Ross Hauser, MD

Tinnitus is the perception of sound when no external sound is present. People may describe ringing, buzzing, humming, clicking, hissing, roaring, or a rhythmic pulse. The symptom can arise from hearing loss, noise exposure, medications, an ear disorder, migraine, temporomandibular joint dysfunction, vascular disease, or changes within the auditory nervous system.

This article examines one part of that broad differential diagnosis: tinnitus that may be influenced by the cervical spine, jaw, upper-cervical nerves, posture, or venous blood flow from the brain.

At Caring Medical, we see patients whose tinnitus occurs alongside neck pain, headaches, dizziness, ear pressure, jaw symptoms, visual complaints, or neurological-type symptoms. Some report that their tinnitus changes when they rotate their neck, extend their head, clench their jaw, or alter their posture. This pattern can suggest a somatosensory or mechanical influence, but it does not prove that cervical instability is the cause.

Not every case of tinnitus is caused by cervical ligament injury, and correcting a neck problem cannot be expected to resolve every type of tinnitus. The first priority is identifying or excluding established auditory, neurological, and vascular causes.

When the tinnitus patient has already had many ear examinations

One patient described the experience this way:

“I had three ear tests and went to a well-known hearing specialist. The doctor looked in my ears and said my ears were healthy. The hearing tests were reviewed, and I was told I did not need hearing aids. The doctor was very nice, but I still had no explanation for the ringing.”

Many people who contact us have already undergone hearing tests, ear examinations, medication trials, sound therapy, behavioral therapy, dental treatment, or other approaches. These treatments can be valuable, but they may not explain tinnitus that changes with neck or jaw movement or that occurs as part of a larger group of head-and-neck symptoms.

Symptoms that may prompt consideration of a somatosensory, jaw, or cervical contribution include:

• tinnitus that changes with head rotation, neck extension, jaw opening, chewing, or clenching;
• tinnitus accompanied by neck pain, reduced neck motion, or headaches;
• jaw pain, temporomandibular joint clicking, or bruxism;
• ear fullness, sound sensitivity, or dizziness;
• tinnitus that began after a whiplash injury or other head-and-neck trauma; and
• tinnitus that is consistently affected by posture.

Unilateral tinnitus, facial numbness, facial weakness, a drooping eyelid, sudden hearing loss, or other neurological findings should not simply be attributed to the neck. These findings require appropriate medical assessment.

Ross Hauser, MD discusses the neurology behind why many people with cervical instability complain of tinnitus.

 

In this video, I discuss the different descriptions of tinnitus we hear from patients. Some experience a high-pitched ringing; others report a low-pitched hum, intermittent clicking, or a pulse that follows the heartbeat.

The proposed cervical mechanisms are not all the same. They may involve altered sensory input from the neck or jaw, irritation of upper-cervical nerves, changes in muscle function around the jaw and Eustachian tube, or—among a carefully selected group of patients—altered blood flow through the carotid sheath and internal jugular vein.

Somatosensory tinnitus: when neck or jaw input changes the sound

Somatosensory tinnitus is tinnitus whose loudness, pitch, or character is influenced by sensory input from the neck, jaw, or surrounding muscles. Research supports connections between the somatosensory system and auditory pathways in the brainstem. This provides a plausible explanation for why cervical or temporomandibular input may change an existing tinnitus signal in selected patients. (1)

The diagnosis cannot be made from neck pain alone. The 2023 review on somatosensory tinnitus cautioned that neck pain and temporomandibular disorders are common and may coexist with tinnitus without causing it. More meaningful clues include tinnitus and neck or jaw pain that increase or decrease together, suboccipital muscle tension, bruxism, and reproducible—but not necessarily universal—modulation of tinnitus during movement. (1)

A large international survey of physical symptoms in people with tinnitus

An international web-based survey included 6,115 participants with tinnitus. Researchers reported:

• 69% had some form of neck pain;
• approximately 7% reported a diagnosed temporomandibular disorder;
• nearly 45% reported bruxism; and
• approximately 14% to 23% could change their tinnitus through voluntary movement, depending on the movement tested.

Among participants whose tinnitus cause had been diagnosed by a physician, 12.2% were classified as having somatosensory tinnitus. Head-and-neck symptoms, tinnitus fluctuation, and the ability to modulate tinnitus through head or jaw movement were more common in the somatosensory group. (2)

These findings establish an association. They do not show that cervical instability was present or that it caused the tinnitus.

Tinnitus, the temporomandibular joint, and the cervical spine

Some patients tell us:
“My tinnitus becomes louder or quieter when I rotate my neck. Looking up and down changes it, and then my jaw starts to hurt.”
The jaw and cervical spine function as connected regions. Muscles used for chewing, swallowing, and head positioning interact, and altered sensory input from either region can influence brainstem processing.

A systematic review involving prevalence data from 13,358 patients and 33,876 controls found that tinnitus occurred more frequently in people with temporomandibular disorders. Across the included studies, median tinnitus prevalence was 42.3% among patients with TMD and 12% among controls. However, treatment evidence was weak because only one of eight TMD-treatment studies included a control group. (3)

A second systematic review and meta-analysis also found higher tinnitus prevalence among people with TMD than among people without TMD. The authors emphasized the limited number and heterogeneity of the available studies. (4)

The correct conclusion is that TMD and tinnitus frequently coexist. These studies do not establish that every case of TMD-related tinnitus begins in the cervical spine. At Caring Medical, our clinical perspective is that cervical mechanics may deserve consideration when jaw symptoms, neck pain, altered posture, and movement-dependent tinnitus occur together.

For additional discussion, see our article on temporomandibular joint syndrome and conservative injection treatments.

Musculoskeletal physical therapy for somatosensory tinnitus

The 2023 review concluded that the strongest current treatment evidence for appropriately identified somatosensory tinnitus supports musculoskeletal care directed at cervical or temporomandibular dysfunction. Published approaches have included education, exercises, manual treatment, and techniques intended to improve mobility, strength, coordination, and muscle tension. (1)

Most studies report reduced tinnitus severity or loudness rather than complete remission. Patient selection remains important, and larger randomized trials are still needed.

This distinction matters. A response to physical therapy may support a mechanical influence, but it does not by itself diagnose cervical ligament instability. Conversely, failure of routine physical therapy does not prove that ligament laxity is present.

Venous hum and pulsatile tinnitus

Pulsatile tinnitus is typically rhythmic and synchronized with the heartbeat. Unlike common subjective tinnitus, it can sometimes arise from an identifiable vascular sound source.

A foundational 1983 paper described venous hum tinnitus arising from abnormal venous flow in the neck or cranial cavity. The authors noted that jugular-origin tinnitus could be sufficiently loud to disturb sleep and hearing. (5)

Our understanding and treatment of venous tinnitus have changed considerably since that paper. Jugular ligation is not a general treatment recommendation for modern tinnitus care. Contemporary assessment focuses on identifying the anatomical and physiological source of the sound and determining whether a vascular finding is truly responsible for the symptom.

Potential vascular or pressure-related contributors to pulsatile tinnitus include:

• venous sinus stenosis;
• abnormalities of the jugular bulb or sigmoid sinus;
• internal jugular vein compression or stenosis;
• enlarged collateral or emissary veins;
• dural arteriovenous fistula;
• carotid artery disease;
• idiopathic intracranial hypertension; and
• other vascular malformations.

Patients can learn more in our detailed article on internal jugular vein compression and stenosis.

New 2026 review: When tinnitus may involve cerebral venous outflow

An independent 2026 narrative review examined tinnitus associated with internal jugular vein compression, jugular stenosis, and other cerebral venous outflow disorders. The authors emphasized that classical venous pulsatile tinnitus and broader tinnitus-like symptoms associated with jugular outflow disturbance may overlap, but they should not be treated as the same diagnosis. (6)

Structural venous abnormalities or external compression may disturb blood flow and create a pulse-synchronous sound. By comparison, proposed mechanisms for non-pulsatile humming, buzzing, or pressure sensations include venous congestion, altered intracranial pressure, cerebral-perfusion changes, and changes in central auditory processing. These broader mechanisms remain hypotheses rather than proven explanations for every patient.

No single imaging test answers every question

The review described several complementary forms of evaluation:

• MRI and MR venography can assess intracranial veins, venous sinuses, soft tissue, tumors, and other possible causes.
• CT angiography or CT venography can better define bony anatomy and external compression involving the styloid process, C1, or neighboring structures.
• Doppler ultrasound can provide information about blood-flow direction and velocity and may permit assessment during selected head positions.
• Catheter venography with manometry can define venous anatomy and measure pressure gradients, but it is invasive and is generally reserved for selected cases in which the result could affect an interventional decision.

The review also emphasized that radiographic narrowing may be incidental. There is not yet a validated framework that combines symptom type, laterality, collateral drainage, imaging, and hemodynamic measurements to determine whether an extracranial jugular abnormality is causing tinnitus. (6)

Jugular narrowing is common on static imaging

A multicenter study of 679 patients who underwent neck CT angiography primarily during stroke evaluation found some degree of internal jugular vein narrowing in 68%. Severe unilateral narrowing of at least 51% was present in approximately 21%, while complete or near-complete occlusion occurred in 8%. Greater narrowing correlated with larger suboccipital collateral veins. (7)

This study provides an important caution: a narrow jugular vein on a scan does not automatically explain tinnitus, headache, dizziness, brain fog, or visual symptoms. The scans were static, and the study did not systematically evaluate tinnitus, positional symptoms, pressure gradients, or cervical instability.

For a venous finding to be considered clinically meaningful, there should be agreement among the patient’s symptom pattern, side and location of the anatomical finding, collateral drainage, objective flow disturbance, positional behavior, and—when appropriate—pressure measurements.

The Caring Medical cervical and carotid-sheath research perspective

In a 2026 retrospective cross-sectional study, our research group reviewed the initial findings of 227 consecutive adults aged 20 to 50 who presented to an outpatient neck center with persistent brain-based symptoms. The cohort had high frequencies of forward-head posture, reduced cervical lordosis, C1–C2 ligamentous instability, small internal jugular vein and vagus nerve cross-sectional areas, and enlarged optic nerve sheath measurements. Internal jugular vein area at C1 increased significantly when patients were positioned on a cervical orthotic compared with ordinary supine positioning. (8)

This was a selected symptomatic clinic population, not a random sample of the public. The study was cross-sectional, had no asymptomatic control group, and did not evaluate treatment outcomes. It demonstrates patterns and associations; it does not prove that cervical instability caused tinnitus or the other reported symptoms.

Our clinical and research hypothesis is that, in a subset of patients, cervical dysstructure or abnormal upper-cervical motion may affect structures within or near the carotid sheath. The independent 2026 venous-tinnitus review supports investigating anatomy, flow, symptoms, and pressure together, but it does not independently validate cervical ligament instability as the cause of jugular obstruction. (6)

Tinnitus can have an explanation and still persist after treatment

One proposed classification divides tinnitus into potentially treatable causes, tinnitus without a clear medical explanation, and tinnitus that persists even after an identified disorder has been treated. (9)

This helps explain why patients can undergo earwax removal, blood-pressure treatment, medication changes, dental care, or another seemingly appropriate intervention and still experience tinnitus. Tinnitus frequently becomes a multifactorial condition involving peripheral hearing, brain processing, sleep, mood, musculoskeletal input, and—in selected cases—vascular physiology.

The Tinnitus Handicap Inventory and the lived experience of tinnitus

The Tinnitus Handicap Inventory, or THI, is commonly used to measure how tinnitus affects daily life. A large observational study of 1,042 adults found that THI scores were influenced by hearing status and sex, supporting a more nuanced interpretation of tinnitus burden. (10)

The questions address concerns familiar to many patients:

• Does tinnitus make you angry or upset?
• Does it interfere with work or household responsibilities?
• Does it create confusion, desperation, or fear of serious disease?
• Does it place stress on relationships?
• Do you feel unable to escape the sound?

A qualitative study also found that the effects of tinnitus on sleep, concentration, social activity, and mood varied greatly among individuals. (11)

These consequences are real regardless of whether the primary mechanism is auditory, neurological, musculoskeletal, vascular, or multifactorial.

Ear pain, ear fullness, sound sensitivity, and Eustachian tube symptoms

In this video, I discuss patients who report tinnitus together with ear pain, ear fullness, reduced hearing, sound sensitivity, dizziness, or a diagnosis such as Ménière’s disease.

The Eustachian tube connects the middle ear to the upper throat and helps regulate pressure. Its opening and closing depend on coordinated muscle and nerve function. We have proposed that altered cervical and cranial-nerve mechanics may contribute to dysfunction in selected patients, but this remains a proposed mechanism rather than an established cause of most Eustachian tube disorders.

For more detail, see our articles on cervical instability and Eustachian tube dysfunction and Ménière’s disease and venous-fluid dynamics.

The existing video includes an individual patient who reported hearing improvement following cervical treatment. This is a clinical example, not evidence that the same outcome should be expected in other patients. Hearing loss requires appropriate audiological and medical evaluation.

Why examining the neck and jaw can still be important

A survey of ear, nose, and throat physicians found that otoscopic examination was routine, while examination for temporomandibular disorders and neck trauma was performed less consistently. (12)

A primary-care review of tinnitus evaluation noted that changes in tinnitus during teeth grinding, resisted head movement, or head turning may suggest a somatosensory component. Neck tenderness, restricted motion, TMJ tenderness, jaw crepitus, or tenderness of the chewing muscles may provide additional clues. (13)

These observations do not replace a hearing evaluation, and they do not establish cervical instability. They help identify patients in whom the neck or jaw may be one contributing part of the tinnitus presentation.

Patient story: tinnitus with brain fog, dizziness, swallowing, and breathing symptoms

Brad’s experience is retained because it illustrates the multisystem symptom combinations reported by some patients after significant neck trauma. His symptoms included:

• ringing and unusual sensations in the ears;
• severe episodes of dizziness;
• brain fog;
• episodic breathing difficulty;
• swallowing difficulty and panic;
• loss of muscular control during rightward head rotation; and
• neck symptoms following a 12-foot fall and hyperextension injury.

He later reported broad improvement after eight Prolotherapy sessions and cervical-curve correction, with only slight residual ringing. This is an individual outcome. It cannot establish which treatment component produced the improvement, and it should not be interpreted as an expected result for every patient with tinnitus.

Cervical nerve research: C2, C3–C4, and C6–C7

Researchers have explored whether altering cervical sensory input can reduce tinnitus in selected patients.

C3 and C4 nerve infiltration

A retrospective study treated 37 patients using infiltration of the third and fourth cervical nerves. Nineteen percent reported reduced tinnitus, usually by approximately 25% to 50%. At an average of 3.8 months, half of those who initially responded continued to report benefit. (14)

This was a small uncontrolled retrospective study. It suggests that cervical afferent input may influence tinnitus in some patients but does not establish an effective general treatment.

C2 dorsal-root-ganglion pulsed radiofrequency

Another study treated 61 consecutive patients with pulsed radiofrequency directed at the C2 dorsal root ganglion. Twenty-five percent reported decreased tinnitus. At approximately 13.5 months, half of the initial responders continued to report benefit. (15)

Caring Medical does not use this treatment. Its relevance here is that altering upper-cervical nerve input affected tinnitus in a subset of patients.

C6 and C7 cervical nerve treatment

A study of 78 patients reported reduced tinnitus in 18% following treatment directed at the C6 and C7 cervical nerves. Benefits were moderate and persisted in approximately half of the initial responders at two and five months. (16)

Taken together, these studies support a possible cervical sensory influence. Their uncontrolled designs, modest response rates, and specialized interventions prevent broad conclusions.

Clocking tinnitus and migraine

Not all movement-associated or intermittent tinnitus originates in the neck. A small study described ten patients with a ticking sound resembling a pendulum or quartz clock. Seven had a history of migraine, and six experienced migraine symptoms during tinnitus attacks. The authors proposed that “clocking tinnitus” could be an auditory manifestation of migraine in some patients. (17)

Migraine therefore belongs in the differential diagnosis, especially when tinnitus occurs with light sensitivity, sound sensitivity, headache, visual aura, nausea, or episodic vertigo.

Tinnitus and the trigeminal nerve

The trigeminal nerve carries sensation from the face and supplies muscles involved in chewing. A population-based study found an increased risk of tinnitus during the year after a trigeminal-neuralgia diagnosis. The authors discussed convergence between auditory and somatosensory pathways in the brainstem as a possible explanation. (18)

This association does not show that trigeminal neuralgia or cervical instability universally causes tinnitus. It reinforces the broader concept that tinnitus can be influenced by non-auditory sensory pathways. See our related article on trigeminal neuralgia.

Improving tinnitus by treating cervical and jaw dysfunction

A case report described a 42-year-old man with intermittent bilateral tinnitus, headaches, blurred vision, neck tightness, restricted cervical motion, and TMJ asymmetry. Resisted cervical contractions increased his tinnitus. Following ten physical-therapy sessions directed at cervical and TMJ dysfunction, his THI score fell from 62 to 0 while cervical motion improved. (19)

A second case involved a 67-year-old woman with five years of unilateral tinnitus, neck pain, and headache. Directional exercises and postural correction were followed by improvement in tinnitus and neck disability scores over six months. (20)

Both cases are useful clinical signals, but neither can prove effectiveness. Case reports are particularly vulnerable to placebo effects, natural symptom fluctuation, co-interventions, and selective publication.

Pulsatile Tinnitus and Cervical Instability

Tinnitus, postural instability, and proprioception

Proprioception is the nervous system’s awareness of body and joint position. One observational paper described substantial overlap among tinnitus, cervical pain, dizziness, postural instability, altered cervical lordosis, and lower-cervical degeneration. The author proposed that abnormal cervical proprioceptive input could participate in some tinnitus presentations. (21)

This remains a proposed pathway. Postural instability and tinnitus have many other possible causes, including vestibular disorders, migraine, medication effects, peripheral neuropathy, visual impairment, and neurological disease.

A documented example of C1-related jugular compression

A 2026 case report described a 73-year-old patient with vertigo, nystagmus, and gait instability whose CT imaging showed left internal jugular vein compression by the C1 transverse process. Symptoms reportedly improved after venous stenting. (22)

This case demonstrates anatomical possibility, not prevalence or general treatment effectiveness. A single report cannot establish that C1-related jugular compression commonly causes tinnitus, dizziness, or balance disorders, and it cannot determine whether stenting is preferable to decompression or conservative treatment.

Research on cervical instability and Prolotherapy

Prolotherapy is a regenerative injection technique intended to stimulate repair at painful or injured ligament and tendon attachments. It has been used for many decades for musculoskeletal pain and instability. An early paper described its use for headache and pain involving the head and neck, but it predates modern trial methodology and should be interpreted as historical rather than definitive evidence. (23)

In 2014, our group published a review connecting capsular-ligament laxity with chronic neck pain and cervical instability. The paper discussed how upper-cervical instability could potentially be associated with headache, dizziness, vertigo, tinnitus, facial pain, and other symptoms. (24)

In 2015, we published a case series describing patients diagnosed with Barré–Liéou syndrome and treated with cervical Prolotherapy. Symptoms reported in the series included neck pain, headache, dizziness, vertigo, tinnitus, and visual or auditory disturbances. (25)

These Caring Medical publications are not randomized controlled trials. The 2014 paper was a narrative review, and the 2015 publication was an uncontrolled case series. They support further study of ligamentous cervical instability and regenerative treatment but do not prove that Prolotherapy cures tinnitus.

Our treatment hypothesis is that when a patient has independently supported cervical ligament instability—and the tinnitus is part of a reproducible cervical symptom pattern—addressing the injured stabilizing structures may reduce abnormal mechanical and sensory input. Outcomes vary, and tinnitus may persist even if neck pain or stability improves.

For more information, see our detailed pages on Prolotherapy and craniocervical and cervical instability.

References

1 Michiels S. Somatosensory Tinnitus: Recent Developments in Diagnosis and Treatment. Journal of the Association for Research in Otolaryngology. 2023;24(5):465–472. [Google Scholar]
2 Michiels S, Harrison S, Vesala M, Schlee W. The Presence of Physical Symptoms in Patients With Tinnitus: International Web-Based Survey. Interactive Journal of Medical Research. 2019;8(3):e14519. [Google Scholar]
3 Skog C, Fjellner J, Ekberg E, Häggman-Henrikson B. Tinnitus as a Comorbidity to Temporomandibular Disorders—A Systematic Review. Journal of Oral Rehabilitation. 2019;46(1):87–99. [Google Scholar]
4 Mottaghi A, Menéndez-Díaz I, Cobo JL, González-Serrano J, Cobo T. Is There a Higher Prevalence of Tinnitus in Patients With Temporomandibular Disorders? A Systematic Review and Meta-Analysis. Journal of Oral Rehabilitation. 2019;46(1):76–86. [Google Scholar]
5 Chandler JR. Diagnosis and Cure of Venous Hum Tinnitus. The Laryngoscope. 1983;93(7):892–895. [Google Scholar]
6 Gao X, Liu J. Tinnitus and Tinnitus-Like Symptoms in Cerebral Venous Outflow Disorders: A Critical Review. Journal of Visualized Experiments. 2026;(236). doi:10.3791/72090. [Google Scholar]
7 Clausen TM, Amans MR, Snyder EM, et al. Prevalence of Internal Jugular Venous Stenosis and Cervical Collaterals in Patients Undergoing Workup for Ischemic Stroke Large Vessel Occlusion. AJNR American Journal of Neuroradiology. 2026;47(10):2538–2543. [Google Scholar]
8 Hauser RA, Griffiths M, Watterson A, Matias D, Steilen C, Rawlings BR. Brain-Based Symptoms Reported in Young Adults Evaluated for Cervical Spine Etiology: A Retrospective, Cross-Sectional Clinical Study With Preliminary Data on Over 200 Patients. Frontiers in Neurology. 2026;17:1749266. [Google Scholar]
9 Lee KJ, Liu K. Tinnitus: A Stepchild in Our Specialty. Otolaryngology–Head and Neck Surgery. 2018;159(4):599–600. [Google Scholar]
10 Skarżyński PH, Rajchel JJ, Gos E, et al. A Revised Grading System for the Tinnitus Handicap Inventory Based on a Large Clinical Population. International Journal of Audiology. 2020;59(1):61–67. [Google Scholar]
11 Colagrosso EMG, Fournier P, Fitzpatrick EM, Hébert S. A Qualitative Study on Factors Modulating Tinnitus Experience. Ear and Hearing. 2019;40(3):636–644. [Google Scholar]
12 Tamir SO, Marom T, Shushan S, Goldfarb A, Cinamon U, Handzel O, Gluck O, Oron Y. Tinnitus Perspectives Among Israeli Ear, Nose and Throat Physicians: A Nationwide Survey. Journal of International Advanced Otology. 2018;14(3):405–410. [Google Scholar]
13 Yew KS. Diagnostic Approach to Patients With Tinnitus. American Family Physician. 2014;89(2):106–113. [Google Scholar]
14 Koning HM. Upper Cervical Nerves Can Induce Tinnitus. International Tinnitus Journal. 2020;24(1):26–30. [Google Scholar]
15 Koning HM, Ter Meulen BC. Pulsed Radiofrequency of C2 Dorsal Root Ganglion in Patients With Tinnitus. International Tinnitus Journal. 2019;23(2):91–96. [Google Scholar]
16 Koning HM. Cervical Nerve Projections to the Auditory Pathway in Tinnitus. International Tinnitus Journal. 2020;24(2):70–74. [Google Scholar]
17 Chen WH, Hsu YL, Chen YS, Yin HL. Clocking Tinnitus: An Audiology Symptom of Migraine. Clinical Neurology and Neurosurgery. 2019;177:73–76. [Google Scholar]
18 Cheng YF, Xirasagar S, Yang TH, et al. Increased Risk of Tinnitus Following a Trigeminal Neuralgia Diagnosis: A One-Year Follow-Up Study. Journal of Headache and Pain. 2020;21(1):46. [Google Scholar]
19 Cherian K, Cherian N, Cook C, Kaltenbach JA. Improving Tinnitus With Mechanical Treatment of the Cervical Spine and Jaw. Journal of the American Academy of Audiology. 2013;24(7):544–555. [Google Scholar]
20 Wu D, Ham D, Rosedale R. Physiotherapy Assessment and Treatment of Chronic Subjective Tinnitus Using Mechanical Diagnosis and Therapy: A Case Report. Journal of Manual & Manipulative Therapy. 2020;28(2):119–126. [Google Scholar]
21 Koning HM. Proprioception: The Missing Link in the Pathogenesis of Tinnitus? International Tinnitus Journal. 2020;24(2):102–107. [Google Scholar]
22 Gutierrez-Trevino O, Martinez HR, Flores-Salcido R, et al. Internal Jugular Vein Stenosis Induced by C1 Transverse Process Successfully Treated With Venous Stenting: A Case Report. Journal of Cerebrovascular and Endovascular Neurosurgery. 2026;28(2):184–189. [Google Scholar]
23 Hackett GS, Huang TC. Prolotherapy for Headache: Pain in the Head and Neck, and Neuritis. Headache. 1962;2:20–28. [Google Scholar]
24 Steilen D, Hauser R, Woldin B, Sawyer S. Chronic Neck Pain: Making the Connection Between Capsular Ligament Laxity and Cervical Instability. The Open Orthopaedics Journal. 2014;8:326–345. [Google Scholar]
25 Hauser RA, Steilen D, Sprague IS. Cervical Instability as a Cause of Barré–Liéou Syndrome and Definitive Treatment With Prolotherapy: A Case Series. European Journal of Preventive Medicine. 2015;3(5):155–166. [Google Scholar]