Neuropsychology is the study of brain-behavior relationships. Clinical neuropsychological assessment is the application of this knowledge to evaluate and to intervene in human behavior as it relates to normal and abnormal functioning of the central nervous system. Neuropsychology involves assessing such areas as memory, abstract reasoning, problem solving, spatial abilities, and the emotional and personality consequences of brain dysfunction. The result of a neuropsychological assessment is ideally a clear, coherent description of the impact that brain dysfunction has had on a person's cognitions, personality, emotions, interpersonal relationships, vocational functioning, educational potential, and ability to enjoy life. The practical importance of this knowledge consists of assisting with case management, rehabilitation planning, and the monitoring of progress, as well as the enlarging of the discipline's research base. Over the past 50 years, clinical neuropsychology has evolved from and represented a synthesis of psychometric testing, clinical psychology, and behavioral neurology. However, it is also distinctly different from the emphasis in neurology: Whereas neurologists might explain how the brain is functioning, the neuropsychologist assesses how the person is functioning as a result of changes in the brain. The major purposes of neuropsychological assessment are to provide answers related to the following four areas: (1) differential diagnosis, (2) treatment planning, (3) rehabilitation, (4) legal proceedings. Differential diagnosis most typically occurs within medical contexts when practitioners are asked to discriminate between neurological disorders and psychiatric disorders. For example, a neurologist with a patient having unexplained seizures might wish to know whether the patient's psychological characteristics are consistent with conversion disorder. This information would then be used to help decide whether the patient should be referred for further medical evaluation or for psychotherapy. The most frequent referral within a general psychiatric context is for assessment of the possible presence of organic functioning as a result of changes in the brain. An invaluable contribution of neuropsychological assessment is detecting and evaluating cerebral dysfunction in the absence of clear anatomical evidence of alterations. Such a condition is most likely to occur following exposure to neurotoxic substances, cognitive decline associated with substance abuse, the behavioral impact of cardiac surgery, and cognitive changes associated with chronic obstructive pulmonary disease. An increasingly important type of differential diagnosis is determining whether an older person who presents with memory complaints is suffering from the early signs of dementia or is merely experiencing the cognitive disruption of depression. Treatment planning involves various decisions related to the nature and the extent of brain dysfunction. A person who had a stroke might consider returning to work. If the person does decide to return to work, he or she might be helped by the development of some awareness regarding the likely job complications that may occur due to the presence of specific mild deficits. Another patient might have had a mild head injury and is experiencing a variety of psychosocial complications. Assessment might focus on his or her readiness for psychotherapy by considering awareness of deficits, motivation to change, and capacity for abstract reasoning. Another patient with a more serious but moderate head injury might need to be evaluated to determine capacity for self-care. Patients with brain dysfunction are frequently considered for neuropsychological rehabilitation. This typically involves a careful consideration of their relative strengths and weaknesses, thereby enabling rehabilitation practitioners to ideally capitalize on the patients' strengths and improve their weaknesses. Unless these areas are clearly evaluated, rehabilitation efforts may be ineffective. For example, patients with poor awareness of their deficits might be placed in a module to improve their attention. Because they are only minimally aware of their deficits, they might be poorly motivated, which could result in little improvement. Another patient might be experiencing a number of brain-related personality changes. This person's rehabilitation might include working with the family to accommodate these changes. A school-age child who is experiencing learning difficulties would require evaluation to more fully understand the nature of his or her difficulties. Once these difficulties are understood in more detail, special education teachers can focus their interventions around the child's difficulties. Finally, monitoring a patient's progress as she or he works through and is later discharged from a program is an important role of neuropsychology. This monitoring role might have important implications for the patient, but it would also help researchers to more fully evaluate specific types of programs for different types of patients. Neuropsychologists have become increasingly involved in legal proceedings. One of their primary roles has been to document the causes, nature, and severity of brain dysfunction in personal injury cases. For example, litigation might stem from damage allegedly caused by a car accident in which the injury was caused by another driver who has been found to be at fault. Alternatively, a large company might not have taken appropriate safety measures to protect employees from exposure to neurotoxic substances. A neuropsychologist might be requested to assess the possible presence and extent of brain dysfunction as well as the patient's potential for recovery. Another scenario might involve neuropsychological assessment to determine the capacity of patients to defend themselves during legal proceedings. Another patient might have committed a violent crime and need to be assessed to determine whether there were mitigating organic factors such as epilepsy that might have influenced the patient's actions. These four areas demonstrate the wide variety of information related to neuropsychological assessment. It should be apparent that such evaluations involve considerably more than just psychological testing. The competent neuropsychologist needs to draw on a wide variety of knowledge areas including abnormal psychology, psychological testing, functional neuroanatomy, neurological disorders, disability issues, community resources, and vocational and educational options. Competent evaluations also involve taking a flexible, creative, problem-oriented approach toward working with individual clients. The field of neuropsychological assessment has traditionally been organized around the following perspectives: specialized neuropsychological tests, domains of functioning, types of disorders, or a functional assessment of the different lobes of the brain. Each of these facets or angles of approach has various strengths and weaknesses. The emphasis in this book is on developing a working knowledge of the most frequently used neuropsychological tests. This approach is familiar to most psychologists, provides relative ease of learning, and can potentially cover a wide band of areas. The danger is that practitioners learning neuropsychology from such a test-oriented focus might rely too much on tests rather than on having the tests function as tools to assist in solving client-related problems. Thus their reports might end up being "test driven" rather than "person driven." Efforts are made throughout the book to correct for this by emphasizing the importance of integrating information from a wide variety of sources, including history, behavioral observations, and medical records. In addition, there is an emphasis on refining the referral question(s) to assist in making decisions related to a client. Further emphasis is given to presenting data according to functional domains (memory, executive functions, etc.) as well as to providing answers to specific referral questions. It is believed that this emphasis will keep clinicians focused on people and their lives rather than on the tools-tests used to understand these people. Clinicians should also broaden their competencies by becoming familiar with other perspectives of clinical neuropsychology. In particular, client functions, and the tests that measure these functions, can be organized according to different domains, the most important of which are memory and learning, mental activity (attention and processing speed), visuoconstructive abilities, verbal functions and academic skills, motor performance, executive functions, and emotional status (see Groth-Marnat, 1999; Lezak, 1995). This approach has the advantage of organizing a client's functions into logical groupings which can relate both to specific tests as well as to client problems. Accordingly, this domain-based approach is also emphasized throughout the book. Test descriptions and test selection focus on functional domains as do issues related to treatment planning and the format of psychological reports. One perspective is to focus either on knowledge of specific types of clinical syndromes or on different types of disorders, along with how these syndromes or disorders might be assessed. For example, various syndromes might include aphasia, alexia, agraphia, acalculias, body scheme disturbances, agnosia, or neglect (see Heilman & Valenstein, 1993). Information might also be organized according to the considerations that are relevant for such disorders including head injuries, learning disabilities, epilepsy, stroke, or exposure to neurotoxic substances. Through an understanding of these syndromes-disorders, a clinician can be guided through the interview-and-assessment process. In some instances, the nature of the disorder is emphasized above and beyond issues related to measurement. In other cases, specialized batteries have been developed for assessing specific syndromes. This is especially true for aphasia, dementia, and neurotoxicity. Yet another approach is to understand the client and the assessment procedures according to the different lobes of the brain (see Kolb & Whishaw, 1996; Walsh, 1991). Knowledge essential for this approach is understanding the types of symptoms that might emerge from damage to a particular lobe as well as the procedures used to assess for these symptoms. For example, parietal lobe injury frequently results in such difficulties as deficits in naming things from touch (tactile agnosia), difficulty constructing (constructional apraxia), disorders of drawing, and right-left confusion. Specific tests to measure these functions might include tests of drawing (Bender Visual Motor Gestalt Test, Rey-Osterrith Complex Figure Test), ability to recognize objects from touch (Tactual Performance Test, Sensory Perceptual Examination), or measures of the ability to distinguish right from left. Competent neuropsychological assessment requires a working knowledge of each of the perspectives mentioned previously.

GARY GROTH-MARNAT, PhD. is a clinical psychologist, an internationally recognized expert on psychological assessment, and author of the bestselling Wiley text Handbook of Psychological Assessment, Third Edition.

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