This recent discovery of mine on the internet is of considerable interest:
The author, a chiropractor, is proposing an association between atlas subluxation and fibromyalgia.
The proposed mechanism is through torque on the dura mater, functionally reducing the space for the cervical spinal cord to transverse the foramen magnum.
In particular he highlights compromised CSF flow, and nerve irritation to give rise to widespread bodily symptoms.
Other sources also highlight the tetherings of the dura at T12 and at the level of the sacrum, providing a more comprehensive explanation for the multilevel spinal symptoms seen with atlas malalignment/subluxation problems.
It is worth also noting that other authorities (Chaitow et Al) “Fibromyalgia Syndrome” observe the occurrence of fibromyalgia, CFS, and a range of affective and neurodevelopmental disorders (ADD, OCD, Tourette Syndrome) but also note that this cluster is found in association with ligamentous laxity.
Such an issue would, naturally increase the risk of atlanto-occipital instability.