Edited Feb 14 2013
Please be aware that the following list is a list of all possible complications and their anatomical and physiological basis and that few people with this condition will have a full hand of symptoms.
However, a proper understanding of anatomy and physiology of the upper cervical area and brainstem should be enough to make it clear that all of the symptoms listed below are predictable given a large enough subluxation.
The joint between the skull and the neck is designed for nodding movements, and it has been documented that the maximum rotation expected on turning well to the left or right is about 3-4 degrees.
The worst case I have seen was a rotatory subluxation of about 25 degrees demonstrated on a CT upper cervical spine. I was dismayed that the radiologist who reported it failed to note the abnormality. I would observe that this probably happened because such subluxations are not regarded as possible within allopathic medicine- and he was not looking for it. I did get the satisfaction of an amended report after conversation with the radiologist involved.
Most symptoms will be intermittent, and at least partially resolve when the patient is fit and active, so there will be great variability between patients. I have had experience with most of these symptoms being relieved in patients I have seen.
Physical and radiological examination will provide clear cut evidence of the existence of the condition.
- Headaches- often involving the base of the skull, and referring to the sides of the head and around the sinuses.
- Migraines, often with marked agitation and nausea. I am speculating that some migraine like headaches might be caused by acute CSF obstruction caused by Dural torsion.
- Neck pains and stiffness and difficulty finding a comfortable position on the pillow at night.
- Sometimes crackling or grating noises at the base of the skull when turning the head. Often there are associated shoulder pains, especially between the shoulder blades.
- Jaw joint pains or dysfunction. Clicking jaw.
- Chest wall pain, and thoracic spine pain- due to mild thoracic kyphosis, distortion of the ribcage and obstruction of normal rib movement.
- Low back pain and/or disc injuries due to abnormal posture.
- Nerve root irritations at any level.
- Pains or injuries in one hip, knee or ankle, often repeated injuries to one side of the body. Some flattening of the arches of the feet.
- Patients may be told they have one leg shorter than the other.
- Other postural difficulties- forward head posture
Symptoms based on nerve and blood vessel compromise.
Vagus nerve: Nausea, heartburn, irritable bowel, constipation, vasovagal (fainting/near fainting) episodes, probably infantile colic. Cough and voice problems.
It is probable that the great majority of vagus nerve symptoms arise from central mechanisms rather than from direct impingement. However the possibility of direct vagal impingement being involved in SIDS cases is raised in “Manual Therapy n Children” Ed Heiner Biedermann.
Internal Jugular Vein and venous drainage of the skull via the foramen magnum: tiredness, mental fogginess (often subtle and this may well contribute to the mental fogginess in ADHD, chronic fatigue syndrome, fibromyalgia and depression).
Issues with dural torsion– twisting of the membranes around the upper spinal cord between the foramen magnum and C2.
Likely outcomes here are
- Impairment of cerebrospinal fluid drainage from the skull- which will be implicated in both neurodegenerative disorders and episodic high CSF pressure- which causes a very characteristic “bursting” type of global headache.
- Impingement upon one or both vertebral arteries causing impairment of the vertebrobasilar circulation and brainstem dysfunction. There is evidence that this is an issue in fibromyalgia, and I believe that it is also likely to be an issue behind the orthostatic intolerance seen in ADHD. I suspect that this is a problem that might be intermittent, and also less of an issue in the recumbent position than standing/sitting.
Functional Neurological Symptoms
These symptoms are largely driven by the abnormal afferent input into the system created by the malalignment.
For instance the image of the world we see depends upon the accurate fusion of visual, balance (vestibular) and proprioceptive information (with a lesser contribution from the other senses.
Proprioceptive input from the upper neck muscles is especially important- and that in turn is dependent on free movement of the upper neck muscles.
An atlas malalignment will create a situation where the muscles on one side are both excessively tight and restricted in movement- creating a real mismatch between sides. It is arguable that the restriction in movement is the greater issue- as it deprives one side of the brainstem of the drive to keep it firing at the right rate.
That can introduce a problem in that on the injured side the tight muscles would be giving information that the head is turned towards the injured side but on the normal side- the information would be that the head is pointing in a different direction. The mismatch varies from day to day (we have all had experiences of waking up with a sore neck) and with posture and activity through the day.
This is called dysafferentation and in itself it can cause problems with balance, coordination, spatial awareness blood pressure regulation and pain regulation- ata bare minimum.
See this post for more detail:
Sympathetic Nervous System:
There are multiple reasons to believe that atlas subluxations may cause sympathetic overactivation (stress response): Poor balance itself is a cause of sympathetic overactivation, also the traction on the brain stem caused by the typical head forward posture of most people with the injury activates a stress response, and there may be further impacts on sympathetic ganglia (nerve cell clusters) that lie close to the spine along the whole length of the spine.
Symptoms would include chronic anxiety and impulsiveness, fine tremor, raised heart rate
Chronic sympathetic overactivation may be lead to:
a)gut problems due to chronic diversion of blood flow away from the gut into the muscles which may well be contributory to peptic ulcers, food allergies ( via increased gut permeability)
b) Adrenal gland activation and chronic over production of cortisone as an expected consequence of chronic sympathetic (stress) response. Adrenal fatigue as a downstream consequence of this.
c) unstable attention- as the body is effectively being given a warning to loo for threat in the environment.
It is clear now that chronic sympathetic activation is a contributory to immune suppression, hypertension, diabetes, osteoporosis, disturbed sleep and depression.
This is a common complication in our experience and may be contributed to by neck discomfort at night, by sympathetic over-activation, or by a number of brain stem effects caused by alteration in balance inputs into the nervous system.. In a number of patients the neck discomfort has triggered tooth grinding which has improved after treatment.
Signs of Atlas Subluxation
The physical signs of atlanto- occipital subluxation are straightforward, and the diagnosis can usually be confirmed without investigations.
Posture- the head is carried forwards of the shoulders. ( In healthy posture the centre of the shoulder joint is vertically directly below the ear canals).
The patient may also have a degree of hunch or a sway back.
The patient will have great difficulty straightening up to hold his head in correct position.
The front on view will often clearly indicate the problem. The head may be tilted to one side, and the neck rotated a few degrees or so off straight ahead.
The midline of the trunk may not be vertical.
One shoulder will be higher than the other- the clearest marker of a mild functional scoliosis
Often the pelvis will visibly be off level as well (Usually high on the side of the low shoulder).
From the back the difference in the level of the shoulders will be more apparent, and one shoulder should be pushed out to the back. The head, shoulders, and hips may be out of alignment (viewed from above).
Viewed from behind the midline of the neck should be vertical and a line drawn across the base of the skull should be at right angles to a line drawn between the mastoid processes. If that angle is not square then there is very likely an issue with atlas alignment.
If there is a subluxation/ alignment issue, the neck will almost always be tender just below the ears and behind the jaw. It may be possible to feel that the neck bone is closer to the jaw on one side than the other. Postural issues, muscle spasm, or a “bull neck” can make this sign difficult to identify. However the joint between the atlas and the skull is not one at which rotation naturally occurs (beyond about 3-4 degrees at the extremes of neck rotation) so this sign is always abnormal if found. ery rarely it will be because of an asymmetrical atlas.
Equally, tenderness at the back of the neck along base of the skull just lateral to the midline is a warning sign for dural torsion– see below..
It is necessary to know some anatomy to understand this- and thankfully there are some excellent anatomy apps to help understand the issues.
This video helps:
However the key landmarks are:
On the skull, the mastoid processes- below each ear.
The occipital protuberance- the bump on the midline of the skull at the back (posteriorly), just above the neck.
The transverse processes of the atlas (C1)- immediately below the mastoid processes.
These should be non tender to the touch and they should be symmetrical- both of them should be pretty much below the ear/mastoid process in the same line down from the ear canal. If one is rotated forwards that is outside the normal range of movement of the atlas. If you can feel the gap between the atlas and the transverse process you should be able to feel the gap open and close if you wiggle your head from side to side a little (The classic Vedic head wobble) If you can’t feel that movement then there is muscle spasm guarding the joint. That’s abnormal.
The muscles are also relevant. Of particular interest are the small subocciptal muscles and the posterior atlanto occipital membrane, rectus capitis superior major and minor. (RCP major and RCP minor).
This wikipedia accounts are adequate for the purposes of this discussion.
The areas of the posterior atlantoocciptal membrane deep to the RCP minor and minor are of particular interest, especially given the frequent dural attachments of RCP minor, and the high pain sensitivity of the dural membrane. These areas should not be tender to the touch and if they are that needs professional review.