Marion McGregor

Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation.

STUDY DESIGN Potential precipitating events and risk factors for vertebrobasilar artery dissection were reviewed in an analysis of the English language literature published before 1993. OBJECTIVES To assess the literature pertaining to precipitating neck movements and risk factors for vertebrobasilar artery dissection in an attempt to determine whether the incidence of these complications can be minimized. SUMMARY OF BACKGROUND DATA Vertebrobasilar artery dissection and occlusion leading to brain stem and cerebellar ischemia and infarction are rare but often devastating complications of cervical, manipulation and neck trauma. Although various investigators have suggested potential risk factors and precipitating events, the basis for these suggestions remains unclear. METHODS A detailed search of the literature using three computerized bibliographic databases was performed to identify English language articles from 1966 to 1993. Literature before 1966 was identified through a hand search of Index Medicus. References of articles obtained by database search were reviewed to identify additional relevant articles. Data presented in all articles meeting the inclusion criteria were summarized. RESULTS The 367 case reports included in this study describe 160 cases of spontaneous onset, 115 cases of onset after spinal manipulation, 58 cases associated with trivial trauma, and 37 cases caused by major trauma (3 cases were classified in two categories). The nature of the precipitating trauma, neck movement, or type of manipulation that was performed was poorly defined in the literature, and it was not possible to identify a specific neck movement or trauma that would be considered the offending activity in the majority of cases. There were 208 (57%) men and 158 (43%) women (gender data not reported in one case) with an average age of 39.3 +/- 12.9 years. There was an overall prevalence of 13.4% hypertension, 6.5% migraines, 18% use of oral contraception (percent of female patients), and 4.9% smoking. In only isolated cases was specific vascular disease such as fibromuscular hyperplasia noted. CONCLUSIONS The literature does not assist in the identification of the offending mechanical trauma, neck movement, or type of manipulation precipitating vertebrobasilar artery dissection or the identification of the patient at risk. Thus, given the current status of the literature, it is impossible to advise patients or physicians about how to avoid vertebrobasilar artery dissection when considering cervical manipulation or about specific sports or exercises that result in neck movement or trauma.

Unpredictability of cerebrovascular ischemia associated with cervical spine manipulation therapy: a review of sixty-four cases after cervical spine manipulation.

Study Design. A retrospective review of 64 medicolegal records describing cerebrovascular ischemia after cervical spine manipulation was conducted. Objectives. To describe 64 cases of cerebrovascular accidents temporally associated with cervical spine manipulation therapy in terms of patient characteristics, potential risk factors, nature of complication, and neurologic sequelae. Summary of Background Data. Approximately 117 cases of postmanipulation cerebrovascular ischemia have been reported in the English language literature. Proposed risk factors include age, gender, migraine headaches, hypertension, diabetes, birth control pills, cervical spondylosis, and smoking. It is often assumed that these complications may be avoided by clinically screening patients and by premanipulation positioning of the head and neck to evaluate the patency of the vertebral arteries. Methods. Three researchers using a uniform data abstraction instrument performed an independent review of 64 previously unpublished medicolegal records describing cerebrovascular ischemia after cervical spine manipulation. These cases were referred to a single physician for review over a 16-year period from across the United States and Canada. Descriptive statistics were calculated for characteristics of the patients and the complications. Means and standard deviations were computed for continuous variables. Frequencies and proportions were calculated for categorical variables. Results. This study was unable to identify factors from the clinical history and physical examination of the patient that would assist a physician attempting to isolate the patient at risk of cerebral ischemia after cervical manipulation. Conclusion. Cerebrovascular accidents after manipulation appear to be unpredictable and should be considered an inherent, idiosyncratic, and rare complication of this treatment approach.

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

Abstract 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.

Dimensions of the lumbar intervertebral foramina as determined from the sagittal plane magnetic resonance imaging scans of 95 normal subjects

OBJECTIVES This was a 2-part study. Part 1 evaluated the reliability of measurements of the intervertebral foramina (IVF) from magnetic resonance imaging (MRI) scans, and part 2 developed a morphometric database of IVF dimensions from normal living subjects. DESIGN Part 1 was a blinded reliability study using 7 observers, and part 2 developed a morphometric database using 2 teams of 3 observers, all blinded to the results of each other. SUBJECTS Ninety-five normal subjects (46 women, 49 men) were stratified by age (range 14-84 years, average 38.8 years). OUTCOME MEASURES Part 1: Interclass correlation coefficients (ICCs) were calculated for intraobserver and interobserver reliability for 3 dimensions of the lumbar IVFs. Part 2: A database was developed using the same measures. In addition, the relationships between IVF dimensions and age, height, weight, sex, and left versus right sides of subjects were evaluated. RESULTS Part 1: All ICCs were very high (> 0.94). Part 2: 8550 measurements were made, and a morphometric database of 95 subjects, stratified by age and sex, was completed. Differences in IVF size associated with age, height, weight, sex, and side were described. CONCLUSIONS Measurements taken from MRI scans of IVFs were performed reliably. The morphometric database and IVF relationships should aid clinicians and researchers in evaluating patients with suspected foraminal stenosis and help further investigate IVF pathology and treatment of such pathology.

Differentiating intraprofessional attitudes toward paradigms in health care delivery among chiropractic factions: results from a randomly sampled survey.

BackgroundAs health care has increased in complexity and health care teams have been offered as a solution, so too is there an increased need for stronger interprofessional collaboration. However the intraprofessional factions that exist within every profession challenge interprofessional communication through contrary paradigms. As a contender in the conservative spinal health care market, factions within chiropractic that result in unorthodox practice behaviours may compromise interprofessional relations and that profession’s progress toward institutionalization. The purpose of this investigation was to quantify the professional stratification among Canadian chiropractic practitioners and evaluate the practice perceptions of those factions.MethodsA stratified random sample of 740 Canadian chiropractors was surveyed to determine faction membership and how professional stratification could be related to views that could be considered unorthodox to current evidence-based care and guidelines. Stratification in practice behaviours is a stated concern of mainstream medicine when considering interprofessional referrals.ResultsOf 740 deliverable questionnaires, 503 were returned for a response rate of 68%. Less than 20% of chiropractors (18.8%) were aligned with a predefined unorthodox perspective of the conditions they treat. Prediction models suggest that unorthodox perceptions of health practice related to treatment choices, x-ray use and vaccinations were strongly associated with unorthodox group membership (X2 =13.4, p = 0.0002).ConclusionChiropractors holding unorthodox views may be identified based on response to specific beliefs that appear to align with unorthodox health practices. Despite continued concerns by mainstream medicine, only a minority of the profession has retained a perspective in contrast to current scientific paradigms. Understanding the profession’s factions is important to the anticipation of care delivery when considering interprofessional referral.

Enhancement of in vitro interleukin-2 production in normal subjects following a single spinal manipulative treatment

BackgroundIncreasing evidence supports somato-visceral effects of manual therapies. We have previously demonstrated that a single spinal manipulative treatment (SMT) accompanied by audible release has an inhibitory effect on the production of proinflammatory cytokines in asymptomatic subjects. The purpose of this study is to report on SMT-related changes in the production of the immunoregulatory cytokine interleukin 2 (IL-2) and to investigate whether such changes might differ with respect to the treatment approach related to the presence or absence of an audible release (joint cavitation).MethodsOf 76 asymptomatic subjects, 29 received SMT with cavitation (SMT-C), 23 were treated with SMT without cavitation (SMT-NC) and 24 comprised the venipuncture control (VC) group. The SMT-C and SMT-NC subjects received a single, similar force high velocity low amplitude manipulation, in the upper thoracic spine. However, in SMT-NC subjects, positioning and line of drive were not conducive to cavitation. Blood and serum samples were obtained before and then at 20 and 120 min post-intervention. The production of IL-2 in peripheral blood mononuclear cell cultures was induced by activation for 48 hr with Staphylococcal protein A (SPA) and, in parallel preparations, with the combination of phorbol ester (TPA) and calcium ionophore. The levels of IL-2 in culture supernatants and serum were assessed by specific immunoassays.ResultsCompared with VC and their respective baselines, SPA-induced secretion of IL-2 increased significantly in cultures established from both SMT-C and SMT-NC subjects at 20 min post-intervention. At 2 hr post-treatment, significant elevation of IL-2 synthesis was still apparent in preparations from SMT-treated groups though it became somewhat attenuated in SMT-NC subjects. Conversely, IL-2 synthesis induced by TPA and calcium ionophore was unaltered by either type of SMT and was comparable to that in VC group at all time points. No significant alterations in serum-associated IL-2 levels were observed in any of the study groups.ConclusionThe present study demonstrates that, the in vitro T lymphocyte response to a conventional mitogen (SPA), as measured by IL-2 synthesis, can become enhanced following SMT. Furthermore, within a period of time following the manipulative intervention, this effect may be independent of joint cavitation. Thus the results of this study suggest that, under certain physiological conditions, SMT might influence IL-2-regulated biological responses.

Amount of health care and self-care following a randomized clinical trial comparing flexion-distraction with exercise program for chronic low back pain.

BackgroundPrevious clinical trials have assessed the percentage of participants who utilized further health care after a period of conservative care for low back pain, however no chiropractic clinical trial has determined the total amount of care during this time and any differences based on assigned treatment group. The objective of this clinical trial follow-up was to assess if there was a difference in the total number of office visits for low back pain over one year after a four week clinical trial of either a form of physical therapy (Exercise Program) or a form of chiropractic care (Flexion Distraction) for chronic low back pain.MethodsIn this randomized clinical trial follow up study, 195 participants were followed for one year after a four-week period of either a form of chiropractic care (FD) or a form of physical therapy (EP). Weekly structured telephone interview questions regarded visitation of various health care practitioners and the practice of self-care for low back pain.ResultsParticipants in the physical therapy group demonstrated on average significantly more visits to any health care provider and to a general practitioner during the year after trial care (p < 0.05). No group differences were noted in the number of visits to a chiropractor or physical therapist. Self-care was initiated by nearly every participant in both groups.ConclusionDuring a one-year follow-up, participants previously randomized to physical therapy attended significantly more health care visits than those participants who received chiropractic care.

Manikin-based clinical simulation in chiropractic education.

OBJECTIVE The purpose of this pilot investigation was to describe the development and implementation of simulation exercises and investigate the feasibility, satisfaction, and relative effectiveness of a manikin-based simulation program in chiropractic undergraduate education. METHODS This investigation consisted of (1) a qualitative review of other simulation environments and evaluation of related simulation literature to develop the educational processes to be used, (2) implementation of simulation scenarios for 95 student interns and their 11 supervising clinicians, and (3) implementation of simulation scenarios in a random sample of 35 1st-year and 24 2nd-year chiropractic students. Assessment of success was based on results from satisfaction and usability questionnaires and perceived achievement of learning outcomes. Anxiety scores were measured for all participants via a visual analog scale. The level of successful integration of 2nd-year basic science material was assessed using a t test comparing test results between students who participated in the pilot and those who did not. RESULTS Implementation methods were developed on the basis of qualitative investigation. Simulation program feedback from all participants indicated high levels of satisfaction, usability, and perceived achievement of learning outcomes. Anxiety levels among interns differed according to role chosen (F = 8.07, p =.00). Mean difference in course examination scores of students who participated in simulations versus those who did not was 3.25% favoring students who participated (t = 1.28, p =.10). CONCLUSIONS High levels of student satisfaction and perceived achievement of learning outcomes were consistently achieved. A trend to successful integration of basic science knowledge provides reason for cautious optimism. More research is recommended.

Assessment of a generalizable methodology to assess learning from manikin-based simulation technology.

Objective : This study combined a learning outcomes-based checklist and salient characteristics derived from wisdom-of-crowds theory to test whether differing groups of judges (diversity maximized versus expertise maximized) would be able to appropriately assess videotaped, manikin-based simulation scenarios. Methods : Two groups of 3 judges scored 9 videos of interns managing a simulated cardiac event. The first group had a diverse range of knowledge of simulation procedures, while the second group was more homogeneous in their knowledge and had greater simulation expertise. All judges viewed 3 types of videos (predebriefing, postdebriefing, and 6 month follow-up) in a blinded fashion and provided their scores independently. Intraclass correlation coefficients (ICCs) were used to assess the reliability of judges as related to group membership. Scores from each group of judges were averaged to determine the impact of group on scores. Results : Results revealed strong ICCs for both groups of judges (diverse, 0.89; expert, 0.97), with the diverse group of judges having a much wider 95% confidence interval for the ICC. Analysis of variance of the average checklist scores indicated no significant difference between the 2 groups of judges for any of the types of videotapes assessed (F = 0.72, p = .4094). There was, however, a statistically significant difference between the types of videos (F = 14.39, p = .0004), with higher scores at the postdebrief and 6-month follow-up time periods. Conclusions : Results obtained in this study provide optimism for assessment procedures in simulation using learning outcomes-based checklists and a small panel of judges.

Elevated production of inflammatory mediators including nociceptive chemokines in patients with neck pain: a cross-sectional evaluation.

OBJECTIVE This study investigated whether the production of inflammatory mediators and chemotactic cytokines (chemokines) is altered in patients with chronic and recurrent neck pain (NP). METHODS Cross-sectional data evaluating blood and serum samples were obtained from 27 NP patients and 13 asymptomatic (control) subjects recruited from a chiropractic outpatient clinic. Cell cultures were activated by lipopolysaccharide (LPS) and phytoheamagglutinin for 24 to 48 hours. The levels of tumor necrosis factor α (TNF-α), monocyte chemotactic protein 1, also known as CCL2 (CCL2/MCP-1), and macrophage inflammatory protein 1α or CCL3 (CCL3/MIP-1α) were determined by specific immunoassays. Serum levels of nitric oxide metabolites were evaluated simultaneously, in vanadium III-reduced samples, by Griess reaction. RESULTS Low levels of constitutive (spontaneous) TNF-α production were present in 7 of the 27 cultures from patients with NP. Both LPS-induced TNF-α production and inducer (LPS/phytoheamagglutin)-stimulated production of CCL2 were significantly elevated (P = .00) in patients compared with controls. In patients, the constitutive synthesis of CCL3 occurred significantly more frequently (P = .00) and ranged from 30 to more than 2000 pg/mL. Finally, serum levels of nitric oxide were significantly elevated (P = .00) in NP patients. CONCLUSIONS Production of inflammatory mediators was consistently elevated in NP patients in this study, both in vitro and in vivo, and activation of inflammatory pathways was accompanied by up-regulation of CC chemokine synthesis. This suggests that, in NP patients, CC chemokines may be involved in regulation of local inflammatory response through recruitment of immune cells to the inflamed tissue and exert pronociceptive effects.