Posts Tagged Finger Extension
[ARTICLE] Effects of Unilateral Upper Limb Training in Two Distinct Prognostic Groups Early After Stroke – Full Text
Background and Objective. Favorable prognosis of the upper limb depends on preservation or return of voluntary finger extension (FE) early after stroke. The present study aimed to determine the effects of modified constraint-induced movement therapy (mCIMT) and electromyography-triggered neuromuscular stimulation (EMG-NMS) on upper limb capacity early poststroke.
Methods. A total of 159 ischemic stroke patients were included: 58 patients with a favorable prognosis (>10° of FE) were randomly allocated to 3 weeks of mCIMT or usual care only; 101 patients with an unfavorable prognosis were allocated to 3-week EMG-NMS or usual care only. Both interventions started within 14 days poststroke, lasted up until 5 weeks, focused at preservation or return of FE.
Results. Upper limb capacity was measured with the Action Research Arm Test (ARAT), assessed weekly within the first 5 weeks poststroke and at postassessments at 8, 12, and 26 weeks. Clinically relevant differences in ARAT in favor of mCIMT were found after 5, 8, and 12 weeks poststroke (respectively, 6, 7, and 7 points; P < .05), but not after 26 weeks. We did not find statistically significant differences between mCIMT and usual care on impairment measures, such as the Fugl-Meyer assessment of the arm (FMA-UE). EMG-NMS did not result in significant differences.
Conclusions. Three weeks of early mCIMT is superior to usual care in terms of regaining upper limb capacity in patients with a favorable prognosis; 3 weeks of EMG-NMS in patients with an unfavorable prognosis is not beneficial. Despite meaningful improvements in upper limb capacity, no evidence was found that the time-dependent neurological improvements early poststroke are significantly influenced by either mCIMT or EMG-NMS.
Several prospective cohort studies among stroke patients have shown that the functional outcome of the upper limb is largely defined within the first 5 weeks poststroke and is mainly driven by (yet poorly understood) mechanisms of spontaneous neurological recovery.1,2 Observational studies showed that the presence of some voluntary finger extension (FE) within 72 hours is a favorable indicator for the return of dexterity poststroke.3,4 This suggests that early control of FE is an important prognostic factor in stratifying patients for upper limb intervention trials early poststroke.2
For those with a favorable prognosis, indicated by some voluntary FE early poststroke, constraint-induced movement therapy (CIMT) or a modified version (mCIMT) may benefit arm-hand activities and self-reported hand function in daily life.5The number of phase II trials on mCIMT within the first days or weeks poststroke is however small and findings are rather inconclusive. For example, Dromerick et al6showed in a proof of concept trial that 1 or 2 hours mCIMT per working day for 2 weeks was not superior to an equal dosage of usual care, whereas a high dose of 3 hours mCIMT per working day resulted in less improvement on functional outcome measured with the Action Research Arm Test (ARAT) at 3 months poststroke.
For those with an unfavorable prognosis for functional outcome at 6 months, that is, patients without voluntary FE,1,3,4 no evidence-based therapies have been reported so far. In subacute and chronic stroke, innovative therapies such as electromyography-triggered neuromuscular stimulation (EMG-NMS) of the finger extensors to improve voluntary control have shown promise in terms of increasing active range of motion.7⇓⇓⇓–11 Furthermore, several studies suggest that EMG-NMS may produce changes in cortical activation patterns and excitability in chronic stroke.12,13 For example, Shin et al13 showed in a small proof of concept trial (n = 14) that a daily 30-minute program for 10 weeks shifted cortical activation patterns as seen in functional magnetic resonance imaging from the ipsilateral sensorimotor cortex to the contralateral sensorimotor cortex in chronic stroke. Despite the growing evidence for enhanced levels of homeostatic neuroplasticity in the first weeks poststroke,14 early started EMG-NMS trials for patients without FE are lacking in this restricted time window.
The first objective of the present study was to investigate the effects of an early mCIMT program on recovery of upper limb capacity during the first 6 months, starting within 14 days poststroke in patients with some voluntary FE. Our second objective was to investigate the effects of early EMG-NMS on the recovery of voluntary FE and upper limb capacity during the first 6 months, starting within 14 days poststroke in patients with no voluntary control of the finger extensors. We hypothesized that an intensive 3-week mCIMT program would result in a clinically meaningful improvement in ARAT scores compared with usual care alone. For the patients with an unfavorable prognosis we hypothesized that a higher percentage of patients (10% or more increase) would regain some dexterity (ARAT score >9 points on a maximum of 57 points) if they received intensive daily EMG-NMS for 3 weeks, compared with usual care alone.
[ARTICLE] When Does Return of Voluntary Finger Extension Occur Post-Stroke? A Prospective Cohort Study – Full Text
Objectives: Patients without voluntary finger extension early post-stroke are suggested to have a poor prognosis for regaining upper limb capacity at 6 months. Despite this poor prognosis, a number of patients do regain upper limb capacity. We aimed to determine the time window for return of voluntary finger extension during motor recovery and identify clinical characteristics of patients who, despite an initially poor prognosis, show upper limb capacity at 6 months post-stroke.
Methods: Survival analysis was used to assess the time window for return of voluntary finger extension (Fugl-Meyer Assessment hand sub item finger extension≥1). A cut-off of ≥10 points on the Action Research Arm Test was used to define return of some upper limb capacity (i.e. ability to pick up a small object). Probabilities for regaining upper limb capacity at 6 months post-stroke were determined with multivariable logistic regression analysis using patient characteristics.
Results: 45 of the 100 patients without voluntary finger extension at 8 ± 4 days post-stroke achieved an Action Research Arm Test score of ≥10 points at 6 months. The median time for regaining voluntary finger extension for these recoverers was 4 weeks (lower and upper percentile respectively 2 and 8 weeks). The median time to return of VFE was not reached for the whole group (N = 100). Patients who had moderate to good lower limb function (Motricity Index leg≥35 points), no visuospatial neglect (single-letter cancellation test asymmetry between the contralesional and ipsilesional sides of <2 omissions) and sufficient somatosensory function (Erasmus MC modified Nottingham Sensory Assessment≥33 points) had a 0.94 probability of regaining upper limb capacity at 6 months post-stroke.
Conclusions: We recommend weekly monitoring of voluntary finger extension within the first 4 weeks post-stroke and preferably up to 8 weeks. Patients with paresis mainly restricted to the upper limb, no visuospatial neglect and sufficient somatosensory function are likely to show at least some return of upper limb capacity at 6 months post-stroke.
Voluntary finger extension (VFE) is an important early predictor of recovery of upper limb capacity at 6 months post-stroke[1;2]. Patients without VFE within the first days post-stroke have been suggested to have a poor prognosis for regaining some upper limb capacity at 6 months[1–3]. Absence of VFE reflects the loss of functional corticospinal tract integrity, acknowledging that the hand muscles are almost solely innervated by contralateral corticospinal pathways. Indirect bilateral innervation of the hand muscles by the reticulospinal tract may also contribute to hand motor control after stroke. However, it remains unclear if the reticulospinal system can influence the digital extensor muscles of the paretic hand.
Despite an initially poor prognosis, some patients without VFE within the first days after stroke do regain upper limb capacity at 6 months. In view of the lack of evidence-based therapies for patients without VFE[7;8], this return of VFE seems most likely to be driven by spontaneous neurobiological processes such as alleviation of diaschisis. Unfortunately, the clinical characteristics as well as the optimal time window for recovery of VFE are unknown, due to lack of prospective cohort studies in which patients are assessed serially at fixed times post-stroke[10;11]. More knowledge regarding this time window is important for future prognostic algorithm development. Up till now, the most optimal timing and added value of neurophysiological and neuroimaging measurements with respect to clinical measurements like VFE are unclear.
The aims of the present study were therefore (1) to determine the clinical time window for return of VFE in ischemic stroke patients without VFE in the first days post-stroke, and (2) to identify clinical characteristics for the return of some upper limb capacity in these patients within the first 6 months after stroke. We hypothesized that return of VFE would occur within the purported time window of spontaneous neurobiological recovery between 0 and 10 weeks after stroke onset[10;12]. We also hypothesized that patients with lesions affecting upper limb function who exhibit no other neurological impairments such as visuospatial neglect and somatosensory dysfunction would have a high probability of regaining some upper limb capacity at 6 months[13–15].