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Schwannomas of the larynx are rare. Most of the few such reports in the literature have described schwannomas that occurred in the aryepiglottic fold or the true vocal folds. In this article, we report what we believe is the first case of a schwannoma arising from the epiglottis.

Organ preservation protocols of high-dose chemoradiotherapy have become fairly common to treat head and neck cancers. However, significant swallowing problems can occur. This study examines swallowing, oral tongue pressures, and tongue base-to-pharyngeal wall pressures in a patient who underwent total laryngectomy for improvement of swallowing after chemoradiotherapy for treatment of a hypopharyngeal tumor. The patient underwent concurrent videofluorographic and manometric examination of swallowing and examination of oral tongue pressures after the laryngectomy. One healthy subject was used as a control. After the laryngectomy, the patient no longer aspirated; however, he could swallow only liquids and pureed foods. He demonstrated difficulty with bolus clearance through the oral cavity and pharyngocervical esophagus. Pharyngeal pressures were reduced compared with those of the control subject. While total laryngectomy will stop unremitting aspiration, swallowing after chemoradiation may be severely compromised. This may not be overcome by total laryngectomy.

BACKGROUND: Paragangliomas are highly vascular tumors of neural crest origin that involve the walls of blood vessels or specific nerves within the head and neck. They may be multicentric, and they are rarely malignant. Surgery is the preferred treatment, and these tumors frequently extend to the skull base. There has been controversy concerning the role of preoperative angiography and embolization of these tumors and the benefits that these procedures offer in the evaluation and management of paragangliomas. METHODS: Forty-seven patients with 53 paragangliomas were treated from the period of 1990-2000. Initial evaluation usually included CT and/or MRI. All patients underwent bilateral carotid angiography, embolization of the tumor nidus, and cerebral angiography to define the patency of the circle of Willis. Carotid occlusion studies were performed with the patient under neuroleptic anesthesia when indicated. The tumors were excised within 48 hours of embolization. RESULTS: Carotid body tumors represented the most common paraganglioma, accounting for 28 tumors (53%). All patients underwent angiography and embolization with six patients (13%), demonstrating complications (three of these patients had embolized tumor involving the affected nerves). Cerebral angiography was performed in 28 patients, and 5 of these patients underwent and tolerated carotid occlusion studies. The range of mean blood loss according to tumor type was 450 to 517 mL. Postoperative cranial nerve dysfunction depended on the tumor type resected. Carotid body tumor surgery frequently required sympathetic chain resection (21%), with jugular and vagal paraganglioma removal frequently resulting in lower cranial nerve resection. These patients required various modes of postoperative rehabilitation, especially vocal cord medialization and swallowing therapy. CONCLUSIONS: The combined endovascular and surgical treatment of paragangliomas is acceptably safe and effective for treating these highly vascular neoplasms. Adequate resection may often require sacrifice of one or more cranial nerves, and appropriate rehabilitation is important in the treatment regimen.

Neurons of the thalamic reticular nucleus (TRN) provide inhibitory input to thalamic relay cells and generate synchronized activity during sleep and seizures. It is widely assumed that TRN cells interact only via chemical synaptic connections. However, we show that many neighboring pairs of TRN neurons in rats and mice are electrically coupled. In paired-cell recordings, electrical synapses were able to mediate close correlations between action potentials when the coupling was strong; they could modulate burst-firing states even when the coupling strength was more modest. Electrical synapses between TRN neurons were absent in mice with a null mutation for the connexin36 (Cx36) gene. Surprisingly, inhibitory chemical synaptic connections between pairs of neurons were not observed, although strong extracellular stimuli could evoke inhibition in single TRN neurons. We conclude that Cx36-dependent gap junctions play an important role in the regulation of neural firing patterns within the TRN. When combined with recent observations from the cerebral cortex, our results imply that electrical synapses are a common mechanism for generating synchrony within networks of inhibitory neurons in the mammalian forebrain.

Neurons of the inferior olivary nucleus (IO) form the climbing fibers that excite Purkinje cells of the cerebellar cortex. IO neurons are electrically coupled through gap junctions, and they generate synchronous, subthreshold oscillations of membrane potential at approximately 5-10 Hz. Experimental and theoretical studies have suggested that both the rhythmicity and synchrony of IO neurons require electrical coupling. We recorded from pairs of IO neurons in slices of mouse brainstem in vitro. Most pairs of neurons from wild-type (WT) mice were electrically coupled, but coupling was rare and weak between neurons of knock-out (KO) mice for connexin36, a neuronal gap junction protein. IO cells in both WT and KO mice generated rhythmic membrane fluctuations of similar frequency and amplitude. Oscillations in neighboring pairs of WT neurons were strongly synchronized, whereas the oscillations of KO pairs were uncorrelated. Spontaneous oscillations in KO neurons were not blocked by tetrodotoxin. Spontaneously oscillating neurons of both WT and KO mice generated occasional action potentials in phase with their membrane rhythms, but only the action potentials of WT neuron pairs were synchronous. Harmaline, a beta-carboline derivative thought to induce tremor by facilitating rhythmogenesis in the IO, was injected systemically into WT and KO mice. Harmaline-induced tremors were robust and indistinguishable in the two genotypes, suggesting that gap junction-mediated synchrony does not play a role in harmaline-induced tremor. We conclude that electrical coupling is not necessary for the generation of spontaneous subthreshold oscillations in single IO neurons, but that coupling can serve to synchronize rhythmic activity among IO neurons.

The clinical and aspiration cytologic details of a case of temporomandibular joint pigmented villonodular synovitis are presented and correlated with imaging, surgical, histopathologic, and clinical follow-up findings; the origin of such lesions is discussed. The lesion originally presented in a 36-year-old, otherwise healthy, white man as a unilateral mass involving the temporal fossa and temporomandibular joint region. The tumor's extent was defined by magnetic resonance imaging and computed tomographic scan; there was destruction of the temporomandibular joint and erosion of the temporal cranial bones by a lesion whose maximum dimensions were estimated by imaging to be 2.75 x 3.25 cm. The lesion was initially sampled and classified by computed tomography-guided fine-needle aspiration biopsy. Following complete resection, the original diagnosis was confirmed with both hematoxylin-eosin-stained paraffin sections and immunohistochemical staining. The patient remains free of disease 7 years postoperatively.

Bioresorbable implants (meshs and plates) are increasingly used in reconstructive craniofacial and skull base surgery. Usually these implants must be contoured to fit the complex craniofacial anatomy ex vivo; occasionally final contouring is performed in vivo and must be done without damaging surrounding structures (e.g., dura, brain). We report a precision method for in vivo contouring of bioresorbable implants using the Shaw hemostatic thermal scalpel

Acoustic analysis of a reading passage was used to identify the abnormal phonatory events associated with adductor spasmodic dysphonia (ADSD) pre- and postinjection of Botulinum Toxin A (Botox). Thirty-one patients (age 22 to 74 years) diagnosed with ADSD were included for study. All patients were new recipients of Botox, and the examination of their voice occurred before and after their initial injection of Botox. Acoustic events were identified from reading samples of the Rainbow Passage produced by each of the patients. These events were examined from sentences containing primarily voiced sound segments. Dependent variables included the number of phonatory breaks, frequency shifts, and aperiodic segments--all variables previously defined by the investigators. Additionally, calculated variables were made of the percentage of time these events occurred relative to the duration of the cumulative voiced segments. A sex- and age-matched control group (+/-2 years) was included for statistical comparison. Results indicated that those with ADSD produced more aberrant acoustic events than the controls. Aperiodicity was the predominant acoustic event produced during the reading, followed by frequency shifts and phonatory breaks. Within the ADSD group, the number of atypical acoustic events decreased following Botox injection. It is important that the occurrence of specific abnormal acoustic events was sufficient to differentiate the disordered speakers from the controls following as well as preceding initial Botox injection, as indicated by discriminant function analysis. This paper complements our previous work using this acoustic analysis method for defining the abnormal events present in the voice of those with ADSD and further suggests that these measures can be used in conjunction with perceptual impressions to differentiate speakers on the basis of initial severity