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At least 145 records · Page 8Linked to original sources
PubMed1987

Sural nerve stimulation and motor control of tibialis anterior muscle in spastic paresis.

In patients with spastic paraparesis, increased extensor tonus can be decreased by stimulation of flexor reflex afferents. This should improve dorsiflexion of the foot and reduce the sense of effort. We therefore examined ability to maintain stable firing of a single motor unit (SMU) in tibialis anterior muscle and force of dorsiflexion in 17 normal subjects and 9 with spastic paresis, during several minutes of tonic nonpainful stimulation (20 Hz, 0.1 msec) of the sural nerve at the ankle (SNS). Subjects were asked to maintain stable SMU firing first with, then without auditory feedback of the motor unit potential. SNS was then applied for several minutes. In normal subjects, the force of dorsiflexion increased 33 +/- 26% with SNS and 2.5% +/- 5% without SNS (p less than 0.0005). Most subjects noted increased resistance to dorsiflexion during SNS that resulted in greater innervation of tibialis anterior muscle. In six abnormal subjects, the force of dorsiflexion increased 30 +/- 30% with SNS, but no increase was recorded without SNS. In normal subjects and those with spastic paresis of the legs, SNS increased innervation of tibialis anterior muscle and awareness of greater effort required to maintain constant innervation. The altered proprioception may depend on facilitation of motor neurons.

Electric Stimulation↗
PubMed2001

Botulinum neurotoxin intramuscular chemodenervation. Role in the management of spastic hypertonia and related motor disorders.

There is a range of interventions available in the management of spastic hypertonia among patients with central nervous system injury. Many of these treatment options can be used concurrently with great effectiveness. Although manifestations of spastic hypertonia vary from patient to patient, they usually are not limited to one site. Nevertheless, problematic spastic muscle overactivity may be localized to one or more specific extremities, and these may be referred to as examples of focal dysfunctional spasticity. Botulinum neurotoxin (BTX) intramuscular chemodenervation procedures are an important therapeutic technique in focal spasticity management. Magnitude and duration of response varies with successful selection and localization of targeted muscles, spasticity severity, BTX dosage, and chosen functional goals. In focal dysfunctional spasticity and related motor disorders, BTX injections have demonstrated efficacy and safety when performed by clinicians familiar with the agent, regional anatomy, the specific condition, and patient being treated.

Anti-Dyskinesia Agents↗
PubMed1996

Spasticity and muscle contracture following stroke.

It has become increasingly recognized that the major functional deficits following brain damage are largely due to "negative' features such as weakness and loss of dexterity rather than spasticity. A variety of studies suggest that spasticity is a distinct problem and separate from the loss of dexterity, but that it may be implicated in the formation of muscle contracture and even in the recovery of strength. In order to address these issues, we examined the relationship between spasticity, contracture, strength and dexterity in the affected upper limb following stroke. Spasticity was measured both as increased tonic stretch reflexes and increased resistance to passive stretch (hypertonia). Twenty-four patients were recruited non-selectively from three rehabilitation units within 13 months of their stroke. Few patients exhibited increased tonic reflexes but half were found to have muscle contracture, the earliest at 2 months following stroke. Hypertonia was associated with contracture but not with reflex hyperexcitability. Increased tonic stretch reflexes were observed only in a subgroup of those with contracture and where present could usually be elicited only at the end of muscle range. This findings suggests that instead of spasticity causing contracture, contracture may actually potentiate spasticity in some patients. However, the majority of patients with contracture did not have increased tonic stretch reflexes. In addition, we found no relationship between spasticity and either weakness or loss of dexterity. Therefore, while hypertonia remains an important problem following cerebral lesions, it would appear that the amount of attention directed to reflex hyperexcitability associated with spasticity is out of proportion with its effects. Consequently, hypertonia needs to be clearly distinguished from reflex hyperexcitability in patients with spasticity.

Adult↗
PubMed2004

Na+,K+-ATPase concentration and fiber type distribution after spinal cord injury.

Complete spinal cord injury (SCI) is characterized, in part, by reduced fatigue-resistance of the paralyzed skeletal muscle during stimulated contractions, but the underlying mechanisms are not fully understood. The effects of complete SCI on skeletal muscle Na(+),K(+)-adenosine triphosphatase (ATPase) concentration, and fiber type distribution were therefore investigated. Six individuals (aged 32.0 +/- 5.3 years) with complete paraplegia (T4-T10; 1-19 years since injury) participated. There was a significantly lower Na(+),K(+)-ATPase concentration in the paralyzed vastus lateralis (VL) when compared to either the subjects' own unaffected deltoid or literature values (from our laboratory, utilizing the same methodology) of VL Na(+),K(+)-ATPase concentration for the healthy able-bodied (141.6 +/- 50.0, 213.4 +/- 23.9, 339 +/- 16 pmol/g wet wt., respectively; P < 0.05). There was also a significant negative correlation between the Na(+),K(+)-ATPase concentration in the paralyzed VL and years since injury (r = -0.75, P < 0.05). These findings are clinically relevant as they suggest that reductions in Na(+),K(+)-ATPase contribute to the fatigability of paralyzed muscle after SCI. Unexpectedly, the VL muscles of our subjects had a higher proportion of their area represented by type I fibers compared to literature values for the VL of the healthy able-bodied (52.6 +/- 25.3% vs. 36 +/- 11.3%, respectively; P < 0.05). As all our subjects had upper motor neuron injuries and, therefore, experienced muscle spasticity, our findings warrant further investigation into the relationship between muscle spasticity and fiber type expression after SCI.

Adult↗
PubMed1996

Postural control in children with spastic diplegia: muscle activity during perturbations in sitting.

To clarify the neural mechanisms controlling equilibrium during sitting, and the implications for the optimal sitting position for children with CP, automatic postural adjustments after perturbations of the support surface during sitting were investigated in seven children with spastic diplegia and in seven age-matched controls. A sudden backward sway of the body evoked brisk responses in ¿ventral' muscles in both groups. However, the order of muscle recruitment, which in most non-disabled children was caudal, was reversed in the children with diplegia, whose first response was in the neck flexors. The children with diplegia also co-activated antagonistic neck and hip muscles. The authors concluded that although children with spastic diplegia may produce a basic muscle activation pattern (first level of the central pattern generator, CPG), they cannot adjust the pattern in response to external changes (second level of the CPG).

Cerebral Palsy↗
PubMed2006

Lack of effect of acupuncture on electromyographic (EMG) activity--a randomised controlled trial in healthy volunteers.

BACKGROUND: Acupuncture is used clinically to treat muscle spasticity and flaccidity. Claims have been made that acupuncture can affect muscle EMG activity, though there is some doubt about the reliability of these studies. This study's aim was to examine the immediate effects of acupuncture on the EMG activity of the common wrist extensor muscles. METHODS: Thirty five right-handed healthy volunteers, 17 male and 18 female, aged 18-70 years were recruited from a convenience sample. Five subjects provided reliability data, and the remaining 30 took part in the main study. The study was a crossover, within-subject design, with the interventions counterbalanced. The three conditions were genuine acupuncture to LI4 (Hegu) and LI10 (Shousanli) for 20 minutes, with de qi; inappropriate acupuncture to PC3 (Quze) and PC6 (Neiguan) for 20 minutes; and 20 minutes of a no intervention control. All participants received each condition in random order. The outcome measure was surface EMG activity recorded over the common wrist extensor muscles during a 10 second, sub-maximal, isometric contraction. The average of three readings was used. The reliability of the outcome measurement was assessed in five volunteers selected at random who received repeated EMG recordings without acupuncture. RESULTS: The reliability tests showed the EMG procedure was highly reliable, with an intraclass correlation coefficient (ICC 2,1) of 0.9996 and a standard error of measurement of 0.014 mV. In the main study, paired t tests for the effect of the order of the first two interventions showed no detectable carry-over effect. Freidman analysis of variance found no difference between the three conditions (P=0.573). CONCLUSION: No meaningful change was detected in EMG activity following acupuncture interventions, but this study provides a sound protocol and normative values on which to plan future research.

Acupuncture Therapy↗
PubMed1989

Histological and morphological aspects of muscle in infantile cerebral palsy.

There is very little in the literature on the histology and morphology of muscle in cerebral palsy. The authors studied the histology of antigravitational spastic muscles, which are different from the nonspastic muscles. The study established that they have no endomysial fibres and that their inelasticity and inextensibility is due to syncytial atrophy. This is in conformity with clinical findings and calls for further research into the ultrastructural nature of the muscle so that treatment can be based on a more complete understanding of the disease and not solely on clinical observations.

Adolescent↗
PubMed1977

A controlled trial of baclofen in children with cerebral palsy.

A double-blind crossover trial against placebo was conducted to assess the effects of the GABA derivative, baclofen, on the disabilities due to muscle spasticity in twenty children suffering from cerebral palsy. Baclofen performed very significantly better than placebo in reducing spasticity and significantly better than placebo in allowing both active and passive limb movements to be carried out. Notable improvement was also seen in scissoring. Side-effects were minimal and responded promptly to dose reduction. The evaluation of drug effects on muscle spasticity and the pharmacodynamics of baclofen are discussed. Recommendations are made regarding dosage of baclogen in childhood.

Adolescent↗
PubMed1985

Simple and quick non-invasive evaluation of circulatory condition of cerebral arteries by clinical application of the "Bi-Digital O-Ring Test".

Using the "Bi-Digital O-Ring Test," generalized abnormal circulation of the distribution of the 3 cerebral arteries at each side of the brain (i.e., anterior cerebral artery, middle cerebral artery and posterior cerebral artery) can be predicted, without any expensive instruments usually in a few minutes. When abnormality was found in the bifurcation area of the common carotid artery by the "Bi-Digital O-Ring Test," there were always abnormal findings of the area of the brain where circulation was coming from either one or both of the anterior or middle cerebral arteries. When abnormal "Bi-Digital O-Ring" response was found at the vertebral artery and posterior cerebral artery representation point, discovered by the author, at the side of the 6th cervical vertebra (corresponding to the entry point of the vertebral artery into the transverse foramen), the areas of the cerebrum, cerebellum and brain stem where circulation is coming from the posterior cerebral artery, basilar artery and vertebral artery were also abnormal. Most of these abnormalities were found to be associated with problems of the cervical vertebrae and spastic muscles of the neck and shoulders and are often reversible. In this study, the author was able to differentiate abnormal brain circulation of any major branch of arteries in the brain due to organic changes or functional reversible changes by relaxing these spastic muscles and improving the circulation of the neck and shoulder area by giving either manual acupuncture, massage, or transcutaneous electrical stimulation. This in turn often improved brain circulation. If it was a functional abnormality, within a few minutes after one of these procedures the "Bi-Digital O-Ring Test" usually showed normal response or improvement. However, if it was an organic abnormality, the abnormality remained. When the supra-orbital arterial blood pressure at both sides of the forehead decreases below 40 or 30 mmHg, most patients develop so-called "Cephalic Hypotension Syndrome," which is characterized by sleep disturbance pattern; difficulty in concentration; easy forgetfulness of recent events; irritability; decreased pain threshold with or without depression; spastic skeletal muscles, particularly the neck, shoulder and back areas. All of these symptoms can be explained by decreased circulation to the Nucleus Raphe Centralis Superior (controls sleep and waking pattern), Nucleus Raphe Magnus (serotonin & modulation of pain), Nucleus Reticularis Giganto Cellularis (controls muscle tone), etc. in reticular formation.(ABSTRACT TRUNCATED AT 400 WORDS)

Acupuncture Therapy↗
PubMed1979

Postural reflexes in man.

In 40 adult patients stabilized on the tilt table, no evidence was found that the amount of activity at rest in spastic muscles depends on the position of the head in space. The influence of postural labyrinthine reflexes (Magnus) was not confirmed. The activity in spastic extensor muscles was significantly higher (t greater than 1%) in the prone position. The activity in spastic flexor muscles was higher (t greater than 1%) in the supine position. Extralabyrinthine forces (tonic stretch reflexes and exteroceptive reflexes) are assumed to be decisive in these changes. In the same group of patients, the symmetric deep neck reflexes were examined. The patient actively flexed his head forwards or backwards. Significant increase in the activity at rest in spastic extensor muscles on dorsal flexion of the head in the prone position was found (t greater than 1%). Significant increase in the activity at rest in spastic flexor muscles on ventral flexion of the head in the supine position was also found (t greater than 5%). The phenomena of irradiation are assumed to be decisive in these changes. In another group of 27 adults the asymmetric deep neck reflexes (Magnus and De Kleijn) were examined. The patient actively turned his head either to the left or to the right, while his arms were raised (Hoff-Schilder maneuver). When the degree of rotation of the head was slight, the trunk and arms deviated in the same direction. When the rotation of the head was extreme, and reached behind the shoulder, the trunk and arms often reversed the direction of deviation. The effect of asymmetric deep neck reflexes was not confirmed. Visual perception and the mechanism of focusing are assumed to be decisive in these changes. The head turns toward the object of interest in the visual field by the mechanism of eye-centering (Bender) and influences the position of the trunk and motor patterns of the upper extremities (motor principle "eyes-hand").

Adolescent↗
PubMed2001

[Botulinum toxin treatment of hip adductor spasticity in multiple sclerosis].

Spasticity results in a resistance to passive movement and decrease of passive mobility of the involved joints and is defined as a state of hypertonicity with exaggeration of tendon reflexes mediated by a loss of inhibitory control of upper motor neurons. In patients with severe stages of multiple sclerosis (MS) spasticity of the lower limbs often leeds to a spastic pattern with hip adduction resulting in decreased range-of-motion (ROM), increased pain, spasms, and functional disability (disturbed gait and sitting position) as well as difficulties with perineal hygiene. Local botulinum toxin type A (Btx-A) injections in spastic muscles offer a new treatment approach for managing spasticity and associated problems. Up to now Btx-A is approved for the treatment of blepharospasm and cervical dystonia and the treatment of equinous gait in children with cerebral palsy in Austria and Germany. Up to now only in Switzerland Botox is licensed for the treatment of focal spasticity. Btx-A is a neurotoxin derived from Clostridium botulinum. In most european countries Btx-A is available as Dysport (vial = 500 units) and Botox (vial = 100 units). In prospective studies a ratio of 1 unit Botox to 3-4 units Dysport was found. Following intramuscular injection Btx-A blocks the release of acetylcholine at the neuromuscular junctions, thereby inhibiting muscle contraction, and decreases spastic muscle tone and muscle spindles afferent information to the spinal cord. The spectrum of side effects includes local weakening of the injected and adjacent muscles as well as pain and haematoma at the injection site. At therapeutic doses side effects are local and transient. According to a double blind, placebo controlled, dose ranging study published by Hyman et al. (2000, Dysport in a dose of 500, 1000 and 1500 units reduced the degree of hip adductor spasticity associated with MS, and this benefit was evident despite concomitant use of oral antispasticity medication. According to the results of the study there was a clear trend towards greater efficacy and duration of effects with higher doses of Dysport. Taking efficacy and adverse events into account (incidence of muscle weakness was higher for the 1500 units group than for placebo) the optimal dose for hip adductor spasticity seems to be 1000 units Dysport divided between the adductor magnus, longus and brevis muscles and between both legs. To increase Btx-A effects following injection of hip adductors additional physiotherapy and casting or orthosis to increase passive hip-abduction is recommended. According to the literature anatomical localisation of the adductor muscles for injection and aspiration following insertion of the needle, to avoid injection of the toxin into a vessel, should be performed. A maximum dose of 1500 units Dysport (400 units Botox) per treatment session and 250 units Dysport (50 units Botox) per injection site is recommended. See table for dose-range of Dysport, and Botox in the treatment of adult patients with hip-adductor spasticity. For evaluation of treatment effects in hip adductor spasticity clinical examination with specific scales and measurements (see Appendix) at baseline, 4 and 12 weeks following BtxA injection is recommended:--Global rating of severity (0-4; patient's self assessment and physician's rating) --Global rating of response (-4 - +4; patient's self assessment and physician's rating)--Visual Analogue Scale (patient's self assessment of pain)--Active and passive ROM (manual goniometer)--Distance between the medial femur condyles in thigh extension (distance in cm)--Modified Ashworth scale (0-4)--Ten meter walking time (seconds)--Functional Ambulation Categories (0-5)--Score of perineal hygiene (0-5).

Adult↗
PubMed1993

Neurological manifestations of baclofen withdrawal.

Baclofen is a central nervous system agent that is commonly used for the treatment of muscle spasticity in spinal cord injury patients. Acute withdrawal of this medication can induce the development of neurological symptoms, including seizure disorder, psychosis, hallucinations and visual disturbances. We report 3 cases of acute central nervous system symptoms that developed in spinal cord injury patients. Each patient had been chronically maintained on a baclofen regimen to control muscle spasticity. Symptoms developed shortly after baclofen therapy was interrupted following genitourinary surgery. It is important that urologists become familiar with the symptomatology of baclofen withdrawal, the methods of its prevention and the appropriate therapy should the syndrome develop.

Adult↗
PubMedDate not supplied

Therapeutic electrical stimulation for spasticity: quantitative gait analysis.

Improvement in motor function following electrical stimulation is related to strengthening of the stimulated spastic muscle and inhibition of the antagonist. A 26-year-old man with familial spastic paraparesis presented with gait dysfunction and bilateral lower limb spastic muscle tone. Clinically, muscle strength and sensation were normal. He was considered appropriate for a trial of therapeutic electrical stimulation following failed trials of physical therapy and baclofen. No other treatment was used concurrent with the electrical stimulation. Before treatment, quantitative gait analysis revealed 63% of normal velocity and a crouched gait pattern, associated with excessive electromyographic activity in the hamstrings and gastrocnemius muscles. Based on these findings, bilateral stimulation of the quadriceps and anterior compartment musculature was performed two to three times per week for three months. Repeat gait analysis was conducted three weeks after the cessation of stimulation treatment. A 27% increase in velocity was noted associated with an increase in both cadence and right step length. Right hip and bilateral knee stance motion returned to normal (rather than "crouched"). No change in the timing of dynamic electromyographic activity was seen. These findings suggest a role for the use of electrical stimulation for rehabilitation of spasticity. The specific mechanism of this improvement remains uncertain.

Adult↗
PubMed1994

Muscle pathology and clinical measures of disability in children with cerebral palsy.

We performed a histologic and morphometric study of spastic muscle from 10 children with diplegic cerebral palsy, comparing muscle structure with the gait parameters of energy expenditure index and dynamic electromyography. Variations in fiber area within and between fiber types were increased significantly in children with cerebral palsy. In each of the control subjects, the combined coefficient of variation for type-1 and type-2 fiber area was less than 25% and the average was 17%; in the subjects with cerebral palsy, the combined coefficient of variation was more than 25% and the average was 36% (p < or = 0.004). The average difference between the mean area of type-1 and type-2 fibers was 26.7 +/- 18.9% for subjects with cerebral palsy and 4.2 +/- 2.4% for control subjects (p < or = 0.004). There was a 67% predominance of one fiber type in the subjects with cerebral palsy compared with a 55% predominance in the control subjects (p < or = 0.03). The difference between the total area of type-1 and type-2 fibers was 57% in the subjects with cerebral palsy and 17% in the control subjects (p < or = 0.002). There was a significant correlation between the combined coefficient of variation of fiber area and the energy expenditure index (r = 0.77, p < or = 0.03). The difference between the mean area of type-1 and type-2 fibers correlated with prolongation of electromyographic activity (r = 0.69, p < or = 0.05). No abnormalities in fiber ultrastructure were found in the subjects with cerebral palsy. Children with cerebral palsy had abnormal variation in the size of muscle fibers and altered distribution of fiber types. The values for variation in fiber area correlated with the energy expenditure index and with prolongation of electromyographic activity during walking.

Adolescent↗