The Unique Case of “50 First Dates” Amnesia

Scene from 50 First Dates with Drew Barrymore and Adam Sandler.

50 First Dates maintains a venerable movie tradition of portraying an amnesiac syndrome that bears no relation to any known neurological or psychiatric condition (Baxendale, 2004).

That isn't true anymore...

Smith et al. (2010) have recently reported an unusual case of functional, or psychogenic amnesia in which FL, a 51 year old woman with 15 years of education and average intelligence, cannot remember what happened to her from one day to the next. Her case history is summarized below.

In May 2005, FL was involved in a motor vehicle accident in which her car was struck from behind. She hit the left side of her head and briefly lost consciousness. She was treated and released from the emergency room, but upon awakening the next morning, she had no memory for the previous day and believed that the accident had just occurred. Every morning since has been similar. She awakens with anxiety, believes it to be the day of the accident, and states that she has no memory for anything that has occurred since the accident. Each morning her husband orients her to time and place and provides her with her journal where she has recorded salient events from previous days and weeks. During the course of the day, she describes her memory as normal, but states that memory for each day is lost at night during sleep.

The plot summary for 50 First Dates, taken from Wikipedia, is as follows:

One morning, Henry (Sandler) meets Lucy Whitmore (Barrymore), a local art teacher, in a café. They hit it off and agree to meet the next day, but when Henry returns, Lucy has no memory of him or their previous meeting. Pulling him aside to where Lucy can't hear them, the café owner explains to Henry that, as a result of a car accident a year earlier, Lucy suffers from Goldfield Syndrome, a fictional form of anterograde amnesia in which each day's events disappear from her memory overnight.

FL reported she did not see the movie before her accident, but noted that Drew Barrymore was her favorite actress. Smith et al. (2010) speculated that FL could have known the plot of the film, which could have influenced her unusual manifestation of memory loss after the auto accident. Her husband mentioned that she had seen the movie several times since her accident.

FL underwent a series of imaging and neuropsychological tests in Dr. Larry Squire's Memory Research Laboratory. Her MRI was read as normal by the neuroradiologist, and quantatitive analysis revealed the volumes of her medial temporal lobe structures [critical for forming new memories] to be quite well matched with a small group of control participants.


Fig. 1 (Smith et al., 2010). (A) A T1-weighted coronal MRI image from FL. The left side of the brain is on the left side of the image. (B) The volume of bilateral hippocampus (HIP) and parahippocampal gyrus (PHG) were similar for FL and controls (n = 4). The volumes are expressed as a percentage of the whole-brain volume for each participant.

FL's neurological exam was normal. She had no previous history of psychiatric disorder. On the basis of these negative neurological and MRI findings, combined with her neuropsychological profile, the psychiatrist diagnosed psychogenic [i.e. functional] amnesia, with one unusual difference: she did not have retrograde amnesia [memory loss for remote events].

Although functional amnesia is not associated with structural brain damage, there is evidence of hypometabolism, especially in the frontal lobe as measured by neuroimaging. Similar findings have also been observed in other psychiatric and neurological conditions (i.e., transient global amnesia, bipolar and major depressive disorder, schizophrenia).

The pattern of impairment in functional amnesia is variable, though it typically presents as severe retrograde amnesia (sometimes including loss of personal identity) in the absence of anterograde amnesia [problems encoding new memories].

However, FL was impaired on some standardized neuropsychological measures of memory when tested the same day, which belied her claim of intact memory for events occurring within a day. But as expected, she was at chance performance for material tested 24 hrs later, after she had slept.

The authors constructed a tricky memory test of their own to see whether FL could retain some memory for items she had learned 24 hrs ago but believed to be presented on the same day. This did work to some extent, as shown in the black bars for FL on the left (Next-day Covert).


Fig. 2 (Smith et al., 2010). Recognition memory for color photographs of scenes. One presentation: FL, Controls (n = 3), and Simulators (n = 2) [asked to fake an amnesia like FL's] saw 160 scenes once each and then took recognition memory tests later on the same day (Same day) as well as on the morning of the next day (Next day). After the Next-day test, participants studied 160 new scenes and then took recognition memory tests later on the same day. In this case, unbeknownst to the participants, the retention tests included scenes that had been studied and tested on the previous day (Next-day Covert). Multiple Presentations: the same scenes that had been studied and tested during the first 2 days were studied an additional time. As above, testing was done in three ways (Same day, Next day, and Next-day Covert). FL exhibited evidence of day-to-day memory in the Next-day covert tests (black bars) and in her improved performance when the same scenes had been viewed across multiple days (compare the two white bars and the two black bars in the left panel).

In an interesting twist to the story, an intensive training program at Johns Hopkins University taught FL to sleep for 3.5 hrs at a time, at which point she could still retain the day's memories.

Initially, she was placed on a sleep deprivation protocol and remained awake for 36 h. There was no loss of memory during this period. The following day the treatment team initiated a regimen in which she was awakened after longer and longer periods of sleep each night. After 1, 2, 3, or 4 h of sleep she retained all memories, but after 6 h of sleep she had recurrence of her memory loss. Thus, she was able to tolerate up to 4 h of continuous sleep without memory loss for the previous day's events.

To conclude, the Baxendale (2004) quote above is correct in asserting that "movie amnesia", in which the protagonist loses all past autobiographical memories and a sense of identity, is unlike what occurs with brain damage in the real world. And 50 First Dates is even further off the mark. But sometimes, life imitates art... or an average Adam Sandler movie.

References

Baxendale S. (2004). Memories aren't made of this: amnesia at the movies. BMJ 329:1480-3.

Smith, C., Frascino, J., Kripke, D., McHugh, P., Treisman, G., & Squire, L. (2010). Losing memories overnight: A unique form of human amnesia Neuropsychologia DOI: 10.1016/j.neuropsychologia.2010.05.025