Cognitive Impairment

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Cognitive Impairment in Traumatic Brain Injury Cases

Our brains are so essential to our mental and physical functioning, it’s no surprise that a serious brain injury can cause incapacitating mental and physical disability. But even mild to moderate head injuries commonly cause subtle mental deficits, and these can ultimately have a significant impact on a person’s quality of life.

By understanding and recognizing the potential cognitive impairments of mild traumatic brain injury, we can identify them and obtain the appropriate therapy or treatment to lessen their impact.

Types of Mental Symptoms

Brain injury sufferers frequently exhibit any combination of these neuropsychological problems:

  • Cognitive impairment – Reduction in intellect, memory, reasoning, math or language skills
  • Behavioral issues – Anger, self-centeredness, aggressiveness, inappropriate behaviors
  • Emotional problems – Depression, apathy, low self-esteem, social withdrawal, irritability

The patient with a serious brain injury may have many of these symptoms to a severe degree. Someone who otherwise seems to be fine after an accidental “bump on the head,” however, may have only a few of these symptoms.

Many of these symptoms are also commonly related to normal life stressors and to some physical diseases and mental disorders. This makes it even more difficult to accurately relate the symptoms to the cause in order to obtain the right treatment.

In a commonly recurring pattern, the mental symptoms of a brain injury appear within the week following the original injury, and most of the time the symptoms clear up within three to four weeks. In other cases, the symptoms may take 6 to 12 months to abate. When the symptoms persist longer than one year, they are frequently permanent, but often manageable with therapy.

Recognizing Cognitive Impairment

Slow Thinking

A subtle impairment clinically detectable only by comparative testing is a slow-down in thought processes. A study comparing the mental reaction times of injured and non-injured people with similar age and social background found the brain-injured patients lagged the control group measurably for several months following their injury. In the majority of cases, they caught up with their uninjured peers within three months without any specific treatment.

Memory Problems

Post-traumatic amnesia frequently occurs in association with a head injury. The patient does not remember events immediately preceding the injury, and often for a fixed period of time after the injury. Researchers are beginning to think that the overall duration of this amnesia is a far more significant indicator of residual mental deficits than the duration of unconsciousness following the injury.

Other types of memory problems also persist after injury. Difficulty in remembering objects (visual memory) is common in younger children, while difficulty in remembering words is frequent in adolescent children. These specific types of deficits are explained by the developmental stages of children’s brains.

Other problems associated with memory functions can include the inability to maintain short-term memory or the inability to store experiences in long-term memory. In an extreme case, a brain-injured man always greeted his wife with great enthusiasm as if he had not seen her in months, even if she had just left the room and returned moments later. More subtle memory issues can be difficult to diagnose as brain injury symptoms because memory can also be affected by psychological, pharmacological, and physical causes beyond brain injury.

Reduced Attention Span or Concentration

The inability to focus or concentrate on a task is frequently reported after a head injury; some cases may be due to the actual injury, while other cases may result from the psychological trauma following an accident. This symptom frequently resolves itself within weeks. When it persists longer, neuropsychological evaluation is called for.

A specific variation on this symptom is the inability to attend to more than one object at a time. An example is a printed paper form having many blanks to fill in that are simply overwhelming to the patient. Some patients can learn to mitigate this problem by covering the form with blank paper so that only one line item is visible at a time.

Another variation of this problem can be the inability to comprehend the contents of a closet. The contents appear as a unit and separate items are not intellectually distinguishable.

Impaired Judgment

The quality of rational judgment is very subjective and can best be compared only for a single individual pre- and post-injury. When the difference is subtle, it can be difficult to determine if it is the result of organic injury or psychological side effects. In either case, if impaired judgment seems to be leading to dangerous situations, intervention of some form or another is called for.

Difficulty Planning and Executing

This is another situation that may be best evaluated based on the patient’s abilities pre-injury and post-injury. Sometimes called “impaired executive function,” it is characterized by the inability to plan and execute several sequential steps needed to complete a task, such as making coffee. This symptom is associated with frontal lobe injury.

Problems with Language

Speech, reading and writing are among the more complex functions to which the human brain has become adapted. Subtle injuries can interfere with these capabilities in a myriad of ways:

  • Problems with reading
  • Unable to express language
  • Unable to recognize words
  • Problems in understanding spoken words
  • Unable to locate the words for writing
  • Unable to focus visual attention
  • Problems with identification of, and verbalization about, objects
  • Problems with drawing objects
  • Unable to name an object
  • Problems in recognizing drawn objects

Reduction in Intellect

Someone who knows the injured person well can usually tell if intellectual function is impaired. The loss of ability to perform math, or decreased problem solving ability may become apparent. More subtle effects may be thought processes becoming more rigid and less flexible.

Very specific problems can arise such as the inability to categorize objects, or being unable to recognize faces. Acute symptoms such as these are often the result of severe injury to specific areas of the brain responsible for these types of functions.