Neck pain is a common problem which often causes significant disability. Chiropractic manipulation has become one of the most popular forms of alternative treatment for such symptoms. This seems surprising considering that neck manipulations are neither convincingly effective nor free of adverse effects.
The current Cochrane review on this subject could not be clearer: “Done alone, manipulation and/or mobilization were not beneficial; when compared to one another, neither was superior.” In the absence of compelling evidence for efficacy, any risk of neck manipulation would tilt the risk/benefit balance into the negative.
Adverse effects of neck manipulations range from mild symptoms, such as local neck tenderness or stiffness, to more severe injuries involving the spinal cord, peripheral nerve roots, and arteries within the neck. A recent paper reminds us that another serious complication has to be added to this already long list: phrenic nerve injury.
The phrenic nerve is responsible for controlling the contractions of the diaphragm, which allows the lungs to take in and release air and make us breathe properly. The phrenic nerve is formed from C3, C4, and C5 nerve fibres and descends along the anterior surface of the scalenus anterior muscle before entering the thorax to supply motor and sensory input to the diaphragm. Its anatomic location in the neck leaves it vulnerable to traumatic injury. Phrenic nerve injury can result in paralysis of the diaphragm and often leads to deteriorating function of the diaphragm, which can lead to partial or complete paralysis of the muscle and, as a result, serious breathing problems.
Patients who experience such problems may require emergency medical treatment or surgery. Sudden, severe damage to the phrenic nerve can make it impossible for the diaphragm to contract on its own. In order to make sure that the patient can breathe, a breathing tube needs to be inserted, a process called intubation. Artificial respiration would then be required.
American neurologists published a case report of a healthy man who consulted a chiropractor for his neck pain. Predictably, the chiropractor employed cervical manipulation to treat this condition. The result was bilateral diaphragmatic paralysis.
Similar cases have been reported previously, for instance, here and here and here and here. Damage to other nerves has also been documented to be a possible complication of spinal manipulation, for instance, here and here.
The authors of this new case report conclude that physicians must be aware of this complication and should be cautious when recommending spinal manipulation for the treatment of neck pain, especially in the presence of preexisting degenerative disease of the cervical spine.
I know what my chiropractic friends will respond to this post:
- I am alarmist,
- I cherry-pick articles that are negative for their profession,
- these cases are extreme rarities,
- conventional medicine is much more dangerous.
To this I reply: Imagine a conventional therapy about which the current Cochrane review says that it has no proven effect for the condition in question. Imagine further that this therapy causes mild to moderate adverse effects in about 50% of all patients in addition to very dramatic complications which are probably rare but, as no monitoring system exists, of unknown frequency. Imagine now that the professionals using this treatment more regularly than any other clinicians steadfastly deny that the risk/benefit balance is way out of kilter.
Would you call someone who repeatedly tries to warn the public of this situation ‘alarmist’?
Would you not consider the professionals who continue to practice the therapy in question to be irresponsible?