Survive in a head-on collision, and why amnesia is not what you think

Hi Habr.

Not so long ago, I got into a car accident, and on my personal experience I experienced what are broken bones, severe head injury and memory loss. In the article I also want to talk about the misconceptions about the symptom of amnesia in modern popular culture. The area is quite confusing and contradictory, but I still wanted to structure the known data and share my personal experience.

Prehistory

It was in early March. Family dinner was delayed and had to call a taxi, because the transport did not go, and I had to go to a nearby town. Not that someone was drunk or something like that, just a driver who was riding on the opposite line did a little sleep on a dark suburban road. I myself was fastened, but from the light Prius, after a collision with a 2-ton Mitsubishi Pajero, there was little left. The driver, unfortunately, died before the arrival of the ambulance.
As a result: an open leg fracture in 2 places (big and small tibial bones + dislocation of the ankle), fracture of the wrist and 3 fingers, dislocation of the elbow joint, numerous minor bruises and cuts, injuries of the cervical spine, severe cranial-brain injury, swelling of the brain and damage to the eye. And also, as a bonus, a coma lasting 10 days.
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Recovery was painful: nauseous headaches that painkillers could not cope with, sounds that gave a painful echo in the skull, pain in the leg and in the arm, and in general throughout the body, insomnia and depression. Even when it was possible to fall asleep, there was no particular relief, since the dream was very restless, nightmares were dreamed.

Of course, I had previously broken on a bike, but from serious injuries (at the time when I was engaged in Enduro) I was always saved by protective equipment - a full-face helmet (similar to used in motocross), armor, support for neck, lining, etc., therefore, for me it has become a new and completely nightmarish experience.
I spent almost 7 weeks in the hospital, I think you yourself can imagine what it is.

Road accident statistics

According to statistics compiled by WHO, in 2016 the number of deaths related to road accidents reached 1.35 million people. And, despite the fact that the mortality rate for 15 years, as a whole has decreased from 18.8 to 18.2 per 100,000 people, the absolute figure continues to grow every year.

Every year from 20 to 50 million people get non-fatal injuries, many become disabled.

Road accidents are the main cause of death for children and young people between the ages of 5 to 29 years old, and occupy the 8th place among people of all ages ^[1] .

About amnesia

disclaimer: I am not a specialist in brain neurophysiology, psychoneurology, psychiatry, or any other specialty related to medicine. Further descriptions are my attempt to understand the often very contradictory materials, and may be wrong, but certainly superficial and not accurate.

After getting out of the coma, I had complete disorientation, there was an inability to understand the contents of the conversations and confusing meaningless speech.

In fact, I did not realize myself, and could not speak. These memories are not preserved (description restored from conversations with the doctor), but somehow I feel cold inside at the mere thought that brain damage could be irreversible.

It’s not even the state itself that frightens, in the end, if you can’t understand anything, then nothing can bother you. More frightening is the thought of how such parents could survive. Even now it hurts me to look at how they are drawn and aged because of this whole situation. But, at least, I try not to strain them once again, and somehow I try to do everything on my own (well, I try to restrain my impulses of a far from soft nature).

Amnesia in mass culture and reality

Descriptions of amnesia in popular culture (films, books, games, etc.) are rather inaccurate. All the examples I ran across from Prince Corvin to Strelka and James Born describe retrograde amnesia, but unrealistic. The exception, oddly enough, are the cartoons shot by the studio Pixar - “Finding Nemo” and “Finding Dory,” where the Dory fish suffers with anterograde amnesia, which I will write about later. The same theme is used by the films “Memento” and “50 First Kisses”, but this movie is not distinguished by realism.

Retrograde amnesia itself is portrayed as follows: there is a hero, he finds himself in some unpleasant situation, and as a result he suffers a head injury, after which, under sad music, he tells his family and friends that he can remember nothing. At the same time, the main character quite remembers how to drive a car, knows how to fight, and behaves like a completely healthy person.

In reality, everything is a little wrong (with such injuries, perhaps, you can start drooling) and in fact, people who have lost their memories of their personality after a traumatic impact, but still have: general knowledge, professional skills, language skills ) or the ability to make half-lives, in general, should not exist, since the memory is disturbed for a certain period of time ^[2] .
If a person does not have memories of his own personality, then he will have skills and knowledge from the period before the realization of his personality, for example, like children, in the period while they are not able to remember their name.

Scriptwriters and writers also have problems with anterograde amnesia. Usually some kind of ridiculous restrictions are introduced: memory loss after 15 minutes or sleep. In fact, in the case of serious problems with memory consolidation , thoughts or events are forgotten immediately after a person becomes distracted.

Classification

Amnesia can be classified in various ways, but in my opinion, it is most logical to first consider the cause of the symptom, then the symptoms and the dynamics of development.

▍ Causes of symptom development:

1. organic ^[2] - caused by brain damage.
   
   Possible causes:
   
   • TBI
   • infections
   • stroke
   • brain diseases (including age)
2. psychogenic - caused by mental disorders.
   
   Possible causes:
   
   • traumatic event
   • prolonged depression
   • psychosis

▍ Symptomatology:

Anterograde amnesia - the inability to memorize new memories. Depending on the severity, fragmentary or partial memories may remain, or not at all.

The reason for the appearance: organic brain damage, mental trauma.
Related brain areas: temporal lobes, diencephalon, hippocampus.
Treatment: there is no drug treatment, you can train the brain to partially memorize ^[3] .


Retrograde amnesia - inability to remember the events preceding the onset of a symptom. The more serious the injury, the longer the period of memory can be hurt. At the same time, early memories are more stable and are restored first ^[4] .

The reason for the appearance: organic brain damage, mental trauma.
Related brain regions : hippocampus, anterior nuclei of the thalamus.
Treatment: depending on the causes of the symptom, but most often they use drugs that improve blood circulation, neuroprotectors, nootropics, antioxidants and B vitamins ^[4] .



Transient global amnesia is a time-limited episode of memory loss (up to 2 days), with no signs of injury.
The ability to memorize, and memory, is lost for a period from a day to several years. Self memory, general and professional skills are preserved.

Reason of appearance: Unknown ^[5] .
Related brain regions : Most likely the hippocampus.
Treatment: Not required.

This is a list of symptoms of MB21.1 from ICD-11. All other types of amnesia are a specific variation or combination of variations of retrograde and anterograde amnesia, so I will not discuss them in detail, except for a symptom that can combine both signs of retrograde amnesia and anterograde, but with a psychogenic cause:

Dissociative amnesia is a loss of memory that can block memories of a person, while maintaining general skills and knowledge ^[6] . Most often there are cases with partial loss of memory for certain events, but sometimes the ability to memorize events is lost.

Reason of appearance: mental injury
Related brain areas: not directly related
Treatment: depending on the patient's condition


There is no evidence ^[6] that this type of amnesia can be caused by physiological or physical effects (that is, substances or injuries) I did not find (but it’s here that the pharmacological and somatic reasons are excluded).

Also, symptoms are often divided according to the dynamics of development: progressive, regressive, or stationary.

The general classification is very confusing. So in the directory of ICD-11, in addition to the symptoms, there is “ Amnesic disorder ”. I do not understand very well why it was necessary to introduce a syndrome. In my opinion, memory loss is not a disease, but a sign of certain diseases, injuries, etc., and you should not produce unnecessary entities. But doctors have a different logic.
Script writers describe dissociative amnesia after a head injury, but this does not happen in real life.

Diagnostics:

The diagnosis is made on the aggregate of the following data ^[4] :

• Anamnesis , confirming the presence of a traumatic factor
• Tests for memory, different countries are used in different ( MMSE , AMI )
• Instrumental diagnostics: EEG , ultrasound , skull radiography, MRI , CT

Memory work

Separately, it should be noted that the memories are not erased from the brain, and problems arise with their reading ^[2] . If to exaggerate, in the human brain as in computers there is a short-term and long-term memory, the consciousness can process information that is in the operational part of the short-term memory using intelligent operations.
Short-term memory is a temporary neural connection located in the frontal (mainly dorsolateral prefrontal) region of the brain and in the parietal cortex.

^{- brain structure, illustration by Wikimedia user Pancrat}
The amount of information in short-term memory is severely limited, as well as the storage time (20-30 seconds). At the same time, consciousness cannot work directly with long-term memory distributed throughout the brain, therefore it is necessary to decode and load data into short-term memory using the hippocampus and, probably, the system of anterior thalamic nuclei responsible for connectivity. The hippocampus is also responsible for saving data from short-term to long-term memory.

▍ Types of long-term memory:

There are many typologies of memory, but I will consider only the division on the organization of memorization and awareness:

1. Declarative memory - includes memorization of words, faces and events.
   
   Declarative memory can be divided into:
   
   
   • Semantic - general knowledge about the world presented in words, for example, if you mention the word "cat", then data about cats should appear in the memory, without emotional coloring
   • Episodic - memories of events from the past (this includes autobiographical memory), allows you to reproduce what happened. It is this memory that is blocked during dissociative amnesia.
   
   
2. Procedural memory - responsible for automatism skills
   
   Example: use the mouse, control the bike and other actions that you do not need to think about

Episodic memory hierarchically depends on the semantic, i.e. first, the semantic basis is invoked, and only then the memories are layered on top.
Semantic and procedural memory are more stable: knowledge and skills are less often forgotten. There are studies confirming that procedural memory has a different memory recording and processing algorithm, so patients with anterograde amnesia maintained the skill of playing the “ Tower of Hanoi ” ^[7] , even if they did not remember that they had assembled the tower before. It is assumed that procedural memory is processed independently of declarative memory and without the participation of consciousness, but at the same time, both types of memory are closely interrelated. For example, if you are an experienced player in Starcraft, you will unknowingly perform hundreds of actions, simultaneously analyzing the situation and planning further actions and tactics.

I never managed to find any evidence that procedural or semantic memory can be saved in the event of serious organic brain damage causing episodic memory failure. It is likely that the algorithm of consolidation from long-term to short-term memory is not very different for different types of memory.

Conclusion

As for me, the signs of anterograde amnesia disappeared 4 days after regaining consciousness, approximately at the same time speech function was restored and most of the memories returned, although I remember very fragmentary and vague about six months or a year before the accident (more precisely, I do not remember anything, it is a partial form of retrograde amnesia).
It doesn’t bother me very much, in the end, people always forget everything, so much more problems are caused by a broken body and severe pains. On the other hand, the topic is quite interesting and important, because who we are, without our memories and the brain. Empty shell, nothing more.

Once, in the hospital, they sent me a full-time psychotherapist, to whom I had a persistent dislike because of foolish mocking advice like "relax and have fun." It is a pity that the hand was not HK-47. But, in general, I very quickly refused to communicate with this horseman, and I do not attend a psychotherapist.

Firstly, I do not believe that this can help in any way, and secondly, why should I pay such money? For chatter? Moreover, finding a good specialist is not an easy task.

Therefore, in order to somehow begin to move away from what happened, I began working on an article about the Knights of the Old Republic series of games (and this is one of my favorite games). I wanted to find out if I could create something or now my limit is to watch the series a couple of hours a day.

It took more than 2.5 months to write the article, and it was all very hard. I had to type with one hand, and take constant breaks, since the slightest effort was very tiring. Well, I had to get used to monocular vision.

Not everything was done as I wanted, but sometimes you just need to complete the project, otherwise you will never be able to finish it. The article itself will be published on Friday (I hope).

At the moment, although I have severe headaches, they are not as unbearable as at first, and in general I already feel better, I can move on my own and even do simple things.

* nervously corrects the dressing gown, taken secretly from the doctor *

I want to wish everyone not to fall into such situations. Take care of your brain. Try to eat right according to the recommendations of the WHO, do not forget about physical activity (it is not necessary to be an extreme sportsman, you can go swimming, Nordic walking or just do exercises). Engage in intellectual and creative activities.

All this reduces the likelihood of developing brain diseases ^[8] .

And a small appeal to drivers:

Remember that not only your life depends on your actions behind the wheel, but also the lives of people around you, so do not forget to relax while traveling.

Materials used in the article:

1. "Road traffic injuries." World Health Organization article .
2. "Understanding Memory: Explaining the Psychology of Memory through Movies." a course of lectures by Professor John Simon on Coursera.
3. "Current Approaches in Psychiatry". Erdogan, Serap (2010), book
4. "Retrograde amnesia." An article on Liqmed.
5. "What is amnesia and how is it treated?". Christian Nordquist, article .
6. “Autosopersonamia (biographical amnesia): Depersonalization? Conversion? Simulation? Organic amnesia? Independent Psychiatric Journal, article .
7. "The rate of learning potential in the REM Article
8. "Dementia". World Health Organization article .

Article is open under license CC BY-SA 4.0

P. s. Unfortunately, I am not able to thank you all personally, so I am writing here.
Thank you all for the kind words and wishes. And for your own stories.