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PubMed1986

[Status of muscle tone in rheumatoid arthritis patients].

Muscle tonus in patients with rheumatoid arthritis (RA) was collated with the activity of the pathological process and functional articular insufficiency (FAI) in different variants of polyneuropathy (P). Hetero- or unidirectional hypotension of muscles was the most characteristic sign in RA. In cases of the sensory variant of P, patients with an early period of the disease and 1-0 degree FAI showed severe damage to the central motor neuron, linked with a dissociated type of muscular dystonia (predominantly hypotension of the flexory group of legs) and a peculiar dystonic phenomenon (a vestibular-cerebellar positioning of the wrist). This kind of wrist positioning was directly correlated with the side of the predominant damage to the central motor neuron. In cases of sensory-motor forms of P, patients with degree II-III FAI, in whom lesions to the peripheral motor neuron were predominant, developed unidirectional muscle hypotension. EMG findings served as an adequate reflection of the nature of changes in the muscle tonus.

Adult↗
PubMed2001

Primary oblique muscle overaction: the brain throws a wild pitch.

BACKGROUND: Sensorimotor and orbital anatomical mechanisms have been invoked to explain primary oblique muscle overaction. METHODS: Review of primitive visuo-vestibular reflexes and neuroanatomical pathways corresponding to vestibulo-ocular reflexes, and correlation with known clinical abnormalities in patients with primary oblique muscle overaction. RESULTS: Bilateral superior oblique muscle overaction, which corresponds to a backward pitch in lateral-eyed animals, can occur when structural lesions involving the brainstem or cerebellum increase central otolithic input to the extraocular muscle subnuclei that modulate downward extraocular muscle tonus. Bilateral inferior oblique overaction, which corresponds to a forward pitch in lateral-eyed animals, may result from visual disinhibition of central vestibular pathways to the extraocular muscle subnuclei that modulate upward extraocular muscle tonus. CONCLUSIONS: Primary oblique muscle overaction recapitulates the torsional eye movements that occur in lateral-eyed animals during body movements or directional luminance shifts in the pitch plane. These primitive ocular motor reflexes become manifest in humans when early-onset strabismus or structural lesions within the posterior fossa alter central vestibular tone in the pitch plane.

Animals↗
PubMed1990

Parkinson's syndrome induced in cats by the use of 6-hydroxydopamine. Observations of behavior and motor disorders.

The possibility of inducing Parkinson's syndrome in cats was investigated in three kinds of lesions: by microinjection of 6-hydroxy dopamine (6-OHDA) into the pars compacta of substantia nigra (SNC), bilateral injection into the SNC and globus pallidus (GP) and into the SNC and caput nuclei caudati (NC). In all three kinds of lesions of the dopaminergic system disturbances of behavior involving specially the motor system were obtained, corresponding to the parkinsonism syndrome--in the form of bradykinesia-akinesia, increased muscle tonus of plastic type, vegetative disorders (sialorrhea, pupils) and psychic disorders such as lack of interest in the surroundings and food. The character of the enhanced muscle tonus typical for extrapyramidal disturbances was confirmed by EMG examination. The parkinsonism-like syndrome induced in the cats was transient and receded after several weeks.

Animals↗
PubMed1983

Raphe unit activity in freely moving cats is altered by manipulations of central but not peripheral motor systems.

Single unit activity of serotonergic neurons in the dorsal raphe nucleus of freely moving cats was recorded in experiments which manipulated central or peripheral motor systems. Unilateral microinjections of the cholinomimetic agent, carbachol, into the pontine tegmentum, produced muscle atonia. During these periods of drug-induced atonia, the activity of serotonergic neurons was reduced 97% below pre-drug baseline rates. In experiments where microinjections of carbachol did not produce muscle atonia, no significant change occurred in serotonergic unit discharge rate. Muscle tonus was also altered by systemic injections of mephenesin, a centrally acting muscle relaxant. A low dose of mephenesin (50 mg/kg) produced mild atonia which was correlated with a 16% reduction in serotonergic neuron discharge rate relative to pre-drug baseline. A higher dose of mephenesin (150 mg/kg) produced complete atonia, during which serotonergic unit activity was reduced by 68% below baseline firing rate. To distinguish between centrally and peripherally induced atonia, we injected either succinylcholine or dantrolene, systemically. These are both drugs whose muscle relaxant properties are known to be mediated by peripheral mechanisms. In neither case was a change in serotonergic unit discharge rate seen following drug-induced atonia. These data demonstrate that manipulation of central, but not peripheral, motor systems can profoundly affect the activity of serotonergic neurons of the dorsal raphe nucleus. Alternate hypotheses are also discussed.

Animals↗
PubMed1995

[Neurosyphilis. A case report and review of the literature on differential neuroborreliosis diagnosis].

A 35-year old man was presented with organic psychosyndrome. Anamnestic reports informed about changes in his behaviour like loss of interest, reduced concentration and short-term-memory loss within the last 2 years. The practicing psychiatrist diagnosed a depressive syndrome in conjunction with a borderline syndrome and administered antidepressive and neuroleptic therapy. Specific serologic tests were not done. Neurologically, there was a picture of influent and slurred speech, and ataxic gait. Muscle tonus was normal, muscle reflexes were of the same diminished intensity on both sides. The psychic status revealed a person mostly oriented in time, location and situation but with severe disorders of recognition, concentration, and memory. Laboratory diagnosis proved the suspected diagnosis of neurosyphilis. Additionally, there were antibodies to Borrelia burgdorferi (Bb) in serum and CSF and a positive CSF/serum index of 9.0 (threshold: 1.9). The neuroradiologic examination (CCT, NMR, SPECT) showed an intense, diffuse, frontotemporal atrophy of the cortex. By NMR, massive gliosis was found in both hippocampi. Angiographically, an aneurysma (1 cm in diameter) of the medial cerebral artery was demonstrated. Specific treatment was performed with Na penicillin (5 Mio. i.v./4 h over 21 days). No remission could be achieved.

Adult↗
PubMedDate not supplied

Ankylosing spondylitis: integrated clinical and physiological perspectives.

This hypothesis paper draws upon clinical epidemiological and physiological perspectives of axial muscle tone relevant to ankylosing spondylitis (AS). Skeletal muscle tonus is the property of intrinsic tension or resistance to stretch with no additional muscle contraction. The interpretations call attention to novel concepts of the intrinsic axial muscular system contributions to enthesopathic lesions in AS. The axial kinematic chain extends from the entire spine to the posterior aspects of the lower extremities and is essential for postural and mobility functions. Muscles and articular cartilage derive from common embryological precursor cells and are complexly coordinated in the maintenance of postures and dynamic functions. A definitive link between axial muscular dysfunction and respective joint pathology has not yet been demonstrated in AS. However, the following clinical epidemiological and physiological observations raise the possibility of a relationship between axial muscular hypertonicity and AS, which will be reviewed sequentially.

Adolescent↗
PubMed2003

Effect of nitrous oxide on dental patients with cerebral palsy -- using an electromyogram (EMG) from orofacial muscles as an index.

The efficacy of nitrous oxide (N2O) inhalation on the elevated orofacial muscle tonus during dental treatment in patients with cerebral palsy (CP) was studied by measuring the mean frequency of electromyographic (EMG) discharge, blood pressure (BP) and heart rate (HR) taking mentally retarded patients (MR) as a control. At a pre-treatment stage, the mean frequency of the EMG was higher in the CP patients than in the MR patients. By forcing the jaw open, the mean frequency of the EMG, BP and HR was elevated significantly in both types of patients. The enhanced level of the mean frequency of the EMG was higher in the CP patients than in the MR patients. After inhalation of N2O, the mean frequency was reduced significantly in both types of patients, however, the reduction rate was higher in the CP patients than the MR patients; BP and HR were not affected. These results demonstrate the selective efficacy of N2O in reducing the orofacial muscle tonus in CP patients during dental treatment probably because of the N2O inhibiting the function of the central nervous system. The present study therefore suggests the beneficial properties of N2O induced sedation performed during dental treatment on CP patients.

Adult↗
PubMed1993

[The influence of neonatal hyperbilirubinemia on neonatal behavior].

Two groups of neonates, 30 cases with hyperbilirubinemia (307.8 +/- 99.86 mumol/L) and 30 normal newborns (control group with bilirubin 80.37 +/- 35.74 mumol/L), were evaluated with Neonatal Behavioral Assessment Scale (NBAS) and followed up at the age of 2 months and 5 months. All cases in the two groups were evaluated with NBAS at ages of 2-3 days, 12-14 days and 26-28 days. The results showed that there were statistically significant differences between the two groups in the aspects of attention and social responsiveness, the ability to modulate state of consciousness, the motor integrity and the reflexes. We also found that while the level of bilirubin was below 205.2 mumol/L, there was no correlation between the level of bilirubin and NBAS (r = -0.095, P > 0.02), but when bilirubin was at or above the level of 205.2 mumol/L, there was significant negative correlation (r = -0.53, P < 0.001) between the two. The follow-up revealed that 9 of 23 jaundiced infants had abnormal auditory reactions or abnormal muscle tonus at the age of 2 months; 8 of the 9 infants recovered, but 1 still had abnormal muscle tonus by the age of 5 months. The study suggests that hyperbilirubinemia above the level of 205.2 mumol/L would affect neonatal behavior and the greater the severity of jaundice, the more significant the influence on neonatal behavior. The effects on some jaundiced infants may last 5 months or more. NBAS is a valuable scale for early detection of mild brain dysfunctions which are less obvious on clinical examination.

Brain↗
PubMed2000

Muscle and tendon stiffness in patients with upper motor neuron lesion following a stroke.

The objective of this study was to investigate muscle and tendon stiffness in the triceps surae muscles in patients who had previously had a stroke. The participants were 12 men showing slight to moderate degrees of muscle tonus in the affected leg. All patients showed minimal or no overt clinical motor symptoms, and all walked without mechanical aid. Muscle strengths in isometric and isokinetic activities were measured, as was passive resistance during plantarflexion in each leg. Walking speed was also measured. Evaluations of physical performance and muscle tone were made. Muscle and tendon stiffness was calculated from measurements whilst passively stretching during electrical stimulation, separately for each leg. Muscle strength was significantly higher in the non-affected than in the affected leg. Muscle stiffness was significantly higher in the affected leg than in the non-affected leg. Tendon stiffness was significantly higher in the non-affected than in the affected leg. The higher muscle stiffness in the affected leg might enhance the possibility for storing elastic energy during preactivation. Lower tendon stiffness in the affected leg might reduce the development of fatigue in movements at low velocities.

Adult↗
PubMed1989

[A case of tardive dystonia].

Tardive dystonia in a chronic dystonia caused by neuroleptics. A 53-year-old man suffering from a neuroleptic induced dyskinesia began to show an abnormal posture. His abnormal posture was caused by changes of muscle tonus and thought to be a dystonic posture. He had no family history of dystonia. This posture was similar to that of idiopathic dystonia in that the muscle tonus was hypertonic in sitting but was hypotonic in lying, and in that the activity of daily living was not disturbed in spite of hypertonia. But he also showed lingual dyskinesia and hyperreflexia and the electromyographic analysis disclosed the fact that his dystonia was similar to that of secondary dystonia. Brain CT showed the atrophy of the head of caudate nucleus but superconducting MRI disclosed no abnormality in basal ganglia. No effective therapeutics was as yet found in tardive dystonia. So it was proposed that the tardive dystonia was due to irreversible functional damage to the basal ganglia.

Antipsychotic Agents↗
PubMedDate not supplied

Effect of continued stretching of the affected arm in patients with cerebrovascular diseases by examining H-reflex characteristics.

To investigate excitability of spinal neural function during stretching excises in patients with cerebrovascular disease (CVD), H-reflex was analyzed before, during and after 1 min. continued stretching of the affected arm. 10 hemiparesis patients with hypertonus and hyperreflex, mean age of 53.2 years were tested. H-reflex was recorded from the abductor pollicis brevis on the affected side after stimulation of median nerve in supine position. The persistence, amplitude and amplitude ratio of H/M during stretching were lower than those before and after in the patients with moderately increased muscle tonus. In patients with slightly and markedly increased, H-reflex was same before, during and after continued stretching. It is suggested that excitability of spinal neural function during 1 min. continued stretching was inhibited in the patients with moderately increased muscle tonus caused by CVD.

Adult↗
PubMedDate not supplied

[Role of the hypothalamus in organizing the wakefulness-primary sleep cycle in the frog Rana temporaria].

New data are presented on the role of the hypothalamus in re-arrangement of tonus of the vegetative nervous system during three forms of rest of the primary sleep in the frog. Temporal organization of the cycle " awakefulness -primary sleep" depends on interaction of the anterior and posterior hypothalamus. The anterior hypothalamus is responsible for manifestation of two forms of rest of the primary sleep, i.e. diurnal resting form (P-1) which is associated with the increase in plastic tone of skeletal muscles, and the other resting form (P-3) which is associated with the decrease in muscle tonus. These forms of rest are accompanied by the predominance of parasympathetic tonus of the vegetative nervous system. The posterior hypothalamus is associated with manifestation of the resting form which includes the increase in the rigidity of muscle tonus (P-2) and transient phasic increase in the heart rate, the latter being observed at all forms of the primary sleep. Statistical treatment of the ECG revealed specific pattern of two-dimensional density of distribution of probabilities of R-R intervals for the resting forms of the primary sleep which is important for identification of different phases in the " awakefulness -primary sleep" cycle in vertebrates.

Animals↗
PubMed2003

Arousal systems.

The brain contains autochthonous neural systems that evoke waking from sleep in response to sensory stimuli, prolong or enhance arousal in response to special stimuli, and also generate and maintain wakefulness regardless of sensory stimuli during the active part of the day. Through ascending projections to the cortex, these arousal systems stimulate cortical activation, characterized by high frequency gamma and low frequency rhythmic theta activity, and through descending projections to the spinal cord, they stimulate muscle tonus along with sensory-motor responsiveness and activity. They are comprised of neuronal aggregates within the brainstem reticular formation, thalamus, posterior hypothalamus and basal forebrain, and they utilize multiple different neurotransmitters. Within the brainstem, neurons of the reticular formation, which predominantly utilize glutamate as a neurotransmitter, stimulate cortical activation by exciting the widespread projecting neurons of the nonspecific thalamo-cortical projection system, which similarly utilize glutamate, and neurons of the ventral extra-thalamic relay systems located in the posterior hypothalamus and basal forebrain, many of which also utilize glutamate. In addition, these systems have descending projections by which they can enhance or modulate muscle tonus and activity. Articulating with these are cholinergic neurons of the ponto-mesencephalic tegmentum and basal forebrain that promote cortical activation during waking and also during rapid eye movement sleep (REMS), in association therein with muscle atonia. Dopaminergic ventral mesencephalic neurons stimulate a highly motivated and positively rewarding state during waking and may also do so during REMS. In contrast, noradrenergic locus coeruleus neurons promote an aroused waking state and prevent REMS as well as slow wave sleep (SWS). Serotonergic raphe neurons promote a seemingly quiet or satiated waking state, which though exclusive of REMS, can actually be conducive to SWS. Histaminergic neurons of the posterior hypothalamus act like noradrenergic neurons in enforcing waking and are joined by neurons in the region that contain orexin, a neuropeptide recently shown to maintain waking and in absentia to be responsible for narcolepsy, or the inability to maintain wakefulness. These multiple arousal systems are grossly redundant, since no one system is absolutely necessary for the occurrence of waking; yet they are differentiated, since each plays a special role in waking and sleep. During SWS, they are submitted to an inhibitory influence arising in part at least from particular GABAergic neurons co-distributed with many neurons of the arousal systems and also concentrated within the basal forebrain and adjacent preoptic region.

Animals↗
PubMed2001

Effects of electrical stimulation of the sciatic nerve on background electromyography and static stretch reflex activity of the trunk muscles in rats: possible implications of neuronal mechanisms in the development of sciatic scoliosis.

STUDY DESIGN: The effects of electrical stimulation of the sciatic nerve on background electromyographic and static stretch reflex activity of the trunk muscles were studied. OBJECTIVES: To verify the hypotheses that sciatic scoliosis is induced reflexively by radiculopathic pain, and that scoliosis might be maintained by prolonged asymmetric alteration of the trunk muscle tonus caused by central sensitization of the spinal neurons that constitute the postural reflex pathways. SUMMARY OF BACKGROUND DATA: Sciatic scoliosis usually occurs with convexity to the side of the herniated disc. The neuronal mechanism of sciatic scoliosis has not been well clarified. Recently, prolonged alteration of motor function in the hindlimbs of animals caused by central sensitization has been reported. METHODS: In spinalized rats (transection of the spinal cord), the sciatic nerve was stimulated electrically as a conditioning stimulus. Muscle stretch elicited by bending of the lumbar spine was applied as a test stimulus. Background and stretch reflex activities of the bilateral oblique abdominal, psoas, and quadratus lumborum muscles were recorded. Rats in which MK-801, an N-methyl-d-aspartate antagonist, was preadministered also were used. RESULTS: The conditioning stimulus enhanced background electromyographic activity in bilateral oblique abdominal, contralateral psoas, and quadratus lumborum muscles. Furthermore, the conditioning stimulus induced prolonged facilitation and depression of stretch reflex activity of the contralateral psoas and quadratus lumborum, and ipsilateral psoas and quadratus lumborum muscles, respectively. Preadministration of MK-801 reduced these excitatory and inhibitory effects. CONCLUSION: It was found that the pattern of electromyographic activity of the trunk muscles evoked by sciatic nerve stimulation coincided with the typical direction of sciatic scoliosis in patients with lumbar disc herniation. It was supposed that the prolonged asymmetric alteration of the trunk muscle tonus was caused by central sensitization, and that central sensitization of spinal neurons may underlie the neuronal mechanism of sciatic scoliosis.

Animals↗
PubMed1990

[A contribution to "stiff man" syndrome].

A patient with the clinical symptoms of the "Stiff-man"-syndrome, but an atypical course was introduced. Symptoms and course were compared with similar cases mentioned in literature. The "Stiff-man"-syndrome is probably a disease of central origin affecting the relationship between inhibitory and excitatory regulation of the muscle tonus, especially the exteroceptive reflex mechanisms. Several pathological processes of the CNS can be held responsible for the disturbance of the balance in this regulatory system.

Deglutition Disorders↗
PubMed1993

[Athetosis].

Athetosis is a peculiar involuntary movement resulting from pathologic involvement of the basal ganglia. Although mechanism of this movement is still far from established, athetosis is clinically differentiated from chorea and dystonia. The purpose of this article is to review and summarise the classification of this involuntary movement disorder. This movement disorder is classified into double athetosis, chorea-athetosis, unilateral athetosis and pseudo-athetosis. The double athetosis is featured by increased muscle tonus and irregular small amplitude movement, which appears the most frequently in patients of cerebral palsy. In chorea-athetosis, irregular abnormal movement is more prominent and larger than double athetosis. This type of movement appears commonly in patients other than cerebral palsy. Unilateral and pseudo-athetosis are derived not from disturbance of the basal ganglia but from impared sensory pathways of the deep sensation due to cerebro-vascular lesion. Stereotactic VL-thalamotomy is effective to relieve increased muscle tonus but not to decrease involuntary movement.

Athetosis↗
PubMed1991

[Subclinical swallowing disorder in patients with abnormal sensation in the throat].

Measurement of swallowing pressure was done in 75 patients who complained of abnormal sensation such as obstructive sensation, difficulty in swallowing, etc. in the throat without noticeable cause. Abnormal swallowing pressure curves were observed in 33 patients (44%), and 76% of them showed abnormal elevation of the pressure at the hypopharyngeal or cervical esophageal region. These results indicated that subclinical swallowing disorder, particularly abnormal high swallowing pressure, can be a possible cause of their complaints. The author assumed that abnormal elevation of swallowing pressure is due to hypertonicity of the hypopharyngeal and cervical esophageal muscles. By the animal experiments using dog, a muscle relaxant, eperizone hydrochloride, revealed to change muscle tonus of the hypopharyngoesophageal muscles. Intravenous administration of the drug decreased swallowing pressure and prolonged the relaxation time of the cricopharyngeal muscle. Clinically the muscle relaxant showed to be effective in ameliorating the complaint of the patients with abnormal high swallowing pressure at the hypopharyngeal or cervical esophageal region. Based on the above results, the author proposed that the clinical entity, hypopharyngeal-cervical esophageal hypertonicity, causes a subclinical swallowing disorder leading to the abnormal sensation in the throat.

Adult↗