Prevalence of Internal Auditory Canal Diverticulum and Its Association with Hearing Loss and Otosclerosis.

BACKGROUND AND PURPOSE: Focal low-attenuation outpouching or diverticulum at the anterolateral internal auditory canal is an uncommon finding on CT of the temporal bone. This finding has been described as cavitary otosclerosis in small case reports and histology series. The purpose of this study was to establish the prevalence of internal auditory canal diverticulum and its association with classic imaging findings of otosclerosis and/or hearing loss. MATERIALS AND METHODS: Temporal bone CT scans of 807 patients, obtained between January 2013 and January 2016, were retrospectively reviewed to identify internal auditory canal diverticula and/or classic imaging findings of otosclerosis. Clinical evaluations for hearing loss were reviewed for patients with internal auditory canal diverticula and/or otosclerosis. RESULTS: Internal auditory canal diverticula were found in 43 patients (5%); classic otosclerosis, in 39 patients (5%); and both findings, in 7 patients (1%). Most temporal bones with only findings of internal auditory canal diverticula (91%) demonstrated hearing loss, with 63% of this group demonstrating sensorineural hearing loss. The hearing loss classification distribution was significantly different (P < .01) from that in the classic otosclerosis group and in the group with both diverticula and otosclerosis. CONCLUSIONS: Internal auditory canal diverticula are not uncommon on CT examinations of the temporal bone and most commonly occur without classic imaging findings of otosclerosis. These lesions are associated with sensorineural hearing loss, and referral for hearing evaluation may be appropriate when present.

Identification of a site in GluR1 and GluR2 that is important for modulation of deactivation and desensitization.

The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid subtype of ionotropic glutamate receptors consists of rapidly gating ion channels. Positive modulation of channel gating may slow gating kinetics through at least two distinct mechanisms, evidenced by the predominant slowing of either the rate of receptor desensitization or the rate of offset after agonist withdrawal (deactivation). This study compares the actions of two positive allosteric modulators [cyclothiazide, which modulates desensitization, and 1-(1,4-benzodioxan-6-ylcarbonyl)piperidine (CX546), which modulates deactivation] in a mutant shown previously to impede modulation by cyclothiazide. These experiments test the hypothesis that the point mutation, GluR1(S493T), would also cause a loss of modulation by CX546. Wild-type GluR1 through -4 receptors were modulated by CX546, as assayed by the potentiation of steady-state currents in the Xenopus laevis oocyte expression system. CX546 potentiated steady-state currents of both splice isoforms of GluR1. Modulation by CX546 was completely abolished in GluR1(S493T) and its homolog, GluR2(S497T), although this mutation did not affect apparent agonist affinity in the absence of CX546. Thus, the GluR1(S493T) mutation has a similar impairment of modulation by either cyclothiazide or CX546, indicating that some residues at the subunit interface of glutamate receptors play an important role in channel deactivation and desensitization.

An overview of herbal medications with implications for the school nurse.

Americans are increasingly using herbs and herbal preparations to treat a wide array of conditions ranging from colds to depression. Children and parents are ingesting herbs in greater quantities, as reflected by increased herb sales and telephone calls to poison information centers. Herbal preparations are being used for the management of insomnia, anxiety, and attention deficit hyperactivity disorders. This trend introduces interesting opportunities and dilemmas for the school nurse. This article provides an overview of the seven most common medicinal herbs (garlic, ginkgo, ginseng, Echinacea, chamomile, valerian, and feverfew). It provides a guide to choosing herbal supplements, a framework for developing school-based herbal policies, and a discussion of the issues faced by school nurses.

Computer mentoring for school nurses: the New York State model.

As computer use in the school health office is becoming a necessity, learning and upgrading technology skills is a high priority for school nurses across the country. The New York State Association of School Nurses and the Statewide Advocacy for School Health Services conducted a needs assessment to determine school nurses' perceptions of information technology skill level and the use of technology in the school health office. From these data, they have collaboratively developed a computer-mentoring program to be used throughout New York State. This program pairs standardized computer training with the assignment of peer mentors to support novice computer users during the adoption of technology into New York's school health services.