The current study used a rat model to investigate the underlying mechanisms of blast-induced tinnitus, hearing loss, and associated traumatic brain injury (TBI). Seven rats were used to evaluate behavioral evidence of tinnitus and hearing loss, and TBI using magnetic resonance imaging following a single 10-msec blast at 14 psi or 194 dB sound pressure level (SPL). The results demonstrated that the blast exposure induced early onset of tinnitus and central hearing impairment at a broad frequency range. The induced tinnitus and central hearing impairment tended to shift towards high frequencies over time. Hearing threshold measured with auditory brainstem responses also showed an immediate elevation followed by recovery on day 14, coinciding with behaviorally-measured results. Diffusion tensor magnetic resonance imaging results demonstrated significant damage and compensatory plastic changes to certain auditory brain regions, with the majority of changes occurring in the inferior colliculus and medial geniculate body. No significant microstructural changes found in the corpus callosum indicates that the currently adopted blast exposure mainly exerts effects through the auditory pathways rather than through direct impact onto the brain parenchyma. The results showed that this animal model is appropriate for investigation of the mechanisms underlying blast-induced tinnitus, hearing loss, and related TBI. Continued investigation along these lines will help identify pathology with injury/recovery patterns, aiding development of effective treatment strategies.

No abstract

Autogenous cartilage grafts are useful in the correction of mild to moderate traumatic saddle nose deformity. The graft is readily available, preserves long-term structural stability, and achieves functional and cosmetic satisfaction in most patients.

In head and neck cancer patients with post-treatment esophageal stricture, iatrogenic cervical esophageal perforations can often be safely managed conservatively. The criteria are: prompt diagnosis within one hour, small perforation (3-7 mm), penetrating type of perforation with circumferential mucosal contact, proximal or cervical esophageal location, and stabilization and improvement of clinical signs and symptoms for 24 hours after initial ICU management.

No abstract