Disease relevance of Laryngeal Nerves

• NHE3 blocker S8218 reduced the superior laryngeal nerve stimulation-induced decrease in phrenic nerve amplitude, minute phrenic activity, and phrenic nerve frequency (all p < 0.05) and reduced superior laryngeal nerve stimulation-induced apnea and duration of poststimulation apnea (p < 0.05) [1].
• One child had generalized neurotoxicity from vincristine including hypotonia, decreased gastrointestinal motility, and painful paresthesias while laryngeal nerve paralysis was the only neurotoxic manifestation in the other patient [2].
• Lung cancer presenting with unilateral facial pain: remission after laryngeal nerve palsy [3].
• In order to study human laryngeal paralysis, the recurrent and superior laryngeal nerves were infiltrated unilaterally with lidocaine hydrochloride in three human volunteers [4].
• No cases of definitive hypoparathyroidism, nor lesions of RLN, of the external branches of the superior laryngeal nerve, nor postoperative hemorrhage were observed in either group [5].

High impact information on Laryngeal Nerves

• To determine whether changes in androgen receptor (AR) expression are associated with trophic actions of androgens, we have examined the laryngeal motor nucleus (N. IX-X) of Xenopus laevis 1 and 5 months after section of the laryngeal nerve [6].
• Permanent hypoparathyroidism and laryngeal nerve injury were not observed [7].
• Use of PRV as a neural tracer shows that during the buccopharyngeal phase of swallowing, vagal afferents from the pharynx and larynx and from the superior laryngeal nerve terminate in the intermediate and interstitial subnuclei of the NTS [8].
• After administration of halothane or sevoflurane to the functionally isolated upper airway, laryngeal C-fiber afferents recorded from the internal branch of the superior laryngeal nerve and identified by a conduction velocity of less than 2.0 m/second were tested for responsiveness to chemical and mechanical stimuli [9].
• 6. By contrast in the same experiments, the cardio-inhibitory and vasoconstrictor responses to excitation of the carotid body chemoreceptors were invariably potentiated by electrical stimulation of a superior laryngeal nerve, as found previously [10].

Biological context of Laryngeal Nerves

• After propranolol (2 mg/kg) and phentolamine (1.5 mg/kg), stimulation of the superior laryngeal nerves (NS; 15 Hz, 7 V, 2 ms, 30 s) caused a decrease in vascular resistance of 11.7 +/- 0.8% and a tracheal contraction of 5.2 +/- 4.7 cmH2O [11].
• The receptors and internal branch of the superior laryngeal nerve were stimulated by inhalation of a nebulized 20% solution of tartaric acid and normal saline [12].
• Tartaric acid-induced cough and the superior laryngeal nerve evoked potential [12].
• Diuresis mediated by the superior laryngeal nerve (SLN) was investigated using pentobarbital-anesthetized rats [13].
• Effects of perineural capsaicin treatment on compound action potentials of superior laryngeal nerve afferents in sevoflurane-anesthetized dogs [14].

Anatomical context of Laryngeal Nerves

• Sequential staining with antibodies against PHI and VIP revealed coexistence of the two peptides in the same population of nerve cell bodies in ganglia situated along the laryngeal nerves and in intrathyroid nerve fibers [15].
• An intracerebroventricular (i.c.v.) injection of TRH to the urethane anesthetized rat stimulates the activity of the superior laryngeal nerve (n.sl) which is a vagal ramus terminating at the thyroid gland and adjacent muscles [16].
• In anesthetized cats, sensory neurons in the superior laryngeal nerves (SLN) were identified with respect to their response to (1) phenyldiguanide (PDG) i.v., (2) mechanical stimulation and (3) lowering temperature in an isolated tracheolaryngeal segment [17].
• In sheep anesthetized with halothane, we have used extracellular microelectrodes to study the effects of stimulation of the superior laryngeal nerve (SLN), the lingual nerve (LN) and the chewing cortex (CCx) upon activities of the swallowing neurons (SNs) [18].
• However, kainic acid injections in the NRA and adjacent reticular formation prolonged the inhibitory phrenic motoneuronal response to superior laryngeal nerve stimulation and abolished or reduced abdominal motoneuronal responses during respiration, vomiting, and superior laryngeal nerve stimulation [19].

Associations of Laryngeal Nerves with chemical compounds

• 2. Action potentials were recorded from 65 individual fibers in the superior laryngeal nerve (SLN) of the hamster [20].
• Our purpose was to determine the role of N-methyl-D-aspartate (NMDA) receptors in modulating early R1 responses (at 9 ms) and/or later more prolonged R2 responses (at 36 ms) during electrical stimulation of the laryngeal afferent fibers contained in the internal branch of the superior laryngeal nerve in the cat [21].
• Therefore we determined the central neural apneic threshold to CO2 and superior laryngeal nerve (SLN) stimulation in halothane-anesthetized newborn (4- to 7-day-old) and older (45- to 56-day-old) lambs [22].
• Responses of laryngeal receptors selected for their responsiveness to 10% intralaryngeal CO2 were recorded in single fibers of the superior laryngeal nerve at a wide range of systemic PCO2 values and before and after carbonic anhydrase inhibition in anesthetized, paralyzed, ventilated cats [23].
• The high dose of capsaicin (1.25 microg/kg) evoked larger chemoreflexive responses and laryngeal nerve activities [24].

Gene context of Laryngeal Nerves

• Some of the ganglionic cells in the recurrent and superior laryngeal nerves showed dopamine-beta-hydroxylase-like immunoreactivity whilst these cells never showed tyrosine hydroxylase- or phenylethanolamine-N-methyltransferase-like immunoreactivity [25].
• Most of the cells in the paraganglia of the recurrent and superior laryngeal nerves showed an intense tyrosine hydroxylase-like immunoreactivity [25].
• Sensorimotor responses to repeated electrical stimulation of the superior laryngeal nerve were compared in 8 patients with adductor spasmodic dysphonia (ADSD) and 11 normal controls to determine if adductor response disinhibition occurred in ADSD [26].
• One laryngeal nerve palsy was registered (0.7%), as was one case of persistent hyperparathyroidism [27].
• The intracerebroventricular (i.c.v.) injection of rabbit antiserum to thyrotropin-releasing hormone (TRH) to the urethane anesthetized rat inhibited the spontaneous electrical discharge of the superior laryngeal nerve (n.sl) [28].

Analytical, diagnostic and therapeutic context of Laryngeal Nerves

• Hypoparathyroidism developed in 4 (21%) of 19 patients who underwent a completion total thyroidectomy; unilateral laryngeal nerve palsy developed in 1 (5.2%) of these 19 patients [29].
• Laryngeal CO2-sensitive receptors from the superior laryngeal nerve were selected by their responsiveness to intralaryngeal pressure and to perfusion of solution equilibrated with 9% CO2 [30].
• Nerve block patients underwent bilateral glossopharyngeal and superior laryngeal nerve blocks with 2% lidocaine (0.5-2 ml per injection site) plus a transtracheal injection of 4% lidocaine (3 ml) [31].
• Evaluation of Physiologic Frequency Range (PFR) and Musical Frequency Range (MRP) of Phonation was performed on 56 adults (singers and nonsingers) presenting with superior laryngeal nerve (SLN) paresis or paralysis confirmed by laryngeal electromyography [32].

References