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.
Transient global amnesia is a sudden, temporary loss of memory for events during, after, and sometimes before the event that caused the amnesia. What causes many cases of transient global amnesia is not known, but one type is caused by drinking too much alcohol or taking certain drugs. People with this amnesia suddenly but temporarily become unable to store new memories and to recall events that happened after the amnesia occurred.