Faculty Bibliography

The anterior clinoid process (ACP), located on the skull base, is a relatively small structure, although its removal provides enormous gain in facilitating the management of lesions--either tumors or aneurysms--in the paraclinoid region and upper basilar artery. The extensive surgical field gained contributes to safer exposure of the neurovascular elements in the vicinity while avoiding excessive and hazardous retraction of the brain. In this report the authors present a technically simpler avenue for performing an extradural anterior clinoidectomy after reviewing the anatomy of the ACP and its anatomical variations. Additionally, the original Dolenc procedure and its subseqtient derivatives are compared and contrasted to the authors' simpler and less laborious technique. Different clinical situations in which to use the procedure are described based on the authors' experience from 60 cases (40 aneurysm cases and 20 tumor cases) during a 4-year period.

CONCLUSION: The development of conceptualization of a biological basis of language during the 20th century has come about, in part, through the appreciation of the central nervous system's ability to utilize varied sensory inputs, and particularly vision, to develop language. OBJECTIVE: Sign language has been a part of the linguistic experience from prehistory to the present day. Data suggest that human language may have originated as a visual language and became primarily auditory with the later development of our voice/speech tract. Sign language may be categorized into two types. The first is used by individuals who have auditory/oral language and the signs are used for special situations, such as communication in a monastery in which there is a vow of silence. The second is used by those who do not have access to auditory/oral language, namely the deaf. MATERIAL AND METHODS: The history of the two forms of sign language and the development of the concept of the biological basis of language are reviewed from the fourth century BC to the present day. RESULTS: Sign languages of the deaf have been recognized since at least the fourth century BC. The codification of a monastic sign language occurred in the seventh to eighth centuries AD. Probable synergy between the two forms of sign language occurred in the 16th century. Among other developments, the Abbey de L'Epee introduced, in the 18th century, an oral syntax, French, into a sign language based upon indigenous signs of the deaf and newly created signs. During the 19th century, the concept of a "critical" period for the acquisition of language developed; this was an important stimulus for the exploration of the biological basis of language. The introduction of techniques, e.g. evoked potentials and functional MRI, during the 20th century allowed study of the brain functions associated with language.

Morphologic distinction of high-grade adenoid cystic carcinoma from basaloid squamous cell carcinoma can be difficult. Equivocal diagnoses can mislead treatment. We have investigated the possibility that immunohistochemical staining for the presence of p63, a novel epithelial stem-cell regulatory protein, could be a useful means of distinguishing these two neoplasms. Archival, routinely processed slides were subjected to citrate-based antigen retrieval, exposure to anti-p63 monoclonal 4A4, and developed with a streptavidin-biotin kit and diaminobenzidine as chromogen. p63 was detected in 100% of the adenoid cystic carcinomas (n=14) and 100% of basaloid squamous cell carcinomas (n=16). Basaloid squamous cell carcinomas consistently displayed diffuse p63 positivity, with staining of nearly 100% of tumor cells. In contrast, adenoid cystic carcinoma displayed a consistently compartmentalized pattern within tumor nests. Compartmentalization was manifested in two patterns: (1) selective staining of a single peripheral layer of p63-positive cells surrounding centrally located tumor cells that were p63-negative and (2) tumor nests consisting of multiple contiguous glandular/cribriform-like units of p63-positive cells surrounding or interspersed with p63-negative cells. p63 immunostaining constitutes a specific and accurate means of distinguishing adenoid cystic carcinoma from basaloid squamous cell carcinoma. p63 positivity in adenoid cystic carcinoma appears to be homologous to that seen in the basal and/or myoepithelial compartments of salivary gland and other epithelia, and may signify a stem-cell-like role for these peripheral cells. Diffuse p63 positivity in basaloid squamous cell carcinoma suggests dysregulation of p63-positive stem cells in poorly differentiated squamous carcinoma

In recent years, new designs of cochlear implant electrodes have been introduced in an attempt to improve efficiency and performance by locating stimulation sites closer to spiral ganglion neurons and deeper into the scala tympani. The goal of this study was to document insertion depth, intracochlear position and insertion trauma with the Nucleus Contour electrode and to compare results to those observed with the earlier generation Nucleus banded electrode. For this comparison eight Nuclears banded electrodes and 18 Contour electrodes were implanted in cadaver temporal bones using a realistic surgical exposure. Two experienced cochlear implant surgeons and two otology fellows with specialized training in cochlear implant surgery were selected for the study to represent a range of surgical experience similar to that of surgeons currently performing the procedure throughout the world. Following insertion of the electrodes, specimens were imaged using plain film X-ray, embedded in acrylic resin, cut in radial sections with the electrodes in place, and each cut surface was polished. Insertion depth was measured in digitized X-ray images, and trauma was assessed in each cross-section. The Contour electrode inserted more deeply (mean depth=17.9 mm or 417 degrees ) than the banded electrode (mean depth=15.3 mm or 285 degrees ). The incidence and severity of trauma varied substantially among the temporal bones studied. However, the nature and frequency of injuries observed with the two devices were very similar. The Contour electrode was clearly positioned closer to the modiolus than the banded model, and also appeared easier to use. Based on this difference in position and data from previous studies we conclude that the Contour electrode may provide lower thresholds and improved channel selectivity, but the incidence of trauma remains a problem with the newer design. The relative influences of electrode positioning and neural degeneration that may result from trauma are as yet unclear

The authors report on a surgical technique involving a one-piece osteoplastic bone flap, which incorporates the frontal, temporal, and lateral portions of the orbital rim as a technically simpler alternative to the standard orbitozygomatic (OZ) craniotomy. The orbital rim component extends just laterally from the supraorbital foramen/notch to the frontozygomatic suture. This craniotomy obviates the need for removing the zygoma and has evolved from the authors' experience in more than 200 patients with a variety of pathological lesions, both vascular and tumorous. The osteoplastic aspect of this technique was initially evaluated in 14 cadaveric sites in seven heads dissected prior to implementing this procedure clinically. The osteoplastic bone flap minimally obstructs the surgical view and provides all the advantages of a standard OZ craniotomy. Temporalis muscle atrophy leading to temporal hollowing is avoided, a bone union to the calvaria is improved, and the possibility of bone infection is decreased. The osteoplastic component of the technique adds to the improved long-term cosmesis and warrants active consideration in the art of neurosurgery.