Glossopharyngeal neuralgia is a unilateral lesion of the IX cranial nerve, manifested by paroxysms of pain in the root of the tongue, tonsils, pharynx, soft palate and ear. It is accompanied by a violation of the taste perception of the posterior 1/3 of the tongue on the side of the lesion, a violation of salivation, a decrease in pharyngeal and palatine reflexes. Diagnosis of pathology includes examination by a neurologist, an otolaryngologist and a dentist, MRI or CT of the brain. Treatment is mainly conservative, consisting of analgesics, anticonvulsants, sedative and hypnotic medications, vitamins and general tonic agents, physiotherapy techniques.
General information
Glossopharyngeal neuralgia is a fairly rare disease. There are about 16 cases per 10 million people. People over the age of 40 usually suffer, men more often than women. The first description of the disease was given in 1920 by Sikar, in connection with which the pathology is also known as Sikar syndrome.
Specialists in the field of neurology distinguish 2 forms of the disease: idiopathic (primary) and symptomatic (secondary), developing with injuries, infectious processes of the posterior cranial fossa, compression of the nerve by a tumor.
Anatomy and functions
The lingopharyngeal nerve (n. glossopharyngeus) originates in several nuclei of the medulla oblongata. It consists of sensitive, motor and vegetative parasympathetic fibers. Sensitive fibers begin in the nucleus of the same name, common to the lingopharyngeal and vagus nerve (n.vagus), innervate the mucous membrane of the tonsils, soft palate, pharynx, tongue, eustachian tube, tympanic cavity. The fibers of taste sensitivity come out of the nucleus of a single pathway shared with an intermediate nerve that provides a sense of taste of the anterior 2/3 of the tongue. The taste fibers of the lingopharyngeal nerve are responsible for the perception of taste by the posterior 1/3 of the surface of the tongue and the epiglottis.
The motor fibers of the pharyngeal nerve originate from the double nucleus, common with the N.vagus, and innervate the pharyngeal muscle that raises the pharynx. Along with the vagus nerve, the motor and sensory fibers of N. glossopharyngeus form reflex arcs of the palatine and pharyngeal reflexes.
The parasympathetic fibers that are part of the lingopharyngeal nerve begin from the lower salivary nucleus, as part of the tympanic, and then the small stony nerve reach the auricular vegetative ganglion, from where they reach the parotid gland with a branch of the trigeminal nerve, the salivation of which they regulate.
The commonality of the nuclei and pathways of the lingopharyngeal and vagus nerves leads to an extremely rare occurrence of isolated pathology of N. glossopharyngeus. More often, with neuritis of the lingopharyngeal nerve, the symptoms of their combined lesion are observed.
Causes
In some cases, the glossopharyngeal neuralgia is idiopathic in nature and it is not possible to accurately determine its etiology. Atherosclerosis, infections of the ENT organs (otitis media, tonsillitis, chronic pharyngitis, sinusitis), acute and chronic intoxication, viral infections (for example, influenza) are considered significant factors in the development of the disease.
Secondary glossopharyngeal neuralgia can occur with infectious pathology of the posterior cranial fossa (encephalitis, arachnoiditis), traumatic brain injuries, metabolic disorders (diabetes mellitus, hyperthyroidism) and compression (irritation) of the nerve at any site of its passage. The latter is possible with intracerebral tumors of the bridge-cerebellar angle (glioma, meningioma, medulloblastoma, hemangioblastoma), intracerebral hematomas, nasopharyngial tumors, hypertrophy of the styloid process, carotid artery aneurysm, ossification of the stylo-lingual ligament, proliferation of osteophytes of the jugular foramen. A number of clinicians say that in some cases, glossopharyngeal neuralgia may be the first symptom of laryngeal cancer or pharyngeal cancer.
Symptoms
Glossopharyngeal neuralgia is clinically manifested by unilateral pain paroxysms, the duration of which varies from a few seconds to 1-3 minutes. Intense pain begins at the root of the tongue and quickly spreads to the soft palate, tonsils, pharynx and ear. Possible irradiation to the lower jaw, eye and neck. Pain paroxysm can be provoked by chewing, coughing, swallowing, yawning, taking excessively hot or cold food, and ordinary conversation. During an attack, patients usually feel dryness in the throat, and after it — increased salivation. However, dry throat is not a permanent sign of the disease, since in many patients, secretory insufficiency of the parotid gland is successfully compensated by other salivary glands.
Swallowing disorders associated with paresis of the pharyngeal muscle are not clinically pronounced, since the role of this muscle in the act of swallowing is insignificant. Along with this, there may be difficulties in swallowing and chewing food associated with a violation of various types of sensitivity, including proprioceptive — responsible for the sensation of the position of the tongue in the oral cavity.
Often, the glossopharyngeal neuralgia has a wave-like course with exacerbations in the autumn and winter periods of the year.
Diagnostics
Glossopharyngeal neuralgia is diagnosed by a neurologist, although to exclude diseases of the oral cavity, ear and throat, a consultation of a dentist and an otolaryngologist is required, respectively. Neurological examination determines the absence of pain sensitivity (analgesia) in the area of the base of the tongue, soft palate, tonsils, upper pharynx. A study of taste sensitivity is being conducted, during which a special flavor solution is applied to symmetrical areas of the tongue with a pipette. It is important to identify an isolated unilateral disorder of the taste sensitivity of the posterior 1/3 of the tongue, since a bilateral taste disorder can be observed in pathology of the oral mucosa (for example, in chronic stomatitis).
The pharyngeal reflex is checked (the occurrence of swallowing, sometimes coughing or vomiting movements, in response to touching the back wall of the pharynx with a paper tube) and the palatine reflex (touching the soft palate is accompanied by raising the palate and its tongue). The unilateral absence of these reflexes speaks in favor of the lesion of N. glossopharyngeus, however, it can also be observed in the pathology of the vagus nerve. The detection during the examination of the pharynx and pharynx of rashes typical of herpetic infection suggests ganglionitis of the nodes of the lingopharyngeal nerve, which has almost identical symptoms to the neuritis of the lingopharyngeal nerve.
In order to determine the cause of secondary neuritis, they resort to neuroimaging diagnostics — CT or MRI of the brain. In the absence of such an opportunity, an echo-EG, an EEG and an ophthalmologist’s consultation for an examination of the fundus (ophthalmoscopy) are prescribed.
Differential diagnosis is carried out with other diseases that cause painful paroxysms in the head and face, namely, trigeminal neuralgia, ear node neuralgia, pterygoid ganglionitis, Oppenheim syndrome; glossalgia of other etiology; pharyngeal tumors, pharyngeal abscess.
Treatment and prognosis
In relation to neuralgia, mainly conservative therapy is carried out. The exception is cases of nerve compression, for which surgical intervention is required to eliminate (for example, resection of the hypertrophied styloid process).
In order to relieve pain paroxysm, 10% cocaine solution is used to lubricate the pharynx and tongue root, which allows to eliminate pain for 6-7 hours. With persistent pain syndrome, a blockade of the lingual nerve of 1-2% of the novocaine solution is indicated. Along with this, non-narcotic analgesics (phenylbutazone, metamizole sodium, naproxen, ibuprofen, etc.) and anticonvulsants (phenytoin, carbamazepine) are prescribed for oral administration. With severe pain syndrome, it is additionally advisable to use hypnotics, sedatives, antidepressants and neuroleptics.
Physiotherapy techniques have a good effect: diadynamotherapy or SMT on the tonsils and larynx, galvanization. Recommended vit. B1, multivitamin complexes, ATP, PHIBS and other general strengthening drugs.
With the successful elimination of the causal disease, especially with the syndrome of compression of the lingopharyngeal nerve, the prognosis of recovery is favorable. However, long-term therapy for several years is necessary for complete relief of neuralgia.