You are in: eMedicine Specialties > Physical Medicine and Rehabilitation > REHABILITATION PROTOCOLS Neuropsychological EvaluationArticle Last Updated: Dec 13, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
 
Author: Atif Malik, MD, Medical Director, Department of Pain Medicine, Washington Adventist Hospital Atif Malik is a member of the following medical societies: American Pain Society Coauthor(s): Megan E Turner, BA, St Mary's College of Maryland; Craig Sadler, Johns Hopkins University Editors: Patrick J Potter, MD, FRCP(C), Director of Spinal Cord Injury Program, Associate Professor, Department of Physical Medicine and Rehabilitation, Parkwood Hospital, Lawson Health Research Institute; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Richard Salcido, MD, Chairman, Erdman Professor of Rehabilitation, Department of Physical Medicine and Rehabilitation, University of Pennsylvania School of Medicine; Kelly L Allen, MD, Consulting Staff, Department of Physical Medicine and Rehabilitation, Lourdes Regional Rehabilitation Center, Our Lady of Lourdes Medical Center; Rene Cailliet, MD, Professor-Chairman Emeritus, Department of Rehabilitation Medicine, University of Southern California School of Medicine; Former Director, Department of Rehabilitation Medicine, Santa Monica Hospital Medical Center Author and Editor Disclosure Synonyms and related keywords: cognitive evaluation, brain function testing, IQ testing, intelligence testing, neuropsychological testing INTRODUCTIONSection 2 of 11
 
Neuropsychological evaluation (NPE) is a testing method through which a neuropsychologist can acquire data about a subject’s cognitive, motor, behavioral, language, and executive functioning. In the hands of a trained neuropsychologist, these data can provide information leading to the diagnosis of a cognitive deficit or to the confirmation of a diagnosis, as well as to the localization of organic abnormalities in the central nervous system (CNS); the data can also guide effective treatment methods for the rehabilitation of impaired patients. NEUROPSYCHOLOGICAL EVALUATIONSection 3 of 11
NPE is used to quantitatively measure the cognitive and behavioral capabilities of a patient. The data from neuropsychological tests can then be compared to normative data based on a number of different demographic criteria, including (but not limited to) age, race, gender, and socioeconomic status. NPE can include testing of intelligence, attention, memory, and personality, as well as of problem solving, language, perceptual, motor, academic, and learning abilities. Whom to Refer for NPE Neuropsychological testing provides diagnostic clarification and grading of clinical severity for patients with obvious or supposed cognitive deficits. Often these include patients with a history of any of the following problems:
INFORMATION OBTAINED FROM A NEUROPSYCHOLOGICAL REPORTSection 4 of 11
Neuropsychological tests are a series of measures that identify cognitive impairment and functioning in individuals. They provide quantifiable data about the following aspects of cognition:
ESTABLISHED APPLICATIONS OF NEUROPSYCHOLOGICAL EVALUATIONSection 5 of 11
Applications of NPE include the following:
Developmental disorders (eg, specific learning disabilities) require detailed assessment of cognition, academic achievement, and psychosocial adjustment for proper identification and as a guide to their management. Academic placement in special education and resource classrooms may be needed. NPE is of limited value in the following cases:
TECHNICAL ISSUES IN NEUROPSYCHOLOGICAL EVALUATIONSection 6 of 11
Results of an NPE must be considered in the context of the patient’s age, education, sex, and cultural background. These factors can affect test performance and limit the conclusions that can be drawn from the evaluation. In addition, issues such as reliability, validity, sensitivity, and specificity need to be considered. Large, population-based norms are available for relatively few measures. Those measures that do boast such norms, such as major intellectual and academic instruments, are of limited usefulness within a neuropsychological test battery. Ideally, patients should be compared with population-based norms, as well as with local norms and subgroup norms (ie, specific patient populations) to examine strengths and weaknesses. Significant gaps can be found in the normative data for all age, educational, and intellectual ranges; major deficiencies have also existed in the development of appropriate measures and norms for minority populations. TEST SELECTION: RELIABILITY, VALIDITY, SENSITIVITY, AND SPECIFICITYSection 7 of 11
Reliability refers to the consistency with which the same information is obtained by the test or set of tests. In the absence of intervening variables (eg, illness, injury, new learning), scores should remain stable even in the event of certain other variables, such as the following:
Validity refers to how well the test measures what it purports to measure. Does the test do what the examiner reports? Specific types of validity that may be questioned include the following:
Generally, findings suggest that performance on tests of motor functioning, speed of cognitive processing, cognitive flexibility, complex attention, and memory are related positively to real-world success. The amount of variance accounted for by cognitive factors alone, however, is typically quite small. Exceptions occur when comparisons made between results of formal NPE and real-world criteria are limited to very simple, very circumscribed, and/or very well-defined functions. Consequently, situational assessment is seen as a critical adjunct to neuropsychological assessment, especially at higher levels of cognitive functioning. Neuropsychological tests, with very few exceptions, were not developed with an eye toward ecologic validity. They were developed as indicators of brain function or dysfunction and generally were validated against neurosurgical, neurologic, and neuroradiologic data. Nevertheless, many tests have proven to be good predictors of future behavior and,therefore,havedemonstratedecologicvalidity. A qualitative process approach may improve the ecologic validity of the neuropsychological test battery. For example, testing the limits with measures of memory and executive functioning allows the examiner to understand better what a person can do under relatively ideal circumstances (not “what” but “how”). The test itself may have little demonstrable ecologic validity, but an accurate analysis and insightful interpretation of findings can be highly valid from an ecologic perspective. Sensitivity and Specificity Sensitivity refers to a test’s ability to detect the slightest abnormalities in CNS function and is a reflection of the test’s true positive rate, that is, its ability to identify persons with a disorder. Specificity refers to the ability to differentiate patients with a certain abnormality from those with other abnormalities or with no abnormality, as indicated by the true negative rate. A score on any test can be a true positive, false positive, true negative, or false negative.
For any evaluation, it is important to understand the rates of each of the 4 categories of results. The Stroop Test, for example, shows a relatively high level of specificity, with a high true negative rate (95.7%) and low false positive rate (4.3%). However, its sensitivity is questionable, as it has a relatively low true positive rate (30.8%) and high false negative rate (69.2%). Each test has strengths and weaknesses in its ability to detect a minimal CNS dysfunction (sensitivity) while being able to indicate a specific CNS dysfunction (specificity). Timed measures of cognitive and/or motor processing are generally sensitive to diffuse cerebral dysfunctions, although the specificity of these tests is generally poor to moderate. Measures of cognitive and/or motor processing that are not timed are generally less sensitive to diffuse dysfunctions but are very useful in identifying specific brain lesions. Overcoming Problems in Assessing Executive Function Perhaps the major drawback of NPE is the lack of ecologic validity when assessing executive functioning.1 NPE is generally conducted within calm and quiet testing rooms where the subject is clearly presented with the task to be completed, is informed of time restrictions, and is prompted to start and stop behaviors. Under these conditions, a subject may achieve a score that indicates no executive dysfunctions, although the individual may be particularly drained from the mental exertion. Completing tasks in the real world, however, requires several executive functions that are not tested in traditional NPE, including recognizing that a task must be completed, starting the task, switching tasks, adapting to changes, and stopping a task. However, changes in executive tests have dramatically increased the environmental validity of executive NPE. These changes include a growing emphasis on subject self-reporting of premorbid and postmorbid functioning, as well as premorbid and postmorbid reports from relatives and significant others in the subject’s life. Oftentimes, the self-report is not sufficient, for executive dysfunctions may be unknown to the subject, or else they may be ego-syntonic. A dramatic approach to overcoming the problem of ecologic validity appears in the Multiple Errands Test (MET). The test takes place in a shopping mall and requires the subject to conduct 3 tasks simultaneously, such as buying an item, meeting at a certain location at a certain time, and acquiring available information (such as a foreign currency exchange rate). This evaluation tests the subject’s abilities in planning, task initiation, and task switching, and even requires the subject to interact with other individuals in an effective manner. The test has shown considerable sensitivity and specificity, and subjects with neurologic deficits have performed considerably worse than controls. A version of this test has also been created for the hospital setting. MAJOR DOMAINS OF NEUROPSYCHOLOGICAL FUNCTIONINGSection 8 of 11
NPE is useful in measuring many categories of functioning, including the following:
EXAMPLES OF COMMONLY USED NEUROPSYCHOLOGICAL TESTSSection 9 of 11
Table 1. Examples of Commonly Used Neuropsychological Tests
OPEN SECTIONSection 10 of 11
REFERENCESSection 11 of 11
Neuropsychological Evaluation excerpt Article Last Updated: Dec 13, 2007 |
