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Fear - light at the end of the tunnel

The Vagus Nerve – Anxiety, Un-learning Fear and PTSD

The vagus nerve has multiple branches that innervate many of our organs, including the heart, lungs and stomach, and much more. However, a new Swiss study by Melanie Klarer et al published in May this year in the Journal of Neuroscience, has shown how afferent vagus pathways are able to modulate our fear and anxiety response, and also affect our ability to ‘un-learn’ previously conditioned fear responses.

Around 80% or more of the vagus nerve fibres are dedicated to sending signals to the brain about the state of the viscera and it is known that healthy vagus nerve communication from gut to brain helps to slow down the fear response, by using neurotransmitters such as acetylcholine and GABA – lowering heart rate and blood pressure and encouraging the parasympathetic response of ‘rest and digest’.

So, for this study, the team at ETH Zurich dissected these afferent nerve fibres to the stomach, to study how interrupting this feedback loop might affect brain and cognitive function.

The researchers were especially interested in the link between innate anxiety and ‘learned’ or ‘conditioned’ fear – in the tests the brain was still able to send signals to the stomach but the brain could not ‘hear’ the stomach’s vagal response.

In anxiety-behaviour experiments, rats without vagal feedback from the gut demonstrated two main findings – a reduced innate fear (e.g. to bright lights, open spaces etc) but also a longer retention of previously learned fears. This confirms the importance of healthy vagal tone to overcome fear conditioning.

Furthermore, the loss of the gut vagus signal altered the production of adrenaline and GABA in the brain, meaning that the rats took much longer to re-associate sounds previously associated with a negative stimulus with a new ‘safe’ or neutral situation.

The Implications for PTSD

Hence these new findings may eventually shine a light on developing new treatments for PTSD (post-traumatic stress disorder) – stimulation or normalisation of the vagus nerve may help people to reassociate non-threatening stimuli which became traumatically associated with triggering fear/anxiety, with a new neutral or non-traumatic experience/response. Vagus nerve stimulation (VNS) is currently used to treat epilepsy and depression, but its efficacy remains controversial.

In a press release Urs Meyer stated:

“We were able to show for the first time that the selective interruption of the signal path from the stomach to the brain changed complex behavioural patterns. This has traditionally been attributed to the brain alone. The study shows clearly that the stomach also has a say in how we respond to fear; however, what it says, i.e. precisely what it signals, is not yet clear.”

This short video from 2011 also discusses the possible use of VNS for patients with PTSD:

 

Read here, from half way down the page ‘Activating the Vagus Nerve Without Machinery‘ for a quick run-down of some ways to improve vagus function or to stimulate the vagus pathway:
Insightful Nutrition – Orthomolecular Health and Nutrition – ‘Activating the Vagus Pathway’

REFERENCES

1. Klarer, M. et al. Gut Vagal Afferents Differentially Modulate Innate Anxiety and Learned Fear. J. Neurosci. 34 , 7067–7076 (2014).

neurons in the brain

Adult Brain Repair Pathway And New Cell-Type Discovered

Researchers have discovered a previously unknown brain cell-type that directly instructs stem cells to produce new neurons. Although the work is still in it’s early stages, the research implies that the adult brain is capable of restoring itself following injury.

The new cells have been found in the subventricular zone of the adult (mouse) brain, and they release an enzyme called choline acetyltransferase (ChAT), which eventually goes on to help make acetylcholine.

By ‘accelerating’ and ‘decelerating’ the impulse frequency of these newly discovered neurons, they observed clear changes in the production of neural stem cells in the brain.

“We have been working to determine how neurogenesis is sustained in the adult brain. It is very unexpected and exciting to uncover this hidden gateway, a neural circuit that can directly instruct the stem cells to make more immature neurons,”
Chay Kuo M.D. – Lead Researcher, Duke University, Durham, NC

It is hoped that by understanding these repair pathways, it will eventually become possible to rebuild the brain following damage.

The work was published in Nature Neuroscience at the beginning of June this year.

 

 

REFERENCES:

1. Paez-Gonzalez, P., Asrican, B., Rodriguez, E. & Kuo, C. T. Identification of distinct ChAT+ neurons and activity-dependent control of postnatal SVZ neurogenesis. Nat Neurosci advance online publication, (2014).

 

 

The Evolution of Head Pain

Headache In Children and Adolescents

Headache and migraine sufferers frequently seek osteopathic intervention to help prevent, alleviate and manage their pain episodes. Headache is a complex clinical presentation, which requires – among other things – that the practitioner is able to take an appropriate case history, and then test for and discover signs such as raised ICP (e.g. papilloedema), ocular anomalies, CN signs and other red-flags that may require referral.

If dealing with children and adolescents who have headache and migraine, it is also important to be aware of physical and psychopathological co-morbidities and the expected prognoses of these conditions. Thus, the case-history, examination, treatment and management of these cases can be improved.

The following three papers, from many available online, form only a starting point to help the Osteopath to understand the bigger clinical picture when dealing with headache in childhood and adolescence, and should also lead to further study.
(See references for links to papers)

 

Headache Co-morbidities in Children and Adolescents

In 2013, Bellini et al reviewed studies that dealt with comorbid features of juvenile headache, in order to understand the risk-factors surrounding a child with this presentation. This interesting, but initially poorly-translated (!) paper particularly focusses on association with depression and anxiety, epilepsy, sleep disorders, ADHD, stroke and patent foramen ovale.

This is worthwhile reading for the osteopathic practitioner who might wish to fully understand the risks involved in both assessment and treatment of child patients. In conclusion the study states:

“Primary headaches in childhood and adolescence are often associated with, and deeply influenced by, many comorbid situations. …it is fundamental to take care of any kind of comorbidity to establish the most effective treatment strategy”

 

The Evolution of Headache

A 2014 study by Antonaci et al looked at the evolution of the clinical features of primary headache and migraine in the transition from childhood to adulthood by systematically reviewing available data from over 25 years. In discussion of these studies, the paper states:

“There is a large consensus that the natural temporal pattern of migraine may change over time: as attack frequency increases, the number of migraine features diminishes during the transformation period.”

Importantly, the paper also underlines the need for awareness of poor reporting in the paediatric case, given that some discrepancies are shown when interpreting variance in the studies’ results:

“Paediatric cases are often diagnosed as child hood periodic syndromes because children might not focus on their head pain, but rather on abdominal symptoms or vertigo. As they grow older their ability to describe their head pain improves and the description of the clinical picture of migraine becomes more detailed and accurate”.

When communicating with parents of children with recurrent headache, the following might also be of some reassurance in terms of expected length of treatment and the objective being pain management as well as improvement of the condition:

“When patients were followed up for 10 years or less, headaches were shown to improve or remit in 60-80% of cases. Persistence of primary headache at 10-year follow-up appears to be more predictive of headache persistence into adulthood, particularly if the primary headache is migraine.”

Given that headache is a major factor contributing to school absenteeism and poorer quality of life not only in childhood but also in adolescence, understanding the natural history during the management of the different headache forms is vital.

The Head-Pain Case History

In this extremely comprehensive paper, Donald Lewis M.D. provides the practitioner with an overview of the spectrum of primary headaches and a practical and rational approach to the evaluation and management of children with these recurring headache syndromes.

The article also uses clinical scenarios to illustrate diagnostic reasoning, explains relevant clinical methods, describes the pathophysiology of migraine in detail (from previous work) and common medications and their side-effects. Needless to say, this takes some investment in reading-time, but again highly informative and relevant to practice (CPD!!).

 

The Osteopathic Approach

It is of course, outside of the scope of this post to fully discuss the osteopathic approach to headache. However, our need to align our palpatory findings with the case history often requires us to ask further questions when discussing, for example, a physically traumatic event. Directionality of impact forces, previous injury or treatment and birth history (among many other factors) can all inform what is eventually palpated in the patient’s tissues.

Future courses from the Rollin E. Becker Institute will specifically address the osteopathic approach to the head pain patient, but more information can also be found on our upcoming 5-day Cranial Course in Swindon (see info here)

 

 

REFERENCES

1. Bellini, B. et al. Headache and comorbidity in children and adolescents. J. Headache Pain 14, 79 (2013).

2. Antonaci, F. et al. The evolution of headache from childhood to adulthood: a review of the literature. J. Headache Pain 15, 15 (2014).

3. Lewis, D. W. Headaches in children and adolescents. Curr. Probl. Pediatr. Adolesc. Health Care 37, 207–46 (2007).

Breastfeeding Child

A Review of the Breastfeeding Literature Relevant to Osteopathic Practice

In 2011 Denise Cornall published “A review of the breastfeeding literature relevant to osteopathic practice“.

This paper draws upon the available research to help clarify the contribution osteopathy might make in promoting and supporting breastfeeding.

The article covers epidemiological, psychological, social and cultural factors that might influence breastfeeding prevalence and success, and a very clear explanation of the neuromuscular mechanics of suckling:

“Nutritive suckling …involves coordination between many muscles of the tongue,pharynx, hyoid, anterior cervical region, and thoracic diaphragm. In particular, electromyography demonstrates most muscle activity occurs in the suprahyoid muscle groups of breastfeeding infants…”

This paper should be required reading for any osteopath involved with supporting breast-feeding children and their mothers, and will help significantly with communication and understanding when discussing these issues with parents.

More recently, a 2013 MRI study again demonstrated the benefits of breastfeeding by linking it with improved myelination and development of key brain areas. Also, children who had breast-fed longer than a year were shown to have particularly improved development in key motor co-ordination areas of the brain.

“Positive relationships between white matter microstructure and breastfeeding duration are also exhibited in several brain regions, that are anatomically consistent with observed improvements in cognitive and behavioral performance measures.”

 

 

REFERENCES

1. Cornall, D. A review of the breastfeeding literature relevant to osteopathic practice. Int. J. Osteopath. Med. 14, 61–66 (2011).
2. Deoni, S. C. L. et al. Breastfeeding and early white matter development: A cross-sectional study. Neuroimage 82, 77–86 (2013).

Hands pressed together representing palpation

How Do You PALPATE?

Palpation skills are paramount to effective osteopathic practice, but teaching students how to palpate and learning palpation is a real pedagogical challenge.

The Centre Ostéopathique du Québec have been using a ‘7-step’ palpation method, described with the acronym P.A.L.P.A.T.E., in an attempt to provide a stronger framework for their learners to develop their palpation skills:

A table showing the details of the 7-step palpation method

In a paper by Andrée Aubin et al, the details and challenges of the 7-step method are discussed, and it is interesting for both newcomers to palpation and those who have more experience in the field. In relation to the effectiveness of the 7-step method the authors state:

“…students seemed more confident and, as predicted, demanded less external validation in technique classes. They understood more clearly the stakes of palpation and the importance of repeating each technical movement. They stayed focused for longer periods in practice sessions and have shown more interest in the palpation process itself rather than in its final result alone.

Some of the higher-level students, who were not systematically exposed to this palpation method and who had major difficulties developing palpation skills, showed interest for this new learning tool in individual follow-ups and have, for the majority, greatly improved their technical performance afterward”

Of course, Rollin E. Becker’s work ‘Diagnostic Touch: Its Principles and Application’ is required reading for those interested in working in OCF, particularly when thinking of the concept of the ‘fulcrum’ which is not addressed in the 7-step method despite the author stating that it was primarily used for teaching Cranial Osteopathy. Becker was always very much concerned with developing a ‘listening approach’, and stated

“It was by deliberately taking the patient’s opinion and setting it aside, taking my diagnosis and setting it aside, and going to the structure-function of the anatomical-physiological mechanisms of the patient’s body that I was able to acquire this knowledge”

Ultimately, palpation is a life-long self-development journey, and every osteopath is responsible for improving this skill throughout their working life. Better palpatory understanding helps us to get closer to the ‘truth’ of the presenting problem in the way that the person’s body knows it – again Becker puts it most clearly:

“A diagnostic touch is as essential in the accuracy of determining the diagnosis of a patient’s problem as is the routine physical examination and the tests made by the laboratory and scientific instruments”

 

Our upcoming 5-day course provides more guidance and practical help with developing your palpation skill

REFERENCES

1. Aubin, A., Gagnon, K. & Morin, C. The seven-step palpation method: A proposal to improve palpation skills. Int. J. Osteopath. Med. 17, 66–72 (2014).

2. Becker, R.E., Diagnostic Touch: Its Principles and Application, Parts 1-4 Life In Motion – The Osteopathic Vision of Rollin E. Becker, Edited by Rachel Brooks

‘Hands’ image by ‘Obraprima’

CT of pelvis and sacrum

Think You Know The Sacrum? – Think Again!

In the Summer of 1945 Sutherland and the Lippincotts together studied prenatal and newborn development, which led to the famous quote

“As the twig is bent, so the tree inclines”

Sutherland meant that if a strain is left in the body early in life, the child’s growing body organises itself around that strain and adapts to it as best it can.

Development Of The Sacrum

Sutherland was alluding to the condylar parts, but this might also be true of the sacrum as more recent MRI studies have shown it has complex and diffuse ossification process.

In 1998 Broome et al conducted MRI, CT and conventional X-ray studies investigating the postnatal maturation of the sacrum and coccyx. Their main finding was that the sacrum and coccyx have up to 60 sacral ossification centres.

They also found that ossification could be asymmetric, carried on to the age of 30 and that understanding this process would help distinguish physeal plates from possible fracture lines.

Palpated Findings?

For cranial osteopaths dealing with sacral compression and other strain patterns, understanding the complexity of sacral ossification and how it changes over time might be important when interpreting palpated findings associated with clinical history, e.g. traumatic or extended birth, pelvic injury or falls in later life.

Get the Full-text PDF here

 

Our upcoming 5-day course provides more information on the anatomy and function of the sacrum, and it’s integration within the OCF concept

 

REFERENCES

Postnatal maturation of the sacrum and coccyx: MR imaging, helical CT, and conventional radiography.

Broome DR1, Hayman LA, Herrick RC, Braverman RM, Glass RB, Fahr LM.

DOI Link

Pelvis CT Image: By Bjoertvedt (Own work) [CC-BY-SA-3.0], via Wikimedia Commons

Tensegrity Structure Icosahedron

How Does The Cranial Vault Retain Stability During Growth? – ‘Tensegrity’ has the answers

Continuing our look at the function of the dural membranes and RTM, researcher and Osteopath Graham Scarr’s paper ‘A model of the cranial vault as a tensegrity structure, and its significance to normal and abnormal cranial development’ proposes a novel understanding of the integrated and dynamic relationship of the bones and membranes.

This model helps to explain how the skull vault bones maintain sutural patency, while preventing early fusion (cranio-synostosis):

“Tensional forces in the dura mater [and suture] have the effect of pushing the bones apart, whilst at the same time integrating them into a single functional unit …Cells of the dura mater respond to brain expansion and influence bone growth, allowing the cranium to match the spatial requirements of the developing brain, whilst remaining one step ahead and retaining a certain amount of autonomy.”

Scarr also alludes to the possibility that the development of positional plagiocephaly may be explained by this model. Seeing as at seven weeks old the prevalence of positional plagiocephaly may be as high as 22% understanding this model is highly relevant to practice.

If this is the first time you’ve come across the concept of tensegrity, Tom Myers, author of Anatomy Trains explains the basics of how the human body is not a compression structure like a building, it is far more dynamic.


Our upcoming 5-day course provides more information on the anatomy and function of the Reciprocal Tension Membrane, and it’s integration within the OCF concept


References:

A model of the cranial vault as a tensegrity structure, and its significance to normal and abnormal cranial development
Scarr, Graham
International Journal of Osteopathic Medicine , Volume 11 , Issue 3 , 80 – 89
http://www.journalofosteopathicmedicine.com/article/S1746-0689(08)00032-1/abstract

 

Prevalence, risk factors, and natural history of positional plagiocephaly: a systematic review.
Bialocerkowski AE1, Vladusic SL, Wei Ng C.
Dev Med Child Neurol. 2008 Aug;50(8):577-86. doi: 10.1111/j.1469-8749.2008.03029.x.

 

Tensegrity Icosahedron Picture

By Bob Burkhardt [CC-BY-2.5], via Wikimedia Commons

 

intracranial dural membranes side view showing falx and tentorium

We Have Got You Covered – how the meninges control brain development

Meningeal layers

A little revision of the meningeal and periosteal layers of the brain and skull

As osteopaths working with OCF, we are already aware of the importance of the ‘reciprocal tension membrane‘ as Sutherland referred to it.

However, according to this research from 2011, the meninges also seem to have an important role in foetal brain development:

“Through the release of diffusible factors, the meninges influence the proliferative and migratory behaviour of neural progenitors and neurons in the forebrain and hindbrain. Meningeal cells also secrete and organize the pial basement membrane, a critical anchor point for the radially-oriented fibers of neuroepithelial stem cells”.

Seeing as much brain development occurs in the first year of life outside the womb, it seems possible that brain development could be affected by continuing deformity or strain within the membrane system, left over from the birth/perinatal process (study anyone?). The authors conclude with this:

“It is also clear that disruption of meningeal function either generally or focally can lead to significant disruption of (foetal) brain development. Future work will inevitably expand our understanding of the human syndromes where brain malformations are caused primarily by defects in meningeal development”.

Check out the PDF below for the full text.

PDF: we have got you covered – how the meninges control brain development

 

Our upcoming 5-day course provides more information on the anatomy and function of the Reciprocal Tension Membrane, and it’s integration within the OCF concept

 

References:
“We’ve got you “covered”: how the meninges control brain development”
Julie A. Siegenthaler and Samuel J. Pleasure
Curr Opin Genet Dev. 2011 June ; 21(3): 249–255. doi:10.1016/j.gde.2010.12.005.

‘Meninges’ image By SVG by Mysid, original by SEER Development Team [1] [Public domain], via Wikimedia Commons

memory research chemicals being stored as memory

Finding the Messenger – memory research visualises neural pathway

When I first read this article I thought it was an April Fool. It put me in mind of previous studies by Karl S. Lashley where researchers tried to find the ‘Engram’ – a physical structure representative of a single memory – and failed. It seems that the storage of memory is non-local, i.e. distributed among a neural network involving many different regions of the brain, which is probably why Lashley’s attempt to ‘splice out’ the memory region of the cortex was unsuccessful.

The Molecular Basis of Memory Function: Tracking mRNA in Brain Cells

However, this research published in ‘Science’ has utilised up-to-date visualisation technology and builds on our understanding that Messenger RNA (mRNA) seems to be involved in the memory pathway, both in formation and retrieval.

On a personal level, this pie chart best illustrates the fickle nature of the every-day reality of memory function…still, check out the video below to see those little brain-messengers at work:

Tree Pangolin showing scales

Pangolins and the Art and Science of Cranial Osteopathy

Researcher Graham Scarr D.O. has proposed a biological mechanism to explain Cranial Osteopaths’ awareness of helical movement in the fasciae of patients’ limbs, when palpating the cranial mechanism (phew!).

animated sinusoidal helixes

‘Helix’ by de:Benutzer:Averse [CC-BY-SA-2.0], via Wikimedia Commons

See here for the full article: http://www.tensegrityinbiology.co.uk/articles/myofascial-helixes.html

His published research on ‘Myofascial Helixes’ explains that the intersection angles of collagen fibres are critical to the physiology of connective tissues, and that the structure of a Pangolin’s skin illustrates this point. However, disturbances in the arrangement of these helixes at both a macro and microscopic level could play a part in chronic musculoskeletal limb disease, such as tennis elbow, due to disturbances in cellular nutrition associated with reduced tissue movement.

For those of you also treating dogs, horses and other animals, Scarr also proposes that ‘this pattern may be an intrinsic part of mammalian limb development’.

If you’d like to begin to understand some of the science behind our experience of palpation, this is a great place to start.

 

(Pangolin Image By Valerius Tygart (Own work) [CC-BY-SA-3.0 or GFDL], via Wikimedia Commons)