Improvement in hearing after chiropractic care: a case series - Deafness Research

Improvement in hearing after chiropractic care: a case series

Joseph O Di Duro*
Address: Palmer Center for Chiropractic Research, 741 Brady Street, Davenport, IA 52803-5287
Email: Joseph O Di Duro* - joseph.diduro@palmer.edu
* Corresponding author
Abstract
Background: The first chiropractic adjustment given in 1895 was reported to have cured deafness. This study examined the effects of a single, initial chiropractic visit on the central nervous system by documenting clinical changes of audiometry in patients after chiropractic care.
Case presentation: Fifteen patients are presented (9 male, 6 female) with a mean age of 54.3 (range 34Ò71). A Welch Allyn AudioScope 3 was used to screen frequencies of 1000, 2000, 4000 and 500 Hz respectively at three standard decibel levels 20 decibels (dB), 25 dB and 40 dB, respectively, before and immediately after the first chiropractic intervention. Several criteria were used to determine hearing impairment. Ventry & Weinstein criteria of missing one or more tones in either ear at 40 dB and Speech-frequency criteria of missing one or more tones in either ear at 25 dB.
All patients were classified as hearing impaired though greater on the right. At 40 dB using the Ventry & Weinstein criteria, 6 had hearing restored, 7 improved and 2 had no change. At 25 dB using the Speech-frequency criteria, none were restored, 11 improved, 4 had no change and 3 missed a tone.
Conclusion: A percentage of patients presenting to the chiropractor have a mild to moderate hearing loss, most notably in the right ear. The clinical progress documented in this report suggests that manipulation delivered to the neuromusculoskeletal system may create central plastic changes in the auditory system.

Background
The broad category of hearing loss is the third most prevalent
chronic condition in older Americans, following
hypertension and arthritis [1]. Between 25% and 40% of
the population aged 65 years or older is hearing impaired
[2]. Hearing impairment refers to limitation of function
or raised hearing threshold (inability to hear tones at a
normal level) and this implies a total or partial loss of the
ability to perceive acoustic information. The impairment
may affect the full range of hearing or be limited to parts
of the auditory spectrum. This impairment is expressed as
decibels of hearing loss (dB HL) relative to the hearing of
a normal population. The Veterans Health Administration
has used the criteria of failure to hear a 40 decibel tone (40
dB threshold) as hearing loss, though other criteria can be
used. Testing is also conducted at specific frequencies
(250, 500, 1000, 2000 and 4000 Hz) as the ear is particularly
sensitive to these signals which include the frequencies
most important for speech processing.
The diminished ability to hear and to communicate is
frustrating in and of itself, but the strong association hear-
ing loss with depression and functional decline adds further
to the burden on older individuals [3]. The onset of
sensorineural loss, or presbycusis, is insidious and
patients themselves are frequently unaware of their hearing
loss. Hearing loss often goes undiagnosed because of
its slow onset and the chiropractic patient population
may be an ideal place for hearing screenings.
Chiropractic has long been associated with hearing. The
first chiropractic adjustment given in 1895 was reported
to have cured deafness. Wagner and Fend [4], from Germany,
reported a case where a 36 year old male soccer
player became suddenly deaf in his right ear with tinnitus
following hitting the ball with his head. An audiogram
showed that loss of hearing at 500 Hz and he was diagnosed
by the physician as almost completely deaf in the
right ear. Following adjustments to the thoracic spine,
(T6) the right sacroiliac joint and restrictions on the right
side of the neck (C2ÒC4) were adjusted, with an audible
pop detected during the manipulation, the patient
reported a sudden improvement of hearing in that he
could hear a whisper from four meters. The post audiogram
showed his hearing had returned.

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