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PloS One 2015Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This...
Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This proprioception induces reflex contractions of the slow-twitch fibers in the levator palpebrae superioris and frontalis muscles to sustain eyelid and eyebrow positions against gravity. The cell bodies of the trigeminal proprioceptive neurons in the mesencephalon potentially make gap-junctional connections with the locus coeruleus neurons. The locus coeruleus is implicated in arousal and autonomic function. Due to the relationship between arousal, ventromedial prefrontal cortex, and skin conductance, we assessed whether upgaze with trigeminal proprioceptive evocation activates sympathetically innervated sweat glands and the ventromedial prefrontal cortex. Specifically, we examined whether 60° upgaze induces palmar sweating and hemodynamic changes in the prefrontal cortex in 16 subjects. Sweating was monitored using a thumb-mounted perspiration meter, and prefrontal cortex activity was measured with 45-channel, functional near-infrared spectroscopy (fNIRS) and 2-channel NIRS at Fp1 and Fp2. In 16 subjects, palmar sweating was induced by upgaze and decreased in response to downgaze. Upgaze activated the ventromedial prefrontal cortex with an accumulation of integrated concentration changes in deoxyhemoglobin, oxyhemoglobin, and total hemoglobin levels in 12 subjects. Upgaze phasically and degree-dependently increased deoxyhemoglobin level at Fp1 and Fp2, whereas downgaze phasically decreased it in 16 subjects. Unilateral anesthetization of mechanoreceptors in the supratarsal Müller muscle used to significantly reduce trigeminal proprioceptive evocation ipsilaterally impaired the increased deoxyhemoglobin level by 60° upgaze at Fp1 or Fp2 in 6 subjects. We concluded that upgaze with strong trigeminal proprioceptive evocation was sufficient to phasically activate sympathetically innervated sweat glands and appeared to induce rapid oxygen consumption in the ventromedial prefrontal cortex and to rapidly produce deoxyhemoglobin to regulate physiological arousal. Thus, eyelid opening with trigeminal proprioceptive evocation may activate the ventromedial prefrontal cortex via the mesencephalic trigeminal nucleus and locus coeruleus.
Topics: Adult; Brain Stem; Eyelids; Female; Hemoglobins; Humans; Male; Mechanoreceptors; Neurovascular Coupling; Prefrontal Cortex; Proprioception; Sweat Glands; Sweating; Trigeminal Nuclei
PubMed: 26244675
DOI: 10.1371/journal.pone.0134659 -
Sensors (Basel, Switzerland) Sep 2023Electrodermal activity (EDA) usually relates to variations in the electrical properties of palmar or plantar skin sites. EDA responses, namely skin conductance responses...
Electrodermal activity (EDA) usually relates to variations in the electrical properties of palmar or plantar skin sites. EDA responses, namely skin conductance responses (SCRs), skin potential responses (SPRs) and skin susceptance responses (SSRs) are shown to be sensitive indexes of sympathetic nervous system activation and are studied in many research projects. However, the association between EDA responses and the five basic human senses has not been investigated yet. Our study aimed to explore the relationship between the three EDA responses (SCRs, SSRs and SPRs) and the five basic human senses. These three EDA responses were measured simultaneously at the same skin site on each of the 38 volunteers. The tested five senses were sight, hearing, touch, taste and smell. The results showed that the different tested senses led to different degrees of EDA responses due to activation of the sympathetic nervous system and corresponding secretion of sweat. Although a controlled study on the degree of EDA as a function of the strength of each stimulus was not performed, we noted that the largest EDA responses were typically associated with the smell sense test. We conclude that EDA responses could be utilized as measures for examining the sensitivity of the human senses. Hence, EDA devices may have important roles in sensory systems for future clinical applications.
Topics: Humans; Galvanic Skin Response; Skin Physiological Phenomena; Skin; Touch; Touch Perception
PubMed: 37837011
DOI: 10.3390/s23198181 -
Frontiers in Neurorobotics 2019The young infant explores its body, its sensorimotor system, and the immediately accessible parts of its environment, over the course of a few months creating a model of...
The young infant explores its body, its sensorimotor system, and the immediately accessible parts of its environment, over the course of a few months creating a model of peripersonal space useful for reaching and grasping objects around it. Drawing on constraints from the empirical literature on infant behavior, we present a preliminary computational model of this learning process, implemented and evaluated on a physical robot. The learning agent explores the relationship between the configuration space of the arm, sensing joint angles through proprioception, and its visual perceptions of the hand and grippers. The resulting knowledge is represented as the peripersonal space (PPS) graph, where nodes represent states of the arm, edges represent safe movements, and paths represent safe trajectories from one pose to another. In our model, the learning process is driven by a form of intrinsic motivation. When repeatedly performing an action, the agent learns the typical result, but also detects unusual outcomes, and is motivated to learn how to make those unusual results reliable. Arm motions typically leave the static background unchanged, but occasionally bump an object, changing its static position. The reach action is learned as a reliable way to bump and move a specified object in the environment. Similarly, once a reliable reach action is learned, it typically makes a quasi-static change in the environment, bumping an object from one static position to another. The unusual outcome is that the object is accidentally grasped (thanks to the innate Palmar reflex), and thereafter moves dynamically with the hand. Learning to make grasping reliable is more complex than for reaching, but we demonstrate significant progress. Our current results are steps toward autonomous sensorimotor learning of motion, reaching, and grasping in peripersonal space, based on unguided exploration and intrinsic motivation.
PubMed: 30853907
DOI: 10.3389/fnbot.2019.00004 -
Frontiers in Neuroscience 2017George Marinesco is the founder of Romanian School of Neurology and one of the most remarkable neuroscientists of the last century. He was the pupil of Jean-Martin...
George Marinesco is the founder of Romanian School of Neurology and one of the most remarkable neuroscientists of the last century. He was the pupil of Jean-Martin Charcot in Salpêtrière Hospital in Paris, France, but visited many other neurological centers where he met the entire constellation of neurologists of his time, including Camillo Golgi and Santiago Ramón y Cajal. The last made the preface of Nervous Cell, written in French by Marinesco. The original title was "La Cellule Nerveuse" and is considered even now a basic reference book for specialists in the field. He was a refined clinical observer with an integrative approach, as could be seen from the multitude of his discoveries. The descriptions of the succulent hand in syringomyelia, senile plaque in old subjects, palmar jaw reflex known as Marinesco-Radovici sign, or the application of cinematography in medicine are some of his important contributions. He was the first who described changes of locus niger in a patient affected by tuberculosis, as a possible cause in Parkinson disease. Before modern genetics, Marinesco and Sjögren described a rare and complex syndrome bearing their names. He was a hardworking man, focused on his scientific research, did not accepted flattering of others and was a great fighter against the injustice of the time.
PubMed: 29317856
DOI: 10.3389/fnins.2017.00726 -
Mayo Clinic Proceedings Aug 2011To review surgical results of endoscopic transthoracic limited sympathotomy for palmar-plantar hyperhidrosis during the past decade.
OBJECTIVE
To review surgical results of endoscopic transthoracic limited sympathotomy for palmar-plantar hyperhidrosis during the past decade.
PATIENTS AND METHODS
We retrospectively reviewed 155 consecutive patients who underwent surgery from June 30, 2000, through December 31, 2009, for medically refractory palmar-plantar hyperhidrosis using a technique of T1-T2 sympathotomy disconnection, designed for successful palmar response and minimization of complications.
RESULTS
Of the 155 patients, 44 (28.4%) were male, and 111 (71.6%) were female; operative times averaged 38 minutes. No patient experienced Horner syndrome, intercostal neuralgia, or pneumothorax. The only surgical complication was hemothorax in 2 patients (1.3%); in 1 patient, it occurred immediately postoperatively and in the other patient, 10 days postoperatively; treatment in both patients was successful. All 155 patients had successful (warm and dry) palmar responses at discharge. Long-term follow-up (>3 months; mean, 40.2 months) was obtained for 148 patients (95.5%) with the following responses to surgery: 96.6% of patients experienced successful control of palmar sweating; 69.2% of patients experienced decreased axillary sweating; and 39.8% of patients experienced decreased plantar sweating. At follow-up, 5 patients had palmar sweating (3 patients, <3 months; 1 patient, 10-12 months; 1 patient, 16-18 months). Compensatory hyperhidrosis did not occur in 47 patients (31.7%); it was mild in 92 patients (62.2%), moderate in 7 patients (4.7%), and severe in 2 patients (1.3%).
CONCLUSION
In this series, a small-diameter uniportal approach has eliminated intercostal neuralgia. Selecting a T1-T2 sympathotomy yields an excellent palmar response, with a very low severe compensatory hyperhidrosis complication rate. The low failure rate was noted during 18 months of follow-up and suggests that longer follow-up is necessary in these patients.
Topics: Adult; Aged; Ambulatory Surgical Procedures; Causality; Comorbidity; Female; Follow-Up Studies; Foot Dermatoses; Galvanic Skin Response; Ganglia, Sympathetic; Hand Dermatoses; Hemothorax; Humans; Hyperhidrosis; Male; Middle Aged; Retrospective Studies; Skin Temperature; Sweating; Sympathectomy; Thoracoscopy; Treatment Outcome
PubMed: 21803954
DOI: 10.4065/mcp.2011.0199 -
International Journal of Environmental... Jan 2023The aim of the pilot project was to research relationships between the occurrence and level of intensity of primitive reflexes in primary school children, the ability to...
The aim of the pilot project was to research relationships between the occurrence and level of intensity of primitive reflexes in primary school children, the ability to read an analogue clock and to tell the time. A group of 28 children (14 girls and 14 boys) who attended Montessori Primary School was examined. In the first stage, participants were assessed for the presence of five primitive reflexes (PR): the asymmetrical tonic neck reflex (ATNR), symmetrical tonic neck reflex (STNR), spinal Galant reflex, tonic labyrinthine reflex (TLR) and Palmar grasp reflex. Romberg's test was employed to identify signs of difficulties with control of balance and/or proprioception. In the second stage, pupils underwent tests that challenged their ability to read a clock and calculate passing time. After summing up points obtained for all tests, a correlation coefficient was made from which the results were derived. There is a negative correlation between the ability to read an analogue clock and the continued presence of some primitive reflexes. Lower neuromotor maturity (higher points of PR) correlates with lower ability to read a clock. The highest correlations between difficulty with telling the time were found with persistence of the STNR, ATNR and Romberg's test.
Topics: Male; Female; Humans; Child; Pilot Projects; Reflex, Abnormal; Reflex; Dyslexia
PubMed: 36767689
DOI: 10.3390/ijerph20032322 -
Cureus Jun 2023Implicit (i.e., unconscious) bias frequently differs from one's explicit or conscious convictions. As humans, we rely on information and experiences that are repeatedly...
Implicit (i.e., unconscious) bias frequently differs from one's explicit or conscious convictions. As humans, we rely on information and experiences that are repeatedly reinforced until they become reflexive, shaping our perceptions of reality. Specialty bias, a form of implicit bias specific to an individual's medical specialty, is a form of this bias. These cognitive processes of making assumptions aid efficient decision-making and likely confers an evolutionary advantage. However, automatic thinking can contribute to stereotyping, prejudice, and discrimination at both explicit and implicit levels. Despite a person's explicit beliefs evolving, the lasting implicit bias significantly impacts their behavioral interactions with individuals from stereotyped groups. We present a case of an 83-year-old non-English speaking gentleman with a reported past medical history of an ischemic stroke who presented with acute encephalopathy and fever without jaundice and Aspartate transaminase/ Alanine transaminase (AST/ALT) of 64 and 34, respectively. He was initially treated for acute meningoencephalitis in the Neurologic Intensive Care Unit. With no clinical improvement in symptoms, his care was transferred to the Internal Medicine service later that week, and it was noted that he had features consistent with liver disease. Further history-taking revealed that the patient was intermittently confused with episodes of constipation. On examination, he had palmar erythema and asterixis, and additional labs showed elevated liver enzymes and ammonia levels. Computerized Tomography of the abdomen was suggestive of cirrhosis. He was treated for hepatic encephalopathy with lactulose and rifampin, with improvement in his mental status. We believe our patient's clinical diagnosis was compromised by incomplete information related to a language barrier, and anchoring biases prevented a thorough history taking from the patient family and later on from the patient. Physician's anchoring bias, a form of implicit bias, can negatively impact outcomes in patients, especially those with limited language proficiency, due to communication barriers leading to misunderstanding of the patient's clinical presentation and overreliance on clinical heuristics.
PubMed: 37456498
DOI: 10.7759/cureus.40405 -
Frontiers in Neurology 2018Finger-thumb coordination is crucial to manual dexterity but remains incompletely understood, particularly following neurological injury such as stroke. While being...
Finger-thumb coordination is crucial to manual dexterity but remains incompletely understood, particularly following neurological injury such as stroke. While being controlled independently, the index finger and thumb especially must work in concert to perform a variety of tasks requiring lateral or palmar pinch. The impact of stroke on this functionally critical sensorimotor control during dynamic tasks has been largely unexplored. In this study, we explored finger-thumb coupling during close-open pinching motions in stroke survivors with chronic hemiparesis. Two types of perturbations were applied randomly to the index with a novel Cable-Actuated Finger Exoskeleton: a sudden joint acceleration stretching muscle groups of the index finger and a sudden increase in impedance in selected index finger joint(s). Electromyographic signals for specific thumb and index finger muscles, thumb tip trajectory, and index finger joint angles were recorded during each trial. Joint angle perturbations invoked reflex responses in the flexor digitorum superficialis (FDS), first dorsal interossei (FDI), and extensor digitorum communis muscles of the index finger and heteronymous reflex responses in flexor pollicis brevis of the thumb ( < 0.017). Phase of movement played a role as a faster peak reflex response was observed in FDI during opening than during closing ( < 0.002) and direction of perturbations resulted in shorter reflex times for FDS and FDI ( < 0.012) for extension perturbations. Surprisingly, when index finger joint impedance was suddenly increased, thumb tip movement was substantially increased, from 2 to 10 cm ( < 0.001). A greater effect was seen during the opening phase ( < 0.044). Thus, involuntary finger-thumb coupling was present during dynamic movement, with perturbation of the index finger impacting thumb activity. The degree of coupling modulated with the phase of motion. These findings reveal a potential mechanism for direct intervention to improve poststroke hand mobility and provide insight on prospective neurologically oriented therapies.
PubMed: 29545767
DOI: 10.3389/fneur.2018.00084 -
International Journal of... Dec 2014We present the first quantitative characterization of electrodermal activity (EDA) patterns on the wrists of healthy adults during sleep using dry electrodes. We compare...
We present the first quantitative characterization of electrodermal activity (EDA) patterns on the wrists of healthy adults during sleep using dry electrodes. We compare the new results on the wrist to the prior findings on palmar or finger EDA by characterizing data measured from 80 nights of sleep consisting of 9 nights of wrist and palm EDA from 9 healthy adults sleeping at home, 56 nights of wrist and palm EDA from one healthy adult sleeping at home, and 15 nights of wrist EDA from 15 healthy adults in a sleep laboratory, with the latter compared to concurrent polysomnography. While high frequency patterns of EDA called "storms" were identified by eye in the 1960s, we systematically compare thresholds for automatically detecting EDA peaks and establish criteria for EDA storms. We found that more than 80% of the EDA peaks occurred in non-REM sleep, specifically during slow-wave sleep (SWS) and non-REM stage 2 sleep (NREM2). Also, EDA amplitude is higher in SWS than in other sleep stages. Longer EDA storms were more likely to occur in the first two quarters of sleep and during SWS and NREM2. We also found from the home studies (65 nights) that EDA levels were higher and the skin conductance peaks were larger and more frequent when measured on the wrist than when measured on the palm. These EDA high frequency peaks and high amplitude were sometimes associated with higher skin temperature, but more work is needed looking at neurological and other EDA elicitors in order to elucidate their complete behavior.
Topics: Adolescent; Adult; Female; Galvanic Skin Response; Humans; Longitudinal Studies; Male; Microelectrodes; Polysomnography; Sleep Stages; Wireless Technology; Wrist; Young Adult
PubMed: 25286449
DOI: 10.1016/j.ijpsycho.2014.09.011 -
Clinical Autonomic Research : Official... Feb 2011We studied patients with palmar hyperhidrosis before and after endoscopic thoracic sympathotomy (ETS) to determine the effect of chronic sympathetic denervation on (1)...
PURPOSE
We studied patients with palmar hyperhidrosis before and after endoscopic thoracic sympathotomy (ETS) to determine the effect of chronic sympathetic denervation on (1) forearm blood flow (FBF) response to mental stress and (2) exercise tolerance.
METHODS AND RESULTS
Twenty-two healthy patients were evaluated before ETS, and 17 returned after surgery (11 F; 19-32 years). We measured heart rate (HR; 12 lead), blood pressure, and FBF (plethysmography, ml dl(-1) min(-1)). Supine HR tended to decrease after ETS (69 ± 10 vs. 66 ± 6, p = 0.2). Mental stress FBF was recorded during baseline, 3-min Stroop color word test, and 2-min recovery. Mental stress responses were unaffected by ETS. However, during post-mental stress recovery period, ETS resulted in a significant elevation in FBF (2 ± 1 vs. 3 ± 1), FVC (3 ± 1 vs. 4 ± 2), and a decrease in FVR (52 ± 22 vs. 32 ± 16, p < 0.01 for all). ETS resulted in a reduction in pre-exercise seated baseline HR (94 ± 2.5 beats/min preoperatively vs. 84 ± 4.3 beats/min postoperatively, p < 0.05), maximal HR response to cycle exercise, and exercise systolic blood pressure (172 ± 5.2 mmHg pre-op vs. 158 ± 5.9 mmHg post-op, p < 0.05) but not mean or diastolic pressure. VO(2)max and exercise duration determined by cycle ergometry was unchanged.
CONCLUSIONS
Functional evidence of upper limb denervation is observed during the FBF recovery period from mental stress and hemodynamic alterations associated with upright cycle exercise. However, the sustained exercise capacity suggests modest clinical consequences.
Topics: Adolescent; Adult; Baroreflex; Endoscopy; Exercise Test; Female; Forearm; Hand; Heart Rate; Hemodynamics; Humans; Hyperhidrosis; Male; Middle Aged; Oxygen Consumption; Postoperative Period; Prospective Studies; Regional Blood Flow; Stress, Psychological; Stroop Test; Sympathectomy; Vasodilation; Young Adult
PubMed: 20700642
DOI: 10.1007/s10286-010-0078-2