The potential role of joint injury and eustachian tube dysfunction in the genesis of secondary Ménière's disease.

Ménière's diseasenot only includes the symptom complex consisting of attacks of vertigo, low-frequency hearing loss, and tinnitus but comprises symptoms related to the eustachian tube, the upper cervical spine, the temporomandibular joints, and the autonomic nervous system. Quantifiable experience shows that the insertion of a middle-ear ventilation tube can alleviate Ménière's disease symptoms, suggesting that eustachian tube dysfunction is a contributing feature. Clinical practice also shows that treating disorders of the upper cervical spine and temporomandibular joints can lessen Ménière's disease symptoms, suggesting a relationship. Similarly, stellate ganglion blocks can be beneficial in controlling Ménière's disease symptoms, highlighting the influence of the autonomic nervous system. Thus, contrasting symptoms associated with the eustachian tube, the upper cervical spine, the temporomandibular joints, and the autonomic nervous system relate to Ménière's disease, but the possible reflex pathway by which a link is established is unclear. We made an attempt in this study to describe a hypothetical reflex pathway that links joint injury and the autonomic nervous system, where eustachian tube function is under their influence and is the critical link. In this hypothetical reflex pathway, irritation of facet joints can first lead to an activated anterior cervical sympathetic system via an independent pathway in the mediolateral cell column; it can simultaneously lead to an axon reflex involving nociceptive neurons, resulting in neurogenic inflammation and the prospect of a eustachian tube dysfunction. The eustachian tube dysfunction is responsible for a disturbed middle ear-inner ear pressure relationship, circumstances that have the potential to develop into secondary Ménière's disease. This reflex pathway is supported by recent animal experiments.