Cervical spondylosis is a condition that no chiropractor would be a stranger to. A form of osteoarthritis, it is a degenerative condition of the spine affecting the upper neck area. This condition arises when there is degeneration of the spinal discs and tissue which then alters structure and function. This in turn alters the biomechanics of the spine, and affects not only the neck but also the thoracic area and the midback, and can have effects on even the lower back (lumbar spine). While it is often age-related, it can occur at any age depending on the persons level of inflammation or trauma.
There are three stages of spinal degeneration associated with spondylosis. In the first phase, we commonly see disc-related changes in the vertebra and subluxation-related dysfunction. That mechanical dysfunction has the potential to set up phase two degeneration where we see bony and joint changes, and further interruptions to the disc. The third stage of degeneration involves even more damage to the disc, joint and bone, with the capacity to create atrophy of nerves as well. This can lead to more changes in function, as well as introducing symptoms like pain associated with the arthritic and degenerative changes that are part of condition.
Bony spurs can also develop. We may also see nerve compression, which occurs when the spaces where the nerves attach to the spine become reduced (intervertebral foramina) with disc degenerative changes. While pain in the neck is a common symptom, other less common symptoms have also been noted, including nausea, headaches, gastrointestinal complaints, impaired memory, palpitations, and visual and auditory impairments. Neurological symptoms such as referred pain, paraesthesia, hyperaesthesia, pins and needles, radiculopathy in the neck or even sciatica in the legs may also develop. So essentially, we see three types of symptoms: mechanical, neurological and inflammatory.
With previously recorded improvements in vision following spinal manipulation [1], a recent review published in the Asia Pacific Chiropractic Journal sought to collate the available evidence of visual impairments observed in association with cervical spondylosis [2]. The authors of the review also examined current research into the efficacy of surgical and spinal manipulative therapies on visual impairment [2]. This is a notable contribution to the chiropractic evidence bank, as it takes brings together existing evidence for chiropractic care and this particular clinical presentation, thus offering more clarity and certainty not only for clinicians but for people who have the condition.
What did the researchers do, and what did they find?
The researchers searched literature databases using the terms ‘chiropractic’, ‘cervical spondylosis’, ‘blurred vision’, ‘visual impairment’, ‘spinal decompression’, and ‘spinal manipulation’. Relevant articles were selected based on the author’s expertise.
Following this process, the authors identified several studies published in the 1990s that revealed improvements in vision following spinal manipulation.
“Studies have documented cases of successful ophthalmological recovery in suspected optic nerve ischemia, microvascular spasm of the optic nerve, bilateral simultaneous optic nerve dysfunction following periorbital trauma, congested visual fields, monocular visual loss following closed head trauma, and severe glaucoma visual field deficit after spinal manipulation.” [3-6]
Multiple surgical interventions were identified within the literature, with some variation in the efficacy. One study utilising functional magnetic resonance imaging (fMRI) observed that there were both structural and functional alterations to the visual cortex in individuals with acute incomplete cervical spinal cord trauma [7].
So, why can cervical spondylosis or a spinal degenerative condition produce symptoms ranging from pain to visual disturbances, even to gastrointestinal complaints? Chiropractic theory suggests that the nervous system is likely to be involved in the symptomatic presentation because of the presence of spinal degeneration and subluxation. The base of the skull and the neck is where a lot of nerves connect between the brain and spinal cord. It is thought that the process of degeneration that occurs around the dura and spinal cord, often reducing the space around nerves and promoting inflammation, drives the atypical symptom of visual impairment.
The review details 3 hypothesised mechanisms for the development of visual dysfunction in cases of cervical spondylosis. Essentially, the argument put forward by the authors is that spinal manipulation may trigger a change in the sympathetic nervous system response and enhance blood flow and oxygenation to tissues. That is to say nothing of the possibilities surrounding normalising cerebrospinal fluid (CSF) flow throughout the Central Nervous System and how that may reduce inflammation and thus symptomatology. Once again, more research is required, but it’s an exciting possibility to postulate on.
It is important to note that visual disturbances, gastrointestinal discomfort, tinnitus (etc.) are more uncommon symptoms and should be approached with caution. However, they have been documented and observed to improve with spinal manipulation even though the exact mechanisms remain unclear. While it is undeniable that surgical interventions have also proven to be effective, it is encouraging to know that there is the beginnings of a trail of evidence pointing to the possibility that chiropractic may be a viable alternative for people who want a drug free, surgery free approach. Moreover, the possibility that chiropractors may have a role in managing difficult cases is a positive thing indeed. Furthermore, the fact that many chiropractors see spinal degenerative conditions and that the chiropractic profession recognises the term ‘subluxation degeneration’ and its impact on biological and mechanical function, necessitates further research into the impact of adjusting degenerative spines.
References:
- Gorman RF. Monocular visual loss after closed head trauma: immediate resolution associated with spinal manipulation. Journal of manipulative and physiological therapeutics. 2019;18(5).
- Leung KY, Chu ECP. Cervical Spondylosis and visual dysfunction: A brief overview. Asia-Pac Chiropr J. 2023;3.3 URL http://www.apcj.net/papers-issue-3-3/#LeungChuCervicalSpondylosis
- Chu ECP, Ng M. Long-term relief from tension-type headache and major depression following chiropractic treatment. J Family Med Prim Care. 2018 May-Jun;7(3):629-631.
- Gorman RF. The treatment of presumptive optic nerve ischemia by spinal manipulation. J Manipulative Physiol Ther. 1995;18:172-177.
- Wingfield BR, Gorman RF. Treatment of severe glaucomatous visual field deficit by chiropractic spinal manipulative therapy: a prospective case study and discussion. J Manipulative Physiol Ther. 2000;23:428-434.
- Stephens D, Gorman RF. Does ‘normal’ vision improve with spinal manipulation? J Manipulative Physiol Ther.1996;19:415-418.
- Chen Z, Wang Q, Liang M, Zhao R, Zhu J, Xiong W, et al. Visual cortex neural activity alteration in cervical spondylotic myelopathy patients: a resting-state fMRI study. Neuroradiology. 2018;60:921-932.
