Faculty Bibliography

CT and MRI are the primary imaging modalities used to evaluate the various regions of the head and neck. From the preceding discussion one can see clearly that the choice of the appropriate imaging modality depends on a number of variables. There is no indisputable 'winner' under all anatomical or pathological circumstances. The advantages and disadvantages of CT and MRI in certain clinical settings have been discussed. The information provided will enable one to exercise a rational choice in the selection of imaging modalities

The development of a retropharyngeal hematoma following a whiplash injury is a rare occurrence. The potential for airway compression necessitates rapid assessment and treatment. An 80-year-old man who had been receiving long-term aspirin therapy sustained a retropharyngeal hematoma following a motor vehicle accident. Management consisted of tracheostomy, neck exploration, and evacuation and drainage of the hematoma. To the best of our knowledge, there are less than 20 citations of traumatic retropharyngeal hematoma in the English literature. Retropharyngeal hematoma has been associated with cervical extension/flexion injuries, anticoagulation therapy, great-vessel trauma, and foreign body ingestion

Bony hemangiomas of the zygomatic bone are rare. This report represents the tenth citing in the literature. The most common signs and symptoms include swelling and pain or tenderness. Diagnosis can be made by plain radiographic studies followed by CT scanning or MRI. The treatment of choice is surgical excision with a rim of normal bone around the tumor. Malignant degeneration has not been reported unless radiotherapy had been used

The laryngocele and saccular cyst are uncommon anomalies of the larynx. Two patients, one with an internal laryngocele and one with a saccular cyst, were successfully treated by endoscopic laser marsupialization of their lesions. Since neither patient was found to be a suitable candidate for prolonged general anesthesia, the patients did not require a tracheotomy and were discharged the day after surgery. Both patients are doing well, with remarkable improvement in their voices persisting in their three year follow-up. The signs, symptoms, diagnosis, treatment, and indications for endoscopic laser treatment of internal laryngoceles and saccular cysts are discussed. Laser marsupialization of internal laryngoceles appears to be an acceptable mode of treatment

Indications for repair of nasal septum perforations include excessive crusting, recurrent bleeding, whistling, and pain. Large subtotal perforations usually are less symptomatic, but smaller defects (less than 1 cm) may need repair. Tragal cartilage with perichondrium autograft was used to repair these perforations. After the septal defect was debrided, this free graft was harvested and used to fill the defect. This technique was attempted in ten patients with septal perforations, none secondary to systemic illnesses. Nine of these patients had successful closure of their perforations

The hypotheses that selective formation of nerve-muscle connections depends upon intrinsic cellular properties, endowed either by the cell's rostral-caudal position in the embryo or its lineage, were tested directly in Xenopus embryonic cell cultures. The position or the lineage of embryonic cells was traced in vitro by previous injection of fluorophore-conjugated dextran molecules into individual blastomeres. Synaptic efficacy was assayed by recording synaptic currents from neurite-contacted muscle cells in the culture, and the physical affinity of neurites for muscle cells of different positional or clonal origins was assayed by counting the frequency of association between the neurites' growth cones and the muscle cells. Both assays showed no apparent preference between nerve and muscle cells of similar rostral-caudal positions or clonal origins, suggesting that there is little position- or lineage-dependent selectivity in the initial nerve-muscle interactions

We have investigated developmental alterations in the tonotopic projection of the gerbil lateral superior olive. Single neurons were characterized in the frequency domain and the recording site marked with fast green. Transverse tissue sections from the auditory brainstem of each animal were visualized with a video-equipped microscope, and the image was digitized for subsequent alignment. The three-dimensional display indicated little variation in the rostrocaudal axis, allowing us to collapse the data into a two-dimensional tonotopic map. The tonotopic map was found to change with age such that the characteristic frequency of neurons in a given anatomical location became successively higher during development. These results are consistent with the hypothesis that the place code gradually shifts in the developing cochlea