Cervical spine manipulation: an alternative medical procedure with potentially fatal complications.

Abstract: There are multiple reports in the literature of serious and at times fatal complications after cervical spine manipulation therapy (CSMT), even though CSMT is considered by some health providers to be an effective and safe therapeutic procedure for head and neck pain syndromes. We report a case of a young female with cervicalgia and headache with fatal posterior circulation cerebrovascular accident after CSMT. Serious complications are infrequent, with a reported incidence between one per 100,000 to one in 2 million manipulations. The most frequent injuries involve artery dissection or spasm. Stroke as a complication of cervical manipulation and dissection of the vertebral arteries (VAD) is a rare but well recognized problem. Neck pain, headache, vertigo, vomiting and ataxia are typical symptoms of VAD, but this vascular injury also can be asymptomatic. The most common risk factors are migraine, hypertension, oral contraceptive pills and smoking. Stroke following CSMT is more common than the literature reports. The best values derive from retrospective surveys. The lack of identifiable risk factors place those who undergo CSMT at risk of neurologic damage. Accurate patient information and early recognition of the symptoms are important to avoid catastrophic consequences.

Key Words: neck pain, cervical spine manipulation therapy, neurologic complications, vertebral artery dissection, stroke

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Damage to the cerebellum and brainstem due to posterior circulation cerebrovascular accidents has been reported as a consequence of cervical spine manipulation therapy (CSMT). (1,2) Damage to such structures can be quickly fatal or may leave permanent neurologic deficit. Spinal manipulation therapy (SMT) is a manual form of treatment aimed mainly at reducing spinal pain and increasing range of motion. (3) It entails high-velocity, low-amplitude manual thrusts to the spinal joints that extend slightly beyond their physiologic range of motion. (4) Although SMT is considered by some health providers to be an effective and safe procedure for treating a variety of head and back pain syndromes, there are several reports in the literature that describe incidents of serious complications after CSMT. (1,2,5-10) We report a case of a young female with cervicalgia and headache with fatal posterior circulation cerebrovascular accident after CSMT.

Case Report

A 27-year-old woman had consulted a chiropractor for the first time because of recurrent episodes of headache and posterior neck pain. As a treatment, she underwent massage therapy with cervical manipulation. She reported that her neck was "twisted repeatedly." Immediately after, she noted ringing in her ears and right-sided body "heaviness," along with vertigo that prevented her from ambulating normally. A few hours later, she had worsening of her headache, nausea, and vomiting. Her family noted slurred speech and mouth drooling. In the Emergency Department, she was lethargic but arousable. She did not have any pre-existing medical conditions or prior surgeries. Her social and family histories were unremarkable. She was not taking any medications and had no allergies to drugs. On physical examination at admission, she had a temperature of 97[degrees] F, pulse of 84/min, respirations of 16/min and a blood pressure of 130/65 mm Hg. The patient was drowsy but following commands, oriented to place and in no acute distress. Her pupils were reactive to light and accommodation, funduscopy showed normal discs and retina. There was a right facial palsy with paretic nystagmus on left lateral gaze. She had flaccid posture but was able to move all her extremities when asked to do so. Sensory examination was normal. Plantar reflexes were absent bilaterally. Deep tendon reflexes were normal and symmetrical. Her gait could not be assessed. The laboratory studies showed: WBC:9.42 X 103/UL, Hb:14.2 G/DL, Hct:41.9%, platelets:199 X 103/UL, Differential count was normal, Na:139 MMOL/L, K:3.8 MMOL/L, CI:107 MMOL/L, HCO3:22 MMOL/L, BUN:15 MG/DL, CR:0.8 MG/DL, GLUC:132 MG/DL. Initial computed tomography (CT) scan of the head without contrast at admission showed no abnormalities.

Within the next 24 hours, she experienced worsening of her mental status requiring intubation and mechanical ventilation. A repeat CT scan of the head showed a left cerebellar infarct and suspected midbrain infarct, along with dilation of the ventricles (Figs. 1 and 2). A CT angiogram of the neck was inconclusive in regards to vertebral artery dissection. Subsequently, the patient lost oculocephalic, gag and corneal reflexes, and her pupils became fixed. Because of hydrocephalus, she underwent emergent ventriculostomy. Opening pressure was greater than 70 mm [H.sub.2]O. The patient had no spontaneous respirations and no brain flow by isotope brain scan. She was pronounced dead. An autopsy showed acute vertebral artery thrombosis with infarct in the left cerebellar hemisphere and areas of the brainstem.

Discussion

Spinal manipulation is recognized as a method of pain relief. This technique, typically performed by chiropractors and physical therapists, is showing an increase in its use. (5) In the US, there are approximately 250 million chiropractor visits every year. (5,11) Nearly one third of these visits end up in some form of CSMT. (5) The most common reasons for providing this intervention are neck pain and headache. (12)

Rotating and tilting the neck stretches the extracranial vertebral arteries and produces a shearing force on the portion of the arteries at the atlantoaxial joint that may produce intimal tearing, dissection or thrombus formation. (9) Studies have failed to show consistent position or movement of the neck that could be considered particularly dangerous. Almost all forms of cervical manipulation have been implicated in these injuries. (11)

Minor complications such as local discomfort or headache are quite frequent after CSMT. (13) Systematic review of 5 prospective investigations of risk of spinal manipulation concluded that mild-to-moderate transient adverse reactions occur in approximately half of the patients who undergo SMT, (3) including cervical manipulation. A study from Switzerland reported an incidence of 1 per 40,000 manipulations with slight neurologic complications. (14) Although serious complications from CSMT have been reported as rare, (5,11,15) recent evidence suggests that cases remain underreported. (16) This makes it difficult to estimate accurately the incidence of serious adverse events. Data from insurance claims in the United States estimate 1 stroke per 2 million after CSMT. (17)

[FIGURE 1 OMITTED]

Review of the literature regarding serious complications shows that the most frequent reported injuries involve artery dissection or spasm with consequent cerebrovascular accident. (3,15) Occlusion of the posteroinferior cerebellar artery (PICA) or one of its branches is the most common vascular lesion that affects the brainstem. (2)

Stroke as a complication of cervical manipulation and dissection of the vertebral arteries is a rare but well-recognized and devastating problem that can occur immediately or a few days after the manipulation. (10,11,18-20) Younger persons are more likely than older persons to have dissection as a cause of stroke, and younger persons are also more likely to undergo SMT. (21) Most patients are between 28 to 55 years of age. (9) Neck pain, headache, vertigo vomiting and ataxia are typical symptoms of vertebral artery dissection (VAD), the incidence of which is unknown as dissection does not always produce neurologic symptoms. (20) A Canadian study reports 1.3 cases of VAD per 100,000 persons receiving CSMT, (18) while other reports mention a rate of stroke that vary from one in 100,000 to one in 2 million after cervical manipulation. (21) The same study from Canada, based on national health records, found that patients with stroke caused by arterial dissection were five times more likely to have recently visited a chiropractor. This study also found evidence that CSMT may exacerbate pre-existing dissection, producing immediate or delayed embolization.

[FIGURE 2 OMITTED]

Different studies described in the literature have attempted to find risk factors associated with VAD and stroke. The most commonly discussed risk factors are migraine, hypertension, oral contraceptive pills and smoking, but these analyses did not show consistent results. (11) Although some studies have reported that CSMT does not appear to be the precipitating cause in most VAD, (11) Smith et al (20) found that SMT, including cervical manipulation, independently increased the risk of VAD and stroke or TIA by approximately six fold. Vertebral artery injuries have been described following yoga, calisthenics, trauma, overhead work, and cervical traction. (6,22) Halderman (11) found in his review of the literature regarding causes of VAD that 31% were caused by SMT, 25% caused by major or trivial trauma and 43% were considered spontaneous.

Conclusion

Although the exact incidence of VAD and stroke following CSMT is unknown, findings in different studies suggest that these complications are more common than reported in the literature. Data about incidence of complications after CSMT mostly comes from retrospective studies, and there is little level 1 evidence from RCT or prospective cohorts. Literature outlining good clinical practices is limited due to the fact that the available systematic reviews are based on poorly designed studies and case series or case reports. (23)

Since there is a large amount of evidence from many reports regarding an association between neurologic damage and cervical manipulation, and because there are no identifiable risk factors, anyone who receives CSMT can be at risk of neurologic damage. It is important for patients to be well informed before undergoing this kind of procedure and for physicians to recognize the early symptoms of this complication so that catastrophic consequences can be avoided.

Despite the fact that some studies report slight benefit of CSMT for pain management, (23) composite data from high quality prospective studies and randomized controlled trials is needed before definitive practice recommendations are outlined and public advice is given regarding the risk, benefits and incidence of serious complications after CSMT. For the time being, this article reinforces the need for extreme caution when recommending CSMT for patients suffering neck pain and headache.

Acknowledgments

The authors would like to acknowledge the Department of Neurology at Texas Tech University Health Sciences Center at El Paso.

References

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Andres Leon-Sanchez, MD, Albert Cuetter, MD, and Gustavo Ferrer, MD

From the Department of Internal Medicine, Texas Tech University Health Sciences Center at El Paso, El Paso, TX.

Reprint requests to Andres Leon-Sanchez, MD, 6032 Caprock Court, Apartment 1904, El Paso, TX 79912. Email: [e-mail]

Accepted September 22, 2006.

RELATED ARTICLE: Key Points

* Cervical spine manipulation therapy may produce serious complications in selected populations.

* Some observational studies suggest that the low incidence of neurologic complications after cervical spine manipulation therapy should not outweigh the benefits of this technique.

* Studies have failed to recognize potential risk factors that may predispose people to develop neurologic complications when they undergo cervical spine manipulation therapy.