The Gazette 1992

GAZETTE

SEPTEMBER 1992

Evaluat ion of Cogni t ive Di sorders Fol lowing Head Injury

recovery. A higher level attention problem is the inability to shift attention from one task to another. Attention/concentration represents a basic level of thinking and disruption of this process may preclude an individual from adequately functioning in society. Visual Processing Problems with visually interpreting the world are also frequently present following brain injury. Although individuals may have difficulty with visual acuity (or how well they see), in this population the primary problem is generally the interpretation of visual information. At the most basic level, brain injury may cause difficulty with the recognition of objects and faces. Other problems can be seen in a patient's analysis of visual stimuli. He or she may be unable to pick out visual detail or discriminate features of objects. Hand-eye coordination may also be disrupted such that a person would have trouble building a model or doing construction. Finally, space and judgement may be impaired. This difficulty may be manifested when a person misjudges the distance between a plate of food and the serving tray such that the food spills on the table. The visual problems, if not remedied, make many activities impossible or unsafe, such as reading, driving and cooking. Memory Deficits Memory deficits are the most common complaint of individuals who have suffered brain injury. Early on, individuals may be unable to remember events from one moment to the next. This gradually improves over time, yet most individuals with severe brain injuries suffer some sort of memory impairment. Memory impairment requires that an individual structure his or her life in certain ways so that the impairment 263

by Dr. Martina O ' Conno r*

The incidence of brain injury following events such as motor vehicle accidents and falls has risen drastically over the past ten years. Various emotional and social sequelae deficits may, result from head injury. The specific area of brain injury being addressed in this article is cognitive disorders, a frequent consequence of brain injury. The term cognitive refers to the state of knowing or understanding. Brain injury often alters a person's ability to know or understand the world about him or her. Such individuals responding appropriately to events in the environment. They may be unable to organise and use their environment in an effective way. Impairments in cognition or thinking may prevent an individual from returning to work or independent living. Cognitive impairments can logically be described as discrete areas of disability (i.e., a memory deficit versus a visual processing impairment). It is important, however, to realise that different cognitive impairments often occur together and that they interrelate. For example, a person may present what appears to be a significant memory deficit when the underlying difficulty is actually a problem with attention and concentration. With this in mind, each of the different types of cognitive impairments will be described and the reader should remember that they are not necessarily distinct and separate disorders. often experience difficulty with information processing or with What Are Cognitive Disorders?

Dr. Martina O'Connor There are six broad areas of cognition that are commonly impaired following brain injury. These include disorders of

1. attention and concentration, 2. visual processing, 3. memory, 4. reasoning and judgement, 5. executive functions, and 6. communication. In addition, there is usually slowed mental processing such that an individual takes longer to think and respond than prior to the brain injury. Some people experience difficulty in all these areas, while others present with more focused disorders. Attention/Concentration Deficits An inability to sustain attention while carrying out a task is often a consequence of brain injury. Patients frequently complain of "losing track of what I'm saying" or "not being able to concentrate and follow the plot of a television programme." Attention problems may be present at an even more basic level where a person is unable to adequately attend and respond to simple stimuli, such as sounds or objects. This is more often seen in the early stages of