Chiropractic originated in 1895 when D.D. Palmer claimed to have restored deaf janitor Harvey Lillard’s hearing by manipulating his spine. This makes no anatomical sense, and few if any chiropractors claim to be able to reverse deafness today. But now a chiropractic website is attempting to vindicate D. D. Palmer. They list deafness among a long (wrong) list of “Conditions That Respond Well to Chiropractic” They list 6 supporting studies. Three are case reports, two are case series, and one is a review of the literature that is labeled in its title as “A Search to Validate” D.D. Palmer.
Study no. 1
One study is a case report entitled “Hearing Loss, Otalgia and Neck Pain: A Case Report on Long-Term Chiropractic Care That Helped to Improve Quality of Life.” I’ll copy the entire abstract to give a flavor of the quality of evidence these chiropractors find acceptable:
Objective: To describe symptom reports, multiple chiropractic assessments and adjustments over 7 years with a patient experiencing neck pain and complex ear symptoms consistent with Meniere’s syndrome.
Clinical Features: A 43-year-old female, injured years earlier in a motor vehicle collision, suffered recurrent exacerbations of otherwise continuous neck pain. Later she developed aural symptoms of severe otalgia, hearing difficulty, tinnitus and dizziness that increased and decreased in severity with her neck pain.
Intervention and Outcome: The intervention was repeated application of chiropractic adjustments using a modified Pettibon adjusting device. Over 7 years of observation, the subject consistently reported reduction in symptom severity after adjustments, with relief lasting up to 2 months. Consistent with the natural history of Meniere’s syndrome, an overall deterioration was noted during the observation period. Hearing fluctuated in approximate synchrony with changes in angular displacements of upper cervical vertebrae during the treatment period.
Conclusion: Observation over an extended period assists in understanding the progression of chronic disorders. This patient experienced substantially reduced symptoms with chiropractic care during the 7-year observation period. Of note is the repeated exacerbation of neck pain that often precedes exacerbation in ear symptoms, along with the relief of both following adjustment and an association between improved hearing and improved cervical alignment.
Comments: This woman’s deafness was part of her Meniere’s disease and was presumably not related in any way to her auto accident or her neck symptoms. The association of reported increases in neck pain with exacerbation of Meniere’s symptoms could be due to the fact that people in pain and people who are in a depressed mood are more likely to report other physical symptoms. Reduction in symptoms after adjustment is compatible with nonspecific effects of any treatment, with placebo response, or with the natural course of illness. Fluctuating hearing loss is one of the characteristics of Meniere’s disease. The Pettibon system is an upper cervical method that is not supported by any credible evidence. The finding of “angular displacements of upper cervical vertebrae” is an upper chiropractic delusion: actual displacements have not been confirmed by conventional radiologists. “Improved cervical alignment” cannot be scientifically demonstrated.
Study no. 2
This was a case report of a 41-year-old woman who had bilateral ear pain, tinnitus, vertigo, “altered or decreased hearing acuity,” and headaches. She had a history of ear infections treated with antibiotics. She had been diagnosed and treated for temporomandibular joint syndrome (TMJ). The chiropractor diagnosed an atlas subluxation and after 9 treatments her symptoms resolved.
Comments: We don’t know what was wrong with this patient. What does “altered or decreased hearing acuity” mean? Hearing can be temporarily decreased by infections with fluid in the middle ear. TMJ does not cause deafness. Atlas subluxations are mythical. Symptoms like these typically fluctuate and may resolve spontaneously over time.
Study no. 3
A case report of a 75 yr old woman with longstanding vertigo, tinnitus and hearing loss. Her symptoms increased over a 5-week period before she sought chiropractic care. Her symptoms improved during upper cervical chiropractic treatment.
Comments: Symptoms fluctuate over time. The chiropractor saw her when the symptoms were at their worst, and regression to the mean explains why she improved. Did she have Meniere’s disease? A fluctuating hearing loss is characteristic of Meniere’s. Upper cervical chiropractic treatment has never been shown to cure anything. There is no reason to think the treatment had anything to do with her improvement.
Study no. 4
“Improvement in Hearing after Chiropractic Care: A Case Series.” Full text available online The subjects were a “sample of convenience” of 15 patients who presented for chiropractic care and whose chief complaint was not hearing loss. All subjects were found to have hearing loss, more in the left ear than the right, and after a single chiropractic visit 8 patients improved in one ear, 3 improved in both ears, four were unchanged, and 3 were worse. The post-treatment tests continued to show worse hearing in the left ear than the right. The author indulges in wild speculation about possible mechanisms including brain plasticity and the effect of peripheral stimulation on thalamic activity in the brain.
Comments: The discussion section of the report admits that this study can’t prove a cause and effect relationship. To support his speculations, the author references Carrick’s ridiculous blind spot study which I critiqued at length in The Scientific Review of Alternative Medicine and briefly on Chirobase. Just citing Carrick’s article is enough to completely discredit the author in my mind. It is junk science and its conclusions depend on circular reasoning. One thing that particularly bothers me about this study is the finding of more hearing loss on the left side. As far as we know, hearing loss should be evenly distributed. What could account for the discrepancy?
Study no. 5
“Vertebrogenic Hearing Deficit, the Spine, and Spinal Manipulation Therapy: A Search to Validate the D.D. Palmer/Harvey Lillard Experience.” This review of the medical and chiropractic literature
suggests that hearing deficits may be associated with spinal joint motion restriction, spondyloarthrosis, irritation of the sympathetic nervous system, decreased cervico-cerebral circulation and/or decrease in tinnitus…It is proposed that some cases may benefit from SMT. Further research is needed to determine the role of SMT in the treatment of vertebrogenic hearing deficits.
Comments: The very title indicates bias. This author cherry-picked the literature in a vain attempt to validate D.D. Palmer. While the literature may “suggest” the associations he lists, it does not “prove” those associations, much less show that any association represents a causal relationship. He does not provide any evidence that SMT can restore hearing. He calls for research into the treatment of “vertebrogenic hearing deficits” but that would just be Tooth Fairy science, since we have no evidence that hearing deficits can be due to vertebral causes.
Study no. 6
“Cervicogenic Hearing Loss.” The author of this case series starts by admitting “there remains a dispute whether a “vertebragenic hearing disorder” exists. This latter disorder is believed accompanied by tinnitus, a feeling of ear pressure, otalgia and deafness as symptoms of a functional deficit of the upper cervical spine.” It studied 259 patients with “well-defined functional deficits of the upper cervical spine and symptoms of cervical vertigo,” and found subjective hearing disorders in 15% and audiometric threshold shifts in 40%. 62 patients with vertebragenic hearing loss improved during chiropractic management. He concludes that the therapy of choice is chiropractic manipulation of the upper cervical spine.
Comments: He doesn’t have any evidence that the disorder exists, but he diagnoses it in 62 patients (!?) At best, this is a case series of questionable significance; at worst it is Tooth Fairy science, studying something that probably doesn’t exist. There were no controls. How can he conclude that the treatment of choice is chiropractic manipulation when he has not compared that to any other treatment?
Elsewhere chiropractic apologists have hypothesized how problems in the spine might lead to effects in the ear. The vertebrobasilar artery passes through the neck and a branch of it supplies the inner ear. Conceivably a neck injury could damage the artery and reduce blood supply to the ear, but it is inconceivable that manipulating the neck could then reverse the damage. Some have posited effects via the autonomic (sympathetic and parasympathetic) nervous system, but they have not demonstrated that an autonomic problem is present, that it could account for the symptoms, or that autonomic effects could be corrected or compensated for by manipulation. Some argue that sensory stimulation of the body can affect stuff in the brain. Sure, if you hit your toe with a hammer, there will be a change in brain activity. That’s a truism, not an argument for spinal manipulation.
There is a rumor (unconfirmed) that Harvey Lillard’s widow later said he was deaf until the day he died. We will never know enough about his case to understand what really happened. But I think we can reasonably conclude that spinal manipulation is not an effective treatment for hearing loss. And that the authors of this website have no understanding of what constitutes credible scientific evidence.
This article was originally published in the Science-Based Medicine Blog.