Faculty Bibliography

Synapses are highly plastic and are modified by changes in patterns of neural activity or sensory experience. Plasticity of cortical excitatory synapses is thought to be important for learning and memory, leading to alterations in sensory representations and cognitive maps. However, these changes must be coordinated across other synapses within local circuits to preserve neural coding schemes and the organization of excitatory and inhibitory inputs, i.e., excitatory-inhibitory balance. Recent studies indicate that inhibitory synapses are also plastic and are controlled directly by a large number of neuromodulators, particularly during episodes of learning. Many modulators transiently alter excitatory-inhibitory balance by decreasing inhibition, and thus disinhibition has emerged as a major mechanism by which neuromodulation might enable long-term synaptic modifications naturally. This review examines the relationships between neuromodulation and synaptic plasticity, focusing on the induction of long-term changes that collectively enhance cortical excitatory-inhibitory balance for improving perception and behavior.

BACKGROUND: Background noise has been found to negatively affect working memory. Numerous studies have also found that older adults perform more poorly on working memory tasks than young adults (YA). Hearing status has often been a confounding factor in older individuals. Therefore, it would be beneficial to investigate working memory functions in adverse listening conditions early in the aging process (i.e., middle-age), when hearing function is relatively unaffected. PURPOSE: The focus of this study was to determine the influence of background babble on working memory in YA and middle-aged adults (MA) with normal hearing. RESEARCH DESIGN: Before testing was begun, we established that all participants could correctly identify words in a degraded experimental testing environment with 100% accuracy. Then, the participants listened to lists composed of five pairs of words in quiet and in 20-talker babble. After the final word pair, the participants were cued with the first word of one of the previous five word pairs. The participants were required to write down the second word of the pair. The percent correct scores for each of the five serial positions were analyzed comparing the two listening conditions for YA and MA. Ten YA and ten MA with normal hearing between 250-8000 Hz and a score of at least 26/30 on the Mini-Mental State Examination participated in the study. As different cognitive processes are used for initial, middle, and final serial positions, averaged scores were obtained for Positions 2 and 3 and for Positions 4 and 5. Subsequently, repeated-measures analyses of variance (ANOVAs) were conducted on mean scores of correctly recalled word pairs with serial positions (initial, middle, and final) and listening condition (quiet, babble) as the within-participant variables and age group (YA, MA) as the between-participant independent variable. This OMNIBUS repeated-measures ANOVA was then followed up with separate repeated-measures ANOVAS for the initial, middle, and final positions. RESULTS: Correct recall scores were lower for early positions compared with the latter positions, irrespective of listening condition. For Position 1, YA-but not MA-performed significantly better in babble than in quiet. For the middle positions (Positions 2 and 3), MA performed significantly more poorly than the YA irrespective of listening condition. For the final positions (Positions 4 and 5), no age differences or effects of listening condition were found. CONCLUSIONS: The results indicate that both YA and MA have trouble recalling earlier pieces of information in quiet and in babble. However, MA exhibited significantly poorer recall scores than YA in babble for Position 1, which suggest that cognitive processes related to memory encoding and retrieval are different in background babble for MA and YA.

Motion sickness can be a limiting factor for sea and air missions. We report the experience of a Pararescue (PJ) team on a Pacific Ocean rescue mission in which motion sickness was prevalent. Cinnarizine, an antagonist of H1-histamine receptors, was used to treat affected PJs. We also report findings of a survey of PJs regarding motion sickness. A family of four on a disabled sailboat 900 miles off the coast of Mexico sent out a distress call because their 1-year-old daughter became severely ill with fever and diarrhea. Four PJs were deployed on a C-130, performed a free-fall parachute insertion into the ocean, and boarded the sailboat. All four PJs experienced onset of motion sickness at some point during the early part of the mission and symptoms persisted through the first 24 hours. Three PJs experienced ongoing nausea, vomiting, dizziness, and sensory imbalances. The captain of the sailboat offered the three sick PJs approximately 18mg of cinnarizine two or three times a day with relief of symptoms and improvement on operational effectiveness. A new, anonymous, voluntary survey of Air National Guard PJs and combat rescue officers revealed that 78.4% of Operators have experienced motion sickness at sea. We discuss the current theories on motion sickness, the effect of motion sickness on operational effectiveness, and research on treatment of motion sickness, including the medication cinnarizine.

BACKGROUND: Multi-stage laryngotracheoplasty (LTP) typically requires a stent be secured to the airway for 2-6 weeks. Our technique has evolved over time to securing the stent to the strap muscles and tying a series of knots long enough to leave the suture tail protruding through the skin incision, which simplifies stent removal. METHODS: Retrospective chart review. RESULTS: Twenty-four patients underwent multi-stage LTP at our institution from 2007 to 2013. Eight patients were excluded from the study because they either did not have a stent placed (n=4), or they had a t-tube placed which was not sutured in place (n=4). Of the remaining 16 patients, 62.5% (n=10) had their stent secured via sutures which were buried below the skin, and 37.5% (n=6) via a long suture tail which was left protruding through the end of the skin incision. An incision was required for stent removal 100% of buried sutures patients, and 33% of exposed suture patients (p=0.0009). Average operative time for stent removal was 60min in the buried sutures group, and 25min in the exposed sutures group (p=0.0075). CONCLUSIONS: Securing stents via an exposed suture technique decreases the need for making a skin incision during the second stage of the operation, and significantly decreases the operative time of the second stage.

OBJECTIVE: To analyze the utility of intraoperative parathyroid hormone (IOPTH) monitoring for patients with primary hyperparathyroidism who had evidence of single-gland disease on preoperative imaging with modified 4-dimensional computed tomography that was done in conjunction with ultrasonography (Mod 4D-CT/US). STUDY DESIGN: Case series with chart review. SETTING: Tertiary care university medical center. SUBJECTS AND METHODS: Patients were drawn from consecutive directed parathyroidectomies performed between December 2001 and June 2013 by the senior authors. All patients had primary hyperparathyroidism and underwent a Mod 4D-CT/US study that showed findings on both studies that were consistent with a single adenoma. The modified Miami criteria were used for IOPTH monitoring (parathyroid hormone decrease by >50% and into the normal range). RESULTS: Of 356 patients who underwent parathyroid surgery, 206 had a single gland localized on the Mod 4D-CT and the US studies. IOPTH monitoring was used in 172 cases, of which 169 had adequate clinical follow-up to assess the surgical outcome. Twenty-one patients (12.4%) had IOPTH values that did not meet modified Miami criteria after removal of one gland, of which 7 were found to have multigland disease (4.1%). Three patients (1.8%) had persistent primary hyperparathyroidism despite an IOPTH that met modified Miami criteria. CONCLUSIONS: Although IOPTH monitoring correctly identifies a small percentage of patients with multigland disease, some patients will be subjected to unnecessary neck explorations that can result in difficult intraoperative decisions, such as whether to remove normal or equivocal-sized glands when they are encountered.

BACKGROUND: Recent advances in research on thyroid carcinogenesis have yielded applications of diagnostic molecular biomarkers and profiling panels in the management of thyroid nodules. The specific utility of these novel, clinically available molecular tests is becoming widely appreciated, especially in perioperative decision making by the surgeon regarding the need for surgery and the extent of initial resection. METHODS: A task force was convened by the Surgical Affairs Committee of the American Thyroid Association and was charged with writing this article. RESULTS/CONCLUSIONS: This review covers the clinical scenarios by cytologic category for which the thyroid surgeon may find molecular profiling results useful, particularly for cases with indeterminate fine-needle aspiration cytology. Distinct strengths of each ancillary test are highlighted to convey the current status of this evolving field, which has already demonstrated the potential to streamline decision making and reduce unnecessary surgery, with the accompanying benefits. However, the performance of any diagnostic test, that is, its positive predictive value and negative predictive value, are exquisitely influenced by the prevalence of cancer in that cytologic category, which is known to vary widely at different medical centers. Thus, it is crucial for the clinician to know the prevalence of malignancy within each indeterminate cytologic category, at one's own institution. Without this information, the performance of the diagnostic tests discussed below may vary substantially.

The present study aims to determine the risk of early secondary nasal revisions in patients with complete unilateral and bilateral cleft lip and palate (U/BCLP) treated with and without nasoalveolar molding (NAM) and examine the associated costs of care. A retrospective cohort study from 1990 to 1999 was performed comparing the risk of early secondary nasal revision surgery in patients with a CLP treated with NAM and surgery (cleft lip repair and primary surgical nasal reconstruction) versus surgery alone in a private practice and tertiary level clinic. The NAM treatment group consisted of 172 patients with UCLP and 71 patients with BCLP, whereas the non-NAM-prepared group consisted of 28 patients with UCLP and 5 with BCLP. The risk of secondary nasal revision for patients with UCLP was 3% in the NAM group and 21% in the non-NAM group. The risk of secondary nasal revision for patients with BCLP was 7% in the NAM group compared with 40% in the non-NAM group. Using multicenter averages, the non-NAM revision rates were calculated at 37.8% and 48.5% for U/BCLP, respectively. Applying these risks of revision, NAM treatment led to an estimated savings of between $491 and $4893 depending on the type of cleft. In conclusion, NAM can reduce the number of early secondary nasal revision surgeries and, therefore, reduce the overall cost of care.

Laryngeal function after oncologic treatment is a key aspect and focus of interest in the contemporary management of head and neck cancers. Although historically the treatment of most locally advanced laryngeal cancers has been total laryngectomy, recent innovations in radiation therapy and combined chemotherapy and radiation therapy have shown that organ and function preservation can be achieved with good oncologic outcomes. Technical improvements, along with better understanding of tumor biology and dose tolerance of critical organs involved in speech and swallowing function, have paved the way for better outcomes. This article reviews in comprehensive detail the recent data of laryngeal function after radiotherapy.