Case #1 Sudden Memory Loss After a Mild Head
A 33 year old neurology resident with a history of migraine fell backward while
attempting a ski jump, struck his occiput on the snow, and suddenly developed
His wife witnessed the incident and reported that he had not lost
consciousness from the fall.
He stood himself up, skied part way down the slope,
and then stopped, telling his wife that he must have amnesia because he did not
know the date, where he was, or how he had gotten there.
He also reported
seeing a scintillating scotoma in the left upper part of his visual field, like that
accompanying his typical migraines.
At first his wife thought that he was joking around, but when he began
the same questions repeatedly,
it soon became clear that he had a serious
unable to retain any new information for longer than 1 to 2
he did not recall any events that occurred during the
including the fact that his wife was pregnant.
Aside from the
memory loss, he had no other significant deficits.
He was taken to a local
hospital, where a head CT was normal , and he was discharged in the care of his
wife and friends.
Being a neurologist, he constantly urged those around him to
test his memory during the long car ride home.
Meanwhile he was able to enjoy
the exciting news that his wife was pregnant over and over again.
5 hours after onset, he was finally able to recall three words after a 3-4 minute
delay, but this ability was still inconsistent.
At about the same time, memories
from the previous year began to return gradually, with the
memories generally returning first.
By the next morning he was able to recall
new facts about as well as at a baseline.
In addition, he remembered everything
from the previous year, except for a period extending from 2-3 hours before the
injury to about 5 hours after the injury.
An MRI scan performed a few days later
Localization and differential diagnosis
On the basis of the signs and symptoms shown above in bold, what type of
memory was impaired in this patient?
How would you describe the
chronological features of this amnesia?
Dysfunction in which locations in the
brain could produce these findings?