Jul 22 2013

Forget Amnesia

A recent article in The Guardian has the provocative title, “American man wakes up with amnesia speaking Swedish.” The article itself contains some significant misconceptions about amnesia, and so is a good opportunity to discuss this interesting topic.

In brief, amnesia is a pathological loss of memories (not just normal forgetting). The most common type of amnesia is traumatic – caused by trauma to the brain. Trauma can cause retrograde amnesia, which is loss of memories prior to the injury, and anterograde amnesia, which is loss of memories following the trauma. Contrary to the common movie cliche, these lost memories cannot be recovered by subsequent head trauma (or by any other means).

Another cause of amnesia, especially anterograde amnesia, is drugs. Alcohol and benzodiazepines in particular can prevent the formation of memories while intoxicated.

In The Guardian article they discuss the case of a man who was apparently found unconscious in a hotel room. When he awoke he was speaking only Swedish and believed his name was Johan Ek. Identification on his person, however, identified him as Michael Boatwright, an American. The man does not remember the name Boatwright and reports not to remember any of the photographs of family that were with him.

The Guardian reports that Boatwright was diagnosed with “transient global amnesia” (a claim they derive from an original report in the Desert Sun). This, however, is almost certainly an incorrect diagnosis. I don’t know if the journalists made this mistake, or the treating doctors who reported it to the media.

Transient global amnesia (TGA) has a very specific presentation, which does not fit the story of Boatwright. In TGA a person is suddenly confused as to their location and situation. They know who they are and will typically recognize people who are familiar to them, but will be completely disoriented to current events and be unable to recall recent events. They won’t know where they are or what they are doing. They appear confused to those around them, who typically bring them to medical attention.

The duration of TGA is typically about a day. After they recover from the TGA episode they will have no memories for the time period in which they had TGA. Therefore, during the TGA episode they are not forming any new memories.

The cause of TGA is not completely known. It is sudden event, which raises the possibility of either a migraine-like process, a seizure, or a transient ischemic attack (TIA or brief stroke that does not cause permanent damage), possibly affecting the hippocampus, which is necessary for the formation of new memories. They can sometimes be triggered by emotional or physiological stress. They are typically isolated incidents, rarely recurring in the same person.

At no point during or after a TGA, however, does the sufferer lose their memory for who they are. In fact, there is no neurological condition in which a person has amnesia for their own identity. This makes sense because your personal identity is so connected to your memories that if you have enough brain power to generate consciousness, you will also be able to know who you are.

A profound form of amnesia is Wernicke-Korsakoff syndrome. The most common cause of this syndrome is thiamine deficiency, often resulting from chronic alcoholism, which results in damage to parts of the brain necessary for memory formation. Patients with severe cases cannot form any new memories. They are living in a three-minute window of short term memory. They also typically have some degree of retrograde amnesia, and so are typically living in the past. (This condition was depicted in the movie Memento.)

What, then, is Mr. Boatwright suffering from if not from any form of amnesia? His clinical presentation, the complete loss of personal identifying memory or memory of one’s previous life, is called a fugue state. This diagnosis exactly fits Boatwright.

A fugue state is characterized by a loss of personal identifying memories, and typically lasts for several days but can last much longer, even months. People in a fugue state will typically have unplanned travel or will wander, and commonly adopt a new persona. Further, the episode is not triggered by drugs, physical trauma, or any neurological event. Fugue episodes typically occur only once, but can recur in the same individual.

Fugue states are purely psychological in nature. This does not mean, however, that the person is “faking” or that they have any insight into what is happening.

Conclusion

Stories of people who suffer from amnesia are fascinating, and scary, which is probably why it is a common theme in movies and fiction. Not surprisingly, the common fictional depiction of amnesia is often inaccurate. I outlined the few basic types of amnesia above. Ironically, what is most commonly depicted as amnesia in fiction is not amnesia, but is a fugue state – the loss of personal biographical memories.

I hope Mr. Boatwright recovers. Most people with a fugue state do, and recovery, once it starts, can be very rapid. I do wonder what effect the media attention is having, if any, on the course of Boatwright’s fugue.

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13 responses so far

13 Responses to “Forget Amnesia”

  1. locutusbrgon 22 Jul 2013 at 8:49 am

    Ugh!
    Hate amnesia in the media. Does Fugue state explain his ability to speak Swedish? I hate when the story appears like this. Makes it sound like he got hit on the heads and now he speaks Swedish. Like we all have a secret unconscious complete knowledge of things “that just need to be released”. The kind of on off switch type of presentation you see in TV and movies.

    I may be wrong but my understandingis that this can only occur if they know the language to begin with. Are there any “real” cases of foreign languages appearing after brain injuries. I mean in people who had exposure to the language but did not commonly speak the language?

  2. arnieon 22 Jul 2013 at 11:22 am

    Although fugue state is not “triggered by a. …..neurological event”, would not the psychological event, traumatic or otherwise, constitute a brain event since the mind is, in essence, the activity of the brain? Might is be possible now, or in the future, to find some clue to what is going on in the brain during the fugue state through an fMRI, pet scan or EEG? For example, might it possibly change the ratio of alpha waves or beta waves or vice versa?

    This also raises the question as to whether one can traumatize the mind (psyche) without, by definition, traumatize the brain.

  3. Easyon 22 Jul 2013 at 3:18 pm

    He is identified in Sweden, he lived here between 1985 and 1990. He seems to have been married to a Swedish girl and made a living performing medieval tournament games (among other things). He currently does not remember any person from Sweden and he probably never went under the Swedish name Johan Ek during his time here.

  4. Nyomon 22 Jul 2013 at 3:59 pm

    I have the same question as locutusbrg in regards the language question. It sounds similar to reports of people waking up from comas speaking with foreign accents

  5. Skeptical Steelon 22 Jul 2013 at 6:13 pm

    Like we all have a secret unconscious complete knowledge of things “that just need to be released”.

    We all do in fact have this, but it is confined strictly to the Swedish language. Typ av skitsnack, men vad ska du göra?

  6. ConspicuousCarlon 22 Jul 2013 at 7:11 pm

    Similarly, all psychics, along with the rest of us, really do have the ability to talk to the dead. But it’s always that one same dead guy named muh-guh-nuh-something who died of head and chest problems… and has amnesia.

  7. Nyomon 23 Jul 2013 at 6:11 am

    Thanks Easy. That answers my question. These sort of reports bug me, as people tend to use them in a woo kind of way.

  8. Bruce Woodwardon 23 Jul 2013 at 8:18 am

    Steve! He unlocked the 90% of his brain he wasn’t using when he got hit on the head!

  9. Bruce Woodwardon 23 Jul 2013 at 8:20 am

    And that overshadowed the 10% he was used to using.

    (Edit button needed for premature posting errors… I was sure the pills I was taking were supposed to stop that)

  10. bluedevilRAon 23 Jul 2013 at 3:01 pm

    Foreign accent syndrome is something very different. I don’t know of any cases of people waking up from comas truly speaking foreign languages to which they had no prior exposure. This does not seem plausible.

    Foreign accent syndrome, however, is when a person has suffered a brain injury (like a brain stem/cerebellar stroke) that could cause both coma and then also result in dysarthria, though FAS is not always associated with coma. The patient is having a difficult time articulating words, so it sounds like a foreign accent. This could be from damage to the language centers of the brain, the cerebellum (coordinated movements of the tongue), or the brain stem (cranial nerves that control movement of the tongue). So in the end, its just that their voice sounds different and (Dr. Gorski will love this) is likely a pareidolia on the part of the listener to assume it is a foreign accent.

  11. Nyomon 24 Jul 2013 at 7:06 am

    Thanks bluedevil!

  12. colli037on 25 Jul 2013 at 6:27 am

    Foreign accent syndrome also has a psychology based cause–patients with this have an accent that sounds “just like” an someone from a specific county speaking English. This was discussed in the post on the cheerleader with the “vaccine injury”. Patients with this type of foreign accent usually have inconsistencies of pronunciation (same words pronounced differently based on sentence position) that a good speech pathologist can tease out.

  13. Yahnaon 26 Jul 2013 at 1:04 pm

    I’ve had amnesia twice.
    The first time was due to an overabundance of alcohol (the smell of wine made me nauseous for yeeeears afterward).

    The second time was after a blow to the head that resulted in brief unconsciousness and an overnight hospital stay where I was apparently coherent – answering questions, talking (although one friend said I was repeating myself a LOT). I remember bits and pieces. Leaving a message for my sister because my phone had died and hers was the only number I could remember, so someone could tell my mom what was going on. And possibly being on a gurney. The first one I know is true because my sister mentioned it specifically (“I knew you were fine when you were cracking jokes about it”) but I never asked about the gurney (my friends were kind of traumatized by it and even years later it makes them uneasy to talk about it, so I don’t ask anymore).

    Everything else is blank. From the point where I knew I was in trouble to the wee hours of the following morning when I got the hourly concussion wake-up visit from the nurses.

    And now that I’ve shared that bit of personal history – at least it’s on topic! – the language thing has fascinated me, too. I’ve a few co-workers who buy those stories hook, line, and sinker; this was mentioned the other day by one of them, so this article was quite timely. :)

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