Bilateral clicking tinnitus due to myoclonus of middle ear muscles.

Isolated middle ear myoclonus can be a cause of objective tinnitus. We present an acoustically documented case of irregular bilateral middle ear myoclonus with loud clicking, and roaring tinnitus associated with essential palatal tremor. A palatal botulinum toxin injection did not eliminate the tinnitus. Division of both middle ear tendons in both ears abolished the clicking tinnitus with no effect on hearing.

Treatment of objective tinnitus with transpalatal Botox® injection in a pediatric patient with middle ear myoclonus: A case report.

We describe a case of bilateral middle ear myoclonus (MEM) that was treated with trans-palatal Botox® injection after failing surgery to section the tensor tympani and stapedial tendons. MEM is a rare disorder resulting from rhythmic contraction of middle ear muscles. An 8-year old girl presented with audible clicking tinnitus, and resultant inability to focus in school. Her parents declined medical therapy, and she underwent surgeries for tendon lysis, with only temporary relief. She had successful response to trans-palatal Botox® injection to the tensor veli palatini aponeurosis. Trans-palatal Botox® injection is a safe and reasonable alternative for treatment of MEM.

TCDD disrupts posterior palatogenesis and causes cleft palate.

Dioxins (e.g. 2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD) cause cleft palate at a high rate. A post-fusional split may contribute to the pathogenesis, and tissue fragility may be a concern. The objective of this study was to investigate the effects of TCDD on the palatal epithelium, bone and muscle, which contribute to tissue integrity. ICR mice (10-12 weeks old) were used. TCDD was administered on E12.5 at 40 mg/kg. Immunohistochemical staining for AhR, ER-α, laminin, collagen IV, osteopontin, Runx2, MyoD, and desmin were performed. Furthermore, western blot analysis for osteopontin, Runx2, MyoD, and desmin were performed to evaluate protein expression in the palatal tissue. Immunohistologically, there was little difference in the collagen IV and laminin localization in the palatal epithelium between control versus TCDD-treated mice. Runx2 and osteopontin immunoreactivity decreased in the TCDD-treated palatal bone, and MyoD and desmin decreased in the TCDD-treated palatal muscle. AhR and ER-α immunoreactivity were localized to the normal palatal bone, but ER-α was diminished in the TCDD-treated palate. On western blot analysis, Runx2, MyoD, and desmin were all downregulated in the TCDD-treated palate. TCDD may suppress palatal osteogenesis and myogenesis via AhR, and cause cleft palates via a post-fusional split mechanism, in addition to a failure of palatal fusion.

Phasic genioglossus and palatoglossus muscle activity during recovery from sevoflurane anesthesia: a prospective observational study in children.

BACKGROUND: Inhalational anesthetic effects on upper airway muscle activity in children are largely unknown. The authors tested the hypothesis that phasic inspiratory genioglossus and palatoglossus activity increases during recovery from sevoflurane anesthesia in a dose-dependent manner in children. METHODS: Sixteen children, aged 2.0 to 6.9 yr, scheduled for elective urological surgery were studied. Electromyogram recordings were acquired using intramuscular needle electrodes during spontaneous ventilation. After a 15-min period of equilibration, electromyogram activity was recorded over 30 s at each of three end-tidal concentrations, 1.5, 1.0, and 0.5 minimum alveolar concentration (MAC), administered in sequence. RESULTS: Phasic genioglossus activity was noted in four children at 1.5 MAC, five at 1.0 MAC, and six children at 0.5 MAC sevoflurane. Phasic palatoglossus activity was noted in 4 children at 1.5 MAC, 6 at 1.0 MAC, and 10 children at 0.5 MAC sevoflurane. Both the proportion of children exhibiting phasic activity, and the magnitude of phasic activity increased during recovery from anesthesia. For the genioglossus, decreasing the depth of sevoflurane anesthesia from 1.5 to 1.0 MAC increased phasic activity by approximately 35% and a further decrease to 0.5 MAC more than doubled activity (median [range] at 1.5 and 0.5 MAC: 2.7 µV [0 to 4.0 µV] and 8.6 µV [3.2 to 17.6], respectively; P = 0.029). A similar dose-related increase was recorded at the palatoglossus (P = 0.0002). CONCLUSIONS: Genioglossus and palatoglossus activity increases during recovery from sevoflurane anesthesia in a dose-dependent manner over the clinical range of sevoflurane concentrations in children.

Objective tinnitus from palatal myoclonus. Use of botulinum toxin: a case report.

Objective tinnitus can have many different etiologies, palatal myoclonus being one of the less frequent. This type of tinnitus is generated by involuntary rhythmic contraction of the soft palate, which generates an audible click for the patient and for the explorer. Botulinum toxin achieves temporary muscle paralysis through presynaptic inhibition of the acetylcholine level at the neuromuscular union. We present a patient with long-term objective tinnitus, along with this patient's response to botulinum toxin injection.

Endonasal approach of salpingopharyngeus muscle for the treatment of ear click related to palatal tremor.

Palatal tremor (PT) is a rare disease associated with rhythmic movements of the soft palate. It can be separated into two distinct clinical entities: symptomatic and essential. Most patients with essential PT complain of the rhythmic ear clicks and in some cases tinnitus, but usually have an uneventful medical history. Symptomatic PT patients are often unaware of the palatal movements and have symptoms and signs of brainstem or cerebellar dysfunction. We describe the case of a 25-year-old patient who developed severe essential PT, with very distressing bilateral objective tinnitus, constantly perceived as ear clicks. Several oral medications were prescribed with poor results. No significant improvement was obtained with repetitive injections of botulinum toxin type A (BTX A) distributed in soft palate muscles. Because of the continuous tinnitus and its impact on the patient's quality of life, chemical denervation of the salpingopharyngeus muscles, which is involved in the production of tinnitus, with BTX A was performed endonasally under endoscopic guidance. The result was very satisfactory. Tinnitus due to essential PT may be satisfactorily treated by endonasal injection of BTX into the salpingopharyngeus and palatopharyngeus muscles.

Effect of tensor veli palatini muscle paralysis on eustachian tube mechanics.

Several physiological functions, such as regulating middle ear (ME) pressure and clearing ME fluid into the nasopharynx, require an opening of the collapsed eustachian tube (ET). The ability to perform these functions has been related to several mechanical properties of the ET: opening pressure (Popen), compliance (ETC), and hysteresis (eta). These global properties may be influenced by the mechanics of the surrounding tissue and/or the mucosa-air interface. In this study, we investigated the influence of tissue mechanics by paralyzing the right tensor veli palatini (TVP) muscle in 12 cynomolgus monkeys via botulinum toxin injection. A previously developed modified forced-response protocol was used to measure Popen, ETC, and eta under normal conditions and after muscle paralysis. The loss of muscle tone and/or stiffness resulted in a significant decrease in Popen (p < .01) and a significant increase in ETC (p < .01). In addition, muscle paralysis reduced the viscoelastic properties of the TVP muscle and therefore resulted in a significant decrease in eta (p < .05). A comparison with previous measurements on the influence of surface tension mechanics indicates that the ET's compliance is primarily determined by tissue elastic properties. The ET hysteresis, however, is equally affected by viscoelastic tissue properties and surface tension hysteretic properties. Knowledge of how these physical components affect the global mechanical environment may lead to improved treatments for ET dysfunction that target the underlying mechanical abnormality.

Respiratory activities in relation to palatal muscle contraction.

This study investigated the activities of the tensor and levator veli palatini muscles related to respiration. During quiet breathing, no activity was observed in either muscle. With either hypercapnic or hypoxemic condition, the tensor veli palatini muscle exhibited phasic activity during inspiration. The levator veli palatini muscle showed phasic activity during expiration with hypoxemia (PaO2 less than 40 mm Hg). NaCN perfused bilaterally through the carotid sinus induced these respiratory activities. The tensor veli palatini muscle was more sensitive than the levator veli palatini muscle to NaCN.

Palatal myoclonus following Behçet's disease ameliorated by ceruletide, a potent analogue of CCK octapeptide.

Systemic administration of ceruletide, a potent analogue of CCK octapeptide (0.8 microgram/kg, i.m.) markedly improved palatal myoclonus. CCK analogues may be useful agents for the treatment of palatal myoclonus. This report suggests that dopaminergic system may also contribute to the underlying biochemical mechanism of palatal myoclonus.

Experimental paralysis of tensor veli palatini muscle.

In an effort to study the effects of experimental paralysis of tensor veli palatini (TVP) muscle on Eustachian tube (ET) function and middle-ear (ME) status, botulinum toxin A (Oculinum) was injected into the TVP muscles of 8 Rhesus monkeys. Tubal function was tested longitudinally in 2 animals with tympanostomy tubes using the forced-response test, while in the remaining 6 animals; ME condition was documented daily using tympanometry. The postinjection tubal function was characterized by abolished active muscular function and decreased closing pressure. Activity associated with tubal dilations gradually reappeared by the fifth week. The lack of lumen constrictions following injection suggested that the TVP muscle is the cause of constriction as well as normal dilation. In 6 animals with intact tympanic membranes, 10 of the 12 ears developed flat tympanograms associated with otitis media with effusion (OME) within 8-30 days of injection and serous effusions were recovered by tympanocentesis in seven ears. These results show that a non-traumatic reversible functional obstruction of the ET was created by injecting botulinum toxin A into the TVP muscle. This functional obstruction was associated with the development of high negative ME pressure and serous effusion.