Retrograde amnesia, after

Amnesia eyes. Loss of memory, inability to recall past experience. Anterograde amnesia refers to an inability to recall events after a drug (e.g. a benzodiazepine) or ECT. Retrograde amnesia refers to the loss of memory occurring prior to the incident that causes amnesia. 

The two main memory disorders are amnesia and aphasia. Amnesia is a partial or total loss of memory caused by emotional trauma, disease, or brain injury (usually due to head trauma, surgical accidents, or chronic alcohol abuse). Memory loss can occur for events just prior to the amnesia-causing incident (retrograde amnesia), or for events occurring after the incident (anterograde amnesia). In severe cases of anterograde amnesia, the person may be unable to form n memories, although recall of material learned before amnesia s onset is usually unaffected. Many cases of amnesia (even severe) are temporary, so that the person recovers his or her memory. 

These agents produce anesthesia within one minute. Recovery after a small dose is rapid, with somnolence and retrograde amnesia. Muscle relaxation occurs at the onset of anesthesia. The duration of anesthetic activity following a single IV dose is 20 to 30 minutes for thiopental and thiamylal, and somewhat shorter for methohexital. 

One of Sam s major problems was that he had significant posttraumatic amnesia (PTA). PTA is a state of confusion and memory loss that can occur following a traumatic brain injury, and is often considered to be an indication of how severe the brain injury is. It can be anterograde, where the person has problems creating new memories after the injury has happened, or retrograde, where there is difficulty recalling events from just prior to the injury. In Sam s case, he had both. To this day, he has no memory for the period of around 2 weeks before the crash, and limited memory for around 4 months after the crash. 

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