A Systematic Review of the Soft-Tissue Connections Between Neck Muscles and Dura Mater: The Myodural Bridge

Subdiaphragmatic phrenic nerve supply: A systematic review

OBJECTIVE

The aim of this systematic review is to study the subdiaphragmatic anatomy of the phrenic nerve.

MATERIALS AND METHODS

A computerised systematic search of the Web of Science database was conducted. The key terms used were phrenic nerve, subdiaphragmat*, esophag*, liver, stomach, pancre*, duoden*, intestin*, bowel, gangli*, biliar*, Oddi, gallbladder, peritone*, spleen, splenic, hepat*, Glisson, falciform, coronary ligament, kidney, suprarenal, and adrenal. The 'cited-by' articles were also reviewed to ensure that all appropriate studies were included.

RESULTS

A total of one thousand three hundred and thirty articles were found, of which eighteen met the inclusion and exclusion criteria. The Quality Appraisal for Cadaveric Studies scale revealed substantial to excellent methodological quality of human studies, while a modified version of the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool denoted poor methodological quality of animal studies. According to human studies, phrenic supply has been demonstrated for the gastro-esophageal junction, stomach, celiac ganglia, liver and its coronary ligament, inferior vena cava, gallbladder and adrenal glands, with half of the human samples studied presenting phrenic nerve connections with any subdiaphragmatic structure.

CONCLUSIONS

This review provides the first systematic evidence of subdiaphragmatic phrenic nerve supply and connections. This is of interest to professionals who care for people suffering from neck and shoulder pain, as well as patients with peridiaphragmatic disorders or hiccups. However, there are controversies about the autonomic or sensory nature of this supply.

Measurement proprieties of the CROM instrument for assessing head posture, neck retraction and protraction

BACKGROUND

The CROM instrument is widely used clinically and in research to measure neck range of motion. However, its measurement proprieties during the assessment of protraction and retraction movements were not examined so far.

OBJECTIVE

To analyse the intra- and inter-rater reliability, the concurrent validity of the CROM for measuring head posture, retraction and protraction in healthy subjects.

METHODS

Thirty-three asymptomatic subjects were recruited and assigned in a random order to one of two raters. After a 10-min break, they were examined by a second rater (Assessment 1). After a 30-min break, both raters repeated the examination (Assessment 2). The examination consisted of measuring the head posture, maximum head protraction and maximum retraction. Each movement was repeated 3 times and measured simultaneously with the CROM and with a 3D capture system laboratory.

RESULTS

The intra-rater reliability of the CROM was excellent for both raters for head posture and all head movements (ICC>0.9, 95% CI: 0.82-0.99, p < 0.01). The inter-rater reliability was excellent for head posture (ICC>0.95, 95% CI: 0.92-0.98, p < 0.01) and good-to-excellent for all movements at both time-points (ICC = 0.73-0.98, 95%CI: 0.45-0.99, p < 0.01). The validity analysis showed moderate-to-strong correlation between instruments for the head posture and head movements [(r) = -0.47 to -0.78), 95% CI: 0.99 to -0.24, p < 0.01].

CONCLUSION

The CROM instrument has good-to-excellent reliability and adequate validity for measuring cervical position and displacement in the sagittal plane.

Application of biomechanical principles to upper cervical spine anatomy to alleviate symptoms of intermittent cranial nerve IX irritation. Directions for successful self-management of headache post-concussion? A case series

BACKGROUND

The neck has been implicated as a potential generator of symptoms such as dizziness and headache in individuals with persistent symptoms post concussion. Anatomically, the neck could also be a potential trigger for autonomic or cranial nerve symptoms. The glossopharyngeal nerve which innervates the upper pharynx is one possible autonomic trigger that might be affected by the upper cervical spine.

CASE DESCRIPTION

This is a case series of three individuals with persistent post-traumatic headache (PPTH) and symptoms of autonomic dysregulation who also had signs of intermittent glossopharyngeal nerve irritation associated with certain neck positions or movements. Biomechanical principles were applied to anatomical research on the path of the glossopharyngeal nerve, in relation to the upper cervical spine and the dura mater, to alleviate these intermittent symptoms. The patients were provided techniques to be used as tools to immediately alleviate the intermittent dysphagia, which also alleviated the constant headache at the same time. As part of the overall long-term management program, patients were also taught daily exercises to improve upper cervical and dural stability and mobility.

OUTCOME

The result was a decrease in intermittent dysphagia, headache, and autonomic symptoms in the long term in persons with PPTH following concussion.

DISCUSSION

Autonomic and dysphagia symptoms may provide clues as to the origin of symptoms in a subgroup of individuals with PPTH.

A valuable subarachnoid space named the occipito-atlantal cistern

The cisterna magna has been defined as the space between the inferior margin of the cerebellar vermis to the level of the foramen magnum, while an enlarged dorsal subarachnoid space at the occipito-cervical junction extending from the foramen magnum to the upper border of the axis (C2) is still ignored. Recently, the myodural bridge complex is proved to drive the cerebral spinal fluid flowing via this region, we therefore introduce the "occipito-atlantal cistern (OAC)" to better describe the subarachnoid space and provide a detailed rationale. The present study utilized several methods, including MRI, gross anatomical dissection, P45 sheet plastination, and three-dimensional visualization. OAC was observed to be an enlarge subarachnoid space, extending from the foramen magnum to the level of the C2. In the median sagittal plane, OAC was a funnel shape and its anteroposterior dimensions were 15.92 ± 4.20 mm at the level of the C0, 4.49 ± 1.25 mm at the level of the posterior arch of the C1, and 2.88 ± 0.77 mm at the level of the arch of the C2, respectively. In the median sagittal plane, the spino-dural angle of the OAC was calculated to be 35.10 ± 6.91°, and the area of OAC was calculated to be 232.28 ± 71.02 mm². The present study provides OAC is a subarachnoid space independent from the cisterna magna. Because of its distinctive anatomy, as well as theoretical and clinical significance, OAC deserves its own name.

Dynamic asymmetry in cerebrospinal fluid pressure: An indicator of regional differences in compliance

Background

Dural compliance influences the shape and magnitude of the cerebrospinal fluid (CSF) pulsations. In humans, cranial compliance is approximately 2× greater than spinal compliance; the differential has been attributed to the associated vasculature. In alligators, the spinal cord is surrounded by a large venous sinus, which suggests that the spinal compartment may have higher compliance than is found in mammals.

Methods

Pressure catheters were surgically implanted into the cranial and spinal subdural spaces of eight subadult American alligators (Alligator mississippiensis). The CSF was propelled through the subdural space by orthostatic gradients and rapid changes in linear acceleration.

Results

CSF pressure recordings taken from the cranial compartment were consistently, and significantly, larger than those taken from the spinal compartment. After the myodural bridge of Alligator was surgically released, the asymmetry in CSF pressure was decreased.

Conclusion

Unlike the situation in humans, the spinal compartment of Alligator has greater compliance than the cranial compartment, presumably due to the presence of the large spinal venous sinus surrounding the dura. The change in CSF pressures after myodural surgical release supports the hypothesis that the myodural bridge functions, at least in part, to modulate dural compliance and the exchange of CSF between the cranial and spinal compartments.

Effects of cervical rotatory manipulation on the cervical spinal cord complex with ossification of the posterior longitudinal ligament in the vertebral canal: A finite element study

Background: There are few studies focusing on biomechanism of spinal cord injury according to the ossification of the posterior longitudinal ligament (OPLL) during cervical rotatory manipulation (CRM). This study aimed to explore the biomechanical effects of CRM on the spinal cord, dura matter and nerve roots with OPLL in the cervical vertebral canal. Methods: Three validated FE models of the craniocervical spine and spinal cord complex were constructed by adding mild, moderate, and severe OPLL to the healthy FE model, respectively. We simulated the static compression of the spinal cord by OPLL and the dynamic compression during CRM in the flexion position. The stress distribution of the spinal cord complex was investigated. Results: The cervical spinal cord experienced higher von Mises stress under static compression by the severe OPLL. A higher von Mises stress was observed on the spinal cord in the moderate and severe OPLL models during CRM. The dura matter and nerve roots had a higher von Mises stress in all three models during CRM. Conclusion: The results show a high risk in performing CRM in the flexion position on patients with OPLL, in that different occupying ratios in the vertebral canal due to OPLL could significantly increase the stress on the spinal cord complex.

Development, maturation and growth of the myodural bridge within the posterior atlanto-axial interspace in the rat

The myodural bridge complex are fibrous bridges that functionally connect the spinal dura mater to the suboccipital musculature. Previously, we described the maturational sequence of the myodural bridge (MDB) within the posterior atlanto-occipital interspace of the rat. The present paper describes the morphology and developmental maturation of the MDB within the posterior atlanto-axial interspace of the rat. In the present study, E18 embryonic rats, newborn rats, and adult rats were selected to evaluate the development and growth of the MDB. Within the posterior atlanto-axial interspace of the rat, the fibers of the MDB and its associated muscles, in the embryonic rat, were observed to be scarce and lightly stained. In contrast, these same structures observed in the postnatal rat were quite apparent and robustly stained. After birth, it was observed that MDB originated from the rectus capitis dorsal major muscle, extended forward and downward, and finally merged with the posterior atlanto-axial membrane. As the rats developed/matured, the observed MDB fibers passing through the posterior atlanto-axial interspace appeared denser and more organized. This study evidenced that the MDB fibers within the posterior atlanto-axial interspace were primarily composed of type I collagen fibers in the postnatal rat. By observing the suboccipital region, we are able to hypothesize that the MDB complex plays a key role in maintaining the subdural space located within the upper cervical segment during growth and development. This study provides a morphological basis for future research on the function of the MDB complex. This article is protected by copyright. All rights reserved.

The morphology of the suboccipital region in snakes, and the anatomical and functional diversity of the myodural bridge

The myodural bridge, that is, skeletal muscle fibers attaching to the cervical dura mater, has been described from a variety of mammals and other amniotes. To test an earlier assumption about the presence of the myodural bridge in snakes, a comparative study was designed using a group of Colubrine snakes. Serial histological sections revealed no evidence of the myodural bridge in any of the snakes examined. Further analyses, including histology, computed tomography (CT), and micro-CT imaging of other distantly related snakes, also turned up no evidence of a myodural bridge. The close apposition of adjacent neural arches in snakes may preclude muscle tendons from passing through the intervertebral joint to reach the spinal dura. It is hypothesized that the myodural bridge functions in the clearance of the cerebrospinal fluid (CSF) by creating episodic CSF pressure pulsations, and that snakes are capable of creating equivalent CSF pressure pulsations through vertebral displacement.

Neck and back muscle chains hypomobility in women with migraine

OBJECTIVE

To compare the mobility of neck and back flexor and extensor muscle chains in women with migraine, chronic migraine and headache-free.

METHODS

This is a cross-sectional study. The muscle chain test was performed based on the theoretical assumptions of the Busquet method, in women with migraine (MG, n = 24), chronic migraine (CMG, n = 36) and headache-free (CG, n = 27). The evaluation of neck and back mobility was performed by an examiner expert in the Busquet method with the aid of cervical range of motion (CROM®) device (neck muscles) and the Tiltmeter® application (back muscles).

RESULTS

Compared to woman headache-free, women with migraine (MD = -12° [CI95% = -19°, -5°] and chronic migraine (MD = -15° [CI95% = -21°, -8°] present reduced mobility in the neck extensor muscle chain. Also, in the back extensor muscle chain, migraine vs headache-free (MD = -9° [CI95% = -15°, -2°]) and chronic migraine vs headache-free (MD = -10° [CI95% = -16°, -4°]) and in the back flexor muscle chain, migraine vs headache-free (MD = -6° [CI95% = -10°, -0.1°]) and chronic migraine vs headache-free (MD = -7 [CI95% = -11°, -2°]), with an effect sizes varying between 1.19 e 2.38. No difference was found between groups for neck flexor muscle chain.

CONCLUSION

Women with migraine and chronic migraine have hypomobility of the neck and back extensor muscle chains, and of the back flexor chain.

Effects of increasing axial load on cervical motor control

To investigate the effects of increasing axial load on cervical motor control. Surrogates of cervical motor control were active cervical range of motion (C-ROM) and joint position error (JPE) assessed in flexion, extension, lateroflexion and rotation directions in 49 healthy young men (mean age: 20.2 years). All measurements were executed with 0-, 1-, 2-, and 3-kg axial loads. Linear mixed models were used to assess the effects of axial loading and cervical movement-direction on C-ROM and JPE. Post-hoc analysis was performed to compare load levels. Axial loading (p = 0.045) and movement direction (p < 0.001) showed significant main effects on C-ROM as well as an interaction (p < 0.001). C-ROM significantly changed with 3-kg axial load by decreaseing extension (− 13.6%) and increasing lateroflexion (+ 9.9%). No significant main effect was observed of axial loading on JPE (p = 0.139). Cervical motor control is influenced by axial loading, which results in decreased C-ROM in extension and increased C-ROM lateroflexion direction.

Effects of Instrumental, Manipulative and Soft Tissue Approaches for the Suboccipital Region in Subjects with Chronic Mechanical Neck Pain. A Randomized Controlled Trial

The INYBI is an instrument used to release the suboccipital myofascial area. There is scarce evidence of its efficacy. A randomized controlled, double-blinded, longitudinal and prospective trial was performed. Ninety-six subjects (aged 29.47 ± 5.16 years) (70 women) with chronic neck pain were randomly assigned to the manual suboccipital inhibition technique (MSIT), instrumental suboccipital inhibition (INYBI) or the INYBI plus upper cervical manipulation technique (INYBI + UCMT) groups and received two sessions with a week interval between them. The Neck Disability Index was used before the first intervention and two weeks after the second intervention. Pre- and post-measurements were taken on both intervention days for pressure pain threshold of the upper trapezius and suboccipital muscles, self-perceived pain and cervical range of motion. In spite of a significant general improvement in time that was found for the three groups for all of the outcome measurements (p < 0.05 in all cases), no between-groups differences were found (p > 0.05 in all cases), with the exception of self-perceived pain for left rotation (p = 0.024), with the MSIT group showing the lower improvement. However, the higher degree of within-group improvements was found for the INYBI + UCMT group. It was concluded that the myofascial release therapy in the suboccipital area is effective in patients with chronic neck pain, either through a manual application or by means of the INYBI tool. Moreover, the addition of craniocervical manipulation achieved the higher within-group improvements, but with no statistical significance.

Abnormal spinal cord motion at the craniocervical junction in hypermobile Ehlers-Danlos patients

OBJECTIVE

The craniocervical junction (CCJ) is anatomically complex and comprises multiple joints that allow for wide head and neck movements. The thecal sac must adjust to such movements. Accordingly, the thecal sac is not rigidly attached to the bony spinal canal but instead tethered by fibrous suspension ligaments, including myodural bridges (MDBs). The authors hypothesized that pathological spinal cord motion is due to the laxity of such suspension bands in patients with connective tissue disorders, e.g., hypermobile Ehlers-Danlos syndrome (EDS).

METHODS

The ultrastructure of MDBs that were intraoperatively harvested from patients with Chiari malformation was investigated with transmission electron microscopy, and 8 patients with EDS were compared with 8 patients without EDS. MRI was used to exclude patients with EDS and craniocervical instability (CCI). Real-time ultrasound was used to compare the spinal cord at C1-2 of 20 patients with EDS with those of 18 healthy control participants.

RESULTS

The ultrastructural damage of the collagen fibrils of the MDBs was distinct in patients with EDS, indicating a pathological mechanical laxity. In patients with EDS, ultrasound revealed increased cardiac pulsatory motion and irregular displacement of the spinal cord during head movements.

CONCLUSIONS

Laxity of spinal cord suspension ligaments and the associated spinal cord motion disorder are possible pathogenic factors for chronic neck pain and headache in patients with EDS but without radiologically proven CCI.

Spinal subdural hemorrhage in abusive head trauma: a pictorial review

A growing body of evidence links abusive head trauma (AHT) to patterns of direct and indirect spinal injuries, such as spinal subdural hemorrhage (SDH). Identification of evidence of spinal injury such as spinal SDH plays a crucial role in the diagnosis and subsequent management of the index child with AHT and his or her siblings. In a value-based practice of medicine, it can be argued that adding spine imaging to identify spinal SDH in the workup of AHT adds value to both the short- and long-term management of the patient. This pictorial review describes the normal appearance of spinal SDH and challenges of identifying spinal SDH, and it explores the mechanism of spinal SDH development in AHT.

Existence and features of the myodural bridge in Gentoo penguins: A morphological study

Recent studies have evidenced that the anatomical structure now known as the myodural bridge (MDB) connects the suboccipital musculature to the cervical spinal dura mater (SDM). In humans, the MDB passes through both the posterior atlanto-occipital and the posterior atlanto-axial interspaces. The existence of the MDB in various mammals, including flying birds (Rock pigeons and Gallus domesticus) has been previously validated. Gentoo penguins are marine birds, able to make 450 dives per day, reaching depths of up to 660 feet. While foraging, this penguin is able to reach speeds of up to 22 miles per hour. Gentoo penguins are also the world’s fastest diving birds. The present study was therefore carried out to investigate the existence and characteristics of the MDB in Gentoo penguin (Pygoscelis papua), a non-flying, marine bird that can dive. For this study, six Gentoo penguin specimens were dissected to observe the existence and composition of their MDB. Histological staining was also performed to analyze the anatomic relationships and characteristic of the MDB in the Gentoo penguin. In this study, it was found that the suboccipital musculature in the Gentoo penguin consists of the rectus capitis dorsalis minor (RCDmi) muscle and rectus capitis dorsalis major (RCDma) muscle. Dense connective tissue fibers were observed connecting these two suboccipital muscles to the spinal dura mater (SDM). This dense connective tissue bridge consists of primarily type I collagen fibers. Thus, this penguin’s MDB appears to be analogous to the MDB previously observed in humans. The present study evidences that the MDB not only exists in penguins but it also has unique features that distinguishes it from that of flying birds. Thus, this study advances the understanding of the morphological characteristics of the MDB in flightless, marine birds.

iTRAQ-based Quantitative Proteomic Analysis of Dural Tissues Reveals Upregulated Haptoglobin to be a Potential Biomarker of Moyamoya Disease

Background:

Moyamoya Disease (MMD) is a rare cerebrovascular disease with a high rate of disability and mortality. Immune reactions have been implicated in the pathogenesis of MMD, however, the underlying mechanism is still unclear.

Objective:

To identify proteins related to MMD specially involved in the immunogenesis, we performed a proteomic study.

Methods:

In this work, dural tissues or plasma from 98 patients with MMD, 17 disease controls without MMD, and 12 healthy donors were included. Proteomic profiles of dural tissues from 4 MMD and 4 disease controls were analyzed by an isobaric tag for relative and absolute quantitation (iTRAQ)- based proteomics. The immune-related proteins were explored by bioinformatics and the key MMDrelated proteins were verified by western blot, multiple reaction monitoring methods, enzyme-linked immunosorbent assay, and tissue microarray.

Results:

1,120 proteins were identified, and 82 MMD-related proteins were found with more than 1.5 fold difference compared with those in the control samples. Gene Ontology analysis showed that 29 proteins were immune-related. In particular, Haptoglobin (HP) was up-regulated in dural tissue and plasma of MMD samples compared to the controls, and its up-regulation was found to be sex- and MMD Suzuki grade dependent. Through Receiver Operating Characteristic (ROC) analysis, HP can well discriminate MMD and healthy donors with the Area Under the Curve (AUC) of 0.953.

Conclusion:

We identified the biggest protein database of the dura mater. 29 out of 82 differentially expressed proteins in MMD are involved in the immune process. Of which, HP was up-regulated in dural tissue and plasma of MMD, with sex- and MMD Suzuki grade-dependence. HP might be a potential biomarker of MMD.

Development of myodural bridge located within the atlanto-occipital interspace of rats

The myodural bridge (MDB) is a dense connective tissue structure that connects the subocciptal musculature to the spinal dura mater. The purpose of this study was to clarify morphological evolution characteristics and compositional changes in the fibrous structures of MDB during its growth and development in the atlanto-occipital interspace. For this, histological sections from Sprague-Dawley (SD) rats (age, E17 to adulthood) were stained with Masson's Trichrome and Picrosirius Red. The results demonstrated that at age E18, the posterior arch of the atlas was completely closed and MDB fibers had already begun to form. In rat embryos (E18-E21), only few fibers and muscles were present in the suboccipital region, and these were lightly stained. In postnatal rats, an obvious increase in the amount of fibers and muscle tissues was noted. At age P1, MDB fibers originated from the rectus capitis posterior minor muscle and merged into the atlanto-occipital membrane, which was closely attached to the spinal dura mater. As rats matured, MDB fibers gradually became denser and more organized. This study also showed that in postnatal rats, MDB was mainly composed of type I collagen fibers. By observing the development of MDB in SD rats, the function of MDB can be further understood. This study provides a morphological basis for future functional studies involving the MDB.

INYBI: A New Tool for Self-Myofascial Release of the Suboccipital Muscles in Patients With Chronic Non-Specific Neck Pain: A Randomized Controlled Trial

STUDY DESIGN

A randomized, single-blinded (the outcome assessor was unaware of participants' allocation group) controlled clinical trial.

OBJECTIVE

To investigate the effects of myofascial release therapy (MRT) over the suboccipital muscles, compared with self-MRT using a novel device, the INYBI tool, on pain-related outcomes, active cervical mobility, and vertical mouth opening, in adults with chronic non-specific neck pain (NSNP).

SUMMARY OF BACKGROUND DATA

MRT is used to manage chronic musculoskeletal pain conditions, with purported positive effects. The efficacy of self-MRT, compared with MRT, has been scarcely evaluated.

METHODS

Fifty-eight participants (mean age of 34.6 ± 4.7 yrs; range 21-40 yrs; 77.6% females, 22.4% males) with persistent NSNP agreed to participate, and were equally distributed into an INYBI (n = 29) or a control group (n = 29). Both groups underwent a single 5-minutes intervention session. For participants in the control group, MRT of the suboccipital muscles was performed using the suboccipital muscle inhibition technique, while those in the INYBI group underwent a self-MRT intervention using the INYBI device. Primary measurements were taken of pain intensity (visual analogue scale), local pressure pain sensitivity, as assessed with an algometer, and active cervical range-of-movement. Secondary outcomes included pain-free vertical mouth opening. Outcomes were collected at baseline, immediately after intervention and 45 minutes later.

RESULTS

The analysis of variance (ANOVAs) demonstrated no significant between-groups effect for any variable (all, P > 0.05). In the within-groups comparison, all participants significantly improved pain-related outcomes, and showed similar positive changes for mouth opening. Cervical range-of-movement- mainly increased after intervention for participants in the control group.

CONCLUSION

Both, MRT and self-MRT using the INYBI, are equally effective to enhance self-reported pain intensity, and local pressure pain sensitivity in chronic NSNP patients. For cervical mobility, MRT appears to be slighlty superior, compared with the INYBI, to achieve improvements in this population.

LEVEL OF EVIDENCE

2.

Scanning Electron Microscopic Observation of Myodural Bridge in the Human Suboccipital Region

STUDY DESIGN

A scanning electron microscopic study performed on three cadaveric specimens focused on the human suboccipital region, specifically, myodural bridge (MDB).

OBJECTIVE

This study showed the connection form of the MDB among the suboccipital muscles, the posterior atlanto-occipital membrane (PAOM) and the spinal dura mater (SDM), and provided an ultrastructural morphological basis for the functional studies of the MDB.

SUMMARY OF BACKGROUND DATA

Since the myodural bridge was first discovered by Hack, researches on its morphology and functions had been progressing continuously. However, at present, research results about MDB were still limited to the gross anatomical and histological level. There was no research report showing the MDB's ultrastructural morphology and its ultrastructural connection forms between PAOM and SDM.

METHODS

A scanning electron microscope (SEM) was used to observe the connection of myodural bridge fibers with PAOM and SDM in atlanto-occipital and atlanto-axial interspaces, and the connection forms were analyzed.

RESULTS

Under the SEM, it was observed that there were clear direct connections between the suboccipital muscles and the PAOM and SDM in the atlanto-occipital and atlanto-axial spaces. These connections were myodural bridge. The fibers of the myodural bridge merged into the spinal dura mater and gradually became a superficial layer of the spinal dura mater.

CONCLUSION

MDB fibers merged into the SDM and became part of the SDM in the atlanto-occipital and atlanto-axial space. MDB could transfer tension and pulling force to the SDM effectively, during the contraction or relaxation of the suboccipital muscles.

LEVEL OF EVIDENCE

N/A.

The Impact of Soft Tissue Techniques in the Management of Migraine Headache: A Randomized Controlled Trial

Objective

Individuals with migraine often present with postural faults and muscle tension that are associated with myofascial trigger points (MTrPs). These trigger points may be a contributory factor to the development of migraine headaches. There are many treatments aimed at eliminating MTrPs, such as soft tissue techniques, laser therapy, and needling therapies. Thus, we performed a randomized controlled trial study to investigate the efficacy of soft tissue techniques in the management of migraine headache.

Methods

This study was conducted among individuals with migraine headache in Shiraz in 2018. Forty participants were randomly divided into 2 groups: the soft tissue techniques (treatment) group and the placebo control group. Participants in the treatment group were treated over 6 sessions in 2 weeks (combined MTrP therapy and stretching). Headache parameters, drug consumption, score on the Headache Disability Index, and pressure pain threshold (PPT) were measured before and after the intervention and after a 1-month follow-up period. Data were analyzed with 2 × 3 repeated-measures analyses of variance to investigate the differences in variables between the 2 groups.

Results

Compared with baseline and the control group, the treatment group showed a significant reduction in headache parameters (P < .001), drug consumption (P < .001), and Headache Disability Index score (P < .001) immediately after the intervention and after a 1-month follow-up period (all Ps < .001). PPT levels increased in the treatment group in comparison with the control group (P < .001).

Conclusion

The soft tissue techniques were helpful for improving certain aspects of migraine, such as headache parameters, drug consumption, functional disability, and PPT levels of cervical muscles.

Implied Evidence of the Functional Role of the Rectus Capitis Posterior Muscles

Context

Osteopathic physicians often target the rectus capitis posterior minor (RCPm) and rectus capitis posterior major (RCPM) muscles when using muscle energy or soft tissue cervical techniques to treat patients with head and neck pain. The RCPm and RCPM muscles are located deep within the posterior occipitoatlantal and atlantoaxial interspaces, respectively.

Objective

To characterize the functional role of RCPm and RCPM muscles by comparing electromyographic (EMG) activation patterns of these muscles with EMG activation patterns of specific flexor and extensor muscles of the head and neck, the sternocleidomastoid (SCM), and the splenius capitis (SC) muscles, respectively.

Methods

Asymptomatic participants were recruited from the Michigan State University College of Osteopathic Medicine student body. Disposable 25-gauge, bipolar fine-wire intramuscular electrodes were used to collect EMG data from the right and left RCPm and RCPM muscles. Surface electrodes were used to collect EMG data from the right and left SCM and SC muscles. Data were collected as participants performed 4 cycles of flexion and extension with an external 4-lb force applied to the back of the head and the forehead.

Results

In RCPM muscles, EMG activity was significantly greater (P<.003) during flexion and extension of the head and neck when an external force was applied to the back of the head. EMG activity in SCM muscles was significantly greater (P<.0001) during flexion and extension of the head and neck when an external force was applied to the forehead. The authors observed that EMG activity in SC muscles was significantly greater (P<.015) during flexion and extension of the head and neck when an external force was applied to the back of the head. No significant difference was found in EMG activity in RCPm muscles (P<.834) during flexion and extension of the head and neck, regardless of whether the external force was applied to the back of the head or the forehead.

Conclusion

The EMG activation patterns of the RCPm muscles suggest that their functional role may be to stabilize the occipitoatlantal joint by helping maintain congruency of the joint surfaces. In contrast, the EMG activation patterns of the RCPM muscles suggest that their functional role may be to contribute to extension of the head, primarily at the occipitoatlantal and the atlantoaxial joints.

[Assessment of postural control and balance in persons with temporomandibular disorders: A systematic review]

The stomatognathic system is the anatomo-functional unit of the cranio-cervico-facial region. Some dysfunctions affect its motor control. The aim of this study was to analyse the clinical usefulness of the various scales and instruments used in the assessment of postural control in people with temporomandibular disorders. A systematic review was carried out by 2independent reviewers in the PubMed, Medline, Ebsco, Science Direct and PEDro databases, selecting observational studies published between January 2006 and March 2017. The risk of bias and methodological quality was analysed following Cochrane indications and the Downs and Black quality scale. Ten studies were included, of which 9used computerised platforms, one added photogrammetry and one used electromyography. Seven studies were classified as moderate quality and 3as low quality. Posturography was the most widely used assessment instrument. Methodological differences did not allow determination of their clinical implications or the relationship between balance and the presence of temporomandibular disorders.

A Neuroscience Perspective of Physical Treatment of Headache and Neck Pain

The most prevalent primary headaches tension-type headache and migraine are frequently associated with neck pain. A wide variety of treatment options is available for people with headache and neck pain. Some of these interventions are recommended in guidelines on headache: self-management strategies, pharmacological and non-pharmacological interventions. Physical treatment is a frequently applied treatment for headache. Although this treatment for headache is predominantly targeted on the cervical spine, the neurophysiological background of this intervention remains unclear. Recent knowledge from neuroscience will enhance clinical reasoning in physical treatment of headache. Therefore, we summarize the neuro- anatomical and—physiological findings on headache and neck pain from experimental research in both animals and humans. Several neurophysiological models (referred pain, central sensitization) are proposed to understand the co-occurrence of headache and neck pain. This information can be of added value in understanding the use of physical treatment as a treatment option for patients with headache and neck pain.

Is There Support for the Paradigm 'Spinal Posture as a Trigger for Episodic Headache'? A Comprehensive Review

PURPOSE OF REVIEW

The International Classification of Headache Disorders provides an extensive framework to classify headaches. Physiotherapy is indicated if neuromusculoskeletal dysfunctions are involved in the pathophysiology. Maladaptive postures seem a dominant trigger in tension-type and cervicogenic headache. Yet, outcomes following physiotherapy vary. The absence of protocol studies to identify determinants concerning the role of spinal posture in headache might explain such variability. Hence, multi-dimensional profiling of patients with headache based on interactions between spinal posture, psychosocial and lifestyle factors might be essential. Therefore, the aim of this paper was to perform a comprehensive review to find support for the paradigm of spinal posture triggering episodic headache based on a multi-dimensional view on tension-type and cervicogenic headache including modern pain neuroscience.

RECENT FINDINGS

A review was conducted to support spinal posture-induced episodic headache. Pubmed, Web of Science, Pedro and the Cochrane database were explored based on the following 'Mesh' or 'Topics': 'Headache', 'Posture', 'Spine', 'Psychosocial', 'Lifestyle'. The contemporary review of neuroanatomical, biomechanical and non-nociceptive pathways, with integration of modern pain neuroscience in tension-type and cervicogenic headache, supports spinal posture as a trigger for episodic headache. Maladaptive postures can activate C1-C3 nociceptors. Convergence with trigeminal afferents at the trigeminocervical nucleus could explain spinal headache. Interactions with psychosocial and lifestyle factors might contribute to peripheral and central sensitisation. Neuroanatomical, biomechanical and non-nociceptive pathways seem to justify profiling patients based on a postural trigger. Further research is needed to determine the contribution of postural dysfunctions in headache and the effect of specific interventions.

Existence and features of the myodural bridge in Gallus domesticus: indication of its important physiological function

The myodural bridge (MDB) is a dense connective tissue that connects muscles with the cervical spinal dura mater via the posterior atlanto-occipital and atlato-axial interspaces. To date, the physiological function of the MDB has not been fully elucidated. Recent studies have identified the presence of the MDB in mammals, but very little information is available on the existence of the MDB in avifauna. We selected Gallus domesticus to explore the existence and the fiber property of the MDB in avifauna. We found that in this species, fibers originating from the ventral aspect of the rectus capitis dorsal minor are fused with the dorsal atlanto-occipital membrane and that numerous trabeculae connect the dorsal atlanto-occipital membrane with the cervical spinal dura mater. Furthermore, the occipital venous sinus is located between the trabeculae. The MDB is mainly composed of collagen type I fibers. Our results show that the MDB is present in G. domesticus and lead us to infer that the MDB is a highly conservative evolutionary structure which may play essential physiological roles.

The myodural bridge in the common rock pigeon (Columbia livia): Morphology and possible physiological implications

The dense connective tissue that connects muscles to the cervical spinal dura mater is known as the myodural bridge in human anatomy and has been a subject of interest to anatomists and clinicians. The myodural bridge was originally discovered in humans, and also has been observed in other mammals and in reptilian sauropsids. We investigated the existence of the myodural bridge in a bird, that is, the Common Rock Pigeon Columba livia, to expand the understanding of the structure and function of the myodural bridge. Gross anatomical dissection of seven specimens and histological analyses of the suboccipital region of eight specimens were performed. The rectus capitis dorsalis minor muscle joins occipital periosteal extensions and inserts with several dense connective tissue cords on the dorsal side of the dura mater of the cervical spinal cord. The myodural bridge consists primarily of collagen Type I fibres, suggesting that the myodural bridge can transmit strong tensional forces generated by the contraction of M. rectus capitis dorsalis minor to the dura mater. The pull on the dura mater may affect the circulation of the cerebrospinal fluid in the subarachnoid space of the spine.

The myodural bridges' existence in the sperm whale

Recent studies have identified that the myodural bridge (MDB) is located between the suboccipital muscles and cervical dura mater in the posterior atlanto-occipital interspace within humans. The myodural bridge has been considered to have a significant role in physiological functions. However, there is little information about the myodural bridge in marine mammals; we conducted this study to investigate and examine the morphology of the myodural bridge in a sperm whale. We also aim to discuss the physiological functions of the myodural bridge. In this study, a 15.1-meter long sperm whale carcass was examined. Multiple methods were conducted to examine the bridges of the sperm whale which included dissection, P45 plastination and histological analysis. This study confirmed the existence of the myodural bridge in the sperm whale and shows there are two types of the bridge in the sperm whale: one type was the occipital-dural bridge (ODB), the other type was the MDB. A large venous plexus was found within the epidural space and this venous plexus is thought to contain a great amount of blood when in deep water and thus the movements of suboccipital muscles could be a unique power source that drives cerebrospinal fluid circulation.

Orientation and property of fibers of the myodural bridge in humans

BACKGROUND CONTEXT

Studies over the past 20 years have revealed that there are fibrous connective tissues between the suboccipital muscles, nuchal ligament, and cervical spinal dura mater (SDM). This fibrous connection with the SDM is through the posterior atlanto-occipital or atlantoaxial interspaces and is called the myodural bridge (MDB). Researchers have inferred that the MDB might have important functions. It was speculated that the function of MDB might be related to proprioception transmission, keeping the subarachnoid space and the cerebellomedullary cistern unobstructed, and affecting the dynamic circulation of the cerebrospinal fluid. In addition, clinicians have found that the pathologic change of the MDB might cause cervicogenic or chronic tension-type headache. Previous gross anatomical and histologic studies only confirmed the existence of the MDB but did not reveal the fiber properties of the MDB. This is important to further mechanical and functional research on the MDB.

PURPOSE

Multiple histologic staining methods were used in the present study to reveal the various origin and fiber properties of the MDB. Muscles and ligaments participating in forming the MDB at the posterior atlanto-occipital or atlantoaxial interspaces were observed, and the fiber properties of the MDB were confirmed. The present study provides a basis for speculating the tensile force values of the MDB on the SDM and a morphologic foundational work for exploring the physiological functions and clinical significances of the MDB.

STUDY DESIGN

Anatomical and histologic analyses of suboccipital structures that communicate with the SDM at the posterior atlanto-occipital or atlantoaxial interspaces were carried out.

METHODS

Multiple histologic staining methods were used to evaluate the histologic properties and composition of the MDB at the posterior atlanto-occipital or atlantoaxial interspaces in five formalin-fixed head-neck human specimens.

RESULTS

The results show that the MDB traversing the atlanto-occipital interspace originated from the rectus capitis posterior minor (RCPmi). The MDB traversing the atlantoaxial interspace originated mainly from the RCPmi, rectus capitis posterior major, and obliquus capitis inferior. These fibers form the vertebral dural ligament in the atlantoaxial interspace and connect with SDM. The MDB is mainly formed by parallel running type I collagen fibers; thus, suboccipital muscle could pull SDM strongly through the effective force propagated by the MDB during head movement.

CONCLUSIONS

Myodural bridge is mainly formed by parallel running type I collagen fibers; thus, it can transmit the strong pull from the diverse suboccipital muscles or ligaments during head movement. The results of the present study will serve as a basis for further biomechanical and functional MDB research.