TMS-Induced Central Motor Conduction Time at the Non-Infarcted Hemisphere Is Associated with Spontaneous Motor Recovery of the Paretic Upper Limb after Severe Stroke.

BACKGROUND: Stroke affects the neuronal networks of the non-infarcted hemisphere. The central motor conduction time (CMCT) induced by transcranial magnetic stimulation (TMS) could be used to determine the conduction time of the corticospinal tract of the non-infarcted hemisphere after a stroke. OBJECTIVES: Our primary aim was to demonstrate the existence of prolonged CMCT in the non-infarcted hemisphere, measured within the first 48 h when compared to normative data, and secondly, if the severity of motor impairment of the affected upper limb was significantly associated with prolonged CMCTs in the non-infarcted hemisphere when measured within the first 2 weeks post stroke. METHODS: CMCT in the non-infarcted hemisphere was measured in 50 patients within 48 h and at 11 days after a first-ever ischemic stroke. Patients lacking significant spontaneous motor recovery, so-called non-recoverers, were defined as those who started below 18 points on the FM-UE and showed less than 6 points (10%) improvement within 6 months. RESULTS: CMCT in the non-infarcted hemisphere was prolonged in 30/50 (60%) patients within 48 h and still in 24/49 (49%) patients at 11 days. Sustained prolonged CMCT in the non-infarcted hemisphere was significantly more frequent in non-recoverers following FM-UE. CONCLUSIONS: The current study suggests that CMCT in the non-infarcted hemisphere is significantly prolonged in 60% of severely affected, ischemic stroke patients when measured within the first 48 h post stroke. The likelihood of CMCT is significantly higher in non-recoverers when compared to those that show spontaneous motor recovery early post stroke.

Effectiveness of AbobotulinumtoxinA in Post-stroke Upper Limb Spasticity in Relation to Timing of Treatment.

Background: Recent studies of botulinum toxin for post-stroke spasticity indicate potential benefits of early treatment (i. e., first 6 months) in terms of developing hypertonicity, pain and passive function limitations. This non-interventional, longitudinal study aimed to assess the impact of disease duration on the effectiveness of abobotulinumtoxinA treatment for upper limb spasticity. Methods: The early-BIRD study (NCT01840475) was conducted between February 2013 and 2018 in 43 centers across Germany, France, Austria, Netherlands and Switzerland. Adult patients with post-stroke upper limb spasticity undergoing routine abobotulinumtoxinA treatment were followed for up to four treatment cycles. Patients were categorized by time from stroke event to first botulinum toxin-A treatment in the study (as defined by the 1st and 3rd quartiles time distribution) into early-, medium- and late- start groups. We hypothesized that the early-start group would show a larger benefit (decrease) as assessed by the modified Ashworth scale (MAS, primary endpoint) on elbow plus wrist flexors compared with the late-start group. Results: Of the 303 patients enrolled, 292 (96.4%) received ≥1 treatment and 186 (61.4%) received 4 injection cycles and completed the study. Patients in all groups showed a reduction in MAS scores from baseline over the consecutive injection visits (i.e., at end of each cycle). Although reductions in MAS scores descriptively favored the early treatment group, the difference compared to the late group did not reach statistical significance at the last study visit (ANCOVA: difference in adjusted means of 0.15, p = 0.546). Conclusions: In this observational, routine-practice study, patients in all groups displayed a benefit from abobotulinumtoxinA treatment, supporting the effectiveness of treatment for patients at various disease stages. Although the data revealed some trends in favor of early vs. late treatment, we did not find strong evidence for a significant benefit of early vs. late start of treatment in terms of reduction in MAS scores.

Does Transcranial Magnetic Stimulation Have an Added Value to Clinical Assessment in Predicting Upper-Limb Function Very Early After Severe Stroke?

BACKGROUND: The added prognostic value of transcranial magnetic stimulation (TMS)-induced motor-evoked potentials (MEPs) to clinical modeling for the upper limb is still unknown early poststroke. OBJECTIVE: To determine the added prognostic value of TMS of the adductor digiti minimi (TMS-ADM) to the clinical model based on voluntary shoulder abduction (SA) and finger extension (FE) during the first 48 hours and at 11 days after stroke. METHODS: This was a prospective cohort study with 3 logistic regression models, developed to predict upper-limb function at 6 months poststroke. The first model showed the predictive value of SA and FE measured within 48 hours and at 11 days poststroke. The second model included TMS-ADM, whereas the third model combined clinical and TMS-ADM information. Differences between derived models were tested with receiver operating characteristic curve analyses. RESULTS: A total of 51 patients with severe, first-ever ischemic stroke were included. Within 48 hours, no significant added value of TMS-ADM to clinical modeling was found ( P = .369). Both models suffered from a relatively low negative predictive value within 48 hours poststroke. TMS-ADM combined with SA and FE (SAFE) showed significantly more accuracy than TMS-ADM alone at 11 days poststroke ( P = .039). CONCLUSION: TMS-ADM showed no added value to clinical modeling when measured within first 48 hours poststroke, whereas optimal prediction is achieved by SAFE combined with TMS-ADM at 11 days poststroke. Our findings suggest that accuracy of predicting upper-limb motor function by TMS-ADM is mainly determined by the time of assessment early after stroke onset.

How Do Fugl-Meyer Arm Motor Scores Relate to Dexterity According to the Action Research Arm Test at 6 Months Poststroke?

OBJECTIVE: To determine the optimal cutoff scores for the Fugl-Meyer Assessment of the Upper Extremity (FMA-UE) with regard to predicting no, poor, limited, notable, or full upper-limb capacity according to frequently used cutoff points for the Action Research Arm Test (ARAT) at 6 months poststroke. DESIGN: Prospective. SETTING: Rehabilitation center. PARTICIPANTS: Patients (N=460) with a first-ever ischemic stroke at 6 months poststroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Based on the ARAT classification of poor to full upper-limb capacity, receiver operating characteristic curves were used to calculate the area under the curve, optimal cutoff points for the FMA-UE were determined, and a weighted kappa was used to assess the agreement. RESULTS: FMA-UE scores of 0 through 22 represent no upper-limb capacity (ARAT 0-10); scores of 23 through 31 represent poor capacity (ARAT 11-21); scores of 32 through 47 represent limited capacity (ARAT 22-42); scores of 48 through 52 represent notable capacity (ARAT 43-54); and scores of 53 through 66 represent full upper-limb capacity (ARAT 55-57). Overall, areas under the curve ranged from .916 (95% confidence interval [CI], .890-.943) to .988 (95% CI, .978-.998; P<.001). CONCLUSIONS: There is considerable overlap in the area under the curve between the ARAT and FMA-UE. FMA-UE scores >31 points correspond to no to poor arm-hand capacity (ie, ≤21 points) on the ARAT, whereas FMA-UE scores >31 correspond to limited to full arm-hand capacity (ie, ≥22 points) on the ARAT.

How reproducible are transcranial magnetic stimulation-induced MEPs in subacute stroke?

PURPOSE: Motor evoked potentials (MEPs) and total motor conduction time (TMCT) induced by transcranial magnetic stimulation (TMS) are used to make assumptions about the prognosis of motor outcome after stroke. Understanding the different sources of variability is fundamental to the concept of reliability. Reliability testing of TMS-MEPs and TMCTs within and between two independent examiners in healthy and stroke subjects is still an unexplored field in the clinical neurophysiology. Assessing the reproducibility of TMS measurements requires studies to investigate the test-retest reliability of TMS-induced MEPs and TMCT. The authors set out to test the reliability of these TMS measurements. METHODS: Eighteen patients with stroke and 8 healthy volunteers were tested twice within a 1-week period by 2 examiners using TMS to determine MEPs and TMCT for the abductor pollicis brevis muscle of their affected and unaffected hands. RESULTS: The authors found moderate to perfect reliability of TMS-induced MEPs in healthy volunteers, noninfarcted hemispheres (perfect agreement), and infarcted hemispheres (Kappa's = 0.45-0.87). Reliability of TMCT was good to excellent in the volunteers (intraclass correlation coefficients = 0.77-0.97), excellent in the noninfarcted hemispheres (intraclass correlation coefficients = 0.97-1.00), and poor to excellent in the infarcted hemispheres (intraclass correlation coefficients = 0.44-0.90). CONCLUSIONS: The reliability of TMS-induced MEPs and TMCT measurements in healthy volunteers and the noninfarcted hemisphere of patients with stroke with an upper paretic limb was good to excellent. In contrast, TMS measurements in the infarcted hemisphere were less consistent. Based on the lower reproducibility of TMCT measurements in the infarcted hemisphere, we recommend to repeat the TMCT measurements to improve the reliability of tests.

Arm motor control as predictor for hypertonia after stroke: a prospective cohort study.

OBJECTIVES: To analyze the development of hypertonia in the hemiparetic elbow flexors, and to explore the predictive value of arm motor control on hypertonia in a cohort of first-ever stroke survivors in the first 6 months poststroke. DESIGN: A prospective cohort study. SETTING: A cohort of stroke survivors from a large, university-affilliated hospital in The Netherlands. PARTICIPANTS: Patients (N=50) with first-time ischemic strokes and initial arm paralysis who were admitted to a stroke unit. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: At 48 hours, 10 to 12 days, 3 and 6 months poststroke, hypertonia and arm motor control were assessed using the Modified Ashworth Scale and the Fugl-Meyer Assessment arm score. RESULTS: The incidence rate of hypertonia reached its maximum before the third month poststroke (30%). Prevalence was 42% at 3 and 6 months. Participants with poor arm motor control at 48 hours poststroke were 13 times more likely to develop hypertonia in the first 6 months poststroke than those with moderate to good arm motor control. These results were not confounded by the amount of arm function training received. CONCLUSIONS: Hypertonia develops in a large proportion of patients with stroke, predominantly within the first 3 months poststroke. Poor arm motor control is a risk factor for the development of hypertonia.