Objective: Spontaneous recovery is an important determinant of upper extremity recovery after stroke and has been described by the 70% proportional recovery rule for the Fugl–Meyer motor upper extremity (FM‐UE) scale. However, this rule is criticized for overestimating the predictability of FM‐UE recovery. Our objectives were to develop a longitudinal mixture model of FM‐UE recovery, identify FM‐UE recovery subgroups, and internally validate the model predictions.Methods: We developed an exponential recovery function with the following parameters: subgroup assignment probability, proportional recovery coefficient r _k, time constant in weeks τ _k, and distribution of the initial FM‐UE scores. We fitted the model to FM‐UE measurements of 412 first‐ever ischemic stroke patients and cross‐validated endpoint predictions and FM‐UE recovery cluster assignment.Results: The model distinguished 5 subgroups with different recovery parameters ( r₁ = 0.09, τ₁ = 5.3, r₂ = 0.46, τ₂ = 10.1, r₃ = 0.86, τ₃ = 9.8, r₄ = 0.89, τ₄ = 2.7, r₅ = 0.93, τ₅ = 1.2). Endpoint FM‐UE was predicted with a median absolute error of 4.8 (interquartile range [IQR] = 1.3–12.8) at 1 week poststroke and 4.2 (IQR = 1.3–9.8) at 2 weeks. Overall accuracy of assignment to the poor (subgroup 1), moderate (subgroups 2 and 3), and good (subgroups 4 and 5) FM‐UE recovery clusters was 0.79 (95% equal‐tailed interval [ETI] = 0.78–0.80) at 1 week poststroke and 0.81 (95% ETI = 0.80–0.82) at 2 weeks.Interpretation: FM‐UE recovery reflects different subgroups, each with its own recovery profile. Cross‐validation indicates that FM‐UE endpoints and FM‐UE recovery clusters can be well predicted. Results will contribute to the understanding of upper limb recovery patterns in the first 6 months after stroke. ANN NEUROL 2020;87:383–393 Ann Neurol 2020;87:383–393

The aim of this study was to develop and validate an automated accelerometry-based system for estimating initial contact (IC) and terminal contact (TC) timing information from walking patterns of healthy control subjects and transtibial amputees that can be used in daily life with minimal interference of researchers. Subjects were instrumented with two uniaxial accelerometers just below the knee while synchronized ground reaction force (GRF) recordings were used as reference measurements. An automated multiphase algorithm was developed to estimate the time of IC and TC in the acceleration signals of five healthy subjects and two transtibial amputees walking at different walking speeds. The accuracy of the detection algorithm in ten control subjects and eight transtibial amputees indicated mean errors ranging between 0.013 and 0.034 s for the TC and IC timing, with 95% confidence interval of the individual step errors ranging between -0.062 and 0.115 s. Correlation coefficients between the estimated stance phase duration and GRF data were 0.98 and 0.97 for controls and amputees, respectively. We concluded that IC and TC can be accurately and easily measured using this system in both healthy subjects and transtibial amputees walking at different walking speeds. The system can be used in clinical situations or gait labs as well as during daily life.

Summary: Routine measurement of outcome of clinical care is increasingly considered important, but implementation in practice is challenging. This article describes (1) how the authors created and implemented a routine outcome measurement cohort of patients with hand and wrist conditions and (2) how these data are used to improve the quality of care and facilitate scientific research. Starting in 2011, routine outcome measurement was implemented at all practice sites (currently 22) of a specialized treatment center for hand and wrist conditions across The Netherlands. The authors developed five “measurement tracks,” including measurements administered at predetermined time points covering all hand and wrist disorders and treatments. An online system automatically distributes measurements among patients, which can be accessed by health care professionals. Using this system, the total number of yearly assigned tracks increased up to over 16,500 in 2018, adding up to 85,000 tracks in 52,000 patients in total. All surgeons, therapists, and other staff have direct access to individual patient data and patients have access to their treatment information using a secure patient portal. The data serve as a basis for studies on, among others, comparative effectiveness, prediction modeling, and clinimetric analyses. In conclusion, the authors present the design and successful implementation of a routine outcome measurement system that was made feasible using a highly automated data collection infrastructure, tightly linked to the patient journey and the workflow of health care professionals. The system serves not only as a tool to improve care but also as a basis for scientific research studies.

Background: The Jamar dynamometer and the Martin vigorimeter, two instruments often used to assess grip strength, have good validity and reliability when employed to evaluate adults. Grip strength measurements are often performed to assess children with hand disorders. However, the reliability of these measurements when used to assess children under the age of twelve years is unknown. In addition, it is not clear whether reliability differs between younger and older children. The purpose of this study was to establish test-retest reliability for different age groups and to determine which instrument is the most reliable. Methods: One hundred and four children from a primary school were included. Subjects were divided into three groups: four to six, seven to nine, and ten to twelve years of age. The grip strength of both hands was measured with the Lode dynamometer (equivalent to the Jamar dynamometer) and with the Martin vigorimeter. The mean of three maximum voluntary contractions was recorded for all measurements. A retest was performed after a mean interval of twenty-nine days. Results: In the total group, the intraclass correlation coefficient for the Lode dynamometer was 0.97 (95% confidence interval, 0.95 to 0.98) for the dominant hand and 0.95 (95% confidence interval, 0.92 to 0.96) for the nondominant hand and the intraclass correlation coefficient for the Martin vigorimeter was 0.84 (95% confidence interval, 0.77 to 0.89) for the dominant hand and 0.86 (95% confidence interval, 0.80 to 0.90) for the nondominant hand. The intraclass correlation coefficients in the different age groups were lower than those in the total group because of a lower between-subject variation. The normalized smallest detectable difference between the test and retest values was approximately 25% for the Lode dynamometer and approximately 31% for the Martin vigorimeter. Conclusions: Both the Lode dynamometer and the Martin vigorimeter are reliable instruments with which to measure the grip strength of children under twelve years of age; however, the Lode dynamometer has better test-retest reliability. Furthermore, comparison of the smallest detectable differences showed the Lode dynamometer to be a more accurate instrument.

Transcranial direct current stimulation (tDCS) has emerged as a non-invasive brain stimulation technique. Most studies show that anodal tDCS increases cortical excitability. However, this effect has been found to be highly variable. To test the effect of anodal tDCS on cortical excitability and the interaction effect of two participant-specific factors that may explain individual differences in sensitivity to anodal tDCS: the Brain Derived Neurotrophic Factor Val66Met polymorphism (BDNF genotype) and the latency difference between anterior-posterior and lateromedial TMS pulses (APLM latency). In 62 healthy participants, cortical excitability over the left motor cortex was measured before and after anodal tDCS at 2 mA for 20 min in a pre-registered, double-blind, randomized, placebo-controlled trial with repeated measures. We did not find a main effect of anodal tDCS, nor an interaction effect of the participant-specific predictors. Moreover, further analyses did not provide evidence for the existence of responders and non-responders. This study indicates that anodal tDCS at 2 mA for 20 min may not reliably affect cortical excitability.