PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “REFLEX, PROPRIOCEPTIVE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28Linked to original sources

Linkage analysis in spinopontine atrophy: correlation of HLA linkage with phenotypic findings in hereditary ataxia.

Because linkage has been reported between HLA and the locus for hereditary ataxia in some families, we studied a 3-generation kindred in which several individuals had dominantly inherited spinopontine atrophy. Affected family members had upper and lower limb ataxia, hypoactive reflexes, loss of proprioception, dysarthria, dysphagia, and pronounced extraocular movement abnormalities. Linkage analysis, based on 25 markers in 28 people, gave strongly negative results with both HLA (z less than -2.0 for theta less than 0.15) and GLO1 (z less than -2.0, theta less than or equal to 0.01). The highest LOD score was for linkage to GPT on chromosome 16 (z = 0.42, theta = 0.0). To assess the relationship between HLA linkage and phenotype, 4 published kindreds with adequate clinical and neuropathological descriptions were used for comparison to the present family. Persons in the 3 families showing evidence for HLA linkage had clinical and pathologic changes consistent with olivopontocerebellar atrophy, type 1. The conditions in the 2 "nonlinked" families were phenotypically distinct from the HLA-linked condition with respect to extraocular movement findings and peripheral sensory nervous system signs. They differed markedly from each other in neuropathologic changes.

Adult↗

Combined intracellular stimulation and high speed video motion analysis of motor control neurons in the cockroach.

A complete understanding of motor control circuitry requires detailed analysis of the behavior produced by the circuitry as well as the connections between individual neurons. A technique is described for combining high speed video motion analysis of leg movements in the cockroach with electrophysiological techniques such as intracellular stimulation/recording from central neurons and EMG recording from leg muscles. Using a restrained preparation, we have quantified leg movements evoked by intracellular stimulation of individual motor neurons and local interneurons. By incorporating motion analysis into the recording paradigm, the transfer functions from electrical activity to movements can be derived. Because distinct and characteristic responses to single and multiple action potentials are seen in slow, intermediate, and fast motor neurons, it is often possible to identify the motor neuron targets of local interneurons. The ability to analyze movement in any plane is especially useful in situations such as blind neuropilar penetrations, where a more restricted motion transducer arrangement may not be in register with the impaled cell. In addition, it is possible to record and analyze such complex phenomena as coordinated movements in multiple joints produced by local interneurons and reflexes produced by proprioceptive feedback due to activity of one motor neuron.

Animals↗

Mechanoreceptors and nerve endings of the triangular fibrocartilage in the human wrist.

PURPOSE: To increase our understanding of the mechanism of pain and the sensation of wrist instability by studying the distribution of the mechanoreceptors in the triangular fibrocartilage (TFC). METHODS: The distribution and density of the nerve endings were investigated in 34 TFC specimens obtained from human cadavers. We studied the dorsal, palmar, ulnar, radial, and central areas after staining by a modified gold chloride technique. RESULTS: The free nerve endings, responsible for sensing pain, predominate in the ulnar and dorsal areas. The Vater-Pacini corpuscles predominate in the radial and dorsal area, promoting perception of the onset or cessation of movement and mechanical stress change. The Golgi-Mazzoni corpuscles were more frequent in the ulnar and ventral areas, linking these areas to function of slow adaptation and sensation of extreme movements. The proprioceptive function receptors were found in all areas of TFC because Ruffini corpuscles have homogeneous distribution in this fibrocartilaginous tissue. CONCLUSIONS: Our results showed that the nerve endings were distributed at the periphery of TFC and showed different concentrations of each type of mechanoreceptors per topographic area, suggesting that they play specific roles in the proprioceptive and nociceptive reflexes of the wrist.

Adolescent↗

The influence of rigid taping on peroneal latency in normal ankles.

Traumatic ankle injury is a frequent clinical presentation. Ankle taping is commonly used in the prophylaxis of sprains and as an adjunct during rehabilitation of ankle injury. The mechanisms behind taping remain unclear however, one possible mechanism is improved proprioception and peroneal reflex responses. This study investigated the peroneal reflex response to rapid inversion (using a trapdoor) with different taping protocols. The dominant leg of 31 healthy subjects was tested in three conditions: no taping; simple prophylactic taping;and circumferential leg taping. A repeated measures ANOVA revealed no statistically significant effect across conditions or trials. The results suggest that neurophysiological responses to sudden inversion are not altered by mechanical or sensory input from taping in normal subjects.

Journal Article↗

Transcriptional regulation of myotube fate specification and intrafusal muscle fiber morphogenesis.

Vertebrate muscle spindle stretch receptors are important for limb position sensation (proprioception) and stretch reflexes. The structurally complex stretch receptor arises from a single myotube, which is transformed into multiple intrafusal muscle fibers by sensory axon-dependent signal transduction that alters gene expression in the contacted myotubes. The sensory-derived signal transduction pathways that specify the fate of myotubes are very poorly understood. The zinc finger transcription factor, early growth response gene 3 (Egr3), is selectively expressed in sensory axon-contacted myotubes, and it is required for normal intrafusal muscle fiber differentiation and spindle development. Here, we show that overexpression of Egr3 in primary myotubes in vitro leads to the expression of a particular repertoire of genes, some of which we demonstrate are also regulated by Egr3 in developing intrafusal muscle fibers within spindles. Thus, our results identify a network of genes that are regulated by Egr3 and are involved in intrafusal muscle fiber differentiation. Moreover, we show that Egr3 mediates myotube fate specification that is induced by sensory innervation because skeletal myotubes that express Egr3 independent of other sensory axon regulation are transformed into muscle fibers with structural and molecular similarities to intrafusal muscle fibers. Hence, Egr3 is a target gene that is regulated by sensory innervation and that mediates gene expression involved in myotube fate specification and intrafusal muscle fiber morphogenesis.

Animals↗

Magnetic resonance imaging in the diagnosis of lymphoma involving the brachial plexus in a cat.

An 11-year-old, neutered, female Domestic Long Hair cat had a 3-week history of left forelimb lameness. Conscious proprioception and postural reflexes were absent on the left thoracic limb. The cat had slightly reduced placing and hopping responses on the left pelvic limb, absent cutaneous trunci muscle reflex on the left side, and left triceps muscle atrophy. Magnetic resonance imaging revealed a 2 x 2 x 2 cm mass in the region of the left brachial plexus. The cat was treated by left forelimb amputation and hemilaminectomy. Histopathology of the brachial plexus revealed lymphoma.

Animals↗

Traumatic partial hypopituitarism in a cat.

Traumatic hypopituitarism was diagnosed in an 11-month-old male neutered cat. The presenting complaints were polydipsia, polyuria and lethargy of three months' duration. Craniocerebral trauma, as a result of a road traffic accident, had preceded the onset of clinical signs by six weeks. Neurological examination revealed right-sided mydriasis, reduced visual and tactile left forelimb placing reflexes and decreased proprioception in both the left fore- and hindlimb. Initial laboratory findings included hypernatraemia, hyperchloraemia, mild azotaemia, eosinophilia and isosthenuria. Low basal cortisol, thyroxine, thyroid-stimulating hormone and insulin growth factor-1 were noted. Subsequent to treatment with prednisolone, a water deprivation test confirmed the presence of central diabetes insipidus and therapy with synthetic antidiuretic hormone successfully ameliorated the polydipsia.

Accidents, Traffic↗

Mechanisms controlling human head stabilization. I. Head-neck dynamics during random rotations in the horizontal plane.

1. Potential mechanisms for controlling stabilization of the head and neck include voluntary movements, vestibular (VCR) and proprioceptive (CCR) neck reflexes, and system mechanics. In this study we have tested the hypothesis that the relative importance of those mechanisms in producing compensatory actions of the head-neck motor system depends on the frequency of an externally applied perturbation. Angular velocity of the head with respect to the trunk (neck) and myoelectric activity of three neck muscles were recorded in seven seated subjects during pseudorandom rotations of the trunk in the horizontal plane. Subjects were externally perturbed with a random sum-of-sines stimulus at frequencies ranging from 0.185 to 4.11 Hz. Four instructional sets were presented. Voluntary mechanisms were examined by having the subjects actively stabilize the head in the presence of visual feedback as the body was rotated (VS). Visual feedback was then removed, and the subjects attempted to stabilize the head in the dark as the body was rotated (NV). Reflex mechanisms were examined when subjects performed a mental arithmetic task during body rotations in the dark (MA). Finally, subjects performed a voluntary head tracking task while the body was kept stationary (VT). 2. Gains and phases of head velocity indicated good compensation to the stimulus in VS and NV at frequencies < 1 Hz. Gains dropped and phases advanced between 1 and 2 Hz, suggesting interference between neural and mechanical components. Above 3 Hz, the gains of head velocity increased steeply and exceeded unity, suggesting the emergence of mechanical resonance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Vibrations and their applications in sport. A review.

In sport, mechanical vibration is used as a massage tool and/or for training purposes. Two varieties of vibration training (VT) can be distinguished: strength exercises with superimposed vibratory stimulation (VS exercises) and motor tasks performed under whole body vibration (the WBV training). Vibratory massage has been used extensively since the beginning of the 20th century while VT is a relatively new technique. In the research literature, the main subjects addressed have been acute and cumulative effects of VS on flexibility and strength. Marked enhancement effects were obtained in medium-duration stretching and short-duration dynamic strength exercises while prolonged efforts did not show positive impact. The observed effects of vibration depend on various neural facilitatory and inhibitory mechanisms. In comparison to VS exercises, WBV tasks generate more global neuromuscular, metabolic and hormonal responses. WBV training resulted in significant changes in several motor variables, with stretch-shortening cycle tests (such as countermovement jumps, serial high jumps, etc.) being the most sensitive to WBV treatment. Based on available knowledge about proprioceptive spinal reflexes-that feedback from the primary endings of motor spindles produces a stimulatory effect via increased discharge of a-motoneurons, and activation of Golgi tendon organs (GTO) evokes inhibition of muscle action-a hypothesis has been proposed that VT enhances excitatory inflow from muscle spindles to the motorneuron pools and depresses inhibitory impact of GTO due to the accommodation to vibration stimuli. The intensity and duration of vibration used in VT dramatically exceed the standards for occupational vibration established by the International Organization for Standardization.

Exercise↗

Neurologic manifestations of trypanosomiasis in a dog.

A 13-month-old Doberman Pinscher was evaluated because of slowly progressive paraparesis and signs of depression. The dog had temporal, supraspinatus, and infraspinatus muscle atrophy, bilateral enophthalmos, superficial inguinal lymphadenopathy, tachycardia with pulse deficits, and lesions of active and inactive chorioretinitis. Neurologic abnormalities included hyperreflexic patellar reflexes, lack of conscious proprioception, signs of superficial pain in the hind limbs, and depressed hopping reflexes in the forelimbs. Cranial nerve abnormalities included decreased sensation in the left nostril and a delayed gag reflex. Results of cerebrospinal fluid analysis were characteristic of nonsuppurative inflammation. A diagnosis of multifocal neurologic disease was made. The dog did not have serum titers for fungal diseases, canine distemper, Ehrlichia canis infection, borreliosis, Rocky Mountain spotted fever, or toxoplasmosis. The dog did not respond to various antimicrobial treatments, and only slightly responded to corticosteroid treatment. The dog died during an anesthetic procedure. The postmortem diagnosis of Trypanosoma cruzi infection (canine Chagas disease) was made on identification of the amastigote form of the organism in sections of brain, spinal cord, and myocardium.

Animals↗

Peripheral polyneuropathy in a dog with functional islet B-cell tumor and widespread metastasis.

A 12-year-old female Irish Setter was examined because of recurrent episodes of hindlimb weakness. The dog was not ataxic, but had generalized muscular atrophy, decreased patellar reflexes, and slow proprioception. Blood glucose content was low (32 mg/dl) and the amended insulin-glucose ratio was high (9,600). Electromyographic studies showed evidence of polyneuropathy. The diagnosis was functional islet B-cell tumor with peripheral neuropathy. Exploratory laparotomy was performed. Widespread metastases were observed and the dog was euthanatized because of the poor prognosis. The dog was necropsied and the diagnosis was confirmed on the basis of microscopic findings.

Adenoma, Islet Cell↗

Intracranial dermoid cyst in a dog.

A 7-year-old spayed bitch had a 3-year history of episodes of hind-limb weakness and ataxia. Neurologic abnormalities consisted of deficits in postural reactions, spinal reflexes, and conscious proprioception. A right-sided head tilt also was observed. Immediately after cervical radiography, CSF tap, and electroencephalography, the dog was alert, but it was found comatose the next morning and died within an hour. At necropsy, a 1.6- x 0.8- x 1.5-cm, thinly encapsulated mass was found on the left cerebellar peduncle. It had caused dorsal displacement of the left portion of the cerebellum and ventral compression of the fourth ventricle. Histologically, the mass was determined to be a dermoid cyst.

Animals↗

[Epidural anesthesia in a patient with Friedreich's ataxia].

Friedreich's ataxia (FA), a hereditary disease with degenerative changes localized chiefly in the spinal cord and cerebellum, is characterized clinically by ataxia, absence of tendon reflexes, loss of proprioceptive sensation, and extensor plantar responses. There are only a few reports on anesthesia for patients with FA. General but not regional anesthesia is usually recommended because a persistent aggravation of symptoms is feared with regional anesthesia. We report a 31-year-old gravida 1 para 0 patient with FA who was admitted at the 20th week of gestation for induced abortion, curettage and tubal ligation. Familial FA was diagnosed at the age of 15, and since the age of 23 the patient had been confined to a wheelchair. As she strictly declined general anesthesia, epidural analgesia with 0.125% bupivacaine and morphine was used for 14 h, during which period induced abortion by prostaglandin was performed. This was followed by epidural anesthesia with 2% lidocaine for curettage and laparoscopic tubal ligation. A reduced dosage of local anesthetics, as commonly recommended during pregnancy, was used. Neurological consultation before and 1 day, 6 weeks, and 7 months after operation revealed no undue exacerbation of symptoms. Our case report suggests that epidural anesthesia can safely be administered to a patient with FA.

Abortion, Induced↗

[Neurologic status of the human fetus during labor and analysis from an evolutionary standpoint].

A study of the human fetus in 62 deliveries (at the moment of head birth and in the first seconds after complete birth up to the onset of pulmonary respiration) revealed that its neurologic status is characterized by muscular atonia, by the absence of spontaneous movements, proprioceptive and exteroceptive reflexes, as well as by the absence of reactions to needle puncture, light, sound and olfactory irritations. The suggestion is substantiated that phenomenal peculiarities of the neurologic status of the fetus during parturition are occasioned by the state of hibernation (autohibernation) secondary to shifts at the level of biologically active substances in the "parturient-placenta-fetus" system.

Animals↗

A short history of neuropathic arthropathy.

Neuropathic joint disease or Charcot joints are a chronic form of a degenerative arthropathy that is associated with decreased sensory innervation of the involved joints. Neuropathic arthropathies are considered to be an accelerated osteoarthritis that is precipitated by trauma to a joint not protected by its proprioceptive or nociceptive reflexes. This process continues until destruction of the joint occurs. The etiology of Charcot joints has varied throughout history as different diseases have become less or more prominent. Some of the offenders include diabetic neuropathy, tabes dorsalis, syringomyelia, and congenital indifference to pain. The morphology and pathogenesis of this condition has intrigued the minds of many, including Musgrave, Charcot, Virchow, Eloesser, Soto-Hall, and Key.

Arthropathy, Neurogenic↗

[Role of cervical proprioceptive afferentation in mechanisms of vestibular dysfunction compensation. 3. Active cervico-ocular reflex in unilateral lesion of labyrinth].

Active cervicoocular reflex (ACOR) was studied in patients with unilateral vestibular dysfunction in decompensation and subcompensation. ACOR was evaluated by coefficient of reactivity, of involvement and phasic shift. ACOR can be used for staging vestibular dysfunction. Decompensation is accompanied by asymmetric ACOR, subcompensation--by symmetric one.

Adolescent↗

[The role of cervical proprioceptive afferentation in compensatory mechanisms of vestibular dysfunction. 1. Passive cervico-ocular reflex in unilateral labyrinthine lesion].

Passive cervicoocular reflex (PCOR) was studied in patients with unilateral affection of the labyrinth at the stage of decompensation and subcompensation according to the following three criteria: nystagmic direction, reactivity coefficient and phasic deviation. In decompensation of unilateral vestibular dysfunction, PCOR presents intensively and asymmetrically while in subcompensation it becomes symmetric and less intensive. The PCOR is characterized as compensatory in unilateral lesion of peripheral vestibular system.

Adult↗