Faculty Bibliography

BACKGROUND: Research has shown that the cochlear implant may improve deaf children's speech and communication skills. However, little is known about its effect on children's ability to socialize with hearing peers. METHODS: Using a standardized psychological measure completed by parents and a longitudinal design, this study examined the development of communication, socialization, and daily living skills of children who used hearing aids or cochlear implants for an average of 11 and 6 years, respectively. RESULTS: Results show that children with cochlear implants, who were more delayed than children with hearing aids at the outset, made significant progress over time. Children with both devices achieved age-appropriate development after years of hearing aid or cochlear implant use. CONCLUSIONS: The pattern of results suggests that cochlear implants may be effective in improving deaf children's communication and social skills

BACKGROUND: We recently identified MUC1 as a target driving selection for 1q21 amplification and validated it as an independent marker of aggressive behavior in thyroid cancer (TC). The aims of this study were to determine whether TC cell lines retain MUC1 expression patterns that are seen in primary tumors, assess the role of MUC1 in tumor maintenance, and develop a virally delivered anti-MUC1 RNA interference (RNAi) that is effective in decreasing MUC1 expression in vitro. METHODS: Fifteen TC cell lines were screened for MUC1 protein expression. Cell lines with varying MUC1 protein levels were treated with anti-MUC1 monoclonal antibody to assess cell viability. A recombinant retroviral short hairpin RNAi delivery system against MUC1 was developed. Efficacy and optimal dosing of short hairpin RNA against MUC1 was determined. RESULTS: MUC1 expression patterns in TC cell lines were found to be similar to that seen in primary tumors. Treatment with anti-MUC1 antibody resulted in a significant decrease in cell viability in MUC1 over-expressing cell lines. MUC1-779 RNAi construct showed excellent infection efficiency and reproducible silencing. CONCLUSION: These data offer functional evidence that implicates MUC1 over-expression as a key molecular event in the pathogenesis of aggressive TC. Retrovirally delivered anti-MUC1 RNAi is effective in silencing MUC1 and merits further investigation to establish therapeutic efficacy and safety in anticipation of potential clinical application

OBJECTIVES/HYPOTHESIS: To compare the sensitivity of an objective, computerized approach to measurement of facial synkinesis with that for a subjective approach and to examine the test-retest reliability of these approaches. STUDY DESIGN: Prospective, nonrandomized, and blinded. METHODS: Remote facial motion at the upper eyelids and oral commissures during a closed-lip smile and eyelid closure were measured using a commercially available computerized motion analysis system. Thirty healthy adults with normal facial nerve function were enrolled to establish normative data and a threshold value for synkinesis. Thirty consecutive patients were analyzed based on the synkinesis threshold value. Blinded subjective evaluations by two observers were also performed independently on the same patients. RESULTS: Facial synkinesis was detected significantly more frequently with objective than subjective analysis for eyelid closure; no significant differences between approaches were shown for the closed-lip smile. Interestingly, five (17%) patients developed early synkinesis within 3 months from the onset of the facial nerve injury. The test-retest reliability of all objective measures was excellent for both expressions. Close agreement in percent of patients with synkinesis between test and retest subjective evaluations was obtained for both observers for both expressions. CONCLUSIONS: The objective, computerized approach to detection of facial synkinesis has excellent reliability and is more sensitive than the subjective approach to assessment to the presence of facial synkinesis associated with eyelid closure. The finding of early synkinesis suggests that central nervous reorganization plays a role in regeneration of the facial nerve

Despite the peripheral and central immaturities that limit auditory processing in juvenile animals, they are able to lateralize sounds using binaural cues. This study explores a central mechanism that may compensate for these limitations during development. Interaural time and level difference processing by neurons in the superior olivary complex depends on synaptic inhibition from the medial nucleus of the trapezoid body (MNTB), a group of inhibitory neurons that is activated by contralateral sound stimuli. In this study, we examined the maturation of coding properties of MNTB neurons and found that they receive an inhibitory influence from the ipsilateral ear that is modified during the course of postnatal development. Single neuron recordings were obtained from the MNTB in juvenile (postnatal day 15-19) and adult gerbils. Approximately 50% of all recorded MNTB neurons were inhibited by ipsilateral sound stimuli, but juvenile neurons displayed a much greater suppression of firing as compared with those in adults. A comparison of the prepotential and postsynaptic action potential indicated that inhibition occurred at the presynaptic level, likely within the cochlear nucleus. A simple linear model of level difference detection by lateral superior olivary neurons that receive input from MNTB suggested that inhibition of the MNTB may expand the response of LSO neurons to physiologically realistic level differences, particularly in juvenile animals, at a time when these cues are reduced

Noise that is amplitude modulated at rates ranging from 40 to 850 Hz can elicit a sensation of pitch. Here, the processing of this temporally based pitch was investigated using a perceptual-learning paradigm. Nine listeners were trained (1 hour per day for 6-8 days) to discriminate a standard rate of sinusoidal amplitude modulation (SAM) from a faster rate in a single condition (150 Hz SAM rate, 5 kHz low-pass carrier). All trained listeners improved significantly on that condition. These trained listeners subsequently showed no more improvement than nine untrained controls on pure-tone and rippled-noise discrimination with the same pitch, and on SAM-rate discrimination with a 30 Hz rate, although they did show some improvement with a 300 Hz rate. In addition, most trained, but not control, listeners were worse at detecting SAM at 150 Hz after, compared to before training. These results indicate that listeners can learn to improve their ability to discriminate SAM rate with multiple-hour training and that the mechanism that is modified by learning encodes (1) the pitch of SAM noise but not that of pure tones and rippled noise, (2) different SAM rates separately, and (3) differences in SAM rate more effectively than cues for SAM detection

OBJECT: The goal of this study is to report the incidence and clinical evolution of neurological deficits in patients who underwent resection of gliomas confined to the parietal lobe. METHODS: Patient demographics, findings of serial neurological examinations, tumor location and neuroimaging characteristics, extent of resection, and surgical outcomes were tabulated by reviewing inpatient and office records, as well as all pre- and postoperative magnetic resonance (MR) images obtained in 28 consecutive patients who underwent resection of a glial neoplasm found on imaging studies to be confined to the parietal lobe. Neurological deficits were correlated with hemispheric dominance, location of the lesion within the superior or inferior parietal lobules, subcortical extension, and involvement of the postcentral gyrus. The tumors were located in the dominant hemisphere in 18 patients (64%); had a mean diameter of 39 mm (range 14-69 mm); were isolated to the superior parietal lobule in six patients (21%) and to the inferior parietal lobule in eight patients (29%); and involved both lobules in 14 patients (50%). Gross-total resection, documented by MR imaging, was achieved in 24 patients (86%). Postoperatively, nine patients (32%) experienced new neurological deficits, whereas seven (25%) had an improvement in their preoperative deficit. A correlation was noted between larger tumors and the presence of neurological deficits both before and after resection. Postoperatively higher-level (association) parietal deficits were noted only in patients with tumors involving both the superior and inferior parietal lobules in the dominant hemisphere. At the 3-month follow-up examination, five of nine new postoperative deficits had resolved. CONCLUSIONS: Neurological deterioration and improvement occur after resection of parietal lobe gliomas. Parietal lobe association deficits, specifically the components of Gerstmann syndrome, are mostly associated with large tumors that involve both the superior and inferior parietal lobules of the dominant hemisphere. New hemineglect or sensory extinction was not noted in any patient following resection of lesions located in the nondominant hemisphere. Nevertheless, primary parietal lobe deficits (for example, a visual field loss or cortical sensory syndrome) occurred in patients regardless of hemispheric dominance

Although abnormalities of vascular anatomy in the forearm are common, variations of the radial and ulnar arteries are rare. Nevertheless, arterial variants in the forearm may present clinically with neurovascular signs or symptoms. Even when anomalous arteries are not apparent, they may complicate surgery of the forearm and hand, as well as reconstructive surgery that involves the harvest of radial or ulnar artery-based forearm free flaps. For example, the superficial ulnar artery has an incidence of 2.7% and has been well described as a 'hidden trap' in the harvest of radial forearm flaps. We present a case report of a variant of the radial artery-the superficial dorsal artery of the forearm. This artery has an estimated incidence of 0.75% and is associated with either an absent or small-caliber radial artery. We believe this is the first report of such an artery presenting to clinical attention, as well as the first imaging of this structure with magnetic resonance angiography. The embryology of this structure and its clinical implications to the hand surgeon, peripheral vascular surgeon, and reconstructive microsurgeon, are also discussed