Posttraumatic Amnesia

1. How is posttraumatic amnesia (PTA) defined?
2. What is the Galveston Orientation and Amnesia Test (GOAT)? How is it scored?
3. How does length of PTA relate to the severity of injury. How does PTA relate to prognosis?
4. What are other prognostic indicators in TBI?

Answers:
1. PTA is the interval of permanently lost memory following injury.
2. The GOAT is a standard technique for assessing PTA, involving orientation questions and memory. It is scored out of 100 pts and 75 is normal. A score of >75 on 2 days in a row marks the end of PTA.
3. 5-10 minutes PTA is mild, 1-24hrs is moderate, 1-7 days is severe, 1-4weeks is very severe, greater than 4 weeks is extremely severe. For moderate severity or less, a quick and full recovery should be expected. For a severe injury, residual deficits are expected.
4. Age (worse age<5>65), rate of early recovery, pupillary reaction to light, time since injury (most recovery within 6 months, use of phenytoin (=> adverse cognitive effects).