Reticular Activating System (Inglés)

What is the RAS, and why is it important to ADD ADHD?

The Reticular Activating System is the attention center in the brain. It is the key to "turning on your brain," and seems to be the center of motivation. The Reticular Activating System is connected at its base to the spinal cord where it receives information projected directly from the ascending sensory tracts. The brain stem reticular formation runs all the way up to the mid brain. As a result, the Reticular Activating System is a very complex collection of neurons which serve as a point of convergence for signals from the external world and from interior environment. In other words, it is the part of your brain where the world outside of you, and your thoughts and feelings from "inside" of you, meet.

This Reticular Activating System is very capable of generating dynamic effects on the activity of the cortex, including the frontal lobes, and the motor activity centers of the brain. It plays a significant role in determining whether a person can learn and remember things well or not, on whether or not a person is impulsive or self-controlled, on whether or not a person has high or low motor activity levels, and on whether or not a person is highly motivated or bored easily.

The Reticular Activating System is the center of balance for the other systems involved in learning, self-control or inhibition, and motivation. When functioning normally, it provides the neural connections that are needed for the processing and learning of information, and the ability to pay attention to the correct task.

If the Reticular Activating System doesn't excite the neurons of the cortex as much as it ought to, then we see the results of an under aroused cortex, such as difficulty learning, poor memory, little self-control, and so on. In fact, if the Reticular Activating System failed to activate the cortex at all one would see a lack of consciousness or even coma.

What would happen if the Reticular Activating System was too excited, and aroused the cortex or other systems of the brain too much? Then we would probably see the individuals with the excessive startle response, hyper-vigilant, touching everything, talking too much, restless and hyperactive. So the Reticular Activating System must be activated to normal levels for the rest of the brain to function as it should.

According to Harvard Medical School, current research strongly suggests that ADHD is caused by a deficiency of Norepinephrine in the ascending reticular activating system, and it is thought that the stimulant medications, such as Ritalin, increase the levels of Norepinephrine in that part of the brain, as well as probably increasing dopamine levels in the frontal lobes.

This treatment strategy works well for the inattentive ADD kids, and somewhat well for the over aroused ADHD kids. However, for the kids who have an over aroused Reticular Activating System to begin with, the use of stimulants will often exacerbate the problems with temper, sleep, and hyper-vigilance or anxiety. For these individuals their physicians will often prescribe a norepinepherine antagonist such as Clonadine.

However, it is not just activation levels of the Reticular Activating System that are a problem with Attention Deficit Disordered individuals. It seems that the same problems that cause the Reticular Activating System to be under or over aroused also restricts the development of neural connections and the required neural density needed to process incoming information.

Picture the incoming information to be processed and learned as a large volume of water, and picture the brain's ability to process this information as a large pipe, like a storm drain pipe. If the brain does not have enough neural connections, or lacks the neural density, to process the incoming information, then it will be like a pipe that is too small to handle a large volume of water. It will take in some, but the rest will be stopped and won't go down the pipe rapidly. Learning may take place, but the time that it takes to process information will be slowed significantly. The impact of this with an ADD child is best seen when the child is given a timed test, even with material that the child understands pretty well. The "timed" aspect of the test requires that the child have a larger storm drain pipe, as it were, to quickly process the problems on the test and recall the answer. Since the pipe is too small, the results of the timed test will probably be very poor. However, take away the timed element on the same test, and allow the water to drain a the slower rate, and the child will probably do well on the test.

So the ADHD child, and adult, needs a greater degree of neural density, and a larger number of neural connections to process information.

ADHD: Recticular Activating System

The next questions might be, then, "What causes these various systems of the brain to get out of balance with ADD ADHD individuals?"

Why would these systems become under aroused or over aroused? Is there one central system that controls or regulates these other systems? 

Reticular Activating System.

The Reticular Activating System is the attention center in the brain. It is the key to “turning on your brain,” and seems to be the center of motivation. The Reticular Activating System is connected at its base to the spinal cord where it receives information projected directly from the ascending sensory tracts.

The brainstem reticular formation runs all the way up to the mid brain. As a result, the Reticular Activating System is a very complex collection of neurons which serve as a point of convergence for signals from the external world and from interior environment. In other words, it is the part of your brain where the world outside of you, and your thoughts and feelings from “inside” of you, meet. 

This Reticular Activating System is very capable of generating dynamic effects on the activity of the cortex, including the frontal lobes, and the motor activity centers of the brain. It plays a significant role in determining whether a person can learn and remember things well or not, on whether or not a person is impulsive or self-controlled, on whether or not a person has high or low motor activity levels, and on whether or not a person is highly motivated or bored easily. The Reticular Activating System is the center of balance for the other systems involved in learning, self-control or inhibition, and motivation. When functioning normally, it provides the neural connections that are needed for the processing and learning of information, and the ability to pay attention to the correct task. 

If the Reticular Activating System doesn’t excite the neurons of the cortex as much as it ought to, then we see the results of an underaroused cortex, such as difficulty learning, poor memory, little self-control, and so on. In fact, if the Reticular Activating System failed to activate the cortex at all one would see a lack of consciousness or even coma. 

What would happen if the Reticular Activating System was too excited, and aroused the cortex or other systems of the brain too much? Then we would probably see the individuals with the excessive startle response, hypervigilant, touching everything, talking too much, restless and hyperactive.

So the Reticular Activating System must be activated to normal levels for the rest of the brain to function as it should. 

Image of Brain:
Reticular Activating System (22K-about 5 sec.)

According to Harvard Medical School, current research strongly suggests that ADHD is caused by a deficiency of Norepinephrine in the ascending reticular activating system, and it is thought that the stimulant medications, such as Ritalin, increase the levels of Norepinephrine in that part of the brain, as well as probably increasing dopamine levels in the frontal lobes. This treatment strategy works well for the inattentive ADD kids, and somewhat well for the overaroused ADHD kids.

However, for the kids who have an overaroused Reticular Activating System to begin with, the use of stimulants will often exacerbate the problems with temper, sleep, and hypervigilance or anxiety. For these individuals their physicians will often prescribe a norepinepherine antagonist such as Clonadine. 

However, it is not just activation levels of the Reticular Activating System that are a problem with Attention Deficit Disordered individuals. It seems that the same problems that cause the Reticular Activating System to be under or over aroused also restricts the development of neural connections and the required neural density needed to process incoming information.

Picture the incoming information to be processed and learned as a large volume of water, and picture the brain’s ability to process this information as a large pipe, like a storm drain pipe. If the brain does not have enough neural connections, or lacks the neural density, to process the incoming information, then it will be like a pipe that is too small to handle a large volume of water. It will take in some, but the rest will be stopped and won’t go down the pipe rapidly. Learning may take place, but the time that it takes to process information will be slowed significantly. 

The impact of this with an ADD child is best seen when the child is given a timed test, even with material that the child understands pretty well. The “timed” aspect of the test requires that the child have a larger storm drain pipe, as it were, to quickly process the problems on the test and recall the answer. Since the pipe is too small, the results of the timed test will probably be very poor. However, take away the timed element on the same test, and allow the water to drain a the slower rate, and the child will probably do well on the test. So the ADHD child, and adult, needs a greater degree of neural density, and a larger number of neural connections to process information. 

This information to be processed includes information from the outside world, including the touch of the clothes on his skin, the buzz of the lights overhead, the sound of the kids playing outside, and the new information that the teacher is talking about at the front of the classroom.

It also includes the information from inside the head, the thoughts and feelings for the ADHD person. All of that must be sorted out and filtered, so that only the important information is paid attention to, and the unimportant information is ignored. Without proper filtering by the Reticular Activating System, the individual will be distracted by “noise,” both from out side of him as well as from inside of him. 

What are the Options? What Can Be Done?

Well certainly medications can be used to help out the various systems of the brain as was mentioned earlier. The most commonly used medication is Ritalin, which is fairly effective with the majority of individuals who have ADD. Of course some individuals suffer side effects from medications, and so they should be used with caution, and must be monitored closely by a physician.

The major drawback to stimulant medications is that they only work for the short term. For example, Ritalin begins to work about 20 minutes after it is ingested, peaks in effectiveness at about 90 minutes, and is used up and gone by about 3 1/2 or 4 hours. Then the subject returns back to where he started and must again take another dose of the medication. For the short term, the function of the brain is improved, sometimes a great deal, but the basic underlying problems are unaffected. Medications are not bad, or evil. They can be very helpful to a lot of people, and should be considered among your list of treatment options.

However, medications are a short-term solution, a Band-Aid to the problem. Now, there are times when Band-Aids are needed and are useful, and I have lots of Band-Aids around my house. I have no problem using Band-Aids as Band-Aids. But Band-Aids don’t heal the cuts and scrapes that they are placed over. They offer a short-term benefit, but only the body itself provides healing.

Many researchers, over the past twenty years or so, have worked hard to try to find real solutions to the problem of ADD, and a few good treatment options have been developed. Up until now, though, these treatment options have been very labor intensive and very costly. Many families simply cannot afford the investment of time and money required for these treatments, so the search continued to find an effective and affordable treatment.

ADD ADHD: How is it Diagnosed?

Everyone in a private practice setting who works with ADD/ADHD children or adults is going to have their own opinion on how Attention Deficit Hyperactivity Disorder - ADD or ADHD - should be diagnosed. Some clinics take the perspective that “more is good,” and will recommend a large battery of tests, often costing many thousands of dollars. Other clinics, typically with hurried physicians, will simply give a brief rating scales to the parent and then make a quick diagnosis and prescribe treatment. Unfortunately neither of these extremes are in the patient’s best interest. 

Over-diagnosis of ADD ADHD is a big problem. There are some children who are diagnosed as having attention disorder that do not have it. It is not uncommon for someone with depression, or anxiety, specific learning disabilities, early onset bi-polar disorder, or Tourette’s Syndrome, to be diagnosed as ADD/ADHD. This is often the result of a diagnostic “work-up” which is too brief and does not take into account the many reasons why a child might be inattentive, impulsive, or over-active.

Under-diagnosis of attention deficit disorder - ADD ADHD - is also a problem. This happens most often in the school setting where the school psychologist writes his report perfectly describing an ADD individual, then refuses to use the label “Attention Deficit Disorder” in his report anywhere. It also often happens in therapist’s offices where the therapist is not familiar with ADD/ADHD, and only sees the characteristic behaviors as “acting out behaviors” due to family problems, etc. 

Some studies suggest that only one out of three people who have an attention disorder will get help. Two out of three people who have an attention disorder will never receive a diagnosis or treatment. They will never really know what it is that’s bothered them through their life. So we have two problems. One is over-diagnosis and the other is under-diagnosis.

How can you be certain?
What makes a good diangostic work-up?

The unfortunate thing is that there are many kids who have been diagnosed as having attention deficit hyperactivity disorder - ADD ADHD - based on only a parent interview that lasts about four minutes, or a real quick rating sheet taken in the doctor’s office. It’s unfortunate when that’s all that happens and the diagnosis of ADHD is made, because that could lead to real problems.

ADHD: Diagnostic Evaluation

Attention Deficit Hyperactivity Disorder - ADD ADHD - is a category found in the Diagnostic and Statistical Manual, version Four (DSM-IV). The diagnostic criteria is divided into sub-groups:

·        Attention Deficit Hyperactivity Disorder (ADHD), Primarily Inattentive Type;

·        Attention Deficit Hyperactivity Disorder (ADHD), Primarily Impulsive-Hyperactive Type; and

·        Attention Deficit Hyperactivity Disorder (ADHD), Combined Type.

We have summarized the diagnostic criteria here.

Here are the things that we recommend if you have a child that ought to be looked at for possible attention deficit disorder...

First, there should be an “adequate” physical exam by the child’s pediatrician or family practice doctor. This doesn’t have to be an extensive, expensive exam, but should be able to rule out possible problems like Mononucleosis, Thyroid problems, lead poisoning (if it is common in your area), and potential attentional problems caused by medications, such as allergy medications. Then, with a clean bill of health, we move on to step two. . . 

Number two, there should be a good parent interview. It’s absolutely essential that somebody sits down with the parents and spends 45 minutes to an hour with them. The psychologist or therapist needs to find out what’s going on now, why did the parents pick up the phone and call now instead of last week, and so on.

Note: Usually a psychologist or other mental health professional will do this evaluation for ADD ADHD. Only get counseling or therapy from professionals who have a lot of experience treating attention deficit hyperactivity disorder. Therapists who do not have a lot of experience with ADHD will just waste your money and probably blame you, the parents, for the child’s disorder. Find experts on Attention Deficit Disorder in your area.

A good developmental history must be taken. Important questions are:

·        How did mom do during pregnancy?

·        Were there any problems at all?

·        Was there any exposure to drugs or alcohol prior to birth?

·        When did he learn to walk or crawl?

·        How about speech development?

·        Did he have very many ear infections?

·        Any head injuries, high fevers, or seizures? Head injuries and seizures can look just like ADD, but aren’t. They may require different treatment options. 

Then a good family history is great. The family trees of Attention Deficit Disorder kids are often very similar. Look at one and you may say, “Gee, there’s no wonder this kid has it,” because most of the time, about 80 percent of the time, you can trace the impact of this gene as it runs through families causing things like obsessive-compulsiveness, depression or alcoholism, attention disorders or learning disabilities throughout the family.

The clinician must also know:

·        Is child depressed?

·        Does he have anxiety problems?

·        Is he hallucinating?

·        Is he delusional?

·        Is it a head injury?

·        Is it a seizure disorder?

Third, parent rating scales are very good. The ADD ADHD scales we like are by Ned Owens out of Texas. Keith Connors has a fine tool that you have probably seen if you are involved with Attention Deficit Disorder children at all. It is very important for the parents to fill out these behavior rating scales. Ideally you get the teachers to fill them out too. 

Ideally you want the teacher’s input because they see 30, 32, 35 kids every single day, year in and year out, and they know what is normal behavior and what is not.

Note: One of the things we have noticed is that lately we are having more trouble with the teacher rating scales because the teachers ten years ago, eight years ago, five years ago used to rate the kids pretty reliably compared with the normal kids in the class, the non-ADD kids in the class. But what we are seeing lately is very often the teachers are comparing the child that we want rated against the worst kid in the class, who might be totally off the wall. And so the rating scale comes back reporting that the child we want rated isn’t much of a problem at all. We have to give directions to the teachers to rate them versus “normal kids,” not against the worst kids in the class. 

Fourth, an in-depth clinical interview with the child is important. This interview is needed to determine the child’s reality testing, his degree of maturity, his degree of verbal skills, and so on. Ask the child if he’s hallucinating. Sometimes he is, but he hasn’t told anyone. Ask the child if he’s anxious. Some kids have tremendous fears, but have not shared them with anyone. There is a lot going on with kids that their parents are not aware of. 

Psychological Testing for ADD ADHD

Psychological testing as part of an evaluation for attention deficit hyperactivity disorder - ADD ADHD - can be helpful. We used to give tests such as the WISC-R, an IQ test, the Wide Range Achievement Test (WRAT), and the Bender-Gestalt test, which is a visual motor integration test. Bored already? Well, they are boring things. But they can be helpful.

There are certain patterns that one might expect on these tests if the subject had attention deficit hyperactivity disorder of some type. But it’s art, not science at that point. The patterns are not “diagnostic” for ADD/ADHD. It's also important to know if the kid has a real low IQ, or a major learning disability. It could be a clue that there is something else going on instead of attention deficit hyperactivity disorder.

What we find to be very valuable is the Test of Variables of Attention (TOVA). The TOVA is an extremely boring computer test that requires the kids to respond to a target stimulus by pressing a button, or to not respond when there’s a non-target stimulus. The fact that it is so boring is a work of genius because it helps to differentiate between kids who have trouble with “boring,” and kids who do all right with “boring.”

The TOVA is really a terrific tool, but it should never be given just by itself. It needs to be given in the context of the whole diagnostic workup.

Also, the TOVA can be given with no medication, and then if medication is going to be used down the road, given again with medication in their system. This can tell the clinician if the subject is at the right dosage or not, or how well he responds to that particular dose of that particular medication. The TOVA is a very helpful tool. 

Clinical observation of the child is very important. If possible, ideally, somebody observes the child in the classroom. In the real world, we don’t know anybody in private practice who can go out in the classroom to observe a child these days, but if a school nurse, school psychologist can go observe them, it can be very, very helpful. 

Obtaining an EEG from a neurologist is rarely helpful. EEGs will show some differences from non-ADD children. Typically there is excessive slow brainwave activity, particularly in the Theta band (4-7 Hz.). However, ninety-five percent of all ADD kids have “normal” EEGs. What we mean by “normal” is they don’t have big epileptic spikes, things like that, that a neurologist would say that are “abnormal.” But when you compare them side by side with a non-ADD kid, they are much different.

An EEG may be helpful if the child is going to be treated through EEG biofeedback, but in terms of being helpful for a diagnostic work-up, it is rarely helpful. However, if the parent interview revealed that the child had some potential neurological problem, as seen in sleep walking, or a history of seizures, and so on, then an EEG would be a good idea. 

In summary, then, an adequate diagnostic interview, designed to give an accurate diagnosis a very high percentage of the time, while not costing the family thousands of dollars, would look like this: 

1.    Physical Exam - Office Visit 

2.    Clinical Interview - Parents (45-60 minutes) 

3.    Clinical Interview - Child (45-60 minutes) 

4.    TOVA test 

5.    Parent and Teacher Rating Scales 

6.    Office visit to review information and develop a treatment plan 

That’s it! If there are further diagnostic questions, then more testing would be required. But in the vast majority of cases, this is all that is needed to make a highly reliable diagnosis. Except for the physician’s examination, the cost for this should be about $400-600. 

Diagnostic Criteria for ADD ADHD Made Easy

The following is a practical summary of the DSM-IV criteria. The actual criteria is available through the DSM-IV manual.

Symptoms of INATTENTION:

·        A lot of people, including his parents, complain that he just doesn’t seem to listen when spoken to;

·        Because of not sustaining attention, or because of acting like a “space cadet,” he doesn’t finish his chores or homework;

·        He can’t keep his mind on what he’s doing for very long;

·        He doesn’t pay close attention to what he’s doing, so he makes a lot of careless mistakes. Video games are excepted.

·        Seen most with homework, chores, and other boring things that you want him to do;

·        He’s really disorganized. Most commonly seen in spending three hours to finally finish his homework, then losing it at school, or forgetting to turn it in;

·        Tries to avoid doing homework or chores;

·        Gets distracted easily, pays attention to the wrong thing;

·        Is often forgetful.

Symptoms of IMPULSIVITY:

·        Blurts out answers in class;

·        Can’t wait his turn;

·        Interrupts others a lot, doesn’t wait well;

·        Not part of the diagnostic criteria, but doesn’t think before he does things.

Symptoms of HYPERACTIVITY

·        Happy hands and feet which fidget and squirm a lot;

·        Can’t stay in his seat when he’s supposed to at school or the dinner table;

·        Runs around too much, climbs on things he’s not supposed to;

·        Too loud;

·        “On the go” as if “driven by a motor”;

·        Talks too much;

·        Leaves footprints across the ceiling

Also: At least some of these symptoms seen before the age of seven. At least some of the symptoms seen both at home and at school. At least some of the symptoms are viewed as being a problem.

So:

For ADHD Inattentive Type: Six or more from the Inattention list.

For ADHD Impulsive-Hyperactive Type: Six or more from the Impulsive or Hyperactive lists.

For ADHD Combined Type: Both criteria are met.

WARNING:

Attempt at legal disclaimer. This is just for your information. Please be aware that there are several reasons why a child could have these symptoms besides ADD. For example, thyroid problems, depression, anxiety disorders, hearing problems, and so on. Please do not attempt to “diagnose” your child. Follow the steps in the Diagnosis section. See your doctor. Go to a qualified mental health professional. Etc., etc.

Neurology of ADD ADHD

What is happening in the ADD brain?

The most recent models which attempt to describe what is happening in the brains of people with ADD suggest that several areas of the brain may be affected by the disorder. They include the frontal lobes, the inhibitory mechanisms of the cortex, the limbic system, and the reticular activating system. Each of these areas of the brain are associated with various functions. 

The frontal lobes help us to pay attention to tasks, focus concentration, make good decisions, plan ahead, learn and remember what we have learned, and behave appropriately for the situation. 

The inhibitory mechanisms of the cortex keep us from being hyperactive, from saying things out of turn, and from getting mad at inappropriate times, for examples. They help us to “inhibit” our behaviors. I’ve heard it said that 70% of the brain is there to inhibit the other 30% of the brain. When the inhibitory mechanisms of the brain aren’t working as hard as they ought to, then we can see results of what are sometimes called “disinhibition disorders” such as impulsive behaviors, quick temper, poor decision making, hyperactivity, and so on. 

Finally, the limbic system is the base of our emotions and our highly vigilant look-out tower. If over-activated, a person might have wide mood swings, or quick temper outbursts. He might also be “over-aroused,” quick to startle, touching everything around him, hyper-vigilant. A normally functioning limbic system would provide for normal emotional changes, normal levels of energy, normal sleep routines, and normal levels of coping with stress. A dysfunctional limbic system results in problems with those areas. 

The ADD/ADHD might effect one, two, or all three of these areas, resulting in several different “styles” or “profiles” of children (and adults) with ADD/ADHD.

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