Ophthalmological adverse effects of (chiropractic) upper spinal manipulation: evidence from recent case reports

Short-Term Effect of Spinal Manipulation on the Magnitude of Exophoria in Adults Who Are Asymptomatic: A Randomized Controlled Trial

OBJECTIVE

This study aimed to assess the immediate and short-term effects of cervical spinal manipulation (SM), compared with a placebo, on the magnitude of near and distance exophoria in adults with asymptomatic exophoria.

METHODS

In this single-blind, randomized controlled trial, individuals with a clinical diagnosis of horizontal exophoria confirmed with the prism alternating cover test (PACT) were allocated to a single intervention session using a high-velocity, low-amplitude cervical SM technique or a sham intervention (manual contact under the head). Outcomes were the magnitude of horizontal heterophoria, as a measure of binocular vision efficiency at near (40 cm) or distance (4 m) fixation, using the PACT. Evaluations were made at baseline, immediately after intervention, and at a 1-week follow-up.

RESULTS

From May to September 2021, 44 volunteers (23 women), with a mean age of 35 (SD = 9.5) years, were recruited and equally distributed into the study groups. All participants completed follow-up assessments, and no adverse events were reported. There was a significant time × group interaction for exophoria at near vision, but not at distance fixation. The SM group showed a significant decrease of near exophoria compared with the control group at the 1-week follow-up (mean difference = -1.09 prism diopters; 95% CI = -0.20 to -1.98 prism diopters).

CONCLUSION

The use of cervical SM therapy resulted in a significant reduction of the magnitude of horizontal exophoria at near vision (medium effect size), compared with the placebo, in young adults who are asymptomatic. However, these effects were not observed at distance fixation and should be considered cautiously due to the pre-post design with a single intervention session and the short-term follow-up.

IMPACT

The findings suggest short-term benefits of SM therapy can manage undiagnosed ocular convergence disorders, although changes were not clinically relevant.

Preretinal hemorrhages following chiropractor neck manipulation

Purpose

To report a case of a new complication following complementary and alternative medicine chiropractor neck manipulation with multiple preretinal hemorrhages.

Observations

A 59-year-old Caucasian female presented with the acute, painless constant appearance of 3 spots in her vision immediately after a chiropractor performed cervical spinal manipulation using the high-velocity, low-amplitude technique. Examination multiple unilateral preretinal hemorrhages with no retinal tears. The preretinal hemorrhages were self-limited and resolved by 2 months later.

Conclusions

Chiropractor neck manipulation has previously been reported leading to complications related to the carotid artery and arterial plaques. This presents the first case of multiple unilateral preretinal hemorrhages immediately following chiropractic neck manipulation. This suggests that chiropractor spinal adjustment can not only affect the carotid artery, but also could lead to preretinal hemorrhages.

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.

The risk associated with spinal manipulation: an overview of reviews

BACKGROUND

Spinal manipulative therapy (SMT) is a widely used manual treatment, but many reviews exist with conflicting conclusions about the safety of SMT. We performed an overview of reviews to elucidate and quantify the risk of serious adverse events (SAEs) associated with SMT.

METHODS

We searched five electronic databases from inception to December 8, 2015. We included reviews on any type of studies, patients, and SMT technique. Our primary outcome was SAEs. Quality of the included reviews was assessed using a measurement tool to assess systematic reviews (AMSTAR). Since there were insufficient data for calculating incidence rates of SAEs, we used an alternative approach; the conclusions regarding safety of SMT were extracted for each review, and the communicated opinion were judged by two reviewers independently as safe, harmful, or neutral/unclear. Risk ratios (RRs) of a review communicating that SMT is safe and meeting the requirements for each AMSTAR item, were calculated.

RESULTS

We identified 283 eligible reviews, but only 118 provided data for synthesis. The most frequently described adverse events (AEs) were stroke, headache, and vertebral artery dissection. Fifty-four reviews (46%) expressed that SMT is safe, 15 (13%) expressed that SMT is harmful, and 49 reviews (42%) were neutral or unclear. Thirteen reviews reported incidence estimates for SAEs, roughly ranging from 1 in 20,000 to 1 in 250,000,000 manipulations. Low methodological quality was present, with a median of 4 of 11 AMSTAR items met (interquartile range, 3 to 6). Reviews meeting the requirements for each of the AMSTAR items (i.e. good internal validity) had a higher chance of expressing that SMT is safe.

CONCLUSIONS

It is currently not possible to provide an overall conclusion about the safety of SMT; however, the types of SAEs reported can indeed be significant, sustaining that some risk is present. High quality research and consistent reporting of AEs and SAEs are needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015030068 .

Complementary medicine and safety: a systematic investigation of design and reporting of systematic reviews

OBJECTIVES

The objective of this study was to examine the methods used in systematic reviews of safety across a range of complementary therapies to assess the variation in approach and the potential for developing guidance on conduct and reporting.

DESIGN

Systematic reviews focusing on safety were retrieved from NHS Evidence and searches of major databases. A pre-prepared template was used for data extraction. Information extracted included details of search strategies, sources, participants, interventions, reported adverse event/effect(s) and causality assessment. Data extraction was carried out by one researcher and a check for accuracy by a second researcher. Methods were assessed against criteria based on guidance provided by the Cochrane Adverse Effects Methods Group.

RESULTS

A total of 2563 citations were screened and 88 systematic reviews were selected for inclusion. The majority focused on the safety of herbs and nutritional supplements. Approximately half the reviews covered all aspects of safety; other reviews addressed specific adverse effects or interactions. Types of data included in the reviews did not always reflect the focus of the review. Search strategies, sources used, quality assessment and assessment of causality also varied.

CONCLUSIONS

Detailed examination and comparison of the methods has highlighted several areas in which there is potential for development of guidelines and consensus on standards. These include search strategies, sources of information, data extraction and assessment of causality. The value of systematic reviews in relation to large outcome studies requires further consideration.

The clinical features of the piriformis syndrome: a systematic review

Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis.

Current understanding of the relationship between cervical manipulation and stroke: what does it mean for the chiropractic profession?

The understanding of the relationship between cervical manipulative therapy (CMT) and vertebral artery dissection and stroke (VADS) has evolved considerably over the years. In the beginning the relationship was seen as simple cause-effect, in which CMT was seen to cause VADS in certain susceptible individuals. This was perceived as extremely rare by chiropractic physicians, but as far more common by neurologists and others. Recent evidence has clarified the relationship considerably, and suggests that the relationship is not causal, but that patients with VADS often have initial symptoms which cause them to seek care from a chiropractic physician and have a stroke some time after, independent of the chiropractic visit.This new understanding has shifted the focus for the chiropractic physician from one of attempting to "screen" for "risk of complication to manipulation" to one of recognizing the patient who may be having VADS so that early diagnosis and intervention can be pursued. In addition, this new understanding presents the chiropractic profession with an opportunity to change the conversation about CMT and VADS by taking a proactive, public health approach to this uncommon but potentially devastating disorder.

Safety of chiropractic interventions: a systematic review

STUDY DESIGN

Systematic review of reported adverse events.

OBJECTIVE

To evaluate the tolerability and safety of chiropractic procedures.

SUMMARY OF BACKGROUND DATA

Despite the increasing popularity of chiropractic, there are few properly designed prospective controlled trials, and there is a disproportionate lack of evaluation of its safety profile. The literature reports multiple neurologic complications of spinal manipulation, some of which are clinically relevant and even life threatening.

METHODS

We performed an electronic search in 2 databases: Pubmed and the Cochrane Library for the years 1966 to 2007. All articles that reported adverse reactions associated with chiropractic were included irrespective of type of design. The outcome measures were the type of adverse events associated or attributed to chiropractic interventions and their frequency.

RESULTS

A total of 376 potential relevant articles were identified, 330 of which were discarded after abstract or complete article analysis. The search identified 46 articles that included data concerning adverse events: 1 randomized controlled trial, 2 case-control studies, 7 prospective studies, 12 surveys, 3 retrospective studies, and 115 case reports. Most of the adverse events reported were benign and transitory, however, there are reports of complications that were life threatening, such as arterial dissection, myelopathy, vertebral disc extrusion, and epidural hematoma. The frequency of adverse events varied between 33% and 60.9%, and the frequency of serious adverse events varied between 5 strokes/100,000 manipulations to 1.46 serious adverse events/10,000,000 manipulations and 2.68 deaths/10,000,000 manipulations.

CONCLUSION

There is no robust data concerning the incidence or prevalence of adverse reactions after chiropractic. Further investigations are urgently needed to assess definite conclusions regarding this issue.

Horner’s syndrome, Pseudo-Horner’s syndrome, and simple anisocoria

This discussion reviews the common causes of Horner's syndrome, with emphasis on case reports from the past several years. Much of the recent literature concerns the use of apraclonidine as a diagnostic test for Horner's syndrome, possibly as an alternative for the current gold standard of cocaine eye drops. This new literature is discussed in the context of the current standards for clinical diagnosis.