Stroke, cerebral artery dissection, and cervical spine manipulation therapy.

Stroke represents an infrequent adverse reaction associated with cervical spine manipulation therapy. Attempts to identify the patient at risk and the type of manipulation most likely to result in these complications of manipulation have not been successful. A retrospective review of 64 medical legal cases of stroke temporally associated with cervical spine manipulation was performed to evaluate characteristics of the treatment rendered and the presenting complaints in patients reporting these complications. These files included records from the practitioner who administered the manipulation therapy, post stroke testing and treatment records usually by a neurologist, and depositions of the patient and the practitioner of manipulation as well as expert and treating physicians. A retrospective review of the files was carried out by three (two in 11 cases) researchers using the same data abstraction instrument to independently assess each case. These independent reviews were followed by a consensus review in which all reviewers reached agreement on file content. Ninety two percent of cases presented with a history of head and/or neck pain and 16 (25 %) cases presented with sudden onset of new and unusual headache and neck pain often associated with other neurological symptoms that may represent a dissection in progress. The strokes occurred at any point during the course of treatment. Certain patients reporting onset of symptoms immediately after first treatment while in others the dissection occurred after multiple manipulations. There was no apparent dose-response relationship to these complications. These strokes were noted following any form of standard cervical manipulation technique including rotation, extension, lateral flexion and non-force and neutral position manipulations. The results of this study suggest that stroke, particularly vertebrobasilar dissection, should be considered a random and unpredictable complication of any neck movement including cervical manipulation. They may occur at any point in the course of treatment with virtually any method of cervical manipulation. The sudden onset of acute and unusual neck and/or head pain may represent a dissection in progress and be the reason a patient seeks manipulative therapy that then serves as the final insult to the vessel leading to ischemia.