Pneumolabyrinth: a late complication of stapes surgery.

As temporal bone imaging techniques continue to improve, it is likely that we will see an increase in the detection of pneumolabyrinth. Several mechanisms have been proposed to explain how air enters the labyrinth. A small number of authors has reported an association between pneumolabyrinth and temporal bone fractures, perilymphatic fistulae, and displaced stapes prostheses. In this article, we describe a new case of pneumolabyrinth that was seen as a late complication of stapes surgery, and we summarize what is known about this rare condition.

Modulation of odor-induced increases in [Ca(2+)](i) by inhibitors of protein kinases A and C in rat and human olfactory receptor neurons.

Protein kinases A and C have been postulated to exert multiple effects on different elements of signal transduction pathways in olfactory receptor neurons. However, little is known about the modulation of olfactory responses by protein kinases in intact olfactory receptor neurons. To further elucidate the details of the modulation of odorant responsiveness by these protein kinases, we investigated the action of two protein kinase inhibitors: H89, an inhibitor of protein kinase A, and N-myristoylated EGF receptor, an inhibitor of protein kinase C, on odorant responsiveness in intact olfactory neurons. We isolated individual olfactory neurons from the adult human and rat olfactory epithelium and measured responses of the isolated cells to odorants or biochemical activators that have been shown to initiate cyclic AMP or inositol 1,4,5-trisphospate production in biochemical preparations. We employed calcium imaging techniques to measure odor-elicited changes in intracellular calcium that occur over several seconds. In human olfactory receptor neurons, the protein kinase A and C inhibitors affected the responses to different sets of odorants. In rats, however, the protein kinase C inhibitor affected responses to all odorants, while the protein kinase A inhibitor had no effect. In both species, the effect of inhibition of protein kinases was to enhance the elevation and block termination of intracellular calcium levels elicited by odorants. Our results show that protein kinases A and C may modulate odorant responses of olfactory neurons by regulating calcium fluxes that occur several seconds after odorant stimulation. The effects of protein kinase C inhibition are different in rat and human olfactory neurons, indicating that species differences are an important consideration when applying data from animal studies to apply to humans.

Vagal paraganglioma: the Jefferson experience.

Vagal paraganglioma is a rare tumor of neural crest origin. Although the literature is in agreement with regard to epidemiology, diagnosis, and tumor biology, there is some controversy over treatment modalities for these patients. We performed a nonrandomized retrospective study in a large single-institution series of patients (n = 19) in whom vagal paraganglioma was diagnosed. General statistics included age, male/female ratio, tumor size, and duration of follow-up. Other variables such as signs and symptoms at presentation, family history, multicentricity, metastatic disease, and secretion of catecholamines were included. CT scan, MRI, and angiography were used in combination for diagnostic purposes as well as for treatment planning. Preoperative embolization was performed in 5 of the more recently treated patients. Current issues regarding the use of preoperative embolization and choice of surgical approach were analyzed. In this article the possibility and sequela of vagus nerve-sparing procedures will be presented. Operative complications and postoperative morbidity related to cranial neuropathies will be discussed. The rationale for performing adjunct procedures, including cricopharyngeal myotomy and vocal fold medialization, to facilitate the rehabilitation of patients with postoperative cranial nerve deficits will be given. Our findings and recommendations will be compared with currently accepted treatment protocols in conjunction with a review of the literature.

Leiomyosarcoma of the larynx: diagnosis aided by advances in immunohistochemical staining.

We present only the 12th reported case of a laryngeal leiomyosarcoma. This tumor was diagnosed with the aid of the newer immunohistochemical stains on archival paraffin-embedded tissue. The diagnosis and management of these tumors is based largely on the patterns seen in the small number of earlier reported cases of head and neck leiomyosarcomas and laryngeal sarcomas.

Clinical impact of sonographically guided biopsy of salivary gland masses and surrounding lymph nodes.

Although fine-needle aspiration biopsy of salivary gland masses has been reported in the otolaryngology literature, the use of sonography to guide the biopsy of nonpalpable masses and masses seen on other cross-sectional imaging studies has not been described. Our goal was to evaluate sonographically guided biopsy of masses and lymph nodes related to the salivary glands. We analyzed the records of 18 patients who had undergone fine-needle aspiration biopsy of a salivary gland mass or lymph node with a 25-, 22-, or 20-gauge needle. A definitive cytologic diagnosis was made for 13 of the 18 patients (72%); cytology was suggestive but not definitive in three patients (17%) and insufficient in two (11%). Definitive diagnoses were made in three cases of reactive lymph node, in two cases each of lymph node metastasis and Warthin's tumor, and in one case each of pleomorphic adenoma, adenoid-cystic carcinoma, schwannoma-neurofibroma, parotid metastasis, parotid lymphoma, and Sjögren's-related lymphoid-epithelial lesion. Sonographically guided biopsy allows for confident needle placement in masses seen on computed tomography and magnetic resonance imaging. Sonography can usually distinguish a perisalivary lymph node from true intrasalivary masses, and it can help the surgeon avoid the pitfall of a nondiagnostic aspiration of the cystic component of masses. We conclude that sonographically guided biopsy of salivary gland masses can provide a tissue diagnosis that can have a direct impact on clinical decision making.

Olfactory neuron-specific expression of NeuroD in mouse and human nasal mucosa.

Human olfactory neuroepithelium (OE) is situated within the olfactory cleft of the nasal cavity and has the characteristic property of continually regenerating neurons during the lifetime of the individual. This regenerative ability of OE provides a unique model for neuronal differentiation, but little is known about the structure and biology of human olfactory mucosa. Thus, to better understand neurogenesis in human OE, we studied the expression of olfactory marker protein (OMP), TrkB and NeuroD in human nasal biopsies and autopsy specimens and compared these data with those obtained from normal and regenerating mouse OE. We show that NeuroD and TrkB are coordinately expressed in human OE. Thus, by using these markers we have been able to extend the known boundaries of the human OE to include the inferior middle turbinate. In normal mouse OE, TrkB and OMP expression overlap in cells closest to the superficial layer, but TrkB is expressed more strongly in the lower region of this layer. In contrast, NeuroD expression is more basally restricted in a region just above the globose basal cells. These characteristic expression patterns of OMP, TrkB and NeuroD were also observed in the regenerating mouse OE induced by axotomy. These results support a role of NeuroD and brain-derived neurotrophic actor (BDNF), the preferred ligand for TrkB, in the maintenance of the olfactory neuroepithelium in humans and mice.

Clinical disorders of smell and taste.

Renewed attention to chemosensory dysfunction has revealed that a substantial portion of the population are affected during their lives, many simply as a result of aging. The authors discuss terminology, assessment, etiology, and prognosis and compare current understanding with that presented by Mackenzie in 1884.

Selectivity and response characteristics of human olfactory neurons.

Transduction mechanisms were investigated in human olfactory neurons by determining characteristics of odorant-induced changes in intracellular calcium concentration ([Ca2+]i). Olfactory neurons were freshly isolated from nasal biopsies, allowed to attach to coverslips, and loaded with the calcium-sensitive indicator fura-2. Changes in [Ca2+]i were studied in response to exposure to individual odors, or odorant mixtures composed to distinguish between transduction pathways mediated by adenosine 3'5'-monophosphate (cAMP; mix A) or inositol 1,4,5-trisphosphate (InsP3; mix B). Overall, 52% of biopsies produced one or more odorant-responsive olfactory neurons, whereas 24% of all olfactory neurons tested responded to odorant exposure with a change in [Ca2+]i. As in olfactory neurons from other species, the data suggest that odorant exposure elicited calcium influx via second-messenger pathways involving cAMP or InsP3. Unlike olfactory neurons from other species that have been tested, some human olfactory neurons responded to odorants with decreases in [Ca2+]i. Also in contrast with olfactory neurons from other species, human olfactory neurons were better able to discriminate between odorant mixtures in that no neuron responded to more than one type of odor or mixture. These results suggest the presence of a previously unreported type of olfactory transduction mechanism, and raise the possibility that coding of odor qualities in humans may be accomplished to some degree differently than in other vertebrates, with the olfactory neuron itself making a greater contribution to the discrimination process.

Elapsed radiation therapy treatment time as a predictor of survival in patients with advanced head and neck cancer who receive chemotherapy and radiation therapy.

PURPOSE: To determine whether elapsed radiation therapy treatment time relates to survival in patients with head and neck cancer treated sequentially with chemotherapy and radiation therapy. MATERIALS AND METHODS: From 1981 to 1988, 76 adult patients with bulky stage II-IV head and neck cancer received induction chemotherapy (fluorouracil and cisplatin). Those with a complete or partial response (n = 46) received full-dose definitive radiation therapy (range, 64.0-77.5 Gy; median, 70 Gy). Those with less than a partial response (n = 21) underwent surgery and postoperative radiation therapy (n = 15), palliative radiation therapy (n = 4), or palliative chemotherapy (n = 2). Nine patients refused to undergo radiation therapy after induction chemotherapy. RESULTS: The 5-year overall survival rates were as follows: 32% in all patients, 38% in patients who underwent chemotherapy and radiation therapy, and 27% in patients who underwent chemotherapy, surgery, and radiation therapy. The number of days between radiation therapy treatments was highly predictive of overall survival. In the groups with treatments less than 55 days apart, 56-65 days apart, and more than 66 days apart, the 5-year survival rates were 56%, 46%, and 15%, respectively (P = .02). CONCLUSION: The time between radiation therapy treatments is strongly predictive of survival in patients undergoing sequential chemotherapy and radiation therapy. The use of induction chemotherapy does not negate the need to avoid treatment interruptions during definitive radiation therapy.

Induction of differentiation of human olfactory neuroblastoma cells into odorant-responsive cells.

Olfactory neuroblastoma is a rare malignancy of the olfactory mucosa that may be derived from the olfactory epithelium. To characterize this tumor, we cultured olfactory neuroblastoma cells in the presence or absence of growth factors (transforming growth factor alpha and basic fibroblast growth factor) known to affect olfactory tissue and assessed their responsiveness to known odorants by measuring changes in intracellular calcium. Untreated cells did not respond to odorants. Basic fibroblast growth factor treatment had cytotoxic effects, and treated cells did not respond to odorants. Transforming growth factor alpha treatment resulted in the induction of odor responsiveness in these cells. Cells responded to odorants at 100 nM to 100 microM concentrations and responded with both increases and decreases in intracellular calcium. Increases in intracellular calcium were mediated by a calcium influx and were reversibly blocked by compounds known to inhibit second messenger pathways in olfactory receptor neurons. The calcium responses of the olfactory neuroblastoma cells were thus specific to the odorants and similar to those found in olfactory receptor neurons. The results support the notion that olfactory neuroblastoma cells may be of olfactory origin and thus they can be used as a model cell line to study human olfaction.

Expression of the human Achaete-scute 1 gene in olfactory neuroblastoma (esthesioneuroblastoma).

Olfactory neuroblastoma (ONB) is a rare neuronal malignancy of the olfactory mucosal. Markers used in the diagnosis of ONB do not distinguish ONB from other neuronal tumors or tumors with neuroendocrine features thus making the diagnosis of ONB difficult. Using a modified RT-PCR technique, we show that the human homologue of the Drosophila achaete-scute gene HASH1 is expressed in 6 primary and one metastatic ONB specimens, whereas Olfactory Marker Protein (OMP) is not. Previous studies have shown that HASH1 is expressed in immature olfactory neurons and is required for their development. OMP, whose function is unknown, is expressed exclusively in mature olfactory neurons. Together, these data suggest that ONB is derived from immature olfactory neurons of neuroectodermal origin. Analysis of RNA expression in primary tumor specimens and in an established cell line make this an ideal system to study olfactory growth and differentiation. Furthermore, these studies represent the first molecular genetic analysis of this rare and unusual neuronal tumor.

Functionally mature olfactory neurons from two anosmic patients with Kallmann syndrome.

Patients with Kallmann syndrome (KS) exhibit hypogonadotropic hypogonadism and anosmia [Kallmann et al., Am. J. Mental Def., 48 (1944) 203-236] secondary to failure of gonadotropin-releasing hormone (GnRH)-producing neurons to migrate from the olfactory placode to the brain, and to agenesis of the olfactory bulbs. It has been hypothesized that olfactory neurons (ON) from individuals with KS are immature partly on the basis of studies in animals showing that lack of synaptic connection of ON with the olfactory bulb results in expression of immature ON [Schwob et al., J. Neurosci., 12 (1979) 880-883]. To test this assumption, we obtained olfactory tissue samples from two males diagnosed with KS on the basis of medical history and MRI studies. Both patients were anosmic. The functioning of cells isolated from biopsies taken from the upper middle turbinate and septum was studied by measuring changes in intracellular Ca2+ concentration ([Cai]) using dual excitation fluorescence microscopy. Biopsies from both patients yielded cells that morphologically appeared to be ON. Seven of 16 cells that morphologically resembled ON responded with a change in [Cai] upon stimulation with an odorant mixture. These studies show that at least some ON in KS individuals are functionally mature and suggest that complete development of the olfactory bulbs is not required for differentiation of mature human ON.

Laryngeal pacing as a treatment for vocal fold paralysis.

We summarize etiologies of vocal fold paralysis and current treatments. The recent literature involving electrical stimulation of the larynx is reviewed. Four canines were involved in a study to test a new laryngeal pacemaker system. This system was used to stimulate both the lateral cricoarytenoid and thyroarytenoid muscles. The data are taken from two of these canines. One of the goals was to stimulate the paralyzed side of the larynx based on the activity of the normal (nonparalyzed) side of the larynx. The best stimulation parameters for full addition of the paralyzed vocal cord were 3-7 V, pulse duration of 0.5 ms at a frequency of 84-100 Hz. Principles for electrode design and electrophysiologic parameters pertaining to laryngeal pacing are discussed. We believe that unilateral vocal fold paralysis may someday be treated by stimulating the paralyzed lateral cricoarytenoid and thyroarytenoid muscles to move in synchrony with the normal, unparalyzed, lateral cricoarytenoid and thyroarytenoid muscles.

Angiomyolipoma of the nasal cavity: case report and review of the literature.

An unusual localization of intranasal angiomyolipoma is described in an adult male patient with no signs of tuberous sclerosis. The lesion was composed of mature fat cells, vascular spaces with lack of elastic tissue, and presence of bundles of mature smooth muscle cells. Antibodies to intermediate filaments revealed presence of vimentin and absence of desmin in both smooth muscle bundles and in vessel walls. A review of the literature has shown that this is only the third reported case of the angiomyolipoma of the nasal cavity, and some important differences between this entity and renal angiomyolipoma are described.

Mechanics of caloric stimulation in a case with a plug in the horizontal semicircular canal.

Horizontal eye movements were recorded by electronystagmography in a subject with a plug of granulation tissue in the unilateral horizontal semicircular canal by the room temperature air caloric stimulation. Stimuli were sequentially presented to both ears with the subject supine and prone, keeping the horizontal canal vertical. Caloric stimuli presented to the unplugged ear resulted in a vestibular nystagmus whose slow phase eye velocity (SPEV) was always directed toward the stimulated side when the subject was supine and toward the opposite side when he was prone. In contrast, calorics presented to the horizontal canal plugged ear showed that SPEV was always directed toward the stimulated side, irrespective of whether the subject was supine or prone. Results were consistent with consensus that the caloric responses noted in the horizontal canal plugged ear reflected horizontal canal afferent activity which may correspond to direct effect of temperature on end organs or afferents. The findings imply that a caloric mechanism exists which is independent of the conventionally accepted one involving concection currents within the canal.

Superior sagittal sinus thrombosis after radical neck dissection.

Dural sinus thrombosis is a rare, potentially fatal complication of a radical neck dissection. The prognosis can vary from complete recovery to rapid death. Magnetic resonance venography provides an effective, noninvasive diagnosis. The goals of therapy are to decrease intracranial pressure and to lyse the thrombus. Systemic anticoagulation and systemic thrombolytics are controversial therapies. The direct intrasinus infusion of thrombolytic agents is under investigation.