensorineural hearing loss, labyrinthine function and labyrinthine asymmetry. Results Topical gentamicin provided a significant reduction in the number of vertiginous spells, although a “placebo effect” was also observed. Sensorineural hearing loss did not occur in the gentamicin group, although some deterioration occurred in the placebo group. Conclusions Intratympanic gentamicin is a safe and efficient treatment for the vertiginous spells associated with Ménières disease. When applied early in the course of the disease, it may prevent some of the sensorineural hearing deterioration associated with it.

Sensor-Based Arm Skill Training in Chronic Stroke Patients: Results on Treatment Outcome, Patient Motivation, and System Usability

As stroke incidence increases, therapists time is under pressure. Technology-supported rehabilitation may offer new opportunities. The objective of this study was to evaluate patient motivation for and the feasibility and effects of a new technology-supported task-oriented arm training regime (T-TOAT). Nine chronic stroke patients performed T-TOAT (2 × 30 min/day, four days/week) during eight weeks. A system including movement tracking sensors, exercise board, and software-based toolkit was used for skill training. Measures were recorded at baseline, after four and eight weeks of training, and six months posttraining. T-TOAT improved arm-hand performance significantly on Fugl-Meyer, Action Research Arm Test, and Motor Activity Log. Training effects lasted at least six months posttraining. Health-related-quality-of-life had improved significantly after eight weeks of T-TOAT with regard to perceived physical health, but not to perceived mental health (SF-36). None of the EuroQol-5D components showed significant differences before and after training. Participants were intrinsically motivated and felt competent to use the system. Furthermore, system usability was rated very good. However, exercise challenge as perceived by participants decreased significantly over eight weeks of training. The results of this study indicate that T-TOAT is feasible. Despite the small number of stroke patients tested, significant and clinically relevant improvements in skilled arm-hand performance were found.

Habituation to galvanic vestibular stimulation for analysis of postural control abilities in gymnasts.

The possible correlation between postural control abilities in gymnasts and the sensitivity for and the degree of short-term habituation to galvanic vestibular stimulation (GVS) was studied. Seven balance trained young girls (Dutch National Junior Gymnasts Championship) versus seven non-trained girls and twenty-five women underwent computer-controlled GVS using a monaural continuous 1-cosinusoidal stimulus of 0.5 Hz and 2 mA, repeated three times on each side [Balter, Stokroos, Boumans, Kingma, Acta Otolaryngol. (in press); Balter, Stokroos, Eterman, Paredis, Orbons, Kingma, Acta Otolaryngol. (in press)]. Results showed that mean total galvanic-induced body sway (GBS) gain was significantly lower in the trained and untrained girls compared to the adult women (P < 0.05). Mean habituation to GVS (learning abilities), however, showed no significant differences between the three groups. We suggest that the superior balance control in professional gymnasts is primarily achieved through motor training and not by learning abilities or a higher sensitivity of the vestibular system [Neurosci. Lett. 225 (1998) 155].