SPECIAL ISSUES IN

NEUROPSYCHOLOGICAL ASSESSMENT

OVERVIEW

A

n almost sure sign of the maturity of neuropsychology as a discipline is the emergence of an increasing number of clinical subspecialties refl ect- ing the variety of settings in which practitioners fi nd themselves based.

Although undoubtedly many neuropsychologists would still consider themselves generalists, an increasing number of clinicians have established narrowly focused niches requiring specialized knowledge and skills. Whereas pediatric and geriatric neuropsychology and forensic neuropsychology are emerging as bona fi de sub- specialties, clinicians who work primarily in psychiatric settings, cross-cultural or bilingual settings, or settings with patients who suffer from signifi cant primary or sensory disabilities must develop expertise in resolving problems that have the potential to severely limit the validity of the available array of testing instruments.

In this chapter, we present some of the issues and concerns a clinician needs to address when asked to assess some of these specialty populations.

ASSESSMENT OF CHILDREN

A number of issues are critical in the neuropsychological assessment of children.

Rapid Reference 6.1 summarizes the factors that complicate the interpretation of neuropsychological test results in children. First and foremost, the assessment of children is complicated by the fact that children are evolving in their physical and emotional development and in the knowledge structures needed to perform the cognitive functions that must be assessed. Such abilities as attention, lan- guage, memory, self-control, and even motor skills rapidly change from birth to adolescence, refl ecting the process of neural development occurring in those years. Although certainly normal developmental trends have been documented, the rates of cognitive development may vary widely, particularly in the fi rst 5 or 6 years of life. In some cases, a few months or even weeks can make the difference

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in the emergence of a function or ability such as a motor skill or language. While undergoing biological development, children are exposed to environments that present the opportunity to acquire new information and skills. Such exposure may also vary tremendously across individuals. Adult neuropsychological tests are de- signed to use a standard range of exposure to common facts and information. For example, verbal memory tasks are often designed using words that are controlled for frequency of appearance in written materials and degree of interrelationship or associative strength. The statistics used to compute these variables known to affect memory performance are based on reading materials available to adults and may not represent similar levels of diffi culty to a child. Basic skills (e.g., reading, writing, following instructions, and sitting still for an interview) that are usually developed during the elementary school years may not be established in younger children. For these reasons, in most cases it is not suffi cient to collect norms for children using the materials developed for an adult test. A test with items that al- low for valid neuropsychological predictions and good sensitivity in a teenager or young adult is often inappropriate for use even with older children. A test that is

Rapid Reference 6.1

Complicating Factors in the Neuropsychological Assessment of Children

• Children are evolving in their physical and emotional development and in their knowledge structures needed to perform the cognitive functions that must be assessed.

• Children differ in their exposure to environments that allow opportunities to acquire new information and skills.

• The database of lesion-based studies for children is far more limited than that available for adults.

• The presence of a defi cit in a child is not necessarily associated with the same lesions producing the same defi cit in an adult.

• The rate of physiological verifi cation in most clinical settings is low for developmental or academic diffi culties in children.

• Parents may not be accurate informants about their child’s academic performance.

• On average, children may have greater diffi culties than adults sitting through lengthy evaluations because of age-dependent distractibility and fi dgety behavior.

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SPECIAL ISSUES IN NEUROPSYCHOLOGICAL ASSESSMENT 179

sensitive and specifi c to the effects of brain dysfunction in older, verbally mature children is usually of no use in the assessment of brain dysfunction in preverbal children or even preschool children.

Test developers can be sensitive to these issues, and numerous tests are de- signed specifi cally for use with developing children (e.g., the NEPSY-II). Some developers have attempted to design tests that appear to share content and con- struct validity with an analogous adult test. The best examples of such tests are again those used to assess IQ, with the Wechsler series the most explicitly de- signed to provide normative and construct continuity from preschool children to adults.

An even more diffi cult issue confronting the pediatric neuropsychologist is fi guring out how these materials may be used to assess brain functions in chil- dren. Although adult neuropsychology—for better or worse—stands on a large accumulated database of lesion-based studies allowing for the development of numerous hypotheses about brain organization in adults, such data are far less available for children. A large literature examines neuropsychological test perfor- mance in children with developmental disorders and various forms of acquired brain disorders; however, the diseases and events that most commonly produce the focal lesions that produce effects on behavior and have been studied in adults are far less common in children. Although it is tempting to draw an analogy be- tween similar behavioral disturbances that may be exhibited by both children and adults during the course of a neuropsychological examination, these behavioral disturbances are not necessarily comparable. A particular test result may refl ect interactions between changes in normal biological development, incomplete ac- quisition of knowledge, and the focal effects of a lesion. Neuropsychological data should not be used to make predictions for children in the same way as for adults unless specifi c data warrant such predictions. The presence of a change in language, memory, or executive func- tions in a child is not necessarily as- sociated with the same lesions that produce such defi cits in adults.

Although neuropsychologists are often asked to evaluate the effects of documented brain damage in children, the most common referral question for clinicians who assess young patients concerns the evalua- tion of developmental or academic diffi culties when no clear-cut event

C A U T I O N

Similar behavioral disturbances exhibited by an adult and a child may not mean the same thing. A particular test result may refl ect interactions between two or more of the following: changes in normal biological development, incomplete acquisition of knowledge, and the focal effects of a lesion.

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or disease state can be physiologically verifi ed. In these cases, the choice to use neuropsychological test data to make predictions about the presence of a struc- tural focal defi cit should be made with great care and conservatism. The data supporting such assertions are in many cases nonexistent and show a very low rate of physiological verifi cation in most clinical settings. The issues surrounding how such data should be used are complex and beyond the scope of this text. The reader is thus cautioned and advised to consult specialty pediatric neuropsychol- ogy texts to learn what scientifi cally verifi able information can be derived from neuropsychological tests in a pediatric population.

Neuropsychological batteries with children typically include some evaluation of educational achievement, particularly in the domains of reading, spelling, and arithmetic processes. Tests such as the Wide Range Achievement Test—Fourth Revision (WRAT-4; Wilkinson & Robertson, 2006); the Wechsler Individual Achievement Test—Second Edition (WIAT-II; Wechsler, 2001a); the Woodcock–

Johnson III Normative Update (WJ III NU; Woodcock, McGrew, & Mather, 2007); and the Kaufman Assessment Battery for Children, Second Edition (Kaufman & Kaufman, 2004a); or the Kaufman Test Educational Achievement, Second Edition (Kaufman & Kaufman, 2004c) might be included. These tests are described in Chapter 4. The clinician should also have detailed information about the child’s academic performance. Note that in many cases parents may not be accurate informants about their child’s academic performance. The neuropsy- chologist should obtain recent school records whenever possible, especially any special education records. When the clinician is asked to sort out the effects of a recent neurological illness and longer standing abilities, it may be necessary to evaluate the entire school record to plot the overall course of the child’s cognitive development.

A common diagnostic question for which children are increasingly referred for neuropsychological evaluation is the presence of attention-defi cit/hyperactivity disorder (ADHD). Although children who obtain this diagnosis sometimes per- form poorly on neuropsychological tests, these measures have not been shown to be useful in making the diagnosis itself because of a lack of specifi city. The diagnosis of ADHD is currently best made based on behavioral description and history using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition—

Text Revision (DSM-IV-TR; American Psychiatric Association, 2000) symptom cri- teria with the goal of observing consistent patterns of behavior across various environments. In the case of ADHD, the clinician should obtain appropriate data from the child’s parents and teachers about behavior patterns at home, at school, and, if possible, in other relevant settings. Several standardized inventories are de- signed for such purposes, including the Attention Defi cit/Hyperactivity Disorder

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SPECIAL ISSUES IN NEUROPSYCHOLOGICAL ASSESSMENT 181

Test (Gilliam, 1995), the Conners’ 3rd Edition (Connors, 2008), and the Behavior Assessment System for Children, Second Edition (Reynolds & Kamphaus, 2004).

More information about these measures can be found in Chapter 4. Neuropsy- chological assessment, although not diagnostic of ADHD, can, of course, pro- vide evidence (or lack, thereof) of the interference of disturbed attention on performance.

Maintaining cooperation and motivation is particularly important in children, who typically cannot sit and attend to testing as long as most adults. Signs of fatigue, wandering attention, and dis-

tractibility must be monitored con- stantly when children are being tested.

Extraneous motor activity and some distractibility may be age appropriate and can potentially undermine the re- liability of test performance, even in relatively normal children. In the case of some developmental abnormali- ties and conditions such as ADHD, distractibility may undermine a clini- cian’s ability to obtain reliable test re- sults that can be used for any purpose other than confi rming the presence

of the defi cit in maintaining attention. In these cases, test sessions may have to be shortened considerably, with the provision of breaks and opportunities to move around before testing is resumed.

Rapid Reference 6.2 offers some general considerations necessary for the neu- ropsychological assessment of children. The Annotated Bibliography at the end

C A U T I O N

Neuropsychological tests have not been shown to be useful in making the diagnosis of ADHD. The diagno- sis of ADHD at this time is best made on the basis of behavioral description and history using the symptom crite- ria specifi ed in DSM-IV-TR. Support for the interference of attentional problems on cognitive tasks may be- come available in neuropsychological evaluation, however.

Rapid Reference 6.2

General Considerations in the Neuropsychological Assessment of Children

• Select tests appropriate to the child’s age and validated for the desired assess- ment purpose.

• Gather birth, developmental, medical, psychological, social, and family history from the child’s parent or caregiver.

• Corroborate history by requesting and reviewing available records.

(continued)

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of this book includes several texts useful in the neuropsychological assessment of the child.

BILINGUALISM AND CULTURAL ISSUES

The vast majority of neuropsychological tests in use today were originally pub- lished in English and normed in the United States. Although some tests originated in other languages such as French (e.g., the Rey Auditory Verbal Learning Test; Rey, 1958) and Italian (the Token Test; De Renzi & Vignolo, 1962), these instruments have been translated into English and renormed using an American population to attain widespread use in the United States or Canada. Performance on these tests depends not only on some mastery of the American dialect of English but also on exposure to experiences and customs that are intrinsic to Western culture. This should not be surprising because the tests are products of the cultural origins and language of their developers. These tests are not necessarily invalid when used outside the cultural and linguistic context in which they are developed. One cannot assume, however, that neuropsychological tests developed in the United States and normed on primarily monolingual English-speaking Americans will retain similar levels of sensitivity and specifi city when translated and applied outside this culture.

Although an increasing number of neuropsychological tests have been translated and renormed to be used with native speakers in their countries of origin, few data address the critical issue of using English-based tests on individuals who are bilin- gual and who live a signifi cant portion of their lives speaking languages other than English. These individuals may appear conversationally fl uent in both languages, but they may not have comparable levels of exposure as demographically similar

• Plan the testing session(s) to accommodate the reduced attention span and fi dgetiness of some children, and keep distractions to a minimum.

• Work to make the child feel at ease during testing.

• If necessary, especially for very young children, allow a parent to be present at the beginning of an evaluation but avoid administering standardized tests before the child acclimates.

• Encourage the child to be as cooperative as possible.

• Provide encouragement and praise for effort.

• Know the tests to be administered to allow the session to progress smoothly.

• Remember to be cautious when interpreting the defi cits seen in children. The defi cits seen in children may not occur for the same reasons they do in adults.

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SPECIAL ISSUES IN NEUROPSYCHOLOGICAL ASSESSMENT 183

monolinguals to information in either language. The data that exist for these populations are contradictory and allow little consistent comparison of similar tests across different bilingual groups. Some data do suggest that some Spanish- speaking bilinguals may be disadvantaged in performance on some tests (Navarrete, 1999), and some bilingual Chinese speakers may be advantaged on others (Hsieh

& Tori, 1993). Kaufman (1994) presents data indicating that a large majority of Hispanic children, even those who speak English adequately, showed large differ- ences on the WISC-III between their Verbal Scale IQs (VIQs) and Performance Scale IQs (PIQs) in favor of their PIQs. These studies concerning different kinds of bilingual individuals taking different kinds of tests also vary in subject selec- tion procedures so that the range of age, education, and socioeconomic status of subjects cannot even be compared across studies. Tests that are translated into a second language may work appropriately when used among native monolingual speakers of the language but may not correct the potential inaccuracies that can occur in testing bilingual individuals. Even though the latest Wechsler Intelligence Scales for children and adults no longer contain the VIQ-PIQ structure of previ- ous Wechsler Intelligence Scales, many subtests have signifi cant language demands that could be expected to infl uence the performances of bilingual individuals.

Even when language is not the primary issue, data suggest that an individual’s ethnicity may in itself affect performance on neuropsychological tests. Although it is not clear why members of some groups score more poorly (or at superior levels) than others, a signifi cant number of studies demonstrate ethnic group differences on IQ, language, and achievement tests, even when individuals tested are monolingual English speakers. These differences can potentially affect both the sensitivity and specifi city of the neuropsychological tests that have only been normed on the general majority population. Because of the greater likelihood of false positive classifi cations of impairment for individuals who are members of ethnic groups with tests scores lower than the population for whom the norms are obtained, it is becoming increasingly important to obtain separate norms for some of the larger ethnic groups in the United States. The issue of separate norms is particularly important for African Americans, who constitute a large ethnic minority group in the United States. African Americans frequently perform more poorly on some neuropsychological tests than the majority population. The rea- son for this is not clear, but this group difference has evoked a range of responses, including a justifi able sensitivity to the political implications of such differences.

Social and political arguments have been made both for and against the develop- ment and use of separate norms for African Americans; however, most admit that at least under current circumstances, separate norms are critical to ensure the accurate interpretation of neuropsychological test results.

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Flanagan and Kaufman (2009) present the Culture–Language Matrix (Flana- gan, Ortiz, & Alfonso, 2007) as a tool clinicians can use to evaluate the infl uence of

language and culture on WISC-IV test performances. The Culture–Language Matrix has the advantage of inform- ing the clinician about the degree of linguistic demand and cultural loading for the WISC-IV subtests allowing an analysis of performances on subtests with the lowest cultural loading and linguistic demand (i.e., Matrix Reasoning and Cancellation) versus those with the highest cultural loading and linguistic demand (i.e., Information, Similarities, Vocabulary, Comprehension, and Word Reasoning) so that any systematic effect

can be determined and taken into ac- count in the interpretation of the test results. In Appendix D of Essentials of Cross-Battery Assessment, Second Edition, Flanagan, Ortiz, and Alfonso (2007) offer test-specifi c culture–language matrices for multiple standardized norm-referenced tests, including the WAIS-III, WISC-IV, WPPSI-III, WJ III, SB5, KABC-II, KBIT-2, RIAS, CMS, and WMS-III (see Chapter 4 for these tests), to determine the infl uence of English language profi ciency and degree of accultura- tion on test performances. The Annotated Bibliography at the end of this book describes other textbooks that are also useful to consult when bilingual and cultural issues affect a neuropsychological evaluation.

GERONEUROPSYCHOLOGY

Adults over age 65 are the fastest growing population requiring neuropsycho- logical assessment. Even 25 years ago tests were rarely published with norms for adults in their 70s and older. Today, however, many tests are published with norms for adults aged between 70 and 90 years. This change refl ects the general demographic shift caused by the large swelling in birth rate that occurred after World War II and the slow but continuous increase in life expectancy since that time. Projections indicate that by the year 2020 the United States will have almost 54 million adults over the age of 65. Furthermore, the population over 75 is projected to be close to 23 million, and the population over 85 is projected to ap- proach 10 million (Centers for Disease Control, 2005). As age increases, so does

DON’T FORGET

Neuropsychological tests may under- estimate language-based and other cognitive abilities in bilingual children and adults.

DON’T FORGET

Neuropsychological test results may not generalize across different cultures.

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