Acoustic experience alters the aged auditory system.

OBJECTIVES: Presbyacusis, one of the most common ailments of the elderly, is often treated with hearing aids, which serve to reintroduce some or all of those sounds lost to peripheral hearing loss. However, little is known about the underlying changes to the ear and brain as a result of such experience with sound late in life. The present study attempts to model this process by rearing aged CBA mice in an augmented acoustic environment (AAE). DESIGN: Aged (22-23 months) male (n = 12) and female (n = 9) CBA/CaJ mice were reared in either 6 weeks of low-level (70 dB SPL) broadband noise stimulation (AAE) or normal vivarium conditions. Changes as a function of the treatment were measured for behavior, auditory brainstem response thresholds, hair cell cochleograms, and gamma aminobutyric acid neurochemistry in the key central auditory structures of the inferior colliculus and primary auditory cortex. RESULTS: The AAE-exposed group was associated with sex-specific changes in cochlear pathology, auditory brainstem response thresholds, and gamma aminobutyric acid neurochemistry. Males exhibited significantly better thresholds and reduced hair cell loss (relative to controls) whereas females exhibited the opposite effect. AAE was associated with increased glutamic acid decarboxylase (GAD67) levels in the inferior colliculus of both male and female mice. However, in primary auditory cortex AAE exposure was associated with increased GAD67 labeling in females and decreased GAD67 in males. CONCLUSIONS: These findings suggest that exposing aged mice to a low-level AAE alters both peripheral and central properties of the auditory system and these changes partially interact with sex or the degree of hearing loss before AAE. Although direct application of these findings to hearing aid use or auditory training in aged humans would be premature, the results do begin to provide direct evidence for the underlying changes that might be occurring as a result of hearing aid use late in life. These results suggest the aged brain retains significantly anatomical, electrophysiological, and neurochemical plasticity.

Incidental Finding of Anomalous Pulmonary Venous Return of the Left Upper Lobe, a Rare Anatomical Variation.

Partial anomalous pulmonary venous return (PAPVR) is a rare congenital abnormality in which 1 to 3 of the pulmonary veins connect to the right atrium rather than the left atrium. In this synthesis of the literature on PAPVR of the left upper lobe, we attempt to illustrate this clinical entity using a case detected incidentally on chest computed tomography, explain the anatomical aspects of this anomaly, and summarize the reported incidence and etiology of left-sided PAPVR. Lastly, differential diagnoses, clinical relevance, and management of left-sided PAPVR are presented. The identification of this variant is important, as it may have serious consequences.

Multimodality appearance of multiple endocrine neoplasia type 1: A case report.

Multiple endocrine neoplasia type 1 is a rare autosomal dominant disorder classically characterized by a predisposition to tumors of the parathyroid glands, anterior pituitary, and enteropancreatic endocrine cells. We present the clinical details of a patient with diarrhea, nephrolithiasis, erectile dysfunction, and new onset abdominal pain, as well as a discussion of the etiology, pathophysiology, and classical imaging findings of this condition.

Popliteal artery embolism of bullet after abdominal gunshot wound.

Bullet embolism to the peripheral arterial system is a rare phenomenon which frequently results in misdiagnosis due to lack of early symptoms. Embolisms can go to either arterial or venous systems with common sites of injury including the left ventricle, pulmonary vein, thoracic and abdominal aorta and peripheral arteries. Herein we present a case of a 19 year old patient with multiple gunshot wounds to the torso with a bullet embolism to the left popliteal artery necessitating embolectomy. This subsequently led to diagnosis and repair of an abdominal aortic psuedoaneurysm not clearly evident on initial imaging.

Acute mesenteric venous thrombosis with a vaginal contraceptive ring.

Mesenteric venous thrombosis is a rare cause of abdominal pain, which if left untreated may result in bowel infarction, peritonitis and death. The majority of patients with this illness have a recognizable, predisposing prothrombotic condition. Oral contraceptives have been identified as a predisposing factor for mesenteric venous thrombosis in reproductive-aged women. In the last fifteen years new methods of hormonal birth control have been introduced, including a transdermal patch and an intravaginal ring. In this report, we describe a case of mesenteric venous thrombosis in a young woman caused by a vaginal contraceptive ring.