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PubMed1995

[The clinical usefulness of botulinum toxin type A for spasmodic torticollis and facial spasm].

We studied the clinical effectiveness of botulinum toxin type A for spasmodic torticollis and that for facial spasm by multicenter, non-blinded study. The freeze-dried crystalline botulinum toxin type A (AGN 191622; Allergan Inc., Irvine, CA) was injected into the hyperactive muscles and the clinical course was followed for 22 weeks. Repeated injections were done, if necessary, with an interval of 4 weeks. The toxin was highly effective in both disorders. In spasmodic torticollis, clinical severity improved in 38 (63.3%) and the global improvement was seen in 39 (65.0%) out of 60 patients. Subjective improvement was seen in 56 (93.3%). In facial spasm, 52 (92.9%) out of 56 patients improved after the treatment. Unfavorable reactions, mainly consisting of neck muscle weakness and dysphagia in torticollis and facial weakness in facial spasm, were mostly due to the excessive action of the toxin. They were usually mild and transient. No patients discontinued the trial because of side effects. Botulinum toxin injection is a very useful and safe method for the symptomatic treatment of spasmodic torticollis and facial spasm.

Adolescent↗

PubMed2005

Cervical muscle strength measurement in two groups of elite Greco-Roman and free style wrestlers and a group of non-athletic subjects.

BACKGROUND: Free style and Greco-Roman are two types of wrestling. [figure: see text] OBJECTIVES: The aim of this study was to examine the maximal isometric strength of cervical extension (ISCE) and the maximal isometric strength of cervical flexion (ISCF) in two groups of elite wrestlers and a group of non-athletic subjects. METHODS: Fourteen elite Greco-Roman wrestlers (aged 19-25 years), 16 elite free style wrestlers (aged 18-25 years), and 16 non-athletic subjects (aged 18-25 years) participated in this study. All wrestlers competed at international level with the Iranian national team. Maximum voluntary contractions (MVC) of cervical extensor and flexor muscles were measured using a custom made device. The ratios of ISCE to weight (ISCE/weight), ISCF to weight (ISCF/weight), and ISCF to ISCE (ISCF/ISCE) were calculated for group comparisons. Pearson product moment test was used to estimate correlation between maximal isometric strength measurements and anthropometric variables. A one way analysis of variance was computed to compare ISCE/weight, ISCF/weight, and ISCF/ISCE among groups. RESULTS: There was significant correlation between maximum cervical extension and flexion strengths and weight in all groups (p<0.05, n = 46). The ratios of cervical muscle strengths to weight were significantly higher in wrestlers than in non-athletic subjects (p<0.00). Greco-Roman wrestlers appeared to be stronger than free style wrestlers following comparison of all ratios. CONCLUSIONS: Neck muscle force measurements may be a useful test for athletes in combat sports like wrestling. They can be applied to identify the weakness of a group of muscles in the neck area and to devise a proper training program.

Adolescent↗

PubMed1992

[Reducing body myopathy--a case report].

A 2-year-old girl with reducing body myopathy was reported. She had no family history of neuromuscular disease. She developed normally with no delay in milestones during infancy. She had no muscle weakness or hypotonia up to 2 years of age when she received mumps vaccination. Three days after the injection, she was first noticed to have limb muscle weakness. The muscle weakness progressed rapidly with increasing difficulty in gait and raising the upper arms, particularly the left. Four months later, she had difficulty in keeping her head up and could no longer climb the stairs. On physical examination, she had proximal dominant generalized muscle weakness, with a preferential neck muscle involvement. She walked waddlingly and stood up with Gowers' maneuver. Facial and ocular muscles were intact. No dysarthria, dysphagia or respiratory difficulty was noted. EMG showed myopathic pattern. Serum creatine kinase level was moderately elevated to 739 IU/l. In the biopsied left biceps muscle, there was marked variation in fiber size, but no apparent necrotic or regenerating fibers. The most striking feature was the presence of numerous eosinophilic inclusions which reduced nitroblue tetrazolium (NBT) and were, therefore, stained dark with menadione-linked alpha-glycerophosphate dehydrogenase even without the substrate of menadione, showing the histochemical characteristics of "reducing" body. The bodies were predominantly seen in fibers with disorganized intermyofibrillar networks and with high acid phosphatase activity. On electron microscopy, the reducing bodies consisted of fine granular material with the similar electron density to the chromatin granules and were located mostly around the degenerated nuclei, suggesting the nuclear degeneration playing a role in forming the reducing bodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗

PubMed1997

[Severe cardiac failure in Kearns-Sayre syndrome].

Mitochondrial disorders are a group of diseases that can affect virtually all organ systems. A 19 year old man was seen in 1993 with neurologic abnormalities consisting of impaired function of muscles, diplopia, progressive loss of vision, impaired phonation and swallowing, during the last 10 years. Physical examination disclosed moderate wasting of the four limb muscles, mild motor weakness of neck muscles, symmetrical hyporeflexia, cerebellar dysfunction, severe external ophtalmoplegia and ptosis. Fundii oculi examination showed retinitis pigmentosa. The electromyogram demonstrated myopathic changes with normal nerve conduction velocities. The cerebrospinal fluid was normal, except for a mild increase in lactic acid. Histochemical study of a muscle biopsy specimen demonstrated ragged red fibers and increase of the subsarcolemal oxidative activity of mitochondriae. The diagnosis of Kearns-Sayre disease was confirmed and he was discharged advising physical therapy. On February 1995, he was again admitted, this time with right cardiac failure and worsening of all his previous symptoms and signs. He complained of myalgias and his muscle weakness was more striking on clinical examination. Echocardiography showed biventricular dilatation and left ventricular hypertrophy with preserved systolic function. A new muscle biopsy revealed an heteroplasmic deletion of 5 Kb with 80% of mutant mitochondrial DNA. In brief, we report a patient with the clinical phenotype of Kearns-Sayre syndrome who presented an acute congestive cardiac failure due to cardiomyopathy, an association which has seldom been, reported in the literature.

Adult↗

PubMed2000

Magnetic resonance imaging of human mandibular elevator muscles after repetitive maximal clenching exercise.

Exercise can enhance the signal intensity (SI) of skeletal limb muscles on T2-weighted magnetic resonance imaging (MRI). The purpose here was to evaluate the effects of repetitive maximal clenching exercises involving the mandibular elevator muscles with T2-weighted MRI. Seven normal volunteers were imaged before and immediately after performing repetitive maximal clenching and at 3, 6, 9, 12, 15, 20 min after the exercise in a 1.5 T GE magnet with spin-echo sequences. SI in the masseter, medial pterygoid and temporalis increased significantly (p < 0.001) and the cross-sectional area (CSA) of masseter increased 10.11% on T2-weighted MRI after exercise. The increased SI and CSA declined approximately to the pre-exercise level in about 20 min after exercise. No SI and CSA changes were found in the inactive neck muscle and no SI changes in the mandibular bone marrow (p > 0.05). The findings suggest that the use of exercise-enhanced MRI might be helpful in the study of the function and dysfunction of muscles in the orofacial region.

Adult↗

PubMed1980

[Neck muscular tension due to repetitive work].

In our laboratory study 19 students effected 4 repetitive tasks of 70 min each. All four conditions had a motor task at the base and in addition two had to deal with discrimination. In the 2 tasks with discrimination, the electromyography of the neck muscles was distinctly higher than in the 2 other conditions. The tasks with discrimination were accompanied by a higher subjective tension, a lower heart rate variability and a slightly increased urinary excretion. The main cause for an augmentation in the muscle tonus might be the immobilisation of the neck.

Electromyography↗

PubMed1985

Cervicocollic reflex: its dynamic properties and interaction with vestibular reflexes.

Electromyographic activity of dorsal neck muscles elicited by sinusoidal rotations of the body and head was studied in decerebrate cats over a wide range of rotational frequencies and amplitudes. Rotation of the body with the head held fixed in space elicited a cervicocollic reflex (CCR) in the biventer cervicis, complexus, obliquus capitis inferior, rectus capitis major, and splenius muscles. As stimulus amplitude increased, CCR amplitude increased first rapidly and then more slowly, displaying two linear incremental sensitivity ranges. In contrast, the vestibulocollic reflex (VCR) elicited by whole body rotation had a minimum stimulus threshold below which no response was observed, whereas the vestibuloocular reflex (VOR) saturated at intermediate stimulus intensities. When stimulus frequency was varied, the CCR exhibited second-order dynamic behavior. At frequencies below 0.5 Hz, muscle EMG activation was in phase with peak platform angular deviation in the direction that stretched the muscle, and the gain measured as the percent modulation of EMG activity per degree of rotation remained constant. As frequency increased to 3-4 Hz, response phase advanced by 120 deg or more and gain increased with a slope approaching 40 dB/decade. The data were well-fitted by second-order transfer functions containing two zeros. Both the dynamic behavior of the CCR and its high sensitivity to small stimuli resemble the properties of muscle spindle primary afferents, suggesting that the latter may provide the major input responsible for the CCR. Dynamic properties and gains of the CCR and VCR were quite similar at frequencies between 0.2 and 3-4 Hz. Transfer functions of both reflexes contained two zeros whose time constants were correlated in a population of 11 cats, suggesting that reflex dynamics may be matched to the mechanical properties of each animal's head-neck system. Interaction of the CCR and VCR was studied under two conditions. When the head was driven by a servomotor while the body remained stationary, EMG activation by the two reflexes added linearly to produce a large response. When the body was rotated with the head allowed to counterrotate about the C1-C2 joint, the two reflexes combined linearly in an antagonistic fashion: the CCR acted to oppose head rotations produced by the VCR, thus preventing the ratio of head counterrotation to body rotation from exceeding 0.5. The data indicate that the CCR and VCR behave approximately linearly, both individually and in combination. Acting together, the two reflexes assist each other in preventing oscillation of the head on a stationary body.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1988

Three-dimensional sensitivity and caudal projection of neck spindle afferents.

1. We recorded from neck muscle spindle afferents in the C2 dorsal root ganglion of the decerebrate cat using floating electrodes. The afferents presumably innervated mainly ventral and ventrolateral perivertebral muscles, and sternocleidomastoid. Stimuli consisted of combinations of rotatory head movements about the roll/pitch or pitch/yaw axes. An important difference from our earlier experiments (10) was the addition of yaw movement to the stimulus paradigm making possible a three-dimensional analysis of afferent behavior. 2. For each afferent we determined the most effective direction of tilt (orientation of the response vector) in three dimensions by using sinusoidal stimuli that combined pitch and roll, or pitch and yaw, or by measuring the gains to responses to roll, pitch, and yaw rotation. 3. Most afferents were sensitive to rotation around all three axes; pitch and yaw were usually more effective than roll. There was no indication of clustering of response vectors, as might be expected if the receptors were located in a small number of muscles each of which has receptors aligned in a homogeneous direction. 4. The responses of afferents were further studied using sinusoidal and trapezoidal stimuli aligned as closely as possible with the orientation of their response vector. The availability of the yaw stimulus made receptor classification based on response linearity, gain, and dynamic index more reliable than in our earlier experiments (10). 5. Muscle spindle responses were divided into three categories: A, B, and ambiguous. The evidence suggests that category A are probably spindle primary receptors and category B are secondaries. Ambiguous receptors have intermediate properties. 6. The caudal projection of spindle afferents was examined by delivering antidromic stimuli with a movable electrode on the surface of the ipsilateral dorsal column. Eighteen percent of the afferents projected to C4, and 14% as far as C5. Long caudal projections can be found in A, B, and ambiguous receptors with a range of directional sensitivities. 7. The evidence suggests that C2 spindle afferents make synapses in the midcervical segments with interneurons and propriospinal neurons that are part of the intraspinal pathway of the tonic neck reflex.

Action Potentials↗

PubMed1997

[Equine motor neuron disease (EMND). A case report].

A 13-year-old warmblood mare was presented because of progressive weight loss, general weakness and trembling. On examination the horse stood with its head lowered and the limbs placed under the body. On lifting its head spasms of the neck muscles could be observed. At the same time the horse developed trembling over the lower neck and muscle fasciculations continued over the whole body. Additional signs included frequent recumbency, polyphagia and facial hyperaesthesia. The horse showed no signs of ataxia. Haematology was normal. Blood biochemistry revealed slight increased aspartate aminotransferase (AST: 1060 U/I) and creatine kinase levels (CK: 441 U/I). Based on the clinical findings equine motor neuron disease was diagnosed. The horse was euthanatized due to poor prognosis and the progression of symptoms. The typical neurodegenerative changes found on histological examination of the spinal cord confirmed the diagnosis.

Animals↗

PubMed2005

Using EMG to anticipate head motion for virtual-environment applications.

In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

Adult↗

PubMed2003

Guidelines for the intramuscular positioning of EMG electrodes in the semispinalis capitis and cervicis muscles.

The objective of the study was to establish guidelines for the application of fine-wire or needle electrodes in the semispinalis cervicis and semispinalis capitis muscles. First of all, measured data for the puncture angle and puncture depth of each muscle were determined in CT scans. Using a regression approach, a model relation of these data with the neck circumference was established. This made it possible to accurately determine the puncture angle and puncture depth on the basis of the known neck circumference. In a further step, the neck muscles of seven human cadavers were punctured with wires in order to check the workability of these guidelines. At the same time, the wires' positions in relation to important structures (nerves, vessels) were studied. Both muscles can be punctured with a high degree of reliability. However, when puncturing the semispinalis cervicis muscle, one has to pass through a layer that contains vessels, nevertheless the risk of injury is regarded as very small. The technique enables intramuscular EMG measurements of the two muscles in manifold clinical problems.

Electrodes↗

PubMed2005

En bloc laminoplasty without dissection of paraspinal muscles.

OBJECT: Although conducting cervical laminoplasty in patients with multisegmental cord compression provides good neurological results, it is not without shortcomings, including C-5 palsy, axial neck pain, and undesirable radiologically detectable changes. Postoperative kyphosis and segmental instability can cause neurological problems and are believed mainly to result from neck muscle disruption. The authors developed a new laminoplasty technique, with the aim of preserving optimal muscle function. METHODS: The present technique is a modification of unilateral open-door laminoplasty. By using an ultrasonic osteotome in small gaps of muscle bellies, a gutter is made without disrupting muscles, spinous processes, or their connections on the hinged side. Ceramic spacers are then positioned between elevated laminae and lateral masses at C-3, C-5, and C-7 on the opened side, which is exposed in a conventional manner. This new procedure was used to treat 37 consecutive patients with compression myelopathy. Postoperative computerized tomography (CT) scanning revealed a significant difference in a cross-sectional area of muscles between the hinged and opened side. The mean follow-up period was 40.2 months (range 24-54 months). Changes in alignment were observed in only one patient, and vertebral slippage developed in two. Performed at regular intervals, CT scanning demonstrated that the elevated laminae remained in situ throughout the study period. CONCLUSIONS: In using the present unilateral open-door laminoplasty technique, deep extensor muscles are left intact along with their junctions to spinous processes on the hinged side. Radiologically documented changes were minimal because the preserved muscles functioned normally immediately after the operation.

Adult↗

PubMedDate not supplied

[Cervicogenic proprioceptive vertigo: etiopathogenesis, clinical manifestations, diagnosis and therapy with special emphasis on manual therapy].

Cervical proprioceptive system (CPS) consisting of mechanoreceptors of cervical intervertebral joints, mechanoreceptors of neck muscles and ligament's insertions, muscle spindles located in deep short muscles of cervical spine and sensitive fibers connecting neck's proprioceptors with neurons of cornu posteriori of spinal cord, plays an essential part in maintaining bodily balance. CPS, via tractus spinovestibularis, is connected to vestibular nuclei. Clinical and neurophysiological studies have shown that functional disorders and/or organic lesions of CPS cause identical symptoms as vestibular diseases: vertigo, nystagmus and balance disorders. Dysfunction (functional blockade) of craniocervical joints is the most frequent cause of cervicogenic proprioceptive vertigo (CPV). The constant tension of the capsule of a blocked joint irritates mechanoreceptors protecting the joint's capsules. The increased activity of mechanoreceptors results in confusion of vestibular system. That is, the impulses from the blocked craniocervical joints do not correspond to the impulses from the vestibular organ and other sensory systems that take part in maintaining bodily balance. The disharmony of impulses results in an inadequate vestibulo-spinal and vestibulo-ocular reaction manifesting as vertigo and nystagmus. Hyperactivity of craniocervical mechanoreceptors also causes disturbances in reflex regulation of postural muscle tonus manifesting as "general instability". Knowledge of CPV as a separate clinical entity is important from diagnostical and therapeutical aspect. As it concerns a peripheral vestibular disorder still unknown to a wider circle of physicians, the article describes etiopathogenesis, clinical manifestations, diagnosis and therapy of CPV with special emphasis on manual therapy.

Cervical Vertebrae↗

PubMed1998

Morphological changes in traumatized skeletal muscle: the appearance of 'opaque fibers' of cervical muscles as evidence of compression of the neck.

Cervical muscles of 15 cases of compression of the neck and the other traumatized skeletal muscles from 54 autopsy cases were examined histologically and immunohistochemically. Round and thick fibers, that is, opaque fibers were observed in the muscles beneath the compression marks on the neck, whereas in areas where no force had been applied, such fibers did not exist. Furthermore, opaque changes appeared around cavities, which formed within severely compressed injured muscle tissue. The pattern of appearance of opaque fibers in the cases of compression of the neck were mainly divided into two types, 'diffuse' pattern and 'focal' pattern. In both blunt and sharp force injuries, the production of opaque fibers were common in the area directly where damage had been inflicted. In stab wounds especially, the appearance of opaque fibers and wavelike fibers, which fanned out and showed a different color from the other areas, was limited to the marginal zone. These results suggest that there is a close relationship between opaque changes and force. Opaque fibers are probably produced by damage to muscles due to extremely applied force. The high incidence of opaque fibers beneath compression marks on the neck should be regarded as a useful indication of strangulation and/or hanging. Furthermore, the distribution and direction of force to the neck might be presumed by the pattern of opaque fibers in cervical muscles, to a certain extent.

Adolescent↗

PubMed2001

Comparative histochemical composition of muscle fibres in a pre- and a postvertebral muscle of the cervical spine.

References to histochemistry are extensive for human limb muscles but occur less frequently in relation to vertebral muscle. Most vertebral muscle literature has been concerned with muscle fibre characteristics in the lumbar and thoracic spine, due in large part to the incidence of low back pain and idiopathic scoliosis. However few studies have investigated the histochemical composition of neck muscles in humans: and, to our knowledge, no previous study has examined the antagonistic longus colli and multifidus muscle pair. In addition, while age-related segmental degeneration is most prominent between C5 and C7, it is not known whether these osteoligamentous changes are paralleled by changes in muscle fibre ratio. Tissue blocks comprising muscle and bone from C5-C7 segments were harvested at autopsy from 16 subjects with ages ranging from 4 to 77 years. The prevertebral longus colli and postvertebral multifidus muscle pairs were randomly selected from one or other side in each subject. The tissue was frozen, sectioned and histochemically stained for myofibrillar adenosine triphosphatase. Analysis of muscle fibre types was performed by light microscopy. Wilcoxon paired t-tests were used to ascertain whether intramuscular and intermuscular differences in fibre composition were significant. In addition, correlation and regression analyses were used to determine whether fibre type proportions changed in either muscle with increasing age. The present study has revealed histochemical differences between longus colli and multifidus at the level of the C5-C7 vertebral segments. Multifidus comprises a significantly greater proportion of type I than type II fibres. Longus colli comprises a significantly greater proportion of type II fibres than multifidus. Further there were no changes in fibre type proportion in either muscle with increasing age. These observations suggest that longus colli responds equally to postural and phasic demands, whereas multifidus is predominantly postural. Also it would appear that age-related structural alterations in lower cervical segments are not paralleled by changes in muscle fibre ratio.

Adenosine Triphosphatases↗

PubMed1989

[Changes of muscle activities in neck and shoulder region during sustained isometric contractions of jaw muscles].

Eight healthy participants performed horizontal isometric jaw movements with maximum voluntary contractions of the jaw muscles until they could not tolerate the task. Electromyographic activities bilaterally recorded from the superior and inferior regions of the sternocleidomastoid muscle and the nuchal and shoulder regions of the trapezius muscle were observed. The results obtained were as follows: 1. In more than 94% of 32 trials, the amplitude of EMGs during the task were higher than those at rest, and in more than 79%, temporal changes in EMG burst were synchronized with the onset-offset of the exercise. 2. In more than 72% of all trials, small amplitude EMG lasted after cessation of the task. 3. Muscle activities of the lateral cervical region during the exercise were superior to the activity of the nuchal and shoulder regions, and amplitude of EMGs in the neck and shoulder regions tended to be the highest during isometric retrusion. 4. These results don't contradict with our hypotheses that occlusal habits might be one cause of the unpleasant sensation in the neck and shoulder regions and that sustained isometric retrusion might have heavier effects on it.

Adult↗

PubMed2003

Awareness affects the response of human subjects exposed to a single whiplash-like perturbation.

STUDY DESIGN: Human subjects were exposed experimentally to a single whiplash-like perturbation. OBJECTIVE: To determine how awareness of the presence and timing of a whiplash-like perturbation affects the onset and amplitude of the neck muscle response and the peak magnitude of head and neck kinematics. SUMMARY OF BACKGROUND DATA: Although most whiplash injuries are sustained in rear-end collisions, which occur without warning, most studies of whiplash injury have used subjects aware of the imminent perturbation. METHODS: Seated subjects (35 women and 31 men) underwent a single forward horizontal perturbation (peak acceleration, 1.5 g). Surface electromyography measured the sternocleidomastoid and cervical paraspinal muscle activity. Three awareness conditions were tested: a countdown for subjects alerted to their perturbation, a perturbation without an alert for subjects who expected it within 60 seconds, and an unexpected perturbation for surprised subjects who were deceived. RESULTS: The muscle and kinematic responses of aware (alerted and unalerted) subjects were not significantly different. Sternocleidomastoid activation occurred 7 ms later in surprised subjects than in aware subjects (P < 0.0002). Cervical paraspinal amplitudes were 260% larger and angular head accelerations in flexion were 180% larger in surprised male subjects than in alerted male subjects. Surprised female subjects exhibited a 25% larger head retraction and a 30% lower forward acceleration of the mastoid process than aware female subjects. CONCLUSIONS: The larger retractions observed in surprised females likely produce larger tissue strains and may increase injury potential. Aware human subjects may not replicate the muscle response, kinematic response, or whiplash injury potential of unprepared occupants in real collisions.

Acceleration↗

PubMed2001

An anatomical investigation of the human cervical facet capsule, quantifying muscle insertion area.

Facet capsule injury has been hypothesised as a mechanism for neck pain. While qualitative studies have demonstrated the proximity of neck muscles to the cervical facet capsule, the magnitude of their forces remains unknown owing to a lack of quantitative muscle geometry. In this study, histological techniques were employed to quantify muscle insertions on the human cervical facet capsule. Computerised image analysis of slides stained with Masson's trichrome was performed to characterise the geometry of the cervical facet capsule and determine the total insertion area of muscle fibres into the facet capsule for the C4-C5 and C5-C6 joints. Muscle insertions were found to cover 22.4+/-9.6% of the capsule area for these cervical levels, corresponding to a mean muscle insertion area of 47.6+/-21.8 mm2. The magnitude of loading to the cervical facet capsule due to eccentric muscle contraction is estimated to be as high as 51 N. When taken in conjunction with the forces acting on the capsular ligament due to vertebral motions, these forces can be as high as 66 N. In that regard, these anatomical data provide quantitative evidence of substantial muscle insertions into the cervical facet capsular ligament and provide a possible mechanism for injury to this ligament and the facet joint as a whole.

Aged↗