Trauma acoustic

Zhuravskii, S. G., Aleksandrova, L. A., Ivanov, S. A., Sirot, V. S., Lopotko, A. I., and Zhloba, A. A. (2004b). Protective effect of carnosine on excitable structures of the auditory apparatus in albino rats with acute acoustic trauma. Bull. Exp. Biol. Med. 137, 98-102. 

The majority of individuals exposed to trauma are resilient and do not develop PTSD. As in humans, lower mammals also have individual differences and heterogeneity of stress responses. Recent animal models of PTSD attempt to take into account this heterogeneity. Cohen et al., 2006 review two measures—performance on the elevated plus maze and acoustic startle response, used to mimic symptoms of PTSD. In their model, they differentiate animals that display stress-induced extreme behavioral responses (EBR) on both of these tests from those that display minimal behavioral responses (MBR). Different types of stress paradigms caused different proportions of EBR and MBR, similar to the suggestion in clinical literature that more severe stress increases incidence of PTSD. In Cohen s study, although stress led to an EBR immediately after the stressor in 100% of the animals, only 25% of the animals continued to show EBR 30 days following stress. 

Ryals, B.M. and Rubel, E.W., Hair cell regeneration after acoustic trauma in adult Coturnix quail. Science, 240(4860), 1988,1774. 

Hearing loss caused by a sudden loud noise in one ear, or by a sudden blow to the head. In most cases, hearing loss is temporary, although there may be some permanent loss. Welding sparks (to the eardrum), blows to the head, and blast noise are examples of events capable of producing acoustic trauma. 

Slowly progressive inner-ear hearing loss resulting from exposure to continuous noise over a long period of time, as contrasted with acoustic trauma or physical injury to the ear. NIHL is permanent, painless, and progressive, but is preventable if hearing protection is worn 100 percent of the time during noise exposure. See also Acoustic Trauma. 

Acoustic Trauma Loud noise from explosions, artillery guns or cannons or from similar sources of pressure waves may mpture the eardmm or damage the stmcture of the middle or inner ear. Such conductive damage has the name acoustic trauma. In some cases there is temporary damage. The injured tissue may heal, restoring hearing to full or nearfull sensitivity. In other cases, the physical injury will produce permanent hearing loss. 

Occasionally, cavernosal tissue injury from a blunt perineal trauma can result in a fibrotic scar encompassing the entire circumference of a corpus cavernosum. Ultrasound shows a hyperechogenic stripe with acoustic shadow dividing the corpus in two portions. The cavernosal artery can be obliterated or warped at the level of the scar (Fig. 18.3). Since the penile septum is usually nearly complete at the base of the penis, the proximal portion of the injured corpus remains hemodinamically isolated from the other portions (Horger et al. 2005). 

There are two independent harmful mechanisms that lead to NIHL chronic degeneration due to long-term high noise-levels and acute acoustic trauma due to powerful impulses close to the ear. (Fleischer, 2008). 

Rezaee, M., Mojtahed, M., Ghasemi, M. Saedi, B. 2011. Assessment of impulse noise level and acoustic trauma in nuhtary personnel. Trauma Monthly, 16, 182-187. 

There are three principal categories of NHL (1) temporary threshold shift (TTS), (2) permanent threshold shift (PTS), and (3) acoustic trauma. TTS occurs when exposure to sound damages the organ of Corti and its receptor cells. However, if the exposure is of relatively short duration, hearing sensitivity returns to preexposure levels after a recovery period (Brauer 1994). PTS, on the other... 

There are three main complications of muscle tear cysts and myositis ossificans and, more rarely, calcific myonecrosis (Peetrons 2002). Intermuscular and intramuscular cysts may be encountered after muscle trauma as well-defined echo-free masses with posterior acoustic enhancement. These cysts have an elongated shape and represent the residue of a local hematoma. Their most common location is the calf (see Chapter 15). In selected cases, they may require percutaneous needle evacuation. Calcific myonecrosis is a space-occupying calcified mass that typically develops in the anterior compartment of the leg late after a closed lower extremity... 

---