However, regardless of whether transudative or exudative, large, refractory pleural effusions causing severe respiratory symptoms can be drained to provide symptomatic relief. The management of exudative effusions depends on the underlying etiology of the effusion. Pneumonia, malignancy, and TB cause most exudative pleural effusions, with the remainder typically deemed idiopathic. Complicated parapneumonic effusions and empyemas should be drained to prevent development of fibrosing pleuritis.
Retrograde amnesia is inability to recall memories before onset of amnesia. One may be able to encode new memories after the incident. Retrograde is usually caused by head trauma or brain damage to parts of the brain besides the hippocampus. The hippocampus is responsible for encoding new memory.
Retrograde (music) A musical line which is the reverse of a previously or simultaneously stated line is said to be its retrograde or cancrizans (walking backward, medieval Latin, from cancer, crab). An exact retrograde includes both the pitches and rhythms in reverse. An even more exact retrograde reverses the physical contour of the notes themselves, though this is possible only in electronic music. Some composers choose to subject just the pitches of a musical line to retrograde, or just the rhythms.