Chiropractic care and the risk of vertebrobasilar stroke: results of a case-control study in U.S. commercial and Medicare Advantage populations

What's the harm? Results of an active surveillance adverse event reporting system for chiropractors and physiotherapists

This prospective, community-based, active surveillance study aimed to report the incidence of moderate, severe, and serious adverse events (AEs) after chiropractic (n = 100) / physiotherapist (n = 50) visit in offices throughout North America between October-2015 and December-2017. Three content-validated questionnaires were used to collect AE information: two completed by the patient (pre-treatment [T0] and 2-7 days post-treatment [T2]) and one completed by the provider immediately post-treatment [T1]. Any new or worsened symptom was considered an AE and further classified as mild, moderate, severe or serious. From the 42 participating providers (31 chiropractors; 11 physiotherapists), 3819 patient visits had complete T0 and T1 assessments. The patients were on average 50±18 years of age and 62.5% females. Neck/back pain was the most common presenting condition (70.0%) with 24.3% of patients reporting no condition/preventative care. From the patients visits with a complete T2 assessment (n = 2136 patient visits, 55.9%), 21.3% reported an AE, of which: 7.9% were mild, 6.2% moderate, 3.7% severe, 1.5% serious, and 2.0% had missing severity rating. The most common symptoms reported with moderate or higher severity were discomfort/pain, stiffness, difficulty walking and headache. This study provides valuable information for patients and providers regarding incidence and severity of AEs following patient visits in multiple community-based professions. These findings can be used to inform patients of what AEs may occur and future research opportunities can focus on mitigating common AEs.

Plausible Mechanisms of Causation of Immediate Stroke by Cervical Spine Manipulation: A Narrative Review

It has been proposed that cervical spine manipulation (CSM) can cause dissection in healthy cervical arteries, with resultant immediate stroke. However, research does not support a causal association between CSM and cervical artery dissection (CAD) in healthy cervical arteries. The objective of this study was to review the literature to identify plausible mechanisms of causation of immediate stroke by CSM. Immediate stroke is defined as a stroke occurring within seconds or minutes of CSM. Our review found plausible thromboembolic and thrombotic mechanisms of causation of immediate stroke by CSM in the literature. The common premise of these mechanisms is CAD being present before CSM, not occurring as a result of CSM. These mechanisms of causation have clinical and medicolegal implications for physicians performing CSM.

Symptoms of Patients With Vertebral Artery Dissection Presenting to Chiropractors: A Systematic Review and Meta-Analysis

Early symptoms of vertebral artery dissection (VAD) may be nonspecific, including neck pain and headache. Neck pain and headache are also common reasons for patients to seek chiropractic care. We hypothesized that neck pain and/or headache would be the most prevalent symptoms among patients with undiagnosed VAD presenting to chiropractors compared to dizziness or other symptoms. We searched PubMed, Ovid, the Index to Chiropractic Literature, Google Scholar, and gray literature through September 2023 for observational studies describing patients aged ≥10 with previously undiagnosed VAD presenting to a chiropractor. Article selection, data extraction, and quality assessment were performed in duplicate. We synthesized the point prevalence of symptoms and other clinical features. We included 10 case reports describing 10 patients (mean age = 37, SD = 7, 60% female). All patients had either neck pain or headache (100%; 95% confidence interval (CI) = 100%-100%). The most prevalent individual symptoms were neck pain (90%; 95% CI = 71%-100%), headache (80%; 95% CI = 55%-100%), visual disturbance (50%; 95% CI = 19%-81%), and dizziness (40%; 95% CI = 10%-70%). The certainty of results was very low due to publication bias. While our findings suggest that neck pain and/or headache are the most prevalent symptoms among patients with undiagnosed VAD visiting a chiropractor, the small sample size and reliance on case reports preclude any definitive conclusions. Further research with larger sample sizes, control groups, and better control of confounders is required to corroborate these results. Chiropractors should be aware of VAD features and refer suspected patients for emergency care.

Vertebral arteries do not experience tensile force during manual cervical spine manipulation applied to human cadavers

BACKGROUND

The vertebral artery (VA) may be stretched and subsequently damaged during manual cervical spine manipulation. The objective of this study was to measure VA length changes that occur during cervical spine manipulation and to compare these to the VA failure length.

METHODS

Piezoelectric ultrasound crystals were implanted along the length of the VA (C1 to C7) and were used to measure length changes during cervical spine manipulation of seven un-embalmed, post-rigor human cadavers. Arteries were then excised, and elongation from arbitrary in-situ head/neck positions to first force (0.1 N) was measured. Following this, VA were stretched (8.33 mm/s) to mechanical failure. Failure was defined as the instance when VA elongation resulted in a decrease in force.

RESULTS

From arbitrary in-situ head/neck positions, the greatest average VA length change during spinal manipulation was [mean (range)] 5.1% (1.1 to 15.1%). From arbitrary in-situ head/neck positions, arteries were elongated on average 33.5% (4.6 to 84.6%) prior to first force occurrence and 51.3% (16.3 to 105.1%) to failure. Average failure forces were 3.4 N (1.4 to 9.7 N).

CONCLUSIONS

Measured in arbitrary in-situ head/neck positions, VA were slack. It appears that this slack must be taken up prior to VA experiencing tensile force. During cervical spine manipulations (using cervical spine extension and rotation), arterial length changes remained below that slack length, suggesting that VA elongated but were not stretched during the manipulation. However, in order to answer the question if cervical spine manipulation is safe from a mechanical perspective, the testing performed here needs to be repeated using a defined in-situ head/neck position and take into consideration other structures (e.g. carotid arteries).

Veterinary Spinal Manipulative Therapy or Animal Chiropractic in Veterinary Rehabilitation

Veterinary rehabilitation is a multimodal diagnostic and treatment approach that is recommended and provided to patients daily. One therapeutic modality that may be beneficial (diagnostically and therapeutically) is veterinary spinal manipulative therapy or animal chiropractic (AC). AC is a receptor-based health-care modality being provided more frequently in veterinary practices. All clinicians should strive to understand the mode of action, indications, contraindications, how it affects the patient from the neuro-anatomical and biomechanical point of view, and most importantly, when not to provide the requested modality, as further diagnostics may be indicated.

The Effects of Four Weeks of Chiropractic Spinal Adjustments on Blood Biomarkers in Adults with Chronic Stroke: Secondary Outcomes of a Randomized Controlled Trial

Certain blood biomarkers are associated with neural protection and neural plasticity in healthy people and individuals with prior brain injury. To date, no studies have evaluated the effects chiropractic care on serum brain-derived neurotrophic factor (BDNF), insulin-like growth factor-II (IGF-II) and glial cell-derived neurotrophic factor (GDNF) in people with stroke. This manuscript reports pre-specified, exploratory, secondary outcomes from a previously completed parallel group randomized controlled trial. We evaluated differences between four weeks of chiropractic spinal adjustments combined with the usual physical therapy (chiro + PT) and sham chiropractic with physical therapy (sham + PT) on resting serum BDNF, IGF-II and GDNF in 63 adults with chronic stroke. Blood samples were assessed at baseline, four weeks (post-intervention), and eight weeks (follow-up). Data were analyzed using a linear multivariate mixed effects model. Within both groups there was a significant decrease in the mean log-concentration of BDNF and IGF-II at each follow-up, and significant increase log-concentration of GDNF at eight-weeks' follow-up. However, no significant between-group differences in any of the blood biomarkers at each time-point were found. Further research is required to explore which factors influence changes in serum BDNF, IGF-II and GDNF following chiropractic spinal adjustments and physical therapy.

Angular Kinematics of Chiropractic Supine Cervical Spine Manipulation: Rotational Measures and Comparisons to Doctor and Recipient Perceptions

OBJECTIVES

The primary purposes of this study were to measure axial rotation during supine cervical spinal manipulative therapy (cSMT) and to record recipients' and doctors' perceptions of rotational magnitudes.

METHODS

Experienced doctors of chiropractic (DCs) provided supine cSMT and acted as recipients of cSMT. Participants who received SMT wore inertial measurement units attached to the forehead and sternum for motion capture. Afterward, recipients and DCs completed questionnaires asking about their perceptions of motion. Data were analyzed for magnitudes of axial rotation at peak thrust and correlations with patient and doctor perceptions. Secondary analyses included angular velocity, angular acceleration, and other kinematic variables.

RESULTS

We recorded 23 SMT events with 14 DCs. Rotation at thrust peaks averaged 32.4° (17.4°). Doctors' and recipients' perceptions of rotation were higher than measured values 45% and 50% of the time, respectively. Maximum angular velocity and acceleration averaged 221.9°/s (124.9) and 4786.5°/s² (2456.6), respectively. We found no correlation between perceptions and velocity or acceleration; doctors' perceptions had an inverse correlation with measurements.

CONCLUSION

On average, we found rotation during supine cSMT to be 32°. Both DCs and SMT recipients overestimated rotation compared with actual measurements. These factors should be considered in discussions of rotation and SMT.

Effects of Cervical Rotatory Manipulation on Hemodynamics and Plaque Stability of Atherosclerotic Internal Carotid Artery in Rabbits

OBJECTIVE

The purpose of this study was to investigate the effects of cervical rotatory manipulation (CRM) on hemodynamics and plaque stability of atherosclerotic internal carotid artery (ICA) in rabbits.

METHODS

Forty rabbits were randomly divided into 4 groups: (1) internal carotid atherosclerosis (ICAS) rabbits treated with CRM (ICAS-CRM group); (2) ICAS rabbits treated without CRM (ICAS group), (3) Normal-CRM group (normal rabbits treated with CRM), and (4) blank control group. In the ICAS-CRM group and ICAS group, the ICAS model was induced by ICA balloon injury combined with a high-fat diet for 12 weeks. CRM was applied to rabbits in the ICAS-CRM and the Normal-CRM groups. During the study, an ultrasonography examination was performed for detecting plaque and hemodynamics on the ICAs. At the end of the study, all atherosclerotic ICAs were removed for histological and immunohistochemical detection.

RESULTS

The hemodynamics (especially end-diastolic velocity, resistance index, and pulsatility index) through the ICAs were adversely affected by atherosclerosis while not adversely affected by CRM. Compared with the ICAS group, the micro-vessel density and average integrated optical densities of macrophages in the ICAS-CRM group were significantly increased. Compared to the ICAS group, in the ICAS-CRM group, the atherosclerosis was more serious, and the tunica intima was more unstable.

CONCLUSIONS

Although CRM did not affect the hemodynamic index of ICA, it was observed to decrease the stability of severe ICAS plaques in rabbits, which may increase the plaque vulnerability.

Multimodal chiropractic care for migraine: A pilot randomized controlled trial

BACKGROUND

Spinal manipulation may reduce migraine frequency, but effects of multimodal chiropractic care on migraine frequency have not been evaluated.

METHODS

We conducted a pilot randomized controlled trial comparing multimodal chiropractic care + enhanced usual care (MCC+) versus enhanced usual care alone (EUC) among adult women with episodic migraine. EUC was comprised of usual medical care and migraine education literature. MCC+ participants received 10 sessions of chiropractic care over 14 weeks. Primary aims evaluated feasibility of recruitment, retention, protocol adherence, and safety. Change in migraine days was a secondary aim.

RESULTS

Of 422 patients screened, 61 were randomized over 20 months. Fifty-seven (93%) completed daily migraine logs during the intervention, 51 (84%) completed final follow-up, and 45 (74%) completed all assessments. Twenty-four of 29 MCC+ participants (83%) attended > 75% of the chiropractic sessions. Ninety-eight non-serious adverse events were reported by 26 participants (43%) with 39 events among 11 EUC participants and 59 events among 15 MCC+ participants. MCC+ participants experienced greater reductions in migraine days (-2.9 days for MCC+ vs. -1.0 days for EUC, difference = -1.9; 95% confidence interval: -3.5, -0.4).

CONCLUSIONS

Pre-specified feasibility criteria were not met, but deficits were remediable. Preliminary data support a definitive trial of MCC+ for migraine.

TRIAL REGISTRATION

This study is registered at Clinicaltrials.gov (NCT03177616).

Full-Coverage Chiropractic in Medicare: A Proposal to Eliminate Inequities, Improve Outcomes, and Reduce Health Disparities Without Increasing Overall Program Costs

OBJECTIVE

The purpose of this article is to discuss evidence that supports the resolution of inequities for Medicare beneficiaries who receive chiropractic care.

DISCUSSION

Medicare covers necessary examinations, imaging, exercise instruction, and treatments for beneficiaries with back pain when provided by medical doctors, osteopaths, and their associated support staff such as nurse practitioners, physician assistants, clinical nurse specialists, and physical therapists. However, if the same patient with back pain presents to a chiropractor, then the only service that is covered by Medicare is manipulation of the spine. Current evidence does not support this inequity in Medicare beneficiary service coverage. There is no evidence to show an increase in serious risks associated with chiropractic treatment of neck or back pain in Medicare beneficiaries. Chiropractors support national public health goals and endorse safe, evidence-based practices. Chiropractic care for Medicare beneficiaries has been associated with enhanced clinical outcomes such as faster recovery, fewer back surgeries a year later, reduced opioid-associated disability, fewer traumatic injuries and falls, and slower declines in activities of daily living and disability over time. Further evidence points to lower costs, fewer medical physician visits for low back pain, less opioid-related expense, and less back-surgery expense with chiropractic utilization. Use is lower among vulnerable populations: seniors, lower income women, and black and Hispanic beneficiaries who may be most affected by current inequities associated with the limited coverage. In this era of evidence-based and patient-centered care, beneficiaries who receive chiropractic care are very satisfied with the care they receive.

CONCLUSION

The current evidence suggests a need for change in US policy toward chiropractic in Medicare and support for HR 3654. Ending inequities by providing patients full coverage for chiropractic services has the potential to enhance care outcomes and reduce health disparities without increasing program costs.

Changes in Vertebral Artery Blood Flow in Different Head Positions and Post-Cervical Manipulative Therapy

OBJECTIVE

The objective of this study was to investigate the hemodynamics of blood flow through the V3 region of the vertebral artery contralateral to the side manipulated during different rotary head positions and post-cervical spinal manipulation.

METHODS

This quasi-experimental study was performed on 25 healthy, asymptomatic participants, both male and female, between 20 and 30 years of age. Each participant presented with a C0/C1 or C1/C2 cervical facet restriction (as determined by motion palpation). Participation was voluntary, and participants had no symptoms of vertebrobasilar artery insufficiency or contraindications to cervical spinal manipulation. Doppler ultrasound was used to measure vertebral artery blood flow (V3 region) hemodynamics, contralateral side of manipulation, as close to C1/C2 region as possible in 4 positions of cervical rotation (neutral, 45°, maximum, and post-manipulation neutral). Doppler ultrasound parameters included peak systolic flow velocity, end diastolic flow velocity, mean flow velocity, vessel diameter, and flow rate. The nonparametric Friedman test was used for analysis across each head and neck position, and post manipulation.

RESULTS

No clinical or statistically significant results (P > .05) were found for any of the hemodynamic parameters in any of the head positions.

CONCLUSIONS

Hemodynamic measurements of the V3 region of the vertebral artery do not show significant changes in the measured head positions or following manipulation of the upper cervical spine in patients without pre-existing risk factors.

The Integrative Migraine Pain Alleviation through Chiropractic Therapy (IMPACT) trial: Study rationale, design and intervention validation

INTRODUCTION

Approximately 15% of the US population experiences migraine, with women afflicted three times as often as men. While medications are often used as first-line treatments, up to 50% of people with migraine pursue complementary and integrative medicine. One promising non-pharmacological approach for migraine is chiropractic care, due to the co-occurrence of migraine disease and musculoskeletal tension and pain. To date, no large-scale trials have evaluated the impact of a comprehensive model of chiropractic care on migraine.

METHODS

The Integrative Migraine Pain Alleviation through Chiropractic Therapy (IMPACT) study is a two-arm pilot pragmatic randomized clinical trial evaluating a multimodal chiropractic care intervention plus enhanced usual care (UC) vs. enhanced UC alone for adult women with episodic migraine. A total of 60 women aged 20-55 who meet criteria for episodic migraine will be randomly assigned to an evidence-informed, musculoskeletal focused multimodal chiropractic care (10 sessions over 14 weeks) plus enhanced UC vs. enhanced UC alone. Enhanced UC includes conventional care, migraine education materials, and biweekly check-in phone calls. Study specific aims include: 1) Determine safety and feasibility of the study design; 2) Provide preliminary data on the effectiveness of chiropractic care on migraine frequency, severity, duration and medication use; and 3) Provide preliminary estimates of the effects of chiropractic care on disability, health-related quality of life, and psychosocial well-being.

DISCUSSION

Findings will be used to inform the design of a full-scale trial evaluating chiropractic care for women with episodic migraines.

Change in young people's spine pain following chiropractic care at a publicly funded healthcare facility in Canada

BACKGROUND

The presence of spinal pain in young people has been established as a risk factor for spinal pain later in life. Recent clinical practice guidelines recommend spinal manipulation (SM), soft tissue therapy, acupuncture, and other modalities that are common treatments provided by chiropractors, as interventions for spine pain. Less is known specifically on the response to chiropractic management in young people with spinal pain. The purpose of this manuscript was to describe the impact, through pain measures, of a pragmatic course of chiropractic management in young people's spinal pain at a publicly funded healthcare facility for a low-income population.

METHODS

The study utilized a retrospective analysis of prospectively collected quality assurance data attained from the Mount Carmel Clinic (MCC) chiropractic program database. Formal permission to conduct the analysis of the database was acquired from the officer of records at the MCC. The University of Manitoba's Health Research Ethics Board approved all procedures.

RESULTS

Young people (defined as 10-24 years of age) demonstrated statistically and clinically significant improvement on the numeric rating scale (NRS) in all four spinal regions following chiropractic management.

CONCLUSION

The findings of the present study provide evidence that a pragmatic course of chiropractic care, including SM, mobilization, soft tissue therapy, acupuncture, and other modalities within the chiropractic scope of practice are a viable conservative pain management treatment option for young people.

Considerations to improve the safety of cervical spine manual therapy

Manipulation and mobilisation of the cervical spine are well established interventions in the management of patients with headache and/or neck pain. However, their benefits are accompanied by potential, yet rare risks in terms of serious adverse events, including neurovascular insult to the brain. A recent international framework for risk assessment and management offers directions in the mitigation of this risk by facilitating sound clinical reasoning. The aim of this article is to critically reflect on and summarize the current knowledge about cervical spine manual therapy and to provide guidance for clinical reasoning for cervical spine manual therapy.

What are the risks of manual treatment of the spine? A scoping review for clinicians

Background

Communicating to patients the risks of manual treatment to the spine is an important, but challenging element of informed consent. This scoping review aimed to characterise and summarise the available literature on risks and to describe implications for clinical practice and research.

Method

A methodological framework for scoping reviews was followed. Systematic searches were conducted during June 2017. The quantity, nature and sources of literature were described. Findings of included studies were narratively summarised, highlighting key clinical points.

Results

Two hundred and fifty articles were included. Cases of serious adverse events were reported. Observational studies, randomised studies and systematic reviews were also identified, reporting both benign and serious adverse events.Benign adverse events were reported to occur commonly in adults and children. Predictive factors for risk are unclear, but for neck pain patients might include higher levels of neck disability or cervical manipulation. In neck pain patients benign adverse events may result in poorer short term, but not long term outcomes.Serious adverse event incidence estimates ranged from 1 per 2 million manipulations to 13 per 10,000 patients. Cases are reported in adults and children, including spinal or neurological problems as well as cervical arterial strokes. Case-control studies indicate some association, in the under 45 years age group, between manual interventions and cervical arterial stroke, however it is unclear whether this is causal. Elderly patients have no greater risk of traumatic injury compared with visiting a medical practitioner for neuro-musculoskeletal problems, however some underlying conditions may increase risk.

Conclusion

Existing literature indicates that benign adverse events following manual treatments to the spine are common, while serious adverse events are rare. The incidence and causal relationships with serious adverse events are challenging to establish, with gaps in the literature and inherent methodological limitations of studies. Clinicians should ensure that patients are informed of risks during the consent process. Since serious adverse events could result from pre-existing pathologies, assessment for signs or symptoms of these is important. Clinicians may also contribute to furthering understanding by utilising patient safety incident reporting and learning systems where adverse events have occurred.

Adverse events associated with the use of cervical spine manipulation or mobilization and patient characteristics: A systematic review

Cervical spinal manipulation (CSM) and cervical mobilization are frequently used in patients with neck pain and headache. Pre-manipulative cervical instability and arterial integrity tests appear to be unreliable in identifying patients at risk for adverse events. It would be valuable if patients at risk could be identified by specific characteristics during the preliminary screening. Objective was to identify characteristics of 1) patients, 2) practitioners, 3) treatment process and 4) adverse events (AE) occurring after CSM or cervical mobilization. A systematic search was performed in PubMed, Embase, CINAHL, Web-of-science, AMED, and ICL (Index Chiropractic Literature) up to December 2014. Of the initial 1043 studies, 144 studies were included, containing 227 cases. 117 cases described male patients with a mean age of 45 (SD 12) and a mean age of 39 (SD 11) for females. Most patients were treated by chiropractors (66%). Manipulation was reported in 95% of the cases, and neck pain was the most frequent indication. Cervical arterial dissection (CAD) was reported in 57% (P = 0.21) of the cases and 45.8% had immediate onset symptoms. The overall distribution of gender for CAD is 55% (n = 71) for female and therefore opposite of the total AE. Patient characteristics were described poorly. No clear patient profile, related to the risk of AE after CSM, could be extracted. However, women seem more at risk for CAD. There seems to be under-reporting of cases. Further research should focus on a more uniform and complete registration of AE using standardized terminology.

Risk of Carotid Stroke after Chiropractic Care: A Population-Based Case-Crossover Study

BACKGROUND

Chiropractic manipulation is a popular treatment for neck pain and headache, but may increase the risk of cervical artery dissection and stroke. Patients with carotid artery dissection can present with neck pain and/or headache before experiencing a stroke. These are common symptoms seen by both chiropractors and primary care physicians (PCPs). We aimed to assess the risk of carotid artery stroke after chiropractic care by comparing association between chiropractic and PCP visits and subsequent stroke.

METHODS

A population-based, case-crossover study was undertaken in Ontario, Canada. All incident cases of carotid artery stroke admitted to hospitals over a 9-year period were identified. Cases served as their own controls. Exposures to chiropractic and PCP services were determined from health billing records.

RESULTS

We compared 15,523 cases to 62,092 control periods using exposure windows of 1, 3, 7, and 14 days prior to the stroke. Positive associations were found for both chiropractic and PCP visits and subsequent stroke in patients less than 45 years of age. These associations tended to increase when analyses were limited to visits for neck pain and headache-related diagnoses. There was no significant difference between chiropractic and PCP risk estimates. We found no association between chiropractic visits and stroke in those 45 years of age or older.

CONCLUSIONS

We found no excess risk of carotid artery stroke after chiropractic care. Associations between chiropractic and PCP visits and stroke were similar and likely due to patients with early dissection-related symptoms seeking care prior to developing their strokes.

Does case misclassification threaten the validity of studies investigating the relationship between neck manipulation and vertebral artery dissection stroke? Yes

Background

For patients and health care providers who are considering spinal manipulative therapy of the neck, it is crucial to establish if it is a trigger for cervical artery dissection and/or stroke, and if it is, the magnitude of the risk.

Discussion

We discuss the biological plausibility of how neck manipulation could cause cervical artery dissection. We also discuss how case misclassification threatens the validity of influential published studies that have investigated the relationship between neck manipulation and dissection. Our position is supported by the fact that the largest epidemiologic studies of neck manipulation safety with respect to neurological outcomes have relied on International Classification of Diseases-9 codes for case identification. However, the application of these codes in prior studies failed to identify dissections (rather than strokes in general) and so conclusions from those studies are invalid.

Conclusion

There are several methodological challenges to understanding the association between neck manipulation and vertebral artery dissection. Addressing these issues is critical because even a modest association between neck manipulation and cervical artery dissection could translate into a significant number of avoidable dissections given the widespread use of neck manipulation by providers from various backgrounds. We believe that valid case classification, accurate measurement of manipulative procedures, and addressing reverse causation bias should be top priorities for future research.

Does case misclassification threaten the validity of studies investigating the relationship between neck manipulation and vertebral artery dissection stroke? No

Background

The purported relationship between cervical manipulative therapy (CMT) and stroke related to vertebral artery dissection (VAD) has been debated for several decades. A large number of publications, from case reports to case–control studies, have investigated this relationship. A recent article suggested that case misclassification in the case–control studies on this topic resulted in biased odds ratios in those studies.

Discussion

Given its rarity, the best epidemiologic research design for investigating the relationship between CMT and VAD is the case–control study. The addition of a case-crossover aspect further strengthens the scientific rigor of such studies by reducing bias. The most recent studies investigating the relationship between CMT and VAD indicate that the relationship is not causal. In fact, a comparable relationship between vertebral artery-related stroke and visits to a primary care physician has been observed. The statistical association between visits to chiropractors and VAD can best be explained as resulting from a patient with early manifestation of VAD (neck pain with or without headache) seeking the services of a chiropractor for relief of this pain. Sometime after the visit the patient experiences VAD-related stroke that would have occurred regardless of the care received.

This explanation has been challenged by a recent article putting forth the argument that case misclassification is likely to have biased the odds ratios of the case–control studies that have investigated the association between CMT and vertebral artery related stroke. The challenge particularly focused on one of the case–control studies, which had concluded that the association between CMT and vertebral artery related stroke was not causal.

It was suggested by the authors of the recent article that misclassification led to an underestimation of risk. We argue that the information presented in that article does not support the authors’ claim for a variety of reasons, including the fact that the assumptions upon which their analysis is based lack substantiation and the fact that any possible misclassification would not have changed the conclusion of the study in question.

Conclusion

Current evidence does not support the notion that misclassification threatens the validity of recent case–control studies investigating the relationship between CMT and VAD. Hence, the recent re-analysis cannot refute the conclusion from previous studies that CMT is not a cause of VAD.

Chiropractic and Spinal Manipulation Therapy on Twitter: Case Study Examining the Presence of Critiques and Debates

Background

Spinal manipulation therapy (SMT) is a popular though controversial practice. The debates surrounding efficacy and risk of SMT are only partially evident in popular discourse.

Objective

This study aims to investigate the presence of critiques and debates surrounding efficacy and risk of SMT on the social media platform Twitter. The study examines whether there is presence of debate and whether critical information is being widely disseminated.

Methods

An initial corpus of 31,339 tweets was compiled through Twitter’s Search Application Programming Interface using the query terms “chiropractic,” “chiropractor,” and “spinal manipulation therapy.” Tweets were collected for the month of December 2015. Post removal of tweets made by bots and spam, the corpus totaled 20,695 tweets, of which a sample (n=1267) was analyzed for skeptical or critical tweets. Additional criteria were also assessed.

Results

There were 34 tweets explicitly containing skepticism or critique of SMT, representing 2.68% of the sample (n=1267). As such, there is a presence of 2.68% of tweets in the total corpus, 95% CI 0-6.58% displaying explicitly skeptical or critical perspectives of SMT. In addition, there are numerous tweets highlighting the health benefits of SMT for health issues such as attention deficit hyperactivity disorder (ADHD), immune system, and blood pressure that receive scant critical attention. The presence of tweets in the corpus highlighting the risks of “stroke” and “vertebral artery dissection” is also minute (0.1%).

Conclusions

In the abundance of tweets substantiating and promoting chiropractic and SMT as sound health practices and valuable business endeavors, the debates surrounding the efficacy and risks of SMT on Twitter are almost completely absent. Although there are some critical voices of SMT proving to be influential, issues persist regarding how widely this information is being disseminated.

Endovascular Treatment of Basilar Artery Thrombosis Secondary to Bilateral Vertebral Artery Dissection with Symptom Onset Following Cervical Spine Manipulation Therapy

Patient: Female, 37

Final Diagnosis: Vertebral artery dissection

Symptoms: Neck pain and focal neurological deficits

Medication: No previous

Clinical Procedure: Endovascular thrombectomy

Specialty: Neurology

Chiropractic Response to a Spontaneous Vertebral Artery Dissection

OBJECTIVE

The purpose of this case report is to describe a case in which early detection and proper follow-up of spontaneous vertebral artery dissection led to satisfactory outcomes.

CLINICAL FEATURES

A 34-year old white woman reported to a chiropractic clinic with a constant burning pain at the right side of her neck and shoulder with a limited ability to turn her head from side to side, periods of blurred vision, and muffled hearing. Dizziness, visual and auditory disturbances, and balance difficulty abated within 1 hour of onset and were not present at the time of evaluation. A pain drawing indicated burning pain in the suboccipital area, neck, and upper shoulder on the right and a pins and needles sensation on the dorsal surface of both forearms. Turning her head from side-to-side aggravated the pain, and the application of heat brought temporary relief. The Neck Disability Index score of 44 placed the patient's pain in the most severe category.

INTERVENTION AND OUTCOME

The patient was not treated on the initial visit but was advised of the possibility of a vertebral artery or carotid artery dissection and was recommended to the emergency department for immediate evaluation. The patient declined but later was convinced by her chiropractor to present to the emergency department. A magnetic resonance angiogram of the neck and carotid arteries was performed showing that the left vertebral artery was hypoplastic and appeared to terminate at the left posterior inferior cerebellar artery. There was an abrupt moderately long segment of narrowing involving the right vertebral artery beginning near the junction of the V1 and V2 segments. The radiologist noted a concern regarding right vertebral artery dissection. Symptoms resolved and the patient was cleared of any medications but advised that if symptoms reoccurred she was to go for emergency care immediately.

CONCLUSION

Recognition and rapid response by the chiropractic physician provided the optimum outcome for this particular patient.