Structural white matter abnormalities in patients with idiopathic dystonia

We investigated whether structural white matter abnormalities, in the form of disruption of axonal coherence and integrity as measured with diffusion tensor imaging (DTI), constitute an underlying pathological mechanism of idiopathic dystonia (ID), independent of genotype status. We studied seven subjects with ID: all had cervical dystonia as their main symptom (one patient also had spasmodic dysphonia and two patients had concurrent generalized dystonia, both DYT1‐negative). We compared DTI MR images of patients with 10 controls, evaluating differences in mean diffusivity (MD) and fractional anisotropy (FA). ID was associated with increased FA values in the thalamus and adjacent white matter, and in the white matter underlying the middle frontal gyrus. ID was also associated with increase in MD in adjacent white matter to the pallidum and putamen bilaterally, left caudate, and in subcortical hemispheric regions, including the postcentral gyrus. Abnormal FA and MD in patients with ID indicate that abnormal axonal coherence and integrity contribute to the pathophysiology of dystonia. These findings suggest that ID is not only a functional disorder, but also associated with structural brain changes. Impaired connectivity and disrupted flow of information may contribute to the impairment of motor planning and regulation in dystonia. © 2006 Movement Disorder Society     

Long-term sickness absence due to back disorders in crane operators exposed to whole-body vibration

In a retrospective (10-year) follow-up study, the incidence of at least one spell of sickness absenteeism of 28 d or longer in crane operators exposed to whole-body vibration and a control group was investigated. In contrast to a previous study on permanent work disability in the same groups, no difference was observed in long-term sickness absenteeism because of lumbar disorders. Spells of sickness absence due to intervertebral disc disorders did last longer in the index group and also more disability pensions with this diagnosis were recorded in the index group. This indicates that these disorders particularly interfere with the work of a crane operator. Exposure to whole-body vibration and strained posture are considered to be responsible for this situation.     

How physical therapists instruct patients with stroke: an observational study on attentional focus during gait rehabilitation after stroke

Purpose: People without neurological impairments show superior motor learning when they focus on movement effects (external focus) rather than on movement execution itself (internal focus). Despite its potential for neurorehabilitation, it remains unclear to what extent external focus strategies are currently incorporated in rehabilitation post-stroke. Therefore, we observed how physical therapists use attentional focus when treating gait of rehabilitating patients with stroke.

Methods: Twenty physical therapist-patient couples from six rehabilitation centers participated. Per couple, one regular gait-training session was video-recorded. Therapists’ statements were classified using a standardized scoring method to determine the relative proportion of internally and externally focused instructions/feedback. Also, we explored associations between therapists’ use of external/internal focus strategies and patients’ focus preference, length of stay, mobility, and cognition.

Results: Therapists’ instructions were generally more external while feedback was more internal. Therapists used relatively more externally focused statements for patients with a longer length of stay (B?=??0.239, p?=?0.013) and for patients who had a stronger internal focus preference (B?=??0.930, p?=?0.035).

Conclusions: Physical therapists used more external focus instructions, but more internally focused feedback. Also, they seem to adapt their attentional focus use to patients’ focus preference and rehabilitation phase. Future research may determine how these factors influence the effectiveness of different attentional foci for motor learning post-stroke.

• IMPLICATIONS FOR REHABILITATION

• Physical therapists use a balanced mix of internal focus and external focus instructions and feedback when treating gait of stroke patients.

• Therapists predominantly used an external focus for patients in later rehabilitation phases, and for patients with stronger internal focus preferences, possibly in an attempt to stimulate more automatic control of movement in these patients.

• Future research should further explore how a patients’ focus preference and rehabilitation phase influence the effectiveness of different focus strategies.

• Awaiting further research, we recommend that therapists use both attentional focus strategies, and explore per patient which focus works best on a trial-and-error basis.

     

Plant neighbor detection through touching leaf tips precedes phytochrome signals

Plants in dense vegetation compete for resources, including light, and optimize their growth based on neighbor detection cues. The best studied of such behaviors is the shade-avoidance syndrome that positions leaves in optimally lit zones of a vegetation. Although proximate vegetation is known to be sensed through a reduced ratio between red and far-red light, we show here through computational modeling and manipulative experiments that leaves of the rosette species Arabidopsis thaliana first need to move upward to generate sufficient light reflection potential for subsequent occurrence and perception of a reduced red to far-red ratio. This early hyponastic leaf growth response is not induced by known neighbor detection cues under both climate chamber and natural sunlight conditions, and we identify a unique way for plants to detect future competitors through touching of leaf tips. This signal occurs before light signals and appears to be the earliest means of above-ground plant-plant signaling in horizontally growing rosette plants.     

Where is the neck?: Alpha angle measurement revisited

Background and purpose

The alpha angle is the most used measurement to classify concavity of the femoral head-neck junction. It is not only used for treatment decisions for hip impingement, but also in cohort studies relating hip morphology and osteoarthritis. Alpha angle measurement requires identification of the femoral neck axis, the definition of which may vary between studies. The original “3-point method” uses 1 single point to construct the femoral neck axis, whereas the “anatomic method” uses multiple points and attempts to define the true anatomic neck axis. Depending on the method used, the alpha angle may or may not account for other morphological characteristics such as head-neck offset.

Methods

We compared 2 methods of alpha angle measurement (termed “anatomic” and “3-point”) in 59 cadaver femora and 83 cross-table lateral radiographs of asymptomatic subjects. Results were compared using Bland-Altman plots.

Results

Discrepancies of up to 13 degrees were seen between the methods. The 3-point method had an “equalizing effect” by disregarding femoral head position relative to the neck: in femora with high alpha angle, it resulted in lower values than anatomic measurement, and vice versa in femora with low alpha angles. Using the anatomic method, we derived a reference interval for the alpha angle in normal hips in the general population of 30–66 degrees.

Interpretation

We recommend the anatomic method because it also reflects the position of the femoral head on the neck. Consensus and standardization of technique of alpha angle measurement is warranted, not only for planar measurements but also for CT or MRI-based measurements.Hip morphology variants may influence the development of osteoarthritis (OA) (Ganz et al. 2008). Femoral morphology variants may be best characterized by concavity, a compound measure determined by the sphericity and offset of the femoral head (determined from relative neck width and femoral head position on the neck). The most used concavity measure is the alpha angle, described initially by Nötzli et al. (2002) to diagnose cam deformity and increasingly used in cohort studies examining the risk of OA development (Johnston et al. 2008, Nicholls et al. 2011, Agricola et al. 2013). Nötzli et al. (2002) measured the alpha angle between 2 lines drawn between 3 points (“3-point method”). One line is called the femoral neck axis based on a single point at the center of the narrowest part of the femoral neck (Figure 1), but it is important to recognize that this line will only correspond to the anatomic femoral neck axis if the femoral head is positioned centrally on the neck.Open in a separate windowFigure 1.3-point and anatomic method compared in high alpha angle (A) and low alpha angle (B). 3-point method (A.1 and B.1) uses the midpoint of the femoral neck at its narrowest point. The anatomic method (B.2 and B.2) defines the femoral neck axis by connecting the centers of 3 circles projected over the neck contour. The axis is translated to the center of the femoral head if necessary, to measure the alpha angle. In this example, alpha angle A.1 = 64˚, A.2 = 73˚. Angle B.1 and B.2 are both 30˚, while the femoral head is positioned central on the femoral neck.However, in many human femora the position of the femoral head on the neck may not be central, but shifted or tilted posteriorly (Murray and Duncan 1971, Hogervorst et al. 2009). In such femora, use of a femoral neck axis line connecting the center of the femoral head and neck will decrease the alpha angle (Figure 1). Use of the anatomic center line (the “anatomic method”) rather than a single point for the femoral neck axis (the “3-point method”) probably more accurately represents femoral head-neck morphology, as it may also account for femoral head translation as measured by the anterior offset ratio (Eijer et al. 2001, Pollard et al. 2010). Furthermore, the increasing number of cohort studies using the alpha angle mandates consensus on measurement technique.Measurements in 155 cross-table radiographs

SOCIETAL BURDEN OF STROKE REHABILITATION: COSTS AND HEALTH OUTCOMES AFTER ADMISSION TO STROKE REHABILITATION

ObjectiveTo estimate societal costs and changes in health-related quality of life in stroke patients, up to one year after start of medical specialist rehabilitation.DesignObservational.PatientsConsecutive patients who received medical specialist rehabilitation in the Stroke Cohort Out-comes of REhabilitation (SCORE) study.MethodsParticipants completed questionnaires on health-related quality of life (EuroQol EQ-5D-3L), absenteeism, out-of-pocket costs and healthcare use at start and end of rehabilitation and 6 and 12 months after start. Clinical characteristics and rehabilitation costs were extracted from the medical and financial records, respectively.ResultsFrom 2014 to 2016 a total of 313 stroke patients completed the study. Mean age was 59 (standard deviation (SD) 12) years, 185 (59%) were male, and 244 (78%) inpatients. Mean costs for inpatient and outpatient rehabilitation were US$70,601 and US$27,473, respectively. For inpatients, utility (an expression of quality of life) increased significantly between baseline and 6 months (EQ-5D-3L 0.66–0.73, p = 0.01; visual analogue scale 0.77–0.82, p < 0.001) and between baseline and 12 months (visual analogue scale 0.77–0.81, p < 0.001).ConclusionOne-year societal costs from after the start of rehabilitation in stroke patients were considerable. Future research should also include costs prior to rehabilitation. For inpatients, health-related quality of life, expressed in terms of utility, improved significantly over time.LAY ABSTRACTThe objective of this study was to estimate societal costs and changes in health-related quality of life in stroke patients, up to one year after the start of rehabilitation. Participants were stroke patients who received inpatient or outpatient rehabilitation. They completed questionnaires on quality of life, absenteeism, out-of-pocket costs and healthcare use at start and end of rehabilitation and 6 and 12 months after the start of rehabilitation. Rehabilitation costs were obtained from the financial records. From 2014 to 2016 a total of 313 patients completed the study. Mean age was 59 years, 185 (59%) were male and 244 (78%) inpatients. Mean costs for inpatient and outpatient rehabilitation were $70,601 and $27,473, respectively. For inpatients, health-related quality of life increased significantly between baseline and 6 months, and between baseline and 12 months. In conclusion, societal costs one year after the start of rehabilitation were considerable and health-related quality of life improved for inpatients.Key words: stroke, rehabilitation, cost analysis, utility, health-related quality of life

The number of people living with stroke in Europe is expected to increase from 1.1 million per year in 2000 to 1.5 million per year in 2025 (1). Stroke survivors may experience severe functional impairments, including impairments in physical functioning (2), cognition (3), and speech/language (4), which, in turn, lead to limitations in activities and participation and to worse quality of life (QoL) (5). Specialist rehabilitation was proven to be effective in improving functional outcomes after stroke (6), such as motor function, balance, walking speed and activities of daily living (7–9). Furthermore, in stroke patients admitted for inpatient rehabilitation, QoL increased significantly between admission and discharge (10).Besides the fact that rehabilitation after stroke is effective, rehabilitation was also found to be the main contributor to the costs of post-stroke care, according to a systematic review published in 2018 including 42 publications (11). Costs of post-stroke care, but not those of acute care, were included. Rehabilitation in different care settings was evaluated, which included primary, secondary and tertiary care, and the costs often applied to part of the patients and were not described in detail. For the delivery of value-based healthcare (VBHC), it is important to consider not only the health effects and patient-reported outcome measures, but to also evaluate the costs of care, since it is important to achieve good patient outcomes per dollar spent (12, 13).The aim of the current study was therefore: (i) to estimate the 1-year societal costs from the start of the rehabilitation in stroke patients treated in a medical specialist rehabilitation facility in The Netherlands; and (ii) to evaluate health changes in terms of utility (an expression of quality of life) over that year.     

Planning of an interceptive movement in children

In the present study, we examined the spatio-temporal organization of the walking and reaching behaviour during an interception task in younger (6–9 years old) and older (10–13 years old) children. To this end, eighteen children had to walk towards an interception point to grasp a moving ball under three visual manipulation conditions. Walking and reaching behaviour were analysed during a condition allowing full vision of the ball trajectory and during two conditions in which vision towards the ball was partly occluded (enhanced planning requirement). The velocity of the ball was adapted to 50 or 70% of the maximum walking velocity of the participant. Results revealed that both younger and older children show a less accurate performance when the ball trajectory was occluded, while the walking profile and timing of the reach was not influenced by the occlusion manipulations. The findings seem to suggest that both groups were less accurate when the necessity of planning was enhanced.     

"The very best of the millennium": longitudinal research and the demand-control-(support) model

This study addressed the methodological quality of longitudinal research examining R. Karasek and T. Theorell's (1990) demand-control-(support) model and reviewed the results of the best of this research. Five criteria for evaluating methodological quality were used: type of design, length of time lags, quality of measures, method of analysis, and nonresponse analysis. These criteria were applied to 45 longitudinal studies, of which 19 (42%) obtained acceptable scores on all criteria. These high-quality studies provided only modest support for the hypothesis that especially the combination of high demands and low control results in high job strain. However, good evidence was found for lagged causal effects of work characteristics, especially for self-reported health or well-being outcomes.