An adults more bony chest wall absorbs more of the force itself rather than transmitting it. Thus children commonly get pulmonary contusions without fractures overlying them, while elderly people are more likely to develop fractures than contusions. One study found that pulmonary contusions were accompanied by fractures 62% of the time in children and 80% of the time in adults. Pathophysiology
Pulmonary contusion results in bleeding and fluid leakage into lung tissue, which can become stiffened and lose its normal elasticity. The water content of the lung increases over the first 72 hours after injury, potentially leading to frank pulmonary edema in more serious cases. As a result of these and other pathological processes, pulmonary contusion progresses over time and can cause hypoxia (insufficient oxygen). Bleeding and edema
In contusions, torn capillaries leak fluid into the tissues around them. The membrane between alveoli and capillaries is torn; damage to this capillary–alveolar membrane and small blood vessels causes blood and fluids to leak into the alveoli and the interstitial space (the space surrounding cells) of the lung. With more severe trauma, there is a greater amount of edema, bleeding, and tearing of the alveoli. Pulmonary contusion is characterized by microhemorrhages (tiny bleeds) that occur when the alveoli are traumatically separated from airway structures and blood vessels. Blood initially collects in the interstitial space, and then edema occurs by an hour or two after injury. An area of bleeding in the contused lung is commonly surrounded by an area of edema.
It is important to note that neurosyphilis may occur at any stage of infection.Meningitis is the most common neurological presentation in early syphilis. It typically occurs in the secondary stage, arising within one year of initial infection. The symptoms are similar to other forms of meningitis. The most common associated with neurosyphilitic meningitis is cranial nerve palsy, especially of the facial nerve.Nearly any part of the eye may be involved. The most common form of ocular syphilis is uveitis. Other forms include episcleritis, vitritis, retinitis, papillitis, retinal detachment, and interstitial keratitis.Meningovascular syphilis usually occurs in late syphilis but may affect those with early disease. It is due to inflammation of the vasculature supplying the central nervous system, that results in ischemia. It typically occurs about 6–7 years after initial infection and it may affect those with early disease. It may present as stroke or spinal cord infarct. Signs and symptoms vary with vascular territory involved. The middle cerebral artery is most often affected.Parenchymal syphilis occurs years to decades after initial infection. It presents with the constellation of symptoms known as tabes dorsalis, because of a degenerative process of the posterior columns of the spinal cord. The constellation includes Argyll Robertson pupil, ataxic wide-based gait, paresthesias, bowel or bladder incontinence, loss of position and vibratory sense, loss of deep pain and temperature sensation, acute episodic gastrointestinal pain, Charcot joints, and general paresis.Gummatous disease may also present with destructive inflammation and space-occupying lesions. It is caused by granulomatous destruction of visceral organs.