Cognitive Difficulties after TBI
The cognitive difficulties experienced by people after traumatic brain injury (TBI), often have more impact on their recovery and outcome than their physical limitations. Most people with traumatic brain injury, even those that are severe in degree, are ambulating after their trauma. Within a year, 90% of them are getting around independently and able to care for themselves. It is however, the cognitive difficulties and behavioral problems that have the most significant impact in terms of one independence.
TBI has a generalized effect, that is the entire brain is affected to some extent. This is different from what occurs with a stroke, where a specific hemisphere or section of the brain is affected. An individual may have aphasia because they have a left hemisphere stroke or significant neglect because they have a right hemisphere stroke. With head injury there are not, for the most part, patterns of significant deficits in some areas with intact abilities in other areas. Every ability, in a lot of cases, is affected.
It helps to think of cognitive abilities as a hierarchy, beginning with very basic skills and then moving on to more complex ones.
- Arousal or alertness is first in the hierarchy. This is the foundation for everything else. An individual first must be aroused in order to do anything cognitively or behaviorally.
- Sensory and motor skills are next. One must be able to sense the world in order to operate in it and manage one's life. Sensing means having the use of one's senses, including vision, hearing, and touch. While few head injuries cause blindness, they can cause double vision or perceptual problems, making it difficult to interpret visual material. With regard to hearing, an individual very rarely becomes deaf as a result of a head injury. However, there may be problems in discerning discreet sounds or in processing auditory material fast enough to be able to keep up. Motor ability involves manipulating one's environment with one's hands, particularly performing basic skills.
- Attention and concentration are at the next level. These skills involve selecting what is important in the environment, as well as shifting one's attention to what is important. It may be easy to pick out what is important, but one must also be able to maintain attention and focus. Then as changes occur, one must be able to shift attention. All of these components of attention can be disrupted by a brain injury.
- Language skills or the ability to communicate with the world follow in the hierarchy. It's very rare that someone with a TBI loses all language abilities such that they cannot comprehend or express themselves. Language skill problems after TBI are more subtle. An individual may be able to express himself in a basic way, but be unable to explain complex things in a logical fashion. One of the more subtle problems that may exist involves word-finding skills. The individual cannot quickly access words from memory. When talking, they tend to talk around the topic. It is difficult for them to "hit the nail on the head". It can be very frustrating finding that correct word.
- Spatial and constructional abilities are at the next level and involve spatial activities, such as drawing or building things and judging distances. This requires visual perception as well as being able to take a mental image and apply it in the environment through motor output. A complex series of events has to take place for this to occur.
- Memory abilities come next. Individuals with traumatic brain injury, even severe injury, often have relatively good recall of events that occurred prior to their trauma. There may be gaps for a week or a month before the injury, but this usually fills in over time. All of that information is already in the memory banks. The head injury does not take that away. It may interfere somewhat with the ability to retrieve some information but it does not erase the existing memory.
The problem faced by people with TBI is with encoding and retrieving new information. Memory for new information is usually the most severe deficit experienced by people with traumatic brain injury. There are several reasons why memory for new information is difficult for people with TBI.
A major factor is the neurochemical cascade that takes place as a result of the TBI that effects the hippocampal areas of the brain, which are essential to memory encoding. In addition, disrupted executive skills may have a significant impact on memory functioning. As a result the individual may not be able to attend to information, organize information for encoding, or appropriately scan memory to retrieve information.
Think of the brain as a very organized filing cabinet. Each drawer is labeled and all the files are arranged and labeled. To locate information you open the correct drawer and locate the right file. With a head injury, it is like the filing cabinet has been turned upside down and all of the files are in the wrong place and so it is hard to organize things again.
- Reasoning skills or the ability to solve problems are at the next level in the hierarchy. First one has to know that there is a problem. Individuals with head injury often do not recognize the need for a solution or they tend to be inflexible. They may come up with one strategy but if that does not work, they cannot think of an alternative. They will stick with that same strategy even though it's not working. The basic "if - then" reasoning that most people use, does not occur for these individuals.
- Intellectual abilities follow. Here we see a combination of many different skills that combine reasoning, memory, spatial skills, etc.
- Academic abilities are at the final level, combining many different skills. For someone who has been through a reasonable educational program, it's rare to lose academic abilities following a TBI. Injured people can usually still read, write, and do math because those are ingrained skills; they're already in the memory banks to the point that the skills are almost automatic. The problem academically is that the individual is not able to add to these skills after the injury because of the memory and reasoning difficulties.
Behavioral/Emotional Difficulties
Behavioral and emotional difficulties cannot be separated from the cognitive difficulties that accompany TBI. Ninety-nine times out of 100 when there is a behavioral problem it is tied to a cognitive problem.
- Restlessness and agitation are common problems, particularly early in recovery. At that point of recovery, people with TBI have significant problems with attention. Restlessness is a normal reaction for a person who cannot pay attention or is easily distracted. The same thing applies with reasoning. When an individual cannot reason effectively enough to accomplish a goal, they tend to be restless and thus more agitated.
- Emotional lability and irritability exhibited by the individual with the head injury are frequently described by family. To understand what is happening, think about it in terms of executive (reasoning) skills as a gating mechanism. These gates keep behavior in control. A lot of what the frontal lobes of the brain do is inhibit actions that are not consistent with our goals. They keep you from doing things that you should not do. For example 3 year old children, whose frontal lobes are not fully activated, do whatever comes to mind, sometimes to their detriment.
When you have a significant brain injury that involves the frontal areas, the gating mechanism can be knocked askew such that the person cannot inhibit behavior as well as prior to the injury. The individual is not reasoning effectively and cannot figure out what to do in a situation to solve a problem. To get the attention needed or to generate a response they may get angry or exhibit other inappropriate behavior. The gates that kept behavior in control are knocked askew and things come out that used to be kept in.
- Confabulation is another behavior problem. A patient may tell staff they were at the Talladega races last weekend when actually they have been in the hospital for the past 2 months. The person is not lying; instead their memory is playing tricks on them. They are not able to organize their memory and therefore cannot retrieve information accurately. This person may have been to Talladega, but in the distant past. Their organizational process, called "time-tagging", of their memories is often disrupted and hence their inaccurate recall.
- Diminished insight on the part of people with TBI is a frequent complaint among caregivers. Self-awareness is a very unique skill of adults. As adults we are able to step outside of ourselves and look at our performance and abilities. This involves being able to process information at a very high level, requiring attention, memory and reasoning abilities. Often a person with severe head injury does not have a very good understanding of their deficits or the impact of those deficits on daily life. They will deny cognitive difficulties that are obvious to others or feel they can engage in activities, such as driving, even while acknowledging significant problems.
- Impulsivity/socially inappropriate behavior results from both diminished reasoning and lack of inhibition. Both have a lot to do with frontal area functioning and the gating mechanism that has already been described. Many families describe the person with the head injury as saying hurtful things and that they are insensitive and blunt. They say things that come into mind without due consideration of the situation. It can be a subtle problem or it can sometimes be severe. The injured person is not able to reason that "If I say this, then something undesirable is going to happen." The appropriate inhibition is not there.
- Poor initiative can be confused with depression. Frontal area injury can affect the ability to plan and to organize. This results in a person not initiating activity. They will sit quietly and contentedly. If directed to do something, they will do it. But they will not go any further than that. The if/then reasoning skills are not present. In addition, attention problems may prevent the individual with TBI from focusing on something long enough to be able to carry through with a plan.
- Lack of emotional response is demonstrated by a lack of initiative and a flattened affect. The individual does not smile or show any emotional response to things going on in the environment. An example is an adult with TBI who was told by his mother that he cannot drive anymore. His reaction was to put his keys on the dresser and walk out without exhibiting any reaction or emotional response. Most adults would react differently. The emotional response is just not there.
- Paranoia or blaming of others for negative events is a natural tendency when individuals do not reason effectively. This can be compounded for individuals having traumatic brain injury because they are not reasoning well enough to know the logical explanation for what is happening. They automatically assume that someone else is doing something to them and project blame automatically. If you are not able to reason through things, you assume that somebody is doing something to you. When the person is not able to remember something that they did, they blame someone else.
- Depression is a common problem for individuals after head injury. The issue is how much of it is organic, related to the brain injury itself, versus reactive to the situation. Fortunately, in either case, the condition is usually responsive to medication and counseling. The danger is that depression can compound the problems that already exist by decreasing activity levels and undermining the expression of skills possessed by the injured person.
- Anxiety occurs, in part, because of reasoning difficulties. The inability to comprehend a situation or anticipate what is going to happen leads to anxiety. Three situations in particular seem to generate anxiety among people with TBI: 1- Riding in a vehicle in heavy traffic, 2- Being in crowds and 3- Being around small children.
Source: Center for Neuro Skills
