Faculty Bibliography

Untreated congenital syphilis is a known cause of hearing loss. In order to ascertain if infants are at risk of hearing loss at birth, 75 neonates with serologic evidence of syphilis and APGAR scores greater than 9 at 5 min were examined by auditory brainstem response (ABR) audiometry. All of the infants had normal ABRs. Ophthalmologic examination revealed no evidence of interstitial keratitis. Lumbar puncture was attempted on all the neonates. Cerebrospinal fluid (CSF) was successfully obtained from 41 infants and revealed no abnormalities. This study demonstrates that asymptomatic infants with serologic evidence of syphilis do not require audiologic evaluation in the neonatal period.

Various population-based studies have suggested that the incidence and epidemiology of bacterial meningitis is changing. No studies have been published which examine a sample population of the United States at large. Records of pediatric patients age 5 and under who were treated for bacterial meningitis (n = 470) at all US Army medical facilities between 1986 and 1991 were reviewed. The incidence of bacterial meningitis declined by 75% in the study group during this period. The largest decrease occurred in infants less than 1 year of age. The bacterial organisms isolated most commonly, in decreasing frequency were: Haemophilus influenza type b (HIB), pneumococcal, streptococcal, and staphylococcal. The most dramatic abatement occurred in Haemophilus meningitis following the introduction of HIB vaccinations. Neurologic sequelae were identified in 10% of meningitis survivors. The 2 most common impairments were hearing loss and speech/language delay. Economic modeling demonstrates tremendous savings in health care dollars from the decrease in disease incidence. These changes will have substantial bearing on training programs and practitioners, since the management of neurologic sequelae requires the expertise of multiple subspecialists. In the face of a medical onslaught, once devastating diseases are in retreat

Neurotologic manifestations associated with the human immunodeficiency virus (HIV-1) are poorly understood. Eight temporal bones of acquired immunodeficiency syndrome (AIDS) cases were dissected and investigated ultrastructurally to determine if pathogens and pathologic changes were present within the cochlea. Extracellular viral-like particles with morphologic characteristics of HIV-1 were identified on the tectorial membrane in three cases. Numerous viral-like particles with cores appeared trapped within lacunae along the tectorial membrane in one specimen. Intracellular viral-like particles, appearing essentially similar to identified HIV-1 particles of infected lymphocyte cultures, were found within the cytoplasm of connective tissue cells. These same cells had gradients of enlarged viral envelopes forming cisterns that contained cores and varying amounts of cistern particulate. Some sectioned profiles of enlarged cytoplasmic cisterns revealed the attachment and inward protrusion of the core from the cistern wall. Other ultrastructural findings included cytoplasmic globular-dense particulate bodies, aggregates of smaller viral-like particles, and mitochondrial changes. This demonstration of prominent viral-like particles and cochlear pathology may help to explain the neurotologic manifestations associated with HIV-1 infection

The clinical courses of children with acquired immunodeficiency syndrome (AIDS) who underwent diagnostic flexible bronchoscopy at Bellevue Hospital from 1987-1992 were reviewed to determine the value of the procedure in patient management. Twenty-eight children (age 13 days to 12 years) underwent 31 bronchoscopies for indications including respiratory distress, fever and abnormal chest radiograph. Procedures were well tolerated. Complications were limited to transient hypoxia and epistaxis. Although 58% of bronchoscopies yielded a diagnosis (Pneumocystis carinii, Streptococcus viridans, Pseudomonas aeruginosa, Cytomegalovirus, atypical mycobacterium, giant cell pneumonia, and mechanical obstruction), empiric medical therapy was altered in only 16% of cases. Bronchoscopic diagnoses are correlated with Centers for Disease Control (CDC) classification, immune status, treatment and outcome

The structure of the submental platysma muscle was evaluated in 20 preserved cadavers. Four distinct patterns were identified, depending on the pattern of merging of the right and left platysma bundles. Fifteen percent of cases showed a complete platysma diaphragm submentally, while in the other 85% there was some degree of midline dehiscence. In the 85% of cases where right and left fibers merged or crossed to form a V or U shape, the apex of the V or U was measured relative to the chin point. The distance between right and left fibers was measured at two locations posterior to the chin point. The width of the midline dehiscence (when present) was 6-24 mm (mean 11.8 mm) 1 cm posterior to its apex and 10-44 mm (mean 20.00 mm) 2 cm posterior to the apex. The wider and more divergent the dehiscence and the more U-shaped the dehiscence between left and right platysma bundles, the greater may be the tendency to a 'turkey gobbler' deformity with inadequate medial support for the skin and subcutaneous tissues

The goal of this study was to determine the distribution and diversity of astrocytes and oligodendrocytes within the lateral superior olive of the gerbil. We used morphometric analyses and several immunocytochemical markers to assess differences in glial cell composition between the lateral (low-frequency projection) and the medial (high-frequency projection) limb of the lateral superior olive. Cell counts from Toluidine-stained semithin sections revealed a similar density of total astrocytes in both the lateral and the medial limbs. However, based on cytologic features, there was a prevalence of fibrous-like astrocytes in the lateral limb and protoplasmic-like astrocytes in the medial limb. In a similar manner, glial fibrillary acidic protein staining of astrocytes was intense in the lateral limb, but was largely restricted to the nucleus borders in the medial limb of the lateral superior olive. While glial fibrillary acidic protein was largely restricted to astrocytic processes, glutamine synthetase and S100 protein staining occurred, for the most part, in glial cell bodies. The density of glutamine synthetase positive cell bodies was homogeneous between the two limbs, while the density of S100-positive somata was significantly greater in the lateral limb. Cell counts obtained from semithin sections demonstrated a greater density of oligodendrocytes in the lateral limb than in the medial limb of the lateral superior olive. In a similar manner, there was a 40% greater density of carbonic anhydrase-positive somata in the lateral limb compared to the medial limb. Transferrin immunostaining was restricted to oligodendrocytes, but the density of labeled somata was identical in the lateral and medial limbs. 2',3'-Cyclic nucleotide 3'-phosphodiesterase and myelin-associated glycoprotein were also localized to the somata of oligodendrocytes, labeling both perisomatic and interfascicular cells. At the ultrastructural level, specialized contacts were found between pairs or clusters of oligodendrocytes. These results suggest that more than one type of astrocyte and oligodendrocyte is present within the gerbil lateral superior olive. Furthermore, glial cells were unevenly distributed, such that a greater density of oligodendrocytes and fibrous-like astrocytes were found in the low-frequency projection region. This heterogeneity is well correlated with known differences in the neuronal morphology within the lateral superior olive

BACKGROUND. No study has examined the nature and extent of swallowing impairment in oral cancer patients following treatment with combined hyperthermia and interstitial radiotherapy. Few studies have examined the effects of voluntary swallow maneuvers (supersupraglottic and Mendelsohn) on pharyngeal phase swallowing in the oral cancer patient treated with surgery or radiotherapy. This study examined the effects of combined radiotherapeutic salvage treatments of hyperthermia and interstitial implantation and swallow recovery using swallow maneuvers in a surgically treated and irradiated oral cancer patient. METHODS. The patient under study, a 51-year-old man, underwent radiotherapy, according to Radiation Therapy Oncology Group (RTOG) protocol #8419, consisting of a combination of interstitial irradiation and hyperthermia to the base of tongue, for a recurrent squamous cell cancer. He underwent videofluorographic (VFG) examination of his swallowing, a modified barium swallow at three time points: 2 days following radiotherapy treatment (VFG1), 4 weeks later (VFG2), and 8 months later (VFG3). Temporal and biomechanical analyses of swallows were performed at each time point. RESULTS. Swallow maneuvers and time resulted in improved laryngeal elevation and laryngeal vestibule closure during the swallows on VFG2. Maximum upper esophageal sphincter (UES) opening width and duration were more normal. Fewer swallows were required for bolus clearance through the pharynx. Base of tongue tissue necrosis occurred as a complication of radiotherapy between VFG2 and VFG3, with resultant severe reduction in posterior movement of the tongue base, incomplete tongue base contact to the posterior pharyngeal wall, reduced laryngeal elevation, and incomplete laryngeal vestibule closure during swallowing at VFG3. UES opening became less normal and a greater number of swallows were required for bolus clearance through the pharynx. CONCLUSIONS. Combined interstitial irradiation and hyperthermia can cause oropharyngeal swallowing problems. Time and swallow therapy can improve these swallow disorders. Tongue base tissue necrosis can cause further swallow impairment, emphasizing the importance of the tongue base in normal deglutition. Further studies are needed to examine the impact of combined hyperthermia and interstitial implantation for treatment of tongue base tumors on swallow functioning in a larger group of patients

Facial nerve tumors can present as masses in the internal auditory canal or cerebellopontine angle and may mimic an acoustic neuroma. These tumors can occur in any segment of the nerve from the brain stem to the neuromuscular junction. Prior to the advent of computed tomography and magnetic resonance imaging with gadolinium, facial nerve tumors were often difficult to diagnose. Even with these modalities it may be difficult to distinguish preoperatively between an acoustic neuroma and a facial schwannoma. Particular signs and symptoms associated with facial nerve tumors (in the spasms, and a facial tic. These symptoms, combined with modem radiologic studies, should allow for more accurate diagnosis, patient counseling, and treatment. This report presents a series of 32 facial nerve tumors diagnosed and treated at The Otology Group from 1975 to 1992. Of these lesions, 12 (38%) were thought to be acoustic neuromas. Eighteen tumors were correctly identified preoperatively as facial nerve tumors. Two facial nerve tumors were found incidentally.

We have previously shown that aggregation of microbeads coated with N-CAM and Ng-CAM is inhibited by incubation with soluble neurocan, a chondroitin sulfate proteoglycan of brain, suggesting that neurocan binds to these cell adhesion molecules (Grumet, M., A. Flaccus, and R. U. Margolis. 1993. J. Cell Biol. 120:815). To investigate these interactions more directly, we have tested binding of soluble 125I-neurocan to microwells coated with different glycoproteins. Neurocan bound at high levels to Ng-CAM and N-CAM, but little or no binding was detected to myelin-associated glycoprotein, EGF receptor, fibronectin, laminin, and collagen IV. The binding to Ng-CAM and N-CAM was saturable and in each case Scatchard plots indicated a high affinity binding site with a dissociation constant of approximately 1 nM. Binding was significantly reduced after treatment of neurocan with chondroitinase, and free chondroitin sulfate inhibited binding of neurocan to Ng-CAM and N-CAM. These results indicate a role for chondroitin sulfate in this process, although the core glycoprotein also has binding activity. The COOH-terminal half of neurocan was shown to have binding properties essentially identical to those of the full-length proteoglycan. To study the potential biological functions of neurocan, its effects on neuronal adhesion and neurite growth were analyzed. When neurons were incubated on dishes coated with different combinations of neurocan and Ng-CAM, neuronal adhesion and neurite extension were inhibited. Experiments using anti-Ng-CAM antibodies as a substrate also indicate that neurocan has a direct inhibitory effect on neuronal adhesion and neurite growth. Immunoperoxidase staining of tissue sections showed that neurocan, Ng-CAM, and N-CAM are all present at highest concentration in the molecular layer and fiber tracts of developing cerebellum. The overlapping localization in vivo, the molecular binding studies, and the striking effects on neuronal adhesion and neurite growth support the view that neurocan may modulate neuronal adhesion and neurite growth during development by binding to neural cell adhesion molecules