MEMORY

Impaired memory is one of the universal problems of people with head injury. All of my patients have complained about memory problems following their injury. Most people think of memory as being "good or bad." As we get older, we recognize that our memory isn't as good as it used to be. It's more complicated than that. There are several different types of memory . Let’s take a look at them.
TYPES OF MEMORY
First, we’ll look at the different types of memory. For example, we all have memory for music. We can be listening to a song on the radio and have a very distinct feeling associated with that music. The brain processes music and puts that information in one part of the brain. We also have memories for taste and smell. We know the taste of chocolate. We know the smell of burning rubber. We have memories for the things we feel (physical). We can remember the difference between the feel of silk and the feel of sand paper. Each type of memory has a different site in the brain. Two of the more important types of memory are vision and hearing (in this case, words). Visual things are the things we see, such as a familiar place or where we’ve left our car. We also have memory for language, including things that we've heard or read (things we've read we translate into language). Verbal information is stored in the left hemisphere with visual information stored in the right hemisphere of the brain.
IMMEDIATE MEMORY
Information going into the brain is processed at several stages. I'm going to simplify at this point and discuss what I call immediate memory. Immediate memory really doesn't last very long--perhaps minutes. When do you use immediate memory? When you call information for a phone number, the operator will tell you a seven digit number. If you're pretty good, you can remember those seven digits long enough to dial the phone. That's immediate memory--information that is briefly saved. With people who have a head injury, immediate memory can be "good" or it can be "bad." The problem for most head-injured people, however, is with short-term memory.
SHORT-TERM MEMORY
There's some variation in how people define short-term memory. I define it as the ability to remember something after 30 minutes. In a head injury, someone's immediate memory may be good, yet they may still have problems with short-term memory. For example, a nurse in the hospital asked a head-injured patient to get up and take a shower and get breakfast. The patient said that he would, but the nurse came back 30 minutes later and the patient was still sitting in bed. When the nurse asked him why he didn't get up and take a shower, he said that the nurse never told him. So immediate memory is something you quickly "spit back", but the problem rests more with short-term memory. For example, someone may tell you to go to the store and get some milk, some eggs, a newspaper, and some dish soap. By the time you get to the store, all that you remember is the milk. In head injury, impaired short-term memory is a very significant problem.
LONG-TERM MEMORY
Long-term memory is information that we recall after a day, two weeks, or ten years. For most head-injured people, their long-term memory tends to be good. One patient told me "I can tell you what happened 10 years ago with great detail; I just can't tell you what happened 10 minutes ago." After you get a head injury, short-term memory isn't working, so information has a hard time getting to long-term memory. For example, head-injured people may double or triple their usual study time in preparing for a test the next day. By the time they get to the exam, they are completely blank on the material. People with head injuries have also told me "you know, time just seems to fly by." The little events of the day are sometimes forgotten, making life "fly by" when you look back at events that have happened since the injury.
LOST MEMORIES--TWO TYPES OF AMNESIA
Before we go on with memory, let's talk about two common things that happen with people with head injuries: retrograde and anterior grade amnesia. Amnesia means you lost a memory that you once had. It's as if someone has erased part of your past. Retrograde amnesia means you have lost memories for events PRIOR to the accident. For some people, retrograde amnesia can cover just a minute or even a few seconds. In other words, they'll recall the car coming right at them but are unable to recall the moment of impact. For other people, retrograde amnesia may affect longer periods of time. The last three or four hours prior to the accident are gone. I had one individual who had lost the last year of his life. As people get better from their head injuries, long-term memories tend to return. However, memories tend to return like pieces of a jigsaw puzzle; these bits and pieces return in random order. In general, the smaller the degree of retrograde amnesia, the less significant the head injury.
Another form of memory loss is called anterior grade amnesia. In this case, events FOLLOWING the accident have been erased. A good part of that is due to the brain injury itself. Complex systems in the brain are injured. The chemical balance in the brain is upset. As brain chemistry normalizes and brain systems begin working, memory also starts to work. I've had patients who have spent several months in the hospital but are only able to recall the last to two to three weeks of their stay.
WHY IS MEMORY IMPAIRED?
Why doesn't my short-term memory work? Well, let's quickly review how the brain works. We know the information flows in through the middle of our brain and branches out like a tree. Before that information goes to different areas, it goes through a channeling/filtering system. It's almost like a mail room--this information goes into this box, and that letter goes into that box. When the brain is injured, these middle areas get pressed upon because of swelling (pressure pushes down on the brain). The middle sections of the brain are also resting on the bone of the skull. Because of forward and backward movement of the brain in an accident, they get sheered or torn. A problem develops when there is a large flow of information coming in which the brain can't process, or when information is not being sent to the right place. So the mail room of the brain is not doing its job.
There is also a second type of memory problem. Once information is stored in the brain, the brain has a hard time finding it. For example, you saw a movie but you can't recall the name of the actor in the movie. You can visualize who the actor is, but can't come up with his name. People typically describe a "tip of the tongue" type of thing--"I know what I want to say but I just can't get it out". Its almost as if the brain is saying, "searching, searching" and not finding. Several minutes later, it just comes to you. So think of it as a library in some sense. If I take a book on history and I just put it anywhere in the library, I'm going to have to search that whole library to get that one book. So there are basically two kinds of memory problems: storage problems and retrieval problems.
WHAT CAN I DO TO IMPROVE MY MEMORY?
Work with a Specialist in Memory--One of the most important things is to get help from people who specialize in head injury. Every head injury program has a specialist who teaches memory strategies. In most cases, this is a Speech Therapist (they don't just help people who have slurred speech). In the Neuro-Recovery program, our Speech Therapist teaches 15 different memory strategies and helps you to pick the 2 or 3 that work best for you. There is often a fair amount of testing in order to figure out the best memory strategy for each head-injured person. For some people, one type of memory may be impaired (verbal recall) but another type be intact (remembering visual information). If I know that my verbal memory is not very good, I write things down and encourage visual memory systems to work. Specialists can help you pick out the best memory strategies to help you. Once you find an effective strategy, keep working on it. Think of memory like a muscle. The more you use it, the stronger it gets.
Get Organized--We learn better if we are organized. Many people have told me that, prior to their head injury, they had incredibly messy desks with papers all over. But if someone came in and said, "I need this particular paper", they could pull it out of a big pile and say "here it is." After a head injury, though, the ability to organize gets really messed up. One symptom of not being organized is when someone says, "I've started 50 projects and haven't finished one of them." If you organize information, it tends to help you recall it. For example, if you are constantly losing your car keys or constantly forgetting where you put your wallet, there's one simple technique to use. Put things in the same place. Always put your car keys in one spot on the dresser. Always put your purse in one spot in the house and nowhere else. Being organized helps your memory and you will be less likely to lose things.
Break It Down--Another thing that we can do to help memory is to break it into small bits. If you have something really tough to learn, try to break it down into small bits and then learn each one little bit at a time. Some people call this "chunking;" you are memorizing little "chunks" of information. For example, your brand new VCR has a remote control with 50 buttons on it. Reading the entire manual in one sitting to learn what all of the 50 buttons do is very hard. So, learn one function and then play with that feature for awhile. Once you've learned that, go on to the next button. We've been using this technique for years to learn simple information like a phone number. The wonderful folks at Bell Labs (they invented the phone) figured out that people will learn a 7 digit phone number if you group 3 digits together and then group 4 digits together (a "chunk" of 3 numbers and a "chunk" of 4 numbers).
Using Association-- Association is really important for retrieving important information. For example, you are taking a literature course and you need to remember a famous essayist--Francis Bacon. You might associate the image of a piece of bacon with the name of this person. So if you're trying to think of this explorer, an image of a piece of bacon will come to you. This approach is particularly helpful with learning names. Remembering names is a difficult task for most people in the world; it is especially hard for most people with a head injury.
Get a Daily Planner--Probably one of the best things you can do to help your memory is to use a daily planner. This brings up two important points:
The First Rule of Memory--write everything down in one spot (your daily planner).
The Second Rule of Memory--write it down when it's fresh in your mind.
For example, you go to your doctor's office and you are asked to return for another appointment. Many people have a calendar stuck on their refrigerator or on a wall at home. By the time you get back home, you've forgotten the date or lost the appointment card. Next time, bring a planner to the doctor's office and write your appointment in it just after the doctor tells you the date. Get a medium size planner or something called an organizer. Don't get something that's too small--you're going to be doing a lot of writing. Write complete notes! Some people make notes so short that they later can't figure out what the note means.
Make A "To Do" List--In addition to a planner, make a "to do" list. For example, you may have a number of chores to do around the house but none of them in any particular order. What you can do is get a small pad of paper and write down the things that they have to do. Once you have this list, decide which task to do first, second, third, and so on. This will work if your list doesn't get too long. If the list gets too long, you're going to run into problems.
Make a "Modified To Do" List--I commonly hear the same problem, "I've got 50 projects going but I haven't finished any of them." This is a combined problem of memory deficits and organizational deficits. One solution is to buy a small dry-erase board and put it up in the home (or office). On the board, you are only allowed to list five items on the "To Do" list. You cannot add another item to the board until you have completed one of the items already on the board. Make a "Modified To Do List" and put it somewhere in your house where the whole family can see it. Family can also offer suggestions to help you to get projects organized. This will in turn help family members get a better understanding of what the head-injured person has to deal with. When you get organized and use the Planner/To Do List, you'll feel better about yourself because you will be getting things accomplished.
THINGS THAT CAN AFFECT MEMORY
Fatigue and Sleep--Memory can be affected by a number of things. Some of these influences can affect even people without a head injury. If you do have a head injury, these effects are multiplied. For example, if you're tired, your memory tends to be poor. If you have to learn something really important, it's best to learn it when you’re fresh. Generally, most people with head injuries learn better in the morning than in the late afternoon. So if you've got something really important (a test for school), studying the night before the exam may not be very useful. The best time to study is in the morning. In addition, people with head injuries commonly have sleep disorders. Its very important that you talk with your doctor about getting your sleep pattern back to normal. If you wake up tired, you're going to make memory problems worse. (See the sections of this book on Sleep Disorders and Fatigue.)
Strong Emotions--Very emotional situations will distort your memory. If someone comes into a bank and waves a gun at you, this will create a very emotional situation (intense fear). Even though there are five people looking at the same person, you will get five different descriptions of the robber (that's one reason why they have cameras in banks). Being afraid, mad, or anxious will alter your memories. What should you do in emotional situations? You can't always control your emotions, but there are situations where you will need to recall important information. For example, going to a doctor's office can be a very emotional experience (many people are afraid or anxious). Most head-injured people find this a very stressful situation. One approach is to bring a family member or friend along. Another approach is to tell your doctor of your memory problems and ask the doctor if you can write down important information.
I have included a Memory Sheet for Doctors’ Appointments. When you get to the doctor's office, you may be so nervous that you forget to tell your doctor ALL of your problems. The next time you see your doctor, you may recall some of the old problems that you forgot on the first visit. A common complaint of doctors who work with head-injured patients is, "Every time I see this person, I hear a new problem." Using the sheet of paper at the back of this book can help you organize your thoughts. Doctors deal better with information when it is presented in a quick and organized form. For each problem, I left a little space for you to write down what the doctor recommends. In this way, you can bring your memory sheet to future appointments and keep track of your progress. For example, maybe you're not sleeping and one medication approach is being tried. If that approach doesn't work or has a limited effectiveness, you will want to keep track of that and bring it up the next time you see your doctor. If you don't write these problems down and monitor them, you'll be less likely to make progress with them.
Certain types of medications (pain killers, for example) can affect memory. In the hospital, people can be on fairly significant amounts of pain killers because they have broken bones or other injuries. Some medications can make you tired, which in turn makes your memory worse. It is important to have an ongoing dialogue with your doctor about your medications. People have told me, "I'd rather be in a little bit pain so I can be more alert." Sometimes the goal of pain medication is not to get rid of all the pain, but to control it. Talk with your doctor about your medications and the possible effect of medications on memory.