Nicole T. Jiam

Aging reduces total neuron number in the dorsal component of the rodent prefrontal cortex.

For many years, aging was thought to be accompanied by significant decreases in total neuron number across multiple brain regions. However, this view was revised with the advent of modern quantification methods, and it is now widely accepted that the hippocampus and many regions of the cortex show substantially preserved numbers of neurons during normal aging. Nonetheless, age‐related changes in neuron number do occur in focal regions of the primate prefrontal cortex (PFC), but the question of whether age‐related neuron loss is an exclusive characteristic of the PFC in primates remains relatively unexplored. To investigate the loss of neurons with normal aging in rodents, we used unbiased stereological methods to quantify the number of principal neurons and interneurons in the PFC of young and aged rats. We observed a significant age‐related decline in the number of principal neurons in the dorsal PFC. The number of interneurons positively stained with antibodies to glutamic acid decarboxylase 67 was also reduced in the dorsal PFC of aged rats. These observations indicate that the dorsal PFC is susceptible to neuron loss with aging in rodent brain and suggest some common basis for vulnerability in cortical circuits across species. J. Comp. Neurol. 520:1318–1326, 2012.

Interference with reelin signaling in the lateral entorhinal cortex impairs spatial memory.

Entorhinal neurons receive extensive intracortical projections, and form the primary input to the hippocampus via the perforant pathway. The glutamatergic cells of origin for the perforant pathway are distinguished by their expression of reelin, a glycoprotein involved in learning and synaptic plasticity. The functional significance of reelin signaling within the entorhinal cortex, however, remains unexplored. To determine whether interrupting entorhinal reelin signaling might have consequences for learning and memory, we administered recombinant receptor-associated protein (RAP) into the lateral entorhinal cortex (LEC) of young Long-Evans rats. RAP prevents reelin from binding to its receptors, and we verified the knockdown of reelin signaling by quantifying the phosphorylation state of reelins intracellular signaling target, disabled-1 (DAB1). Effective knockdown of reelin signaling was associated with impaired performance in the hippocampus-dependent version of the water maze. Moreover, inhibition of reelin signaling induced a localized loss of synaptic marker expression in the LEC. These observations support a role for entorhinal reelin signaling in spatial learning, and suggest that an intact reelin signaling pathway is essential for synaptic integrity in the adult entorhinal cortex.

Hearing loss and falls: a systematic review and meta-analysis

Falls are a devastating condition in older individuals. Identifying potentially modifiable risk factors such as hearing loss would provide a substantial public health benefit.

Flat-Panel CT Imaging for Individualized Pitch Mapping in Cochlear Implant Users.

Objective: This study aims to identify electrode contact location and to assess frequency deviation between predicted and actual frequency allocation maps in cochlear implant (CI) users. Study Design and Methods: This is a retrospective clinical study. Flat-panel computed tomography (FPCT) scans were collected for 17 CI users. Cochlear length was measured using three-dimensional curved multiplanar reconstruction on high-resolution secondary reconstructions. Each electrodes percentage of distance from the base of the helicotrema was measured, and a modified Greenwoods function was applied. The patients’ frequency allocation maps were retrieved from electronic medical records and compared with their calculated characteristic frequencies. Results: Our results revealed that reprogramming based on FPCT imaging findings might improve 83% (n = 216) of 260 electrode contacts. The most basal and apical electrodes (12, 11, 10, 5, 4, 3, 2, and 1) most consistently deviated (>83% of the time) from their theoretical characteristic frequencies; the basal electrodes undershot and the apical electrodes overshot their theoretical values. Frequency mismatch between the characteristic frequencies of auditory neurons and programmed center frequencies ranges from 0.41 to 1.51 in octave bands. Conclusions: Using FPCT imaging and a modified Greenwoods function, we identify a mathematical discrepancy between theoretical and actual CI placement with respect to frequency–place mapping. We demonstrate a clinically reproducible and direct assessment of frequency–place mismatch. Our individualized calculations account for inter-individual variability in cochlear lengths, operative differences in insertion depths, and electrode array kinking within the cochlea. The benefits of allocating electrode contact frequencies to their tonotopy-derived locations in the cochlea were not investigated in this study, and future prospective trials are needed to demonstrate the consequences of personalized pitch mapping for CI users with respect to speech and pitch perception.

Voice emotion perception and production in cochlear implant users

Voice emotion is a fundamental component of human social interaction and social development. Unfortunately, cochlear implant users are often forced to interface with highly degraded prosodic cues as a result of device constraints in extraction, processing, and transmission. As such, individuals with cochlear implants frequently demonstrate significant difficulty in recognizing voice emotions in comparison to their normal hearing counterparts. Cochlear implant-mediated perception and production of voice emotion is an important but relatively understudied area of research. However, a rich understanding of the voice emotion auditory processing offers opportunities to improve upon CI biomedical design and to develop training programs benefiting CI performance. In this review, we will address the issues, current literature, and future directions for improved voice emotion processing in cochlear implant users.

Assessment and improvement of sound quality in cochlear implant users

Cochlear implants (CIs) have successfully provided speech perception to individuals with sensorineural hearing loss. Recent research has focused on more challenging acoustic stimuli such as music and voice emotion. The purpose of this review is to evaluate and describe sound quality in CI users with the purposes of summarizing novel findings and crucial information about how CI users experience complex sounds.

Medical Harm: Patient Perceptions and Follow-up Actions

Objectives Much research has been conducted to describe medical mistakes resulting in patient harm using databases that capture these events for medical organizations. The objective of this study was to describe patients’ perceptions regarding disclosure and their actions after harm. Methods We analyzed a patient harm survey database composed of responses from a voluntary online survey administered to patients by ProPublica, an independent nonprofit news organization, during a 1-year period (May 2012 to May 2013). We collected data on patient demographics and characteristics related to the acknowledgment of patient harms, the reporting of patient harm to an oversight agency, whether the patient or the family obtained the harm-associated medical records, as well as the presence of a malpractice claim. Results There were 236 respondents reporting a patient harm (mean age, 49.1 y). In 11.4% (27/236) of harms, an apology by the medical organization or the clinician was made. In 42.8% (101/236) of harms, a complaint was filed with an oversight agency. In 66.5% (157/236) of harms, the patient or the family member obtained a copy of the pertinent medical records. A malpractice claim was reported in 19.9% (47/236) of events. Conclusions In this sample of self-reported patient harms, we found a perception of inadequate apology. Nearly half of patient harm events are reported to an oversight agency, and roughly one-fifth result in a malpractice claim.

Surgical Treatment of Chronic Rhinosinusitis after Sinus lift

Background The sinus lift (or sinus augmentation) is a common procedure to improve maxillary bone stock before dental implantation. Chronic rhinosinusitis (CRS) is a potential complication of this procedure and may be refractory to medical treatment. Functional endoscopic sinus surgery has previously been used to address CRS, however, results of previous studies indicated that implant removal is required. There are limited follow-up data available. Objective The purpose of this study was to characterize the long-term outcomes and efficacy of endoscopic sinus surgery for refractory CRS after sinus lift, including the ability to salvage dental implants. Methods This was a retrospective case series that described nine patients who, between June 2011 and September 2016, underwent endoscopic sinus surgery for CRS after a sinus lift procedure. The presenting symptoms of the patients, medical management, imaging results, operative procedures, and outcomes were reviewed. Results The majority of patients developed symptoms (mucopurulent nasal drainage, facial pain and/or pressure, nasal congestion, and foul smell) within 3 months of implant placement and were treated with at least three courses of antibiotics before referral to an otolaryngologist. All the patients underwent wide endoscopic maxillary antrostomy, with no surgical complications or postoperative reports of infection. There was a statistically significant improvement in 22-item Sino-Nasal Outcome Test scores (t(8) = -2.908; p = 0.02) and discharge, inflammation, and polyps/edema endoscopic scores ([z = -2.539; p = 0.011) between pre- and postsurgical treatment. Four patients had their dental implants removed before presentation. Among the five patients who presented with intact dental implants, none required removal before or after functional endoscopic sinus surgery. Conclusion Functional endoscopic sinus surgery was a reasonable and efficacious treatment option for patients who presented with paranasal sinus disease after a sinus lift. Dental implant removal may not be a requirement for successful treatment of CRS associated with sinus lift procedures.

The Effect of Round Window vs Cochleostomy Surgical Approaches on Cochlear Implant Electrode Position: A Flat-Panel Computed Tomography Study

IMPORTANCE The round window insertion (RWI) and cochleostomy approaches are the 2 most common surgical techniques used in cochlear implantation (CI). However, there is no consensus on which approach is ideal for electrode array insertion, in part because visualization of intracochlear electrode position is challenging, so postoperative assessment of intracochlear electrode contact is lacking. OBJECTIVE To measure and compare electrode array position between RWI and cochleostomy approaches for CI insertion. DESIGN, SETTING, AND PARTICIPANTS Retrospective case-comparison study of 17 CI users with Med-El standard-length electrode arrays who underwent flat-panel computed tomography scans after CI surgery at a tertiary referral center. The data was analyzed in October 2015. EXPOSURES Flat-panel computed tomography scans were collected between January 1 and August 31, 2013, for 22 electrode arrays. The surgical technique was identified by a combination of operative notes and imaging. Eight cochleae underwent RWI and 14 cochleae underwent cochleostomy approaches anterior and inferior to the round window. MAIN OUTCOMES AND MEASURES Interscalar electrode position and electrode centroid distance to the osseous spiral lamina, lateral bony wall, and central axis of the modiolus. RESULTS Nine participants were men, and 8, women; the mean age was 54.4 (range, 21-64) years. Electrode position was significantly closer to cochlear neural elements with RWI than cochleostomy approaches. Between the 2 surgical approaches, the RWI technique produced shorter distances between the electrode and the modiolus (mean difference, -0.33 [95% CI, -0.29 to -0.39] mm in the apical electrode; -1.42 [95% CI, -1.24 to -1.57] mm in the basal electrode). This difference, which was most prominent in the first third and latter third of the basal turn, decreased after the basal turn. CONCLUSIONS AND RELEVANCE The RWI approach was associated with an increased likelihood of perimodiolar placement. Opting to use RWI over cochleostomy approaches in CI candidates may position electrodes closer to cochlear neural substrates and minimize current spread. These findings need to be interpreted in light of the increased potential for osseous spiral lamina trauma with reduced distances between the electrode array and modiolus.

Surgical malpractice claims in the United States

Despite ongoing reform, there is still significant physician concern regarding the impact of medical claims on their practices. It is important that physicians and healthcare risk management professionals have a good understanding of the outcomes of medical malpractice to participate in its restructuring as needed and to prevent potentially harmful practices. In our study, we reviewed National Practitioner Data Bank (NPDB) paid malpractice claim reports from September 1, 1990, through July 30, 2011, and identified the 10 most common surgery-related allegations against physicians, excluding those listed as unspecified. Data were collected on the number of claims, the cost of the claims, and physician and patient characteristics.