We aimed to investigate the effects of transcutaneous spinal direct current stimulation (tsDCS) on descending activation of spinal motor neurons in healthy adults. Cathodal tsDCS facilitated peak tor...
Individuals with lesions of central motor pathways frequently suffer from sustained involuntary muscle activity. This symptom shares clinical characteristics with dystonia but is observable in individuals classified as spastic. The term spastic dystonia has been introduced, although the underlying mechanisms of involuntary activity are not clarified and vary between individuals depending on the disorder. This study aimed to investigate the nature and pathophysiology of sustained involuntary muscle activity in adults with cerebral palsy and stroke. Seventeen adults with cerebral palsy (Gross Motor Function Classification System I–V), 8 adults with chronic stroke and 14 control individuals participated in the study. All individuals with cerebral palsy or stroke showed increased resistance to passive movement with Modified Ashworth Scale >1. Two-minute surface EMG recordings were obtained from the biceps muscle during attempted rest in three positions of the elbow joint; a maximally flexed position, a 90-degree position and a maximally extended position. Cross-correlation analysis of sustained involuntary muscle activity from individuals with cerebral palsy and stroke, and recordings of voluntary isometric contractions from control individuals were performed to examine common synaptic drive. In total, 13 out of 17 individuals with cerebral palsy and all 8 individuals with stroke contained sustained involuntary muscle activity. In individuals with cerebral palsy, the level of muscle activity was not affected by the joint position. In individuals with stroke, the level of muscle activity significantly (P < 0.05) increased from the flexed position to the 90 degree and extended position. Cumulant density function indicated significant short-term synchronization of motor unit activities in all recordings. All groups exhibited significant coherence in the alpha (6–15 Hz), beta (16–35 Hz) and early gamma band (36–60 Hz). The cerebral palsy group had lower alpha band coherence estimates, but higher gamma band coherence estimates compared with the stroke group. Individuals with increased resistance to passive movement due to cerebral palsy or stroke frequently suffer sustained involuntary muscle activity, which cannot exclusively be described by spasticity. The sustained involuntary muscle activity in both groups originated from a common synaptic input to the motor neuron pool, but the generating mechanisms could differ between groups. In cerebral palsy it seemed to originate more from central mechanisms, whereas peripheral mechanisms likely play a larger role in stroke. The sustained involuntary muscle activity should not be treated simply like the spinal stretch reflex mediated symptom of spasticity and should not either be treated identically in both groups.
3 May 2024 in Multiple Sclerosis and Related Disorders
Persons with multiple sclerosis (pwMS) frequently suffer from bladder problems that are not identified and managed optimally, reducing quality of life and increasing risk of health consequences. This study aimed to investigate associations between bladder problems and well-being of pwMS. The study included 1872 pwMS from France, Germany, Italy, and the UK self-reporting on demographics, MS status, bladder problems and management, and well-being. Logistic regression analyses were performed to investigate associations with self-reported well-being. Population mean age was 51 years and 79 % were women. Among pwMS, 55 % reported bladder problems indicating overactive bladder (OAB), and 40 % reported self-experienced urinary retention. Self-management of bladder problems was reported by 32 %, 33 % were yet to have problem resolution, and 45 % reported a wish to receive bladder management help. Additionally, 35 % of pwMS reported that bladder problem onset preceded awareness of a link to MS. OAB, problem self-management, and urinary complications were significantly associated with lower well-being. Bladder problems affect pwMS across disease subtypes and many attempt self-management. Consequently, pwMS with bladder problems are more likely to experience lower well-being, suggesting an unmet need. Raising awareness of the link between bladder problems and well-being could benefit pwMS living with bladder problems.
2 April 2022 in European Journal of Applied Physiology
Background/Objectives: To perform a physicochemical characterization of urine and sediment in intermittent catheterization (IC) users and evaluate the impact of IC with micro-hole zone catheters (MHZC) and conventional two-eyelet catheters (CEC). Methods: Analysis of anonymized urine samples collected from four IC user groups with lower urinary tract dysfunction (LUTD): Newly diagnosed individuals with spinal cord injury (SCI) from an inpatient SCI clinic (A), and community-based IC users with SCI (B), multiple sclerosis (MS) (C), or other conditions than SCI or MS (D). Urine analysis included physicochemical properties, bacterial load, and sediment size, both after collection and following passage through MHZC and CEC. Results: Urine samples from 53 participants were analyzed (groups A: 11, B: 11, C: 9, D: 22). The physicochemical properties of urine were similar to reference values despite the prevalence of bacteriuria ranging from 54.5% to 77.3%. The median [99th percentile] sediment size in the total group was 8.6 µm [50.7 µm] and 8.5 µm [54.1 µm] for group A, 9.2 µm [40.3 µm] for group B, 7.9 µm [48.3 µm] for group C, and 8.9 µm [50.3 µm] for group D. Following catheter passage, the median sediment size for the total group was 8.9 µm with the MHZC and 8.9 µm with the CEC. Conclusions: This two-part study initially presented a novel approach to characterizing urine samples, including sediment from IC users, and, thereafter, an in vitro experiment using the samples to test sediment passage through MHZC and CEC. The results indicated similar urine properties and sediment sizes across groups and did not suggest differences or issues relating to urine and sediment passage through these IC technologies for these groups.
Study Design: Observational study on anonymized urine samples from individuals with lower urinary tract dysfunction (LUTD). Objectives: Characterizing urine including sediment in intermittent catheterisation (IC) users and evaluating the impact of IC with micro-hole zone catheters (MHZC) and conventional two-eyelet catheters (CEC). Setting: Urine collection from four IC user groups with LUTD: Newly-diagnosed individuals with spinal cord injury (SCI) from an inpatient SCI clinic (A), and community-based IC users with SCI (B), multiple sclerosis (MS) (C), or other conditions than SCI or MS (D). Methods: Urine samples were tested for physicochemical properties, bacterial load, and sediment size after collection and after passage through MHZC and CEC. Results: 53 participants were included (groups A: 11, B: 11, C: 9, D: 22). The physicochemical properties of urine were similar to reference values despite the prevalence of bacteriuria ranging from 54.5% to 77.3%. The median [99th percentile] sediment size in the total population was 8.6 µm [50.7 µm], and 8.5 µm [54.1 µm] for group A, 9.2 µm [40.3 µm] for group B, 7.9 µm [48.3 µm] for group C, and 8.9 µm [50.3 µm] for group D. Following catheter passage, the median sediment size was 8.9 µm with the MHZC and 8.9 µm with the CEC. Conclusions: This study presented a novel approach to characterizing urine including sediment in IC users which demonstrated that physicochemical properties were comparable to reference values and did not indicate components that could compromise drainage by MHZC or CEC. Sponsorship: This study was sponsored by Coloplast A/S.