We have repeatedly discussed the risks of chiropractic spinal manipulation (see, for instance here, here and here). Some chiropractors seem to believe that using a hand-held manipulator, called ‘activator’, better controls the forces used on the spine and therefore is safer. This recent paper raises doubts on this hypothesis.
A neurosurgeon from Florida published the case-report of a 75-year-old active woman who presented to a local hospital emergency room with a 3-day history of the acute onset of severe left temporal headache, initially self-treated with non-steroidals, to which they were resistant. Additional complaints included some vague right eye blurring of vision and a mild speech disturbance. Her primary-care physician had ordered an outpatient MRI, which was interpreted as showing a small sub-acute left posterior temporal lobe haemorrhage. He then referred her to the emergency room where she was categorized as a “stroke alert” and evaluated according to the hospital “stroke-alert” protocol.
There was no prior history of migraine, but some mild treated hypertension. The patient subsequently gave a history of chronic neck and back pain, but no headache, for which she had intermittently received chiropractic adjustments. Her current problem started after an activator treatment to the base of the left side at the junction of the skull with the upper cervical spine. She became concerned enough a few days later, because of the persistence of unremitting headache, to contact her primary-care physician. The patient was not taking any anticoagulants or antiplatelet agents and had a relatively unremarkable past medical and surgical history. Although she did not have a formal visual field examination or an ophthalmology consultation, she was found to have an incomplete right homonymous hemi-anopsia on clinical exam by the neurologist.
Based on MRI characteristics, the haemorrhage was determined to be primarily subarachnoid and displacing but not involving any brain parenchyma, and without any extra-axial component. After a 4-day hospitalization for evaluation and observation, the patient was discharged, neurologically improved in terms of visual and speech symptoms as well as headache complaints, to outpatient follow-up. She has remained well with resolution of imaging abnormalities and no reoccurrence of symptoms.
The authors explain how difficult it is to prove specific causation in such cases. It is frequently inferred by epidemiological reasoning or evidence. While there are other potential causes of the haemorrhage that occurred in this case, none is as or more likely than the activator stimulus. In support of the activator as the cause of the haemorrhage, the symptoms began almost immediately after the activator treatment (a temporal relationship), the area to which the activator was applied is almost directly superficial to the area of haemorrhage (a spatial relationship), the anatomic location of this haemorrhage is statistically unusual for any underlying and/or preexisting conditions, including stroke. The MRI confirmed that there was no infarction underlying the area of haemorrhage. The MRA disclosed no dissections or vascular lesions present. The only mechanisms left are trauma or cryptic vascular lesion that ruptured, obliterated itself, and occurred coincident to the activator stimulus. Although Activator stimulus is not high energy, it nonetheless was targeted to the cervico-occipital junction, an area where neural tissue is among the most vulnerable and least protected and closest to the skin (as opposed to the lower cervical or any of the thoracic or lumbar spine). There are many articles that make reference to minor or trivial head injury as a likely cause of intracranial haemorrhage.
The author concluded that he was unable to find a single documented case in which a brain hemorrhage in any location was reported from activator treatment. As such, this case appears to represent the first well-documented and reported brain hemorrhage plausibly a consequence of activator treatment. In the absence of any relevant information in the chiropractic or medical literature regarding cerebral hemorrhage as a consequence of activator treatment, this case should be instructive to the clinician who is faced with a diagnostic dilemma and should not forget to inquire about activator treatment as a potential cause of this complication. Our case had a benign course, but we do not rule out a more serious or potentially dangerous clinical course or adverse outcome. This is of heightened concern in the elderly and/or those with treatment-induced coagulopathy or platelet inhibition.
In light of all of the difficulties inherent in linking chiropractic treatments, including activator treatments, with serious neurological events, it is very possible that intracranial hemorrhage is far more frequent than reported. Several articles comment on the likelihood that complications of this type are almost certainly underreported. Most of the incidents mentioned in case series or surveys had never been previously reported. Neurologists, neurosurgeons, and chiropractors should be more vigilant both in the application and evaluation of these methods in all patients who report new neurologic-type symptoms following a manipulation (including an activator application) to the occiput or the cranio-cervical junction.
I think that case-report speaks for itself.
Chiropractors will, of course, argue (yet again) that:
- conventional treatments cause much more harm,
- spinal manipulation is highly effective,
- such complications are extreme rarities,
- the risk/benefit profile of spinal manipulation is positive,
- some studies have failed to show a risk of spinal manipulation,
- case-reports cannot establish causality.
We have rehearsed these arguments ad nauseam on this blog. The bottom line is well-expressed in the above conclusions: it is very possible that intracranial hemorrhage is far more frequent than reported. And that obviously applies to all other types of complications after chiropractic treatments.