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Comprehensive Physiology Dec 2023The human sensorimotor control system has exceptional abilities to perform skillful actions. We easily switch between strenuous tasks that involve brute force, such as...
The human sensorimotor control system has exceptional abilities to perform skillful actions. We easily switch between strenuous tasks that involve brute force, such as lifting a heavy sewing machine, and delicate movements such as threading a needle in the same machine. Using a structure with different control architectures, the motor system is capable of updating its ability to perform through our daily interaction with the fluctuating environment. However, there are issues that make this a difficult computational problem for the brain to solve. The brain needs to control a nonlinear, nonstationary neuromuscular system, with redundant and occasionally undesired degrees of freedom, in an uncertain environment using a body in which information transmission is subject to delays and noise. To gain insight into the mechanisms of motor control, here we survey movement laws and invariances that shape our everyday motion. We then examine the major solutions to each of these problems in the three parts of the sensorimotor control system, sensing, planning, and acting. We focus on how the sensory system, the control architectures, and the structure and operation of the muscles serve as complementary mechanisms to overcome deviations and disturbances to motor behavior and give rise to skillful motor performance. We conclude with possible future research directions based on suggested links between the operation of the sensorimotor system across the movement stages. © 2024 American Physiological Society. Compr Physiol 14:5179-5224, 2024.
Topics: Humans; Brain; Movement
PubMed: 38158372
DOI: 10.1002/cphy.c220032 -
European Journal of Neurology Sep 2023Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease, and the time from symptom onset to diagnosis remains long. With the advent of... (Review)
Review
BACKGROUND
Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease, and the time from symptom onset to diagnosis remains long. With the advent of disease-modifying treatments, the need to identify and diagnose ALS in a timely fashion has never been greater.
METHODS
We reviewed the literature to define the severity of ALS diagnostic delay, the various factors that contribute to this delay (including patient and physician factors), and the role that site of symptom onset plays in a patient's diagnostic journey.
RESULTS
Diagnostic delay is influenced by general practitioners' lack of recognition of ALS due to disease rarity and heterogenous presentations. As a result, patients are referred to non-neurologists, have unnecessary diagnostic testing, and may ultimately be misdiagnosed. Patient factors include their illness behavior-which impacts diagnostic delay-and their site of symptom onset. Limb-onset patients have the greatest diagnostic delay because they are frequently misdiagnosed with degenerative spine disease or peripheral neuropathy.
CONCLUSION
Prompt ALS diagnosis results in more effective clinical management, with earlier access to disease-modifying therapies, multidisciplinary care, and, if desired, clinical trial involvement. Due to lack of commercially available ALS biomarkers, alternative strategies to identify and triage patients who likely have ALS must be employed. Several diagnostic tools have been developed to encourage general practitioners to consider ALS and make an urgent referral to ALS specialists, bypassing unnecessary referrals to non-neurologists and unnecessary diagnostic workup.
Topics: Humans; Amyotrophic Lateral Sclerosis; Delayed Diagnosis; Neurodegenerative Diseases; Retrospective Studies; General Practitioners
PubMed: 37209406
DOI: 10.1111/ene.15874 -
Physical Medicine and Rehabilitation... Nov 2023Burns are the fifth leading cause of non-fatal childhood injuries. Physiological differences between children and adults lead to unique considerations when treating... (Review)
Review
Burns are the fifth leading cause of non-fatal childhood injuries. Physiological differences between children and adults lead to unique considerations when treating young burn survivors. In addition to the physical and psychological concerns which must be considered in adult burn rehabilitation, pediatric burn rehabilitation must also consider the developmental stage of the child, preexisting developmental delays, and the impact of scaring on growth and motor skill attainment. Treatment of pediatric burn survivors requires a multidisciplinary approach centered around caring for not only the child but also for their parents, siblings, and other caregivers. For children who sustain burns early in life, long-term follow-up is essential and should be conducted under the guidance of a burn center for the early identification of needed interventions during periods of growth and development. This article considers pediatric-specific factors, which may present during the rehabilitation of a child with a burn injury.
Topics: Child; Humans; Survivors; Burns
PubMed: 37806700
DOI: 10.1016/j.pmr.2023.05.004 -
Human Molecular Genetics Sep 2023N-glycanase 1 (NGLY1) deficiency is a debilitating, ultra-rare autosomal recessive disorder caused by loss of function of NGLY1, a cytosolic enzyme that deglycosylates...
N-glycanase 1 (NGLY1) deficiency is a debilitating, ultra-rare autosomal recessive disorder caused by loss of function of NGLY1, a cytosolic enzyme that deglycosylates other proteins. It is characterized by severe global developmental delay and/or intellectual disability, hyperkinetic movement disorder, transient elevation of transaminases, (hypo)alacrima and progressive, diffuse, length-dependent sensorimotor polyneuropathy. A prospective natural history study (NHS) was conducted to elucidate clinical features and disease course. Twenty-nine participants were enrolled (15 onsite, 14 remotely) and followed for up to 32 months, representing ~29% of the ~100 patients identified worldwide. Participants exhibited profound developmental delays, with almost all developmental quotients below 20 on the Mullen Scales of Early Learning, well below the normative score of 100. Increased difficulties with sitting and standing suggested decline in motor function over time. Most patients presented with (hypo)alacrima and reduced sweat response. Pediatric quality of life was poor except for emotional function. Language/communication and motor skill problems including hand use were reported by caregivers as the most bothersome symptoms. Levels of the substrate biomarker, GlcNAc-Asn (aspartylglucosamine; GNA), were consistently elevated in all participants over time, independent of age. Liver enzymes were elevated for some participants but improved especially in younger patients and did not reach levels indicating severe liver disease. Three participants died during the study period. Data from this NHS informs selection of endpoints and assessments for future clinical trials for NGLY1 deficiency interventions. Potential endpoints include GNA biomarker levels, neurocognitive assessments, autonomic and motor function (particularly hand use), (hypo)alacrima and quality of life.
Topics: Humans; Child; Prospective Studies; Quality of Life; Congenital Disorders of Glycosylation; Biomarkers
PubMed: 37379343
DOI: 10.1093/hmg/ddad106 -
Perinatal depression and infant and toddler neurodevelopment: A systematic review and meta-analysis.Neuroscience and Biobehavioral Reviews Apr 2024Many studies have focused on the effect of perinatal depression on neurodevelopment among children and adolescents. However, only a few studies have explored this... (Meta-Analysis)
Meta-Analysis Review
Many studies have focused on the effect of perinatal depression on neurodevelopment among children and adolescents. However, only a few studies have explored this relationship in infants and toddlers with inconsistent results. We performed a systematic review and meta-analysis to evaluate the association between perinatal depression and infant and toddler neurodevelopment during the first two postnatal years. Twenty-three studies were included in this meta-analysis. Perinatal depression was associated with poorer cognitive (Cohen's d = -0.19, SE= 0.06, 95% CI = -0.30 to -0.08), language (Cohen's d = -0.24, SE = 0.09, 95% CI = -0.40 to -0.07), and motor (Cohen's d = -0.15, SE = 0.05, 95% CI = -0.26 to -0.05) development. Subgroup analyses showed that the types of maternal depression (prenatal depression vs. postnatal depression), the method of measuring maternal depression (rating scale vs. diagnostic interview), and the time interval between assessment of exposure and outcome had an impact on the observed effect about neurodevelopment of infants and toddlers. In addition, the results of our study pointed to a stronger significant association between prenatal depression and cognitive, language, and motor delays in infants and toddlers, whereas the association between postnatal depression and cognitive, language, and motor delays in infants and toddlers was not statistically significant. In conclusion, this study provided convincing evidence that the perinatal window is a sensitive period for offspring neurodevelopment.
Topics: Infant; Pregnancy; Female; Adolescent; Humans; Child, Preschool; Depression, Postpartum; Depression
PubMed: 38342472
DOI: 10.1016/j.neubiorev.2024.105579