Analysis of muscle fiber conduction velocity during finger flexion and extension after stroke

Background: Stroke survivors experience greater strength deficits during finger extension than finger flexion. Prior research indicates relatively little observed weakness is directly attributable to muscle atrophy. Changes in other muscle properties, however, may contribute to strength deficits.

Objectives: This study measured muscle fiber conduction velocity (MFCV) in a finger flexor and extensor muscle to infer changes in muscle fiber-type after stroke.

Methods: Conduction velocity was measured using a linear EMG surface electrode array for both extensor digitorum communis and flexor digitorum superficialis in 12 stroke survivors with chronic hand hemiparesis and five control subjects. Measurements were made in both hands for all subjects. Stroke survivors had either severe (n = 5) or moderate (n = 7) hand impairment.

Results: Absolute MFCV was significantly lower in the paretic hand of severely impaired stroke patients compared to moderately impaired patients and healthy control subjects. The relative MFCV between the two hands, however, was quite similar for flexor muscles across all subjects and for extensor muscles for the neurologically intact control subjects. However, MFCV for finger extensors was smaller in the paretic as compared to the nonparetic hand for both groups of stroke survivors.

Conclusions: One explanation for reduced MFCV may be a type-II to type-I muscle fiber, especially in extrinsic extensors. Clinically, therapists may use this information to develop therapeutic exercises targeting loss of type-II fiber in extensor muscles.     

The effect of isolating the paretic limb on weight-bearing distribution and EMG activity during squats in hemiplegic and healthy individuals

Background: Neural reorganization for movement therapy after a stroke is thought to be an important mechanism that facilitates motor recovery. However, there is a lack of evidence for the effectiveness of exercise programs in improving the lower limbs.

Objective: We investigated the immediate effect of isolating the paretic limb using different foot positions ((i) foot parallel; both feet parallel, (ii) foot asymmetry; paretic foot backward by 10 cm, and (iii) foot lifting; nonparetic foot lifting by normalization to 25% of knee height) on weight-bearing distribution and electromyography (EMG) of the thigh muscle during squats.

Methods: In total, 20 patients with hemiplegia and 16 healthy subjects randomly performed three squat conditions in which the knee joint was flexed to 30°. Weight distribution was measured using the BioRescue system. Muscle activity was measured using a surface EMG system.

Results: Patients with hemiplegia exhibited significantly decreased weight bearing on the paretic foot at 0° and 30° knee flexion compared with the nondominant foot of a healthy subject. The muscle activity of the quadriceps was significantly lower in patients with hemiplegia compared to healthy subjects. Weight bearing and EMG activity of the quadriceps femoris on the paretic or nondominant side significantly increased during a knee flexion of 30° with under the foot asymmetry and foot lifting positions compared with the parallel foot position.

Conclusion: Isolating the paretic limb using the asymmetric foot positions and lifting of the foot during squats might help patients with hemiplegia to improve weight-bearing and achieve greater activation of the quadriceps muscle in the paretic limb.     

The improvement in respiratory function by inspiratory muscle training is due to structural muscle changes in patients with stroke: a randomized controlled pilot trial

Background: The changes effected by the inspiratory muscle training (IMT) on the structure of inspiratory muscles such as on the diaphragm, in patients with stroke, is unclear.

Objective: To investigate the effect of IMT on inspiratory function, diaphragm thickness, walking endurance, and fatigue in patients with stroke.

Methods: A total of 30 patients with stroke were randomized to either the experimental group or the control group. The experimental group (n = 15) underwent inspiratory muscle training with resistance adjusted to 30% of maximal inspiratory pressure, 90 breaths a day, 5 times a week for 6 weeks. Both groups received regular physical therapy for the same amount of time. The primary outcome measure was the diaphragm thickness ratio. The secondary outcomes were inspiratory function; maximal inspiratory pressure and inspiratory muscle endurance; and gait endurance and fatigue.

Results: There were significant differences between the two groups in the thickness ratio on the affected diaphragm thickness (medium effect size), maximal inspiratory pressure (medium effect size), and inspiratory muscle endurance (large effect size; Bonferroni correction p < 0.005). The gait endurance (medium effect size) and fatigue (small effect size) showed no significant differences in the between group comparison.

Conclusion: Inspiratory muscle training was effective in improving respiratory function and inducing structural changes, especially in the affected diaphragm.     

POWER training in chronic stroke individuals: differences between responders and nonresponders

Background: Lower extremity muscle weakness is a primary contributor to post-stroke dysfunction. Resistance training is an effective treatment for hemiparetic weakness and improves walking performance. Post-stroke subject characteristics that do or do not improve walking speed following resistance training are unknown.

Objective: The purpose of this paper was to describe baseline characteristics, as well as responses to training, associated with achieving a minimal clinically important difference (MCID) in walking speed (≥0.16 m/s) following Post-stroke Optimization of Walking Using Explosive Resistance (POWER) training.

Methods: Seventeen participants completed 24 sessions of POWER training, which included intensive progressive leg presses, jump training, calf raises, sit-to-stands, step-ups, and over ground fast walking. Outcomes included SSWS, FCWS, DGI, FMA-LE, 6-MWT, paretic knee power, non-paretic knee power, and paretic step ratio.

Results: Specific to those who reached MCID in SSWS (e.g. “responders”), significant improvements in SSWS, FCWS, 6-MWT, paretic knee power, and non-paretic knee power was realized. Paretic knee power and non-paretic knee power significantly improved in those who did not achieve MCID for gait speed (e.g. “non-responders”).

Conclusion: The potential for POWER training to enhance general locomotor function was confirmed. Baseline paretic knee strength/power may be an important factor in how an individual responds to this style of training. The lack of change within the non-responders emphasizes the contribution of factors other than lower extremity muscle power improvement to locomotor dysfunction.     

Structural muscular adaptations in upper limb after stroke: a systematic review

Background: Stroke is a leading cause of disability in the adult population, impairing upper limb (UL) movements affecting activities of daily living. Muscle weakness has been associated to disabilities in this population, but much attention is given to central nervous system alterations and less to skeletal muscles.

Objective: The objective of this review is to carry out a systematic literature review to identify structural muscle alterations in the UL of poststroke individuals.

Method: The search was performed in December, 2017. MEDLINE, PubMed, SCOPUS, CINAHL, and Science Direct were used as electronic databases. There was no restriction regarding language and publication dates. Studies conducted on poststroke subjects and results on UL skeletal muscle alterations identified by imaging tests were included.

Results: Seven studies were included. The sample size and the variables varied among the studies. All the studies compared the paretic UL with the nonparetic UL and one of the studies also compared healthy subjects. Ultrasonography was the most used measurement tool to assess muscle adaptation.

Conclusions: This review demonstrated little evidence with poor to fair quality on the structural muscle adaptations in the poststroke subjects, showing muscle atrophy, a higher stiffness, and amount of fibrous and fat tissue without alterations in lean tissue of distal muscles of the paretic UL compared to the nonparetic limb. However, the nonparetic side also presented alterations, which makes it an inappropriate comparison. Thus, well-designed studies addressing this issue are required.     

Ultrasonographic measurements of the metacarpal and talar cartilage thicknesses in hemiplegic patients after stroke

Background: Immobilization of the extremities after stroke is known to be the foremost reason of articular cartilage degeneration and musculoskeletal ultrasound (US) has become increasingly important in the assessment of joint cartilage. To the best of our knowledge, US measurements of the metacarpal and talar cartilage thicknesses in hemiplegic patients after stroke have not been performed before.

Objectives: The aim of the study was to explore whether metacarpal and talar cartilage thicknesses were affected after stroke using US.

Methods: Fifty-eight patients (33 M and 25 F) with unilateral hemiplegia after stroke were enrolled between April and June 2015. Age, sex, body mass index, paretic side, and underlying etiology (ischemic or hemorrhagic) were noted. Modified Ashworth scale, Brunnstrom motor recovery stage (BMRS), motor functional independence measure and functional ambulation category were recorded. A 5–12 MHz linear array probe was used for ultrasonographic cartilage measurements at 2nd, 3rd, and 4th metacarpal heads and talus.

Results: When compared with the non-paretic side, metacarpal (but not talar) cartilage thicknesses were found to be less on the paretic side (significant for the 3rd and 4th ones) (both p < 0.05). Subgroup analysis yielded thinner 3rd and 4th metacarpal cartilage thicknesses between the groups in patients with BMRS 1–3 (p = 0.009 and 0.054, respectively) but not in patients with BMRS 4–6 (p = 0.416 and 0.571, respectively).

Conclusions: We may conclude that metacarpal (but not talar) cartilage is thinner on the paretic side of stroke patients that seems to be less with better motor functioning.     

Strain sonoelastographic evaluation of biceps muscle intrinsic stiffness after botulinum toxin-A injection

Background: The most commonly used clinical tools for measuring spasticity are modified Ashworth scale (MAS) and Tardieu scale but both yield subjective rather than objective results. Ultrasound elastography (EUS) provides information on tissue stiffness and allows the qualitative or quantitative measurements of the mechanical properties of tissues.

Objective: To assess the stiffness of biceps brachialis muscles in stroke patients by strain EUS and to investigate the sonoelastographic changes and its correlations with clinical evaluation parameters after botulinum toxin-A (BTA) injections.

Methods: This is a prospective study. A total of 48 chronic stroke patients requiring BTA injections to biceps brachialis muscles were included in the study. All patients received injections with BTA to biceps brachialis muscles under ultrasound guidance. MAS, goniometric measurements, and strain EUS assessments were performed at preintervention and at 4-week postintervention.

Results: Strain index values of biceps muscle on the affected side were significantly increased compared with those on the unaffected side (p < 0.01). At 4 weeks after BTA injection, significant improvements were observed in MAS grades and goniometric measurements (p < 0.05). Statistically significant differences were also found between the MAS grades and strain index values in both pre-/postintervention period (p < 0.01). No significant correlations were observed between clinical parameters and strain EUS findings.

Conclusions: Strain EUS is a promising diagnostic tool for assessing stiffness in spastic muscles, in establishing the treatment plan and monitoring the effectiveness of the therapeutic modality.     

Promoting physical activity in hospitalized patients with mild ischemic stroke: a pilot study

Background: Patients with acute stroke spend most of their hospital day inactive. However, a method to promote physical activity (PA) in stroke has not been established.

Objective: To evaluate the effectiveness of promoting PA by enhancing self-efficacy in hospitalized patients with mild ischemic stroke.

Design: Pre–post interventional study.

Methods: Hospitalized patients with mild ischemic stroke who could walk without assistance were recruited. We measured the daily number of steps taken as the index of daily hospitalized PA using an accelerometer. At the baseline measurement, patients did not receive accelerometer-based feedback. To promote hospitalized PA, a physical therapist provided instruction on the self-monitoring approach and discussed PA targets, encouraged the patients to walk more, and instructed them on the importance of PA after stroke. We also measured self-efficacy for PA using an assessment tool at the baseline and during the intervention.

Results: Twenty-two patients (62.5 years old, 68.2% men) were included. PA during the intervention was higher than that at the baseline measurement (5709.4 ± 2236.1 vs. 2813.9 ± 1511.9 steps/day, p < 0.001). Self-efficacy for PA during the intervention was also higher than that at the baseline measurement (76.4 ± 18.8 vs. 58.9 ± 29.0 points, p < 0.001).

Conclusions: Promoting PA by enhancing self-efficacy may increase PA and self-efficacy for PA in hospitalized patients with mild ischemic stroke. The present results might provide new strategies of PA promotion in these hospitalized patients.     

Pilot randomized controlled trial to assess a physical therapy program on upper extremity function to counteract inactivity in chronic stroke

Background: In chronic stroke, feasible physical therapy (PT) programs are needed to promote function throughout life.

Objective: This randomized controlled pilot trial investigated the feasibility and effect of a PT program composed of strengthening exercises with elastic bands and bimanual functional training, with clearly defined doses based on the rate of perceived exertion (Borg scale), to counteract inactivity in chronic stroke.

Methods: Fifteen subjects > 6 month post-stroke were randomized to three-month of UE function training (UE group), or to lower extremity function training (LE group). At baseline (T0), post-intervention (T1) and three-month follow-up (T2) assessment included the Fugl-Meyer Assessment scale (FMA), Wolf Motor Function test (WMFT), grip strength, and muscle tone. Feasibility was also evaluated.

Results: The mixed-model ANOVAs revealed a significant interaction between the time and group factors for FMA (p < .001) and WMFT (p = .009). The UE group improved upper extremity function and motor recovery significantly more than the LE group. There was no significant interaction between treatment group and change in grip strength over time (p = .217). No between-group differences (p > .05) were found in muscle tone. In the UE group, the attendance rate was ≥85% for 71.4% of subjects and 85.7% showed high satisfaction. No adverse events were recorded. After treatment, adherence to the program was higher in the UE group.

Conclusions: The suggested PT program may be useful to improve the paretic UE function and motor recovery in chronic stroke. Moreover, it may be helpful to facilitate lifelong active involvement of stroke subjects in exercise.     

Levodopa,placebo and rotigotine change biomarker levels for oxidative stress

Introduction: Homocysteine increase and glutathione derivative cysteinyl-glycine fall are indirect biomarkers for oxidative stress, for instance due to dopamine D₁ receptor stimulation.

Objectives: To investigate the influence of the D₁ receptor agonists levodopa and rotigotine compared with placebo on homocysteine and cysteinyl-glycine in plasma of patients with Parkinson’s disease.

Methods: Patients received 100 mg levodopa, 4 mg rotigotine or placebo. Cysteinyl-glycine and homocysteine were measured every 30 min over three hours.

Results: Homocysteine rose during levodopa- and placebo administration. Rotigotine had no effect. Cysteine-glycine only increased after placebo- but not after levodopa- or rotigotine.

Discussion: Homocysteine elevation results from hepatic and gastrointestinal methylation processes. Transdermal rotigotine circumvents these methylation locations. Turnover of segregated alkyl residuals from rotigotine serves as methyl group donors, which counteract homocysteine increment. The placebo-related cysteinyl-glycine increase results from reduced free radical exposure. Low levodopa dosing and antioxidants in the rotigotine patch matrix prevented cysteinyl-glycine fall.     

Comparison of the Mini-Balance Evaluations Systems Test with the Berg Balance Scale in relationship to walking speed and motor recovery post stroke*

Background: The Mini-BESTest is a recently developed balance assessment tool that incorporates challenging dynamic balance tasks. Few studies have compared the psychometric properties of the Mini-BESTest to the commonly used Berg Balance Scale (BBS). However, the utility of these scales in relationship to post stroke walking speeds has not been explored.

Objectives: The purpose of this study was to compare the sensitivity and specificity of the Mini-BESTest and BBS to evaluate walking speeds in individuals with stroke.

Design: A retrospective exploratory design.

Methods: Forty-one individuals with chronic stroke were evaluated with the Mini-BESTest, BBS, and 10-meter self-selected walk test (10MWT). Based on their self-selected gait speeds (below or above 0.8 m/s), participants were classified as slow and fast walkers.

Results: Significant linear correlations were observed between the Mini-BESTest vs. BBS (r = 0.72, p ≤ 0.001), Mini-BESTest vs. 10MWT (r = 0.58, p ≤ 0.001), and BBS vs. 10MWT (r = 0.30, p = 0.05). Independent t-tests comparing the balance scores for the slow and fast walkers revealed significant group differences for the Mini-BESTest (p = 0.003), but not for the BBS (p = 0.09). The Mini-BESTest demonstrated higher sensitivity (93%) and specificity (64%) compared to the BBS (sensitivity 81%, specificity 56%) for discriminating participants into slow and fast walkers.

Conclusions: The Mini-BESTest has a greater discriminative ability than the BBS to categorize individuals with stroke into slow and fast walkers.     

Neurological impairments in hypoxic neonates and lactate levels

Introduction: Metabolic acidosis with increasing lactate concentration develops due to the lack of oxygen in the tissues.

Objectives: The effect of lactic acidosis on neurological development in the first year of life.

Materials and Methods: Our study included 50 newborns with perinatal hypoxia requiring oxygen therapy and 50 healthy newborns. pH, pCO2, pO2, base excess (BE) and lactates from arterialized capillary blood were determined in both groups of newborns, in the first and second hours after birth, and neurological development in the first year of life was estimated.

Results: pH, pCO2, pO2, BE and lactates differed significantly between the groups in the first and second hours after birth p < 0.01. Hypotonia was recorded in 20/50 cases and hypertonia was recorded in 10/50 cases in the first year of life.

Conclusion: Lactate concentration may be an indicator of neurological damage in neonates with perinatal hypoxia.     

Cervical myelitis presenting as occipital neuralgia

Aim: Occipital neuralgia is a common form of headache that is characterized by paroxysmal severe lancinating pain in the occipital nerve distribution.

Methods: The exact pathophysiology is still not fully understood and occipital neuralgia often develops spontaneously. There are no specific guidelines for evaluation of patients with occipital neuralgia.

Result: Cervical spine, spinal cord and posterior neck muscle lesions can induce occipital neuralgia. Brain and spine imaging may be necessary in some cases, according to the nature of the headache or response to treatment.

Discussion: We report a case of cervical myelitis presenting as occipital neuralgia.     

Social phobia,depression and eating disorders during middle adolescence: longitudinal associations and treatment seeking

Background: Longitudinal associations between social phobia (SP), depression and eating disorders (EDs), and the impact of antecedent SP and depression on subsequent treatment seeking for EDs have rarely been explored in prospective adolescent population studies.

Aim: We aimed to examine these associations in a large-scale follow-up study among middle adolescents.

Method: We surveyed 3278 Finnish adolescents with a mean age of 15 years for these disorders. Two years later, 2070 were reached and again surveyed for psychopathology and treatment seeking. Longitudinal associations between the self-reported disorders and treatment-seeking patterns for self-acknowledged ED symptoms were examined in multivariate analyses, controlling for SP/depression comorbidity and relevant socioeconomic covariates.

Results: Self-reported anorexia nervosa (AN) at age 15 years predicted self-reported depression at age 17 years. Furthermore, self-reported SP at age 15 years predicted not seeking treatment for bulimia nervosa (BN) symptoms, while self-reported depression at age 15 years predicted not seeking treatment for AN symptoms during the follow-up period.

Conclusions: Adolescents with AN should be monitored for subsequent depression. Barriers caused by SP to help seeking for BN, and by depression for AN, should be acknowledged by healthcare professionals who encounter socially anxious and depressive adolescents, especially when they present with eating problems.     

Nerve root anomalies detected intra-operatively technical nuances towards achieving a successful surgical outcome: our experience of three case reports at a tertiary level centre

Objective: Analysis of three case reports of nerve root anomalies detected intra-operatively and its implications.

Design: Data collected during one year prospective non-randomised study using hospital records.

Setting: Single tertiary care centre.

Subjects: 3 patients in one year period.     

Investigation of subdural electrode displacement in invasive epilepsy surgery workup using neuronavigation and intraoperative MRI

Objectives: One of the main obstacles of electrode implantation in epilepsy surgery is the electrode shift between implantation and the day of explantation. We evaluated this possible electrode displacement using intraoperative MRI (iopMRI) data and CT/MRI reconstruction.

Methods: Thirteen patients (nine female, four male, median age 26 ± 9.4 years) suffering from drug-resistant epilepsy were examined. After implantation, the position of subdural electrodes was evaluated by 3.0 T-MRI and thin-slice CCT for 3D reconstruction. Localization of electrodes was performed with the volume-rendering technique. Post-implantation and pre-explantation 1.5 T-iopMRI scans were coregistered with the 3D reconstructions to determine the extent of electrode dislocation.

Results: Intraoperative MRI at the time of explantation revealed a relevant electrode shift in one patient (8%) of 10 mm. Median electrode displacement was 1.7 ± 2.6 mm with a coregistration error of 1.9 ± 0.7 mm. The median accuracy of the neuronavigation system was 2.2 ± 0.9 mm. Six of twelve patients undergoing resective surgery were seizure free (Engel class 1A, median follow-up 37.5 ± 11.8 months).

Conclusion: Comparison of pre-explantation and post-implantation iopMRI scans with CT/MRI data using the volume-rendering technique resulted in an accurate placement of electrodes. In one patient with a considerable electrode dislocation, the surgical approach and extent was changed due to the detected electrode shift.

Abbreviations: ECoG: electrocorticography; EZ: epileptogenic zone; iEEG: invasive EEG; iopMRI: intraoperative MRI; MEG: magnetoencephalography; PET: positron emission tomography; SPECT: single photon emission computed tomography; 3D: three-dimensional.     

Effect of whole body vibration on spasticity in hemiplegic legs of patients with stroke

Background: Several reports have focused on the effects of whole body vibration (WBV) on spasticity with differing results. Most studies used modified Ashworth scale (MAS) for qualitative measurements, but the effect was small.

Objective: To investigate the effect of WBV on spasticity in hemiplegic legs of patients with stroke using F-wave parameters.

Methods: Sixteen patients with stroke (mean age, 54.7 ± 13.5 years: time after stroke, 28.0 ± 26.3 months) were enrolled in a comparative before-and-after intervention trial. WBV was applied at 30 Hz (4–8 mm amplitude) for 5 min on the hamstrings, gastrocnemius, and soleus muscles in a sitting position. Spasticity was assessed according to the F-wave parameters, MAS, and active and passive range of motion (A-ROM and P-ROM, respectively). These assessments were obtained before, immediately after, and 20 min after each intervention.

Results: The F-wave parameters, MAS score, and P-ROM improved significantly after the WBV and remained below the baseline level, even after 20 min; no such change was noted in the unaffected limb via the F-wave parameters. The WBV also improved volitional movement immediately after intervention, as indicated by the A-ROM.

Conclusions: These results confirmed a significant reduction of motor neuron excitability until 20 min after the WBV, as indicated by F-wave parameters.     

Possible error in the Danish version of the WHO Quality of Life (WHOQOL-BREF) Questionnaire

Background: The WHOQOL-BREF is widely used to measure quality of life.

Aims: The goal of the present study was to use the questionnaire in a doctoral study.

Methods: We studied all the instructions provided by the WHO.

Results: In the Danish version of the WHOQOL-BREF there is a discrepancy between the negatively phrased question 9 and both the syntax file and the verbal instructions for coding the data provided by the WHO.

Conclusions: This is a notification of possible error interpretations in projects that use the questionnaire. This could be corrected by manual correction in the coding process or by changing the negatively phrased question 9.     

Voxel-based morphometry of disgust sensitivity

Background: Difficulties with the regulation of negative affect have been extensively studied in neuroimaging research. However, dysregulation of a specific emotion, disgust, has hardly been investigated. In the present study, we used voxel-based morphometry to identify whether gray matter volume (GMV) of frontal regions is correlated with personality traits associated with general and disgust-specific emotion regulation difficulties.

Method: We analyzed T1-weighted images of 49 females (mean age = 22.8 years, SD = 3.2). The women rated their disgust sensitivity (DS) (temporally stable tendency to experience disgust as uncontrollable and extremely aversive) as well as general difficulties with emotion regulation.

Results: DS and general emotion regulation deficits were positively associated with a heightened GMV of the orbitofrontal cortex. DS additionally showed a negative association with GMV of the medial prefrontal cortex.

Conclusion: The present study revealed shared and distinct contributions of frontal brain regions to disgust-specific and general emotion regulation difficulties.     

The curious case of processing unaccusative verbs in aphasia

Background: Individuals with agrammatic Broca’s aphasia (IWBA) exhibit a delay in lexical activation in S-V-O word order sentences and delayed lexical reactivation in sentences that contain syntactic dependencies. This pattern is in contrast to neurologically unimpaired individuals who immediately evince lexical reactivation at the gap in sentences that contain syntactic dependencies. However, in the case of sentences that contain unaccusative verbs, neurologically unimpaired individuals also exhibit a delay in lexical reactivation. This delay provides a unique opportunity to further examine lexical delays in IWBA.

Aim: The purpose of the current studies is to investigate the online comprehension of sentences that contain unaccusative verbs in IWBA and in a group of age-matched control (AMC) individuals.

Methods and Procedures: Cross-modal picture priming was used to test for priming of a displaced lexical item (direct object noun) immediately after the unaccusative verb (at the gap) during the ongoing auditory stream and at three additional time points downstream from the verb (500 ms, 750 ms, and 1,250 ms).

Outcomes and Results: Delayed reactivation of the displaced lexical item downstream from the gap (similar to prior reports of delayed reactivation with younger unimpaired listeners) for both the AMCs and the IWBA was found.

Conclusion: These results provide support that IWBA do not evince a delayed time course of lexical reactivation for unaccusative verbs compared to neurologically unimpaired individuals.