Medical Fiction Questions Answered 1/11/10

Okay, gang... the Doctor is IN!

Disclaimer: The information provided in this post is intended for writing purposes only and does not represent medical advice. (Sorry, my lawyer-boy husband makes me say that.)

Heather,
I saw your post on Query Tracker how you answer medical questions for fiction. So interesting!

I have a question for you. How would a doctor diagnose retrograde amnesia and how would a patient act or think with this type of amnesia?

Thanks and I really loved your website too.
Christy

Ah, amnesia! That's a great topic for conversation in the land of fiction.

Basically, there are two kinds of amnesia... anterograde and retrograde. A patient may suffer from one or both, depending on the circumstances.

Retrograde is RETRO, meaning backwards in time. A patient with retrograde amnesia has lost memories or information from before the insulting event.

ANTERO, as you may have guessed, means forward. A patient with anterograde amnesia has trouble forming new memories or storing new information, and therefore loses information from after the insulting event.

These losses may be temporary or permanent, depending on the injury or insult involved.

For a patient with a head injury due to a sledding accident, for example, they might remember talking about going sledding and getting dressed for the snow and the next thing they might remember is lying on a gurney in a hospital emergency room. They may be confused for several hours or even days afterwards, and ask questions several times over again, having forgotten the answers or that the question had already been asked. They may have no memory of sledding at all, let alone the accident, or the paramedics arriving, ambulance ride, etc. This would be a mixture of anterograde and retrograde amnesia, as the patient would have lost memories from both before and after the event.

Someone with a significant traumatic brain injury, might have anterograde amnesia symptoms on a permanent basis. Patients with Alzheimer's disease often suffer from anterograde amnesia symptoms, becoming less and less able to make new memories, and then moving into retrograde amnesia and losing past memories as well.

Regarding your question of a pure retrograde amnesia, this suggests the common plot device in movies and television stories where the victim suffers a head injury and suddenly forgets everything about their own pasts, including their identities. This is actually extremely unlikely to happen. Even patients with devastating retrograde amnesia generally maintain their sense of identity. And even less likely is the common "remedy" displayed in the media where a second trauma restores the lost memories.

In reality, retrograde amnesia is typically limited to a relatively brief period immediately before whatever insult caused the loss of memory (which could be a brain injury-- either through head trauma, or oxygen deprivation, a seizure, drug and/or alcohol exposure, and any experience that could cause loss of consciousness). Longer periods of time may be lost in the case of repeated exposures to physical/psychological traumas, as in the case of severe child abuse or sexual abuse, due to a defense mechanism called repression.

For diagnosis of amnesia, the physician would primarily rely on the patient's history, as obtained by talking to the patient and his or her family and friends (if available), as well as simple tasks to evaluate the patient's ability to remember new things (such as giving the patient a string of numbers or a random trio of words to remember).

As far as how the patient would act in this situation, this would widely depend on the extent of the memory loss and whether or not there was a co-existing anterograde component. If they were coherent enough to realize they were suffering from memory loss, they would likely be frustrated and possibly embarrassed. They may try to avoid situations that demonstrate their weaknesses. For example, a patient who had trouble remembering words, may avoid talking in public or to strangers.

Amnesia is a fascinating problem, but can be very tricky to deal with in a realistic manner when writing fiction. I hope this information is helpful, and I wish you the best of luck!

Remember, if YOU have a medical fiction question, email me at hldyer at querytracker.net and include "medical question" in the subject title. You'll receive an automatic reply confirming that your question has safely arrived in my email box.