Ankle-Foot-Orthosis "Hermes" Compensates Pathological Ankle Stiffness of Chronic Stroke-A Proof of Concept.

Individuals with an upper motor neuron syndrome, e.g., stroke survivors, may have a pathological increase of passive ankle stiffness due to spasticity, that impairs ankle function and activities such as walking. To improve mobility, walking aids such as ankle-foot orthoses and orthopaedic shoes are prescribed. However, these walking aids generally limit the range of motion (ROM) of the foot and may therewith negatively influence activities that require a larger ROM. Here we present a new ankle-foot orthosis "Hermes", and its first experimental results from four hemiparetic chronic stroke patients. Hermes was designed to facilitate active ankle dorsiflexion by mechanically compensating the passive ankle stiffness using a negative-stiffness mechanism. Four levels of the Hermes' stiffness compensation (0%, 35%, 70% and 100%) were applied to evaluate active ROM in a robotic ankle manipulator and to test walking feasibility on an instrumented treadmill, in a single session. The robotic tests showed that Hermes successfully compensated the ankle joint stiffness in all four patients and improved the active dorsiflexion ROM in three patients. Three patients were able to walk with Hermes at one or more Hermes' stiffness compensation levels and without reducing their preferred walking speeds compared to those with their own walking aids. Despite a small sample size, the results show that Hermes holds great promise to support voluntary ankle function and to benefit walking and daily activities.

Development and validity of an innovative test to assess guideline-consistent clinical reasoning by physical therapists in stroke rehabilitation.

OBJECTIVE: To evaluate the validity of a script concordance test to assess guideline-consistent clinical reasoning by physical therapists in stroke rehabilitation, and to identify critical features of physical therapists specializing in stroke rehabilitation. METHODS: A script concordance test was developed according to current standards. Four subgroups of physical therapists (those specializing in neurology, those focusing on neurology or geriatrics, other, and non-specialized undergraduate students) were asked to complete the test. The construct validity of the script concordance test was evaluated with 1-way analysis of variance (ANOVA) to estimate differences between subgroups. Associations between physical therapist characteristics, and script concordance test scores were analysed with bivariate regression analysis followed by multivariate analyses. RESULTS: The script concordance test, with 59 items, was completed by 211 physical therapists. ANOVA analysis showed statistically significant differences between the script concordance test scores of the 4 groups (p<0.001), with higher scores by the physical therapists specializing in neurology compared with the other, non-specialized, subgroups. The multivariate analysis showed that better guideline knowledge (B = 1.07; CI = 0.48-1.65; p =<0.001), successful completion of the Dutch Neurorehabilitation course (B = 4.1; CI = 1.37-6.87; p = 0.003), and participation in professional development activities (B = 2.4; CI = 0.05-4.68; p = 0.046) were associated with higher script concordance test scores. CONCLUSION: The script concordance test has good construct validity. Greater self-reported guideline knowledge, successful completion of the post-bachelor Dutch Neurorehabilitation course, as well as systematic participation in professional development activities facilitate important factors that enhance specialization. The script concordance test is a valid feedback tool for physical therapists to support professional development in the domain of stroke rehabilitation.

Is cognitive functioning 1 year poststroke related to quality of life domain?

Previous studies on the association between poststroke cognitive impairment and quality of life (QoL) have shown divergent results. In this study, we investigated the relationships between cognitive functioning and various QoL domains at 1 year poststroke. This was a cross-sectional study, examining 92 patients at 1 year poststroke. Cognitive functioning was measured with a neuropsychological test battery covering language, attention and psychomotor function, memory, visuoperception, and neglect. QoL domains were functional independence (Barthel Index), social participation (Frenchay Activities Index), depressive mood (Center for Epidemiological Studies Depression Scale), and life satisfaction (Life Satisfaction Questionnaire). Bivariate and multivariate relationships between cognitive and QoL variables were analyzed, the latter both with and without controlling for demographic variables and motor impairment. The prevalence of cognitive impairments varied between 19.3% (neglect) and 72% (attention and psychomotor function). Correlations between cognitive functioning and QoL were strongest for social participation (0.41-0.60, P < .01) and functional independence (0.13-0.58, P < .05). The percentages of variance explained by the total cognition score were 19% for functional independence, 40% for participation, 8% for life satisfaction, and 5% for depression. Controlling for demographic factors and motor impairments resulted in negligible percentages of variance additionally explained by cognitive functioning. The percentages of explained variance were somewhat lower in the analyses with the separate cognitive domains and not significant for depression. Poor cognitive functioning was associated with reduced functional independence, social participation, depressive mood, and life satisfaction 1 year post; however, motor impairment was a stronger determinant of long-term QoL than cognitive functioning.

Long-term deficits in episodic memory after ischemic stroke: evaluation and prediction of verbal and visual memory performance based on lesion characteristics.

We investigated the relationship between ischemic lesion characteristics (hemispheric side, cortical and subcortical level, volume) and memory performance, 1 year after stroke. Verbal and visual memory of 86 patients with stroke were assessed with Rey Auditory-Verbal Learning Test and the Doors Test, respectively. Lesion characteristics and presence of white matter lesions were assessed on magnetic resonance imaging early after stroke. Multiple regression analyses were used to investigate prediction of verbal and visual memory performance by lesion side (left v right hemisphere), lesion level (cortical v subcortical), and lesion volume. We controlled for the influence of demographic characteristics, language disability, and visuospatial difficulties on memory. The results demonstrated that poor verbal memory (immediate and delayed recall and recognition) could be predicted by lesion characteristics: patients with left hemispheric, subcortical, and large lesions showed poor memory performance. Poor visual recognition memory could not be predicted by lesion characteristics but only by low educational level. Our results suggest that lesion characteristics play an important role in episodic verbal memory poststroke if demographic and clinical characteristics are taken into account.

Impact of internal capsule lesions on outcome of motor hand function at one year post-stroke.

OBJECTIVE: To investigate the association between damage to different levels of the corticofugal tract and long-term hand motor recovery. DESIGN: Prospective cohort study. PATIENTS: Seventy-five first-ever middle cerebral artery stroke survivors. METHODS: Hand motor function was assessed with the Fugl-Meyer Motor Assessment Scale at one year post-stroke. Localization of the corticofugal tract was assessed on axial magnetic resonance imaging slices using a corticofugal mask defining involvement of the motor cortex, corona radiata or internal capsule and combinations of these structures, adjusted for lesion volume. RESULTS: Longitudinal involvement of all 3 levels of the corticofugal tract and partial involvement of the internal capsule were associated with a significant probability of poor motor hand function recovery. The probability of regaining hand function ranged from 54% if the corticofugal tract was only partly affected to 13% if both motor cortex and internal capsule were affected. CONCLUSION: At one year post-stroke, lesions of the internal capsule were associated with a significantly lower probability of return of isolated hand motor function than lesions of the cortex, subcortex and corona radiata. Since recovery of isolated hand and finger movements is important for regaining a functional upper limb in everyday living, these patients should be identified early post-stroke in order to evaluate specific hand function training.

Predicting long-term independency in activities of daily living after middle cerebral artery stroke: does information from MRI have added predictive value compared with clinical information?

BACKGROUND AND PURPOSE: To investigate whether neuroimaging information has added predictive value compared with clinical information for independency in activities of daily living (ADL) 1 year after stroke. METHODS: Seventy-five first-ever middle cerebral artery stroke survivors were evaluated in logistic regression analyses. Model 1 was derived on the basis of clinical variables; for model 2, neuroimaging variables were added to model 1. Independent variables were stroke severity (National Institutes of Health Stroke Scale), consciousness (Glasgow Coma Scale), urinary continence, demographic variables (age, gender, relationship, educational level), hospital of admission, and clinical instruments: sitting balance (trunk control test), motor functioning (Motricity Index), and ADL (Barthel Index). Neuroimaging variables, determined on conventional MRI scans, included: number of days to scanning, lesion volume, lesion localization (cortex/subcortex), hemisphere, and the presence of white matter lesions. ADL independency was defined as 19 and 20 points on Barthel Index. Differences in accuracy of prediction of ADL independence between models 1 and 2 were analyzed by comparing areas under the curve (AUC) in a receiver operating characteristic analysis. RESULTS: Model 1 contained as significant predictors: age and ADL (AUC 0.84), correctly predicting 77%. In model 2, number of days to scanning, hemisphere, and lesion volume were added to model 1, increasing the AUC from 0.84 to 0.87, accurately predicting 83% of the surviving patients. CONCLUSIONS: Clinical variables in the second week after stroke are good predictors for independency in ADL 1 year after stroke. Neuroimaging variables on conventional MRI scans do not have added value in long-term prediction of ADL.