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The Journal of Hand Surgery Jun 2023Stimulation of the dorsoradial ligament (DRL) of the first carpometacarpal joint (CMC-1) has shown a ligamento-muscular reflex pathway between the DRL and CMC-1...
PURPOSE
Stimulation of the dorsoradial ligament (DRL) of the first carpometacarpal joint (CMC-1) has shown a ligamento-muscular reflex pathway between the DRL and CMC-1 stabilizing muscles in healthy volunteers. However, it remains unclear how this ligamento-muscular reflex pattern is altered after anesthetizing sensory skin receptors and administering a further periarticular block around the CMC-1 joint, which may influence the dynamic aspects of joint stability.
METHODS
Ligamento-muscular reflexes were obtained from the extensor pollicis longus, abductor pollicis longus, abductor pollicis brevis, and the first dorsal interosseous muscles in 10 healthy participants after establishing superficial anesthesia of the skin around the CMC-1. The DRL was stimulated with a fine wire electrode while EMG activities were recorded during isometric tip, key, and palmar pinch. The measurements were repeated after an additional periarticular CMC-1 block using 5 ml of 1% lidocaine. Average EMG values were analyzed to compare the prestimulus and poststimulus activity.
RESULTS
Statistically significant changes in poststimulus EMG activity were observed in all 4 muscles and all 3 tested thumb positions. A markedly reduced activity in all 4 muscles was observed in the palmar position, followed by the tip and key pinch positions. Almost no reactions were observed in the first 20 ms poststimulus for all muscles in all positions.
CONCLUSIONS
Superficial skin anesthesia and an additional periarticular CMC-1 block anesthesia resulted in a reduced ligamento-muscular reflex pattern in all 4 muscles.
CLINICAL RELEVANCE
Ligamento-muscular reflexes play an important role in dynamic CMC-1 joint stability. The elimination of early reactions, those considered joint-protective reflexes, is a potential risk factor for developing osteoarthritis or injury because it results in an inability to adequately protect and stabilize the joint in sudden movements.
Topics: Humans; Thumb; Muscle, Skeletal; Hand; Reflex; Carpometacarpal Joints
PubMed: 35241318
DOI: 10.1016/j.jhsa.2022.01.005 -
Frontiers in Neural Circuits 2021Primitive reflexes are evident shortly after birth. Many of these reflexes disappear during postnatal development as part of the maturation of motor control. This study...
Primitive reflexes are evident shortly after birth. Many of these reflexes disappear during postnatal development as part of the maturation of motor control. This study investigates the changes of connectivity related to sensory integration by spinal dI3 interneurons during the time in which the palmar grasp reflex gradually disappears in postnatal mice pups. Our results reveal an increase in GAD65/67-labeled terminals to perisomatic Vglut1-labeled sensory inputs contacting cervical and lumbar dI3 interneurons between postnatal day 3 and day 25. In contrast, there were no changes in the number of perisomatic Vglut1-labeled sensory inputs to lumbar and cervical dI3 interneurons other than a decrease between postnatal day 15 and day 25. Changes in postsynaptic GAD65/67-labeled inputs to dI3 interneurons were inconsistent with a role in the sustained loss of the grasp reflex. These results suggest a possible link between the maturation of hand grasp during postnatal development and increased presynaptic inhibition of sensory inputs to dI3 interneurons.
Topics: Animals; Hand Strength; Interneurons; Mice; Reflex; Sensation; Spinal Cord
PubMed: 35153680
DOI: 10.3389/fncir.2021.768235 -
Journal of the Neurological Sciences Sep 2021Delirium is a common complication in acute ischemic stroke, possibly caused by alterations in the regulation of the sympathetic autonomic nervous system. We investigated...
Delirium is a common complication in acute ischemic stroke, possibly caused by alterations in the regulation of the sympathetic autonomic nervous system. We investigated whether such an association could be demonstrated with two easy-to-use measurement techniques: Measurement of palmar skin conductance level (SCL) and pupillometry measuring the dilation velocity in the pupillary light reflex (PLR). The cohort study included 64 patients admitted with acute ischemic stroke. During the study period (median 4.1 days, interquartile range 2.1 days) patients were assessed for delirium once daily as well as with measurements of SCL and PLR up to twice daily. SCL and PLR during delirium were lower than without delirium present. For SCL the unadjusted difference was -40.8% (95% CI (-55.1 to -22.0), P value <.001) and for PLR the unadjusted difference was -0.22 mm/s (95% CI (-0.42 to -0.01), P value = .041). The results demonstrate changes in sympathetic autonomic nervous system regulation during delirium in acute stroke patients.
Topics: Autonomic Nervous System; Brain Ischemia; Cohort Studies; Delirium; Humans; Reflex, Pupillary; Stroke
PubMed: 34284172
DOI: 10.1016/j.jns.2021.117582 -
Spinal Cord Series and Cases Jun 2021Functional electrical stimulation (FES) can enhance motor learning of hand fine motor skills in neurological diseases with upper motoneuron lesions. Nevertheless, FES is...
OBJECTIVE
Functional electrical stimulation (FES) can enhance motor learning of hand fine motor skills in neurological diseases with upper motoneuron lesions. Nevertheless, FES is rarely applied in patients with chronic Guillan-Barré syndrome (GBS) with preserved deep tendon reflexes allowing for stimulation via nerve. This single case report documents the results of an FES-supported, task-oriented grasp training to regain hand closure and pinch grip.
STUDY DESIGN
Single-subject repeated measures study.
SETTING
International FES Centre®, Swiss Paraplegic Centre Nottwil.
METHODS
Three individually defined goals were formulated and scored by using the goal attainment scale. With a focus on these goals, FES was applied bilaterally to improve hand closure and pinch grip. Based on principles of motor learning FES was executed together with task-oriented movements. The hand closure distance (cm) between the tip of the middle finger and the palmar side of the hand was measured and the achievement of personal, predefined goals evaluated.
RESULTS
After 16 weeks of daily stimulation, hand closure could be voluntarily performed. Regained opposition of the thumb to the index finger enabled improved individually defined fine motor control. Restored function remained unchanged in the follow-up at 6 months without stimulation.
CONCLUSION
Improving fine motor skills in chronic GBS with intact deep tendon reflexes was possible utilizing FES combined with task-oriented grasp training. These improvements were maintained over time indicating the combination was effective in promoting functionally meaningful motor gains.
Topics: Electric Stimulation; Electric Stimulation Therapy; Guillain-Barre Syndrome; Hand; Hand Strength; Humans
PubMed: 34183649
DOI: 10.1038/s41394-021-00419-0 -
Archivos de La Sociedad Espanola de... Jun 2021Our visual system has evolved to provide us with an image of the scene that surrounds us, informing us of its texture, colour, movement, and depth with an enormous... (Review)
Review
Our visual system has evolved to provide us with an image of the scene that surrounds us, informing us of its texture, colour, movement, and depth with an enormous spatial and temporal resolution, and for this purpose, the image formation (IF) dedicates the vast majority of our retinal ganglion cell (RGC) population and much of our cerebral cortex. On the other hand, a minuscule proportion of RGCs, in addition to receiving information from classic cone and rod photoreceptors, express melanopsin and are intrinsically photosensitive (ipRGC). These ipRGC are dedicated to non-image-forming (NIF) visual functions, of which we are unaware, but which are essential for aspects related to our daily physiology, such as the timing of our circadian rhythms and our pupillary light reflex, among many others. Before the discovery of ipRGCs, it was thought that the IF and NIF functions were distinct compartments regulated by different RGCs, but this concept has evolved in recent years with the discovery of new types of ipRGCs that innervate subcortical IF regions, and therefore have IF visual functions. Six different types of ipRGCs are currently known. These are termed M1-M6, and differ in their morphological, functional, molecular properties, central projections, and visual behaviour responsibilities. A review is presented on the melanopsin visual system, the most active field of research in vision, for which knowledge has grown exponentially during the last two decades, when RGCs giving rise to this pathway were first discovered.
Topics: Circadian Rhythm; Retinal Cone Photoreceptor Cells; Retinal Ganglion Cells; Retinal Rod Photoreceptor Cells; Vision, Ocular
PubMed: 34092284
DOI: 10.1016/j.oftale.2020.06.020 -
Psychophysiology Nov 2020Advances in mobile and wireless technology have expanded the scope of electrodermal research. Since traditional electrodermal measurement sites are not always suitable... (Comparative Study)
Comparative Study
Advances in mobile and wireless technology have expanded the scope of electrodermal research. Since traditional electrodermal measurement sites are not always suitable for laboratory research and are rarely appropriate for ambulatory measurements, there is a need to explore and contrast alternate measurement locations. We evaluated bilateral electrodermal activity (EDA) from five measurement sites (fingers, feet, wrists, shoulders, and calves). In a counterbalanced, randomized, within-subjects design study, participants (N = 115) engaged in a 4-min-long breathing exercise and were exposed to emotionally laden and neutral stimuli. High within-subject correlations were found between the EDA measured from fingers bilaterally (r = .89), between the left fingers and both feet (r = .72). Moderate correlations were found between EDA measured from the left fingers and wrists (r = .30 and r = .33), low correlations between the left fingers and the shoulders (r = -.03 and r = -.06) or calves (r = .05 and r = .14). Response latency was the shortest on the fingers while it was the longest on the lower body. Short response windows would miss some of the responses from the palmar surfaces and a substantial number from other evaluated locations. The fingers and the feet are the most reliable locations to measure from, followed by the wrists. We suggest setting site-specific response windows for different measurement locations. An investigation of repeatability showed that within-subject correlations, response frequencies, response amplitudes show a similar pattern from the first measurement time to a later one.
Topics: Adolescent; Adult; Emotions; Female; Fingers; Foot; Galvanic Skin Response; Humans; Leg; Male; Neuropsychological Tests; Random Allocation; Shoulder; Wrist; Young Adult
PubMed: 32931044
DOI: 10.1111/psyp.13645 -
International Journal of Developmental... Aug 2020Maple Syrup Urine Disease (MSUD) is caused by a severe deficiency in the branched-chain ketoacid dehydrogenase complex activity. Patients MSUD accumulate the...
Maple Syrup Urine Disease (MSUD) is caused by a severe deficiency in the branched-chain ketoacid dehydrogenase complex activity. Patients MSUD accumulate the branched-chain amino acids leucine (Leu), isoleucine, valine in blood, and other tissues. Leu and/or their branched-chain α-keto acids are linked to neurological damage in MSUD. When immediately diagnosed and treated, patients develop normally. Inflammation in MSUD can elicit a metabolic decompensation crisis. There are few cases of pregnancy in MSUD women, and little is known about the effect of maternal hyperleucinemia on the neurodevelopment of their babies. During pregnancy, some intercurrences like maternal infection or inflammation may affect fetal development and are linked to neurologic diseases. Lipopolysaccharide is widely accepted as a model of maternal inflammation. We analyzed the effects of maternal hyperleucinemia and inflammation and the possible positive impact the use of ibuprofen in Wistar rats on a battery of physics (ear unfolding, hair growing, incisors eruption, eye-opening, and auditive channel opening) and neurological reflexes (palmar grasp, surface righting, negative geotaxis, air-righting, and auditory-startle response) maturation parameters in the offspring. Maternal hyperleucinemia and inflammation delayed some physical parameters and neurological reflexes, indicating that both situations may be harmful to fetuses, and ibuprofen reversed some settings.
PubMed: 32379904
DOI: 10.1002/jdn.10035 -
Heart Rhythm Aug 2020Bilateral cardiac sympathetic denervation (BCSD) is an effective therapy for ventricular arrhythmias (VAs) in cardiomyopathies (CMPs). After BCSD, residual autonomic...
BACKGROUND
Bilateral cardiac sympathetic denervation (BCSD) is an effective therapy for ventricular arrhythmias (VAs) in cardiomyopathies (CMPs). After BCSD, residual autonomic nervous system (ANS) function is unknown.
OBJECTIVE
The purpose of this study was to assess ANS responses in patients with CMP before and after BCSD as compared with demographically matched healthy controls.
METHODS
Patients with CMP undergoing BCSD and matched healthy controls were recruited. Noninvasive measures-finger cuff beat-to-beat blood pressure (BP), electrocardiography, palmar electrodermal activity (EDA), and finger pulse volume (FPV)-were obtained at rest and during autonomic stressors-posture change, handgrip, and mental stress. Maximal as well as specific responses to stressors were compared.
RESULTS
Eighteen patients with CMP (mean age 54 ± 14 years; 16 men, 89%; left ventricular ejection fraction 36% ± 14%) with refractory VAs and 8 matched healthy controls were studied; 9 patients with CMP underwent testing before and after (median 28 days) BCSD, with comparable ongoing medication. Before BCSD, patients with CMP (n = 13) had lower resting systolic BP and FPV than did healthy controls (P < .01). Maximal FPV and systolic BP reflex responses, expressed as percent change were similar, while diastolic BP, mean BP, and EDA responses were blunted. After BCSD, resting measurements were unchanged relative to presurgical baseline (n = 9). EDA responses to stressors were abolished, confirming BCSD, while maximal FPV and BP responses were preserved. Diastolic BP, mean BP, and FPV responses to orthostatic challenge pointed toward a better tolerance of active standing after BCSD as compared with before. Responses to other stressors remained unchanged.
CONCLUSION
Patients with CMP and refractory VAs on optimal medical therapy have detectable but blunted adrenergic responses, which are not disrupted by BCSD.
Topics: Autonomic Nervous System; Blood Pressure; Electrocardiography; Female; Follow-Up Studies; Heart Rate; Humans; Male; Middle Aged; Reflex; Retrospective Studies; Sympathectomy; Tachycardia, Ventricular; Treatment Outcome
PubMed: 32325196
DOI: 10.1016/j.hrthm.2020.04.022 -
Reproduction, Fertility, and Development Sep 2019The aim of this study was to evaluate whether paternal exposure to bupropion hydrochloride (BUP), an inhibitor of dopamine and noradrenaline reuptake, would affect the...
The aim of this study was to evaluate whether paternal exposure to bupropion hydrochloride (BUP), an inhibitor of dopamine and noradrenaline reuptake, would affect the postnatal development of offspring. Male mice were divided into a BUP-treated (40mgkg-1day-1 by gavage, 45 days) or control (saline by gavage, 45 days) group (n=20 in each group). From Day 35 to Day 45 of treatment, males were allowed to mate with drug-naïve female mice. Postnatal development of the offspring (both sexes) was evaluated from Postnatal day (PND) 1 to PND60. Physical development parameters (weight gain, body length, incisor eruption, pinna detachment), anogenital distance, vaginal opening, reflexes (palmar grasp, surface righting, negative geotaxis and adult gait) and some behavioural parameters (locomotor activity and anxiety-like behaviour) were altered in the offspring of BUP-treated males. The results demonstrate that paternal exposure to BUP induces long-lasting changes in the postnatal development of the offspring.
Topics: Animals; Animals, Newborn; Behavior, Animal; Bupropion; Female; Growth and Development; Male; Mice; Motor Activity; Paternal Exposure; Pregnancy; Prenatal Exposure Delayed Effects; Reflex
PubMed: 31270008
DOI: 10.1071/RD18403