Glossopharyngeal neuralgia with syncope: a case report

We present the case of a 60-year-old woman with known glossopharyngeal neuralgia who was admitted to hospital because of recurrent syncopes associated with episodes of painful sensations in the caudal region of her tongue. Rhythm observation showed prolonged asystole, which was accompanied by a loss of consciousness. The asystole was preceded by an episode of pain. We concluded that the bradyarrhythmia and syncopes where associated with the glossopharyngeal neuralgia. Because of the life-threatening condition, we inserted a permanent dual-chamber pacing device. After implantation of the pacemaker, the patient had no further syncopes, although she still complained of episodic tongue pain.     

Centrifugal decrement in diameter of myelinated afferent fibres innervating frog taste organ

1. Regional changes in the diameter of single myelinated afferent nerve fibres innervating the taste disc of the fungiform papillae on the bullfrog tongue were investigated morphologically and functionally. 2. The diameter of myelinated afferents in the medial lingual branch of the glossopharyngeal nerve averaged 8.4 microns at the proximal end of the tongue and gradually decreased at the rate of 0.8 micron/cm length of the fibres as they ran in the apical direction of the tongue. 3. The conduction velocity of single myelinated afferent fibres within the tongue decreased gradually as they ran peripherally. 4. Electrophysiological inspection of neural connections between the fungiform papillae suggests that a gradual centrifugal decrease in the diameter of a single myelinated afferent fibre is not due to multiple bifurcations of the fibre at various sites within the tongue, but due to a natural gradual decrease in the thickness of the myelin sheath and the diameter of axon.     

Favorable outcome of decompression of the trigeminal nerve in a case of bilateral neuralgia

A case of the bilateral trigeminal neuralgia produced by compression of the V cranial nerve roots by the branch of the anterior lower cerebral artery and post-hemorrhagic aggregates is presented. Complete recovery was obtained in the result of 2-stage, intracranial relief of the right and left trigeminal nerve roots. Neurologists share the opinion that intracranial surgical relief of the V cranial nerve root produces favourable result in case of trigeminal neuralgia resistant to pharmacotherapy.     

Histoarchitectonics of the cholinergic innervation of the frog tongue

Acetylcholinesterase (AChE) activity was studied in dorsal tongue surface structures and in both tongue nerves (hypoglossal and glossopharyngeal) of frogs (Rana temporaria). AChE was found in nerve fibers of fungiform and filiform papillae, blood vessels, glandular ducts of tongue mucosa, both nerve fibers and also in the bodies of cholinergic neurons in subepithelial connective tissue and along the glossopharyngeal nerve. Their parasympathetic origin was suggested. The experiments with butirilthiocholin have revealed no activity of non-specific cholinesterases in the above structures. Possible role of cholinergic system in the regulation of tongue receptor function is discussed.     

Trigeminal neuralgia in a patient with multiple sclerosis treated with high cervical spinal cord stimulation. Case report

A 42-year-old male with advanced multiple sclerosis had severe left-sided trigeminal neuralgia in the maxillary and mandibular divisions that was extremely difficult to control with medications. Glycerol injection in the gasserian cystern provided only temporary results. Two electrodes were implanted epidurally at the C1-2 level, one in the midline and the other to the left of midline. Electrical stimulation produced complete relief from the painful paroxysms.     

Five-and-a-half years' experience with percutaneous retrogasserian glycerol rhizotomy in treatment of trigeminal neuralgia

The results of treating trigeminal neuralgia with percutaneous retroganglionic glycerol rhizotomy in 319 patients from an overall series of 394 patients with 459 operations carried out over a period of 5 1/2 years are reported. Idiopathic trigeminal neuralgia was the diagnosis in 252 patients. 34 patients had trigeminal neuralgia associated with multiple sclerosis. The remaining 33 patients suffered from symptomatic trigeminal neuralgia or atypical facial pain. 230 patients (91.3%) with idiopathic trigeminal neuralgia and 30 patients (88.2%) with multiple sclerosis reported complete freedom from pain. In 12 patients (4.8%) of those with tic douloureux and in 1 patient (2.9%) with multiple sclerosis, pain was alleviated, and the patients required a reduced pharmacotherapy. 10 patients (3.9%) and 3 patients (8.8%) were considered to be treatment failures. The rate of recurrences within the first 2 years was 10.9 and 40.0%, respectively. In the long-term, the rate of recurrences in patients with tic douloureux was 36.9%. 144 patients (45.1%) noticed a hypesthesia. 132 patients (41.4%) had hypalgesia following the procedure, and there was a decrease of symptoms in the long-term observation in 20.0% of the patients. 59 patients (18.5%) developed dysesthesia postoperatively which regressed only to an inappreciable extent in the long-term course. In 16 patients (5.0%) exclusively with a preexisting organic lesion or who had received surgical pretreatment, there was a loss of corneal sensation. The investigation showed on the one hand the effectiveness of the method, but on the other hand also the possibility of marked sensory disorder in selected cases.     

The origin of slow potentials on the tongue surface induced by frog glossopharyngeal efferent fiber stimulation

When the glossopharyngeal (GP) nerve of the frog was stimulated electrically, electropositive slow potentials were recorded from the tongue surface and depolarizing slow potentials from taste cells in the fungiform papillae. The amplitude of the slow potentials was stimulus strength- and the frequency-dependent. Generation of the slow potentials was not related to antidromic activity of myelinated afferent fibers in the GP nerve, but to orthodromic activity of autonomic post-ganglionic C fibers in the GP nerve. Intravenous injection of atropine abolished the positive and depolarizing slow potentials evoked by GP nerve stimulation, suggesting that the slow potentials were induced by the activity of parasympathetic post-ganglionic fibers. The amplitude and polarity of the slow potentials depended on the concentration of adapting NaCl solutions applied to the tongue surface. These results suggest that the slow potentials recorded from the tongue surface and taste cells are due to the liquid junction potential generated between saliva secreted from the lingual glands by GP nerve stimulation and the adapting solution on the tongue surface.     

Taste-responsive neurons in the nucleus of the solitary tract receive gustatory information from both sides of the tongue in the hamster

Taste receptors on the left and right sides of the anterior tongue are innervated by chorda tympani (CT) fibers, which carry taste information to the ipsilateral nucleus of the solitary tract (NST). Although the anterior tongue is essential for taste, patients with unilateral CT nerve damage often report no subjective change in their taste experience. The standing theory that explains the taste constancy is the "release of inhibition", which hypothesizes that within the NST there are inhibitory interactions between inputs from the CT and glossopharyngeal nerves and that the loss of taste information from the CT is compensated by a release of inhibition on the glossopharyngeal nerve input. However, the possibility of compensation by taste input from the other side of the tongue has never been investigated in rodents. We recorded from 95 taste-responsive neurons in the NST and examined their responsiveness to stimulation of the contralateral CT. Forty-six cells were activated, mostly with excitatory responses (42 cells). Activation of NST cells induced by contralateral CT stimulation was blocked by microinjection of lidocaine into the contralateral NST but was not affected by anesthetization of the contralateral parabrachial nuclei (PbN). In addition, the NST cells that were activated by contralateral CT stimulation showed reduced responsiveness to taste stimulation after microinjection of lidocaine into the contralateral NST. These results demonstrate that nearly half of the taste neurons in the NST receive gustatory information from both sides of the tongue. This "cross talk" between bilateral NST may also contribute to the "taste constancy".     

Perceived Irritation during Ingestion of Capsaicin or Piperine: Comparison of Trigeminal and Non-trigeminal Areas

The aim of this study was to investigate the perception of chemosensoryirritation in the oropharyngeal region during the ingestionof irritants. In two experiments subjects sipped and swallowedsmall samples of an ascending concentration series of capsaicinor piperine and rated the intensity of sensations of irritationperceived at four locations: the anterior tongue, the posteriortongue, the roof of the mouth and the throat. Both experimentsrevealed that the responsiveness to irritation from capsaicinwas significantly higher in the throat than at either the frontor back of the tongue. There was no difference between irritationratings for the throat and the roof of the mouth. Compared withcapsaicin, the responsiveness to piperine was more uniform alongthe rostro-caudal axis; for example, irritation ratings forthe throat were similar to those for the anterior tongue. Theseresults support previous findings which indicated that the oralmucosae were not uniformly sensitive to chemical irritants,and suggest further that the throat, which is innervated byboth the glossopharyngeal and vagus nerves, plays and importantrole in the perception of chemesthetic stimuli during ingestion.Chem. Senses 22: 257–266, 1997.     

Effects of anesthesia of the facial nerve on taste

Two cranial nerves, the facial (7th) and the glossopharyngeal(9th), play important roles in taste perception, yet patientswith damage to the 7th nerve often fail to experience reducedtaste intensities. In an effort to explain this, branches ofthe 7th (the chorda tympani which innervates the anterior two-thirdsof the tongue and the greater superficial petrosal which innervatesthe posterior palate near the junction of the hard and softpalates) were temporarily anesthetized in healthy volunteers.Even bilateral anesthesia of both branches of the 7th nerveproduced only small taste decrements (the largest from NaCl).When smaller portions of the 7th nerve were anesthetized, sometastes actually became more intense. This suggests that the7th nerve normally inhibits the 9th nerve. When the 7th nerveis anesthetized, that inhibition is released and more intensetaste sensations are evoked from the 9th nerve.     

Sensory symptom profiles and co-morbidities in painful radiculopathy

Painful radiculopathies (RAD) and classical neuropathic pain syndromes (painful diabetic polyneuropathy, postherpetic neuralgia) show differences how the patients express their sensory perceptions. Furthermore, several clinical trials with neuropathic pain medications failed in painful radiculopathy. Epidemiological and clinical data of 2094 patients with painful radiculopathy were collected within a cross sectional survey (painDETECT) to describe demographic data and co-morbidities and to detect characteristic sensory abnormalities in patients with RAD and compare them with other neuropathic pain syndromes. Common co-morbidities in neuropathic pain (depression, sleep disturbance, anxiety) do not differ considerably between the three conditions. Compared to other neuropathic pain syndromes touch-evoked allodynia and thermal hyperalgesia are relatively uncommon in RAD. One distinct sensory symptom pattern (sensory profile), i.e., severe painful attacks and pressure induced pain in combination with mild spontaneous pain, mild mechanical allodynia and thermal hyperalgesia, was found to be characteristic for RAD. Despite similarities in sensory symptoms there are two important differences between RAD and other neuropathic pain disorders: (1) The paucity of mechanical allodynia and thermal hyperalgesia might be explained by the fact that the site of the nerve lesion in RAD is often located proximal to the dorsal root ganglion. (2) The distinct sensory profile found in RAD might be explained by compression-induced ectopic discharges from a dorsal root and not necessarily by nerve damage. These differences in pathogenesis might explain why medications effective in DPN and PHN failed to demonstrate efficacy in RAD.     

Penetration of the oral mucosa by parasite-like sperm bags of squid: a case report in a Korean woman

We report a case of oral stings by spermatophores of the squid Todarodes pacificus . A 63-yr-old Korean woman experienced severe pain in her oral cavity immediately after eating a portion of parboiled squid along with its internal organs. She did not swallow the portion, but spat it out immediately. She complained of a pricking and foreign-body sensation in the oral cavity. Twelve small, white spindle-shaped, bug-like organisms stuck in the mucous membrane of the tongue, cheek, and gingiva were completely removed, along with the affected mucosa. On the basis of their morphology and the presence of the sperm bag, the foreign bodies were identified as squid spermatophores.     

Non-synaptic transformation of gustatory receptor potential by stimulation of the parasympathetic fiber of the frog glossopharyngeal nerve

When the glossopharyngeal nerve (GP) in the frog was strongly stimulated electrically, slow potentials were elicited from the tongue surface and taste cells in the fungiform papillae. Injection of atropine completely blocked these slow potentials. The present and previous data indicate that the slow potentials induced in the tongue surface and taste cells are due to a liquid junction potential between saliva secreted from the lingual glands due to parasympathetic fiber activity and an adapting solution on the tongue surface. Intracellularly recorded depolarizing receptor potentials in taste cells induced by 0.5 M NaCl and 3 mM acetic acid were enhanced by depolarizing slow potentials induced by GP nerve stimulation, but were depressed by the hyperpolarizing slow potentials. On average, the receptor potential of taste cells for 0.5 M NaCl was increased by 25% by the GP nerve-induced slow potential, but the receptor potential of taste cells for 3 mM acetic acid was decreased by 1% by the slow potential. These transformations of receptor potentials in frog taste cells were not due to a synaptic event initiated between taste cells and the efferent nerve fiber, but due to a non-synaptic event, a lingual junction potential generated in the dorsal lingual epithelium by GP nerve stimulation.     

Tonsillolithiasis and orofacial pain

Tonsilloliths are rare calcified structures that usually result from chronic inflammation of the tonsils. Concretions show differences in size, shape and colour. They are usually asymptomatic but can be associated with halitosis, foreign body sensation, dysphagia and odynophagia, otalgia, and neck pain. A patient was referred because panoramic radiography performed by a general dentist revealed radiopaque shadows over the ascending rami of the mandible, located bilaterally: a solitary structure on the higher portion of the right side and two small structures on the left side. Paroxysmal attacks of orofacial pain and symptoms such as dysphagia and swallowing pain on the left side distributed within the tonsillar fossa and pharynx and the angle of the lower jaw were present. The computed tomography images revealed bilateral tonsilloliths. Clinically, there was no sign of inflammation, and the patient's past history revealed an approximately 2-year history of dysphagia, swallowing pain and left-sided neck pain. At the request of the patient, no surgical intervention was carried out. Glossopharyngeal neuralgia is a rare entity, and the aim of this report was to indicate the importance of tonsilloliths as a cause of orofacial pain.     

Bronchiectasis and hoarseness of voice in takayasu arteritis: a rare presentation

ABSTRACT: BACKGROUND: Takayasu arteritis is a large vessel vasculitis occurring in young females. We report a rare presentation of Takayasu arteritis in a Sri Lankan woman. She presented with bronchiectasis and left recurrent laryngeal nerve palsy prior to the onset of vascular symptoms. This case illustrates an atypical presentation of this disease and the diagnostic dilemma that the physician may be faced with. CASE PRESENTATION: A 39-year-old woman presented with chronic cough, haemoptysis and hoarseness of voice. She had left recurrent laryngeal nerve palsy and high inflammatory markers on investigation. CT thorax revealed aortic wall thickening and traction bronchiectasis. 2 D echocardiogram revealed grade 1 aortic regurgitation compatible with aortitis. She did not have weak peripheral pulses or a blood pressure discrepancy and did not meet American College of Rheumatology (ACR) criteria for diagnosis of Takayasu arteritis at this stage. Tuberculosis, syphilis and sarcoidosis was excluded. While awaiting angiography, she developed left arm claudication and a pericardial effusion. Angiography revealed evidence of Takayasu arteritis and absence of flow in the left subclavian artery. Takayasu arteritis was diagnosed at this stage after a period of eight months from the onset of initial symptoms. She is currently on prednisolone, azathioprine and aspirin. CONCLUSION: Bronchiectasis and recurrent laryngeal nerve palsy is a rare presentation of Takayasu arteritis. Atypical presentations can occur in Takayasu arteritis prior to the onset of vascular symptoms. Elevation of inflammatory markers are an early finding. A high degree of suspicion is needed to identify these patients in the early course of the disease.     

Taste responses to amino acids in the southern leopard frog, Rana sphenocephala

Integrated taste recordings of the glossopharyngeal (IX) nerve innervating the tongue of the southern leopard frog were studied in response to various amino acids and quinine hydrochloride. Amino acids and quinine hydrochloride elicited primarily phasic taste responses. Acidic (L-aspartic and L-glutamic) and basic (L-lysine and L-arginine) amino acids, adjusted to pH8, were effective taste stimuli. All glossopharyngeal nerve twigs that responded to amino acid stimuli also responded to quinine; however, not all quinine-sensitive IX nerve bundles were responsive to amino acids. Electrophysiological thresholds for amino acids were estimated to be 2.5-10 mM, whereas threshold for quinine hydrochloride averaged approximately 10 microM.     

Upper airway muscle paralysis reduces reflex upper airway motor response to negative transmural pressure in rat.

The reflex upper airway (UA) motor response to UA negative pressure (UANP) is attenuated by neuromuscular blockade. We hypothesized that this is due to a reduction in the sensitivity of laryngeal mechanoreceptors to changes in UA pressure. We examined the effect of neuromuscular blockade on hypoglossal motor responses to UANP and to asphyxia in 15 anesthetized, thoracotomized, artificially ventilated rats. The activity of laryngeal mechanoreceptors is influenced by contractions of laryngeal and tongue muscles, so we studied the effect of selective denervation of these muscle groups on the UA motor response to UANP and to asphyxia, recording from the pharyngeal branch of the glossopharyngeal nerve (n = 11). We also examined the effect of tongue and laryngeal muscle denervation on superior laryngeal nerve (SLN) afferent activity at different airway transmural pressures (n = 6). Neuromuscular blockade and denervation of laryngeal and tongue muscles significantly reduced baseline UA motor nerve activity (P < 0.05), caused a small but significant attenuation of the motor response to asphyxia, and markedly attenuated the response to UANP. Motor denervation of tongue and laryngeal muscles significantly decreased SLN afferent activity and altered the response to UANP. We conclude that skeletal muscle relaxation reduces the reflex UA motor response to UANP, and this may be due to a reduction in the excitability of UA motor systems as well as a decrease of the response of SLN afferents to UANP.     

Glossopharyngeal evoked potentials in normal subjects following mechanical stimulation of the anterior faucial pillar

The anterior faucial pillar, which is innervated by the glossopharyngeal nerve, is thought to be important in eliciting the pharyngeal swallow in awake humans. Glossopharyngeal evoked potentials (GPEP), elicited by mechanically stimulating this structure, were recorded from 30 normal adults using standard averaging techniques and a recording montage of 16 scalp electrodes. Ten of the subjects experienced a desire to swallow in response to stimulation. Repeatable responses were recorded from all 30 subjects. The GPEPs recorded from the posterior scalp were W-shaped and consisted of P1, N1, P2, N2 and P3 peaks. Mean latencies of P1, N1 and P2 were 11, 16 and 22 msec, respectively, for both left and right pillar stimulation. In contrast, latencies of N2 and P3 varied significantly between left and right pillar stimulation. Mean latencies of N2 and P3 were 27 and 34 msec for left, and 29 and 35 msec for right pillar stimulation. Topographical maps acquired at peak latencies for P1, N1 and P2 revealed consistent asymmetrical voltage distributions between the two hemispheres; the largest responses were recorded from the hemisphere ipsilateral to the side of stimulation. The scalp topography of N2 and P3 varied between male and female subjects as well as between left and right pillar stimulation. These findings support the hypothesis that mechanical stimulation to the anterior faucial pillar alone can elicit repeatable responses from the central nervous system. The integration of this subcortical/cortical activity with that of the medullary swallowing center may play an important role in eliciting the pharyngeal swallow.     

Labeling afferent nerves in the tongue by peripheral transganglionic transport of HRP and WGA-HRP in the rat

Peripheral transganglionic transport of horseradish pcroxidase(HRP) and wheat germ agglutinin–horseradish peroxidaseconjugate (WGA–HRP) was used to label afferent fibersin the taste buds and lingual epithelium of the rat. Microinjectionsof the tracer were made in the brain stem central projectionarea of the afferent nerves to the tongue. Optimal labelingof nerve endings in the tongue was obtained when 2 µlof 20% HRP was injected into the brain stem and postinjectionsurvival times of 24–36 h were used. The distributionof single nerves was studied by using this tracing procedurein combination with strategic transections of the various afferentnerves supplying the tongue. Labeled nerve fibers from the combinedchorda tympani–lingual nerve were found in the epitheliumand in taste buds in the fungiform and anterior foliate papillaeof the anterior 3/4 of the tongue. Labeled nerve fibers in theepithelium of the anterior 2/3 of the tongue but none in tastebuds were found when the lingual nerve alone was studied, althoughnumerous perigeminal fibers were found. The glossopharyngealnerve was found to innervate die posterior 1/4 of the tongueepithelium including the taste buds of the circumvallate papillae.The glossopharyngeal nerve on one side was found to innervatethe taste buds on both sides of the midline. The results showthat this tracing procedure can be a useful supplement to othermethods for studying afferent nerves in the tongue.