The neuropsychological examination is the ultimate extension of the mental status examination (MSX). Neuropsychological testing involves the administration of standardized, validated, and reliable instruments to patients, usually under the supervision of a professional neuropsychologist. Referral for this testing is necessary in some patients who have undergone prior levels of MSX and require even more investigation. The mental status examiner must know when to refer for neuropsychological testing, the nature of the tests administered, and how to interpret the results. When this testing is obtained, the referring clinician must integrate and incorporate the results into the complete neurocognitive profile of the patient. This chapter addresses these points. Rather than a compendium of neuropsychological instruments, it is an overview of the neuropsychological process including common test batteries and the neuropsychologist’s report.
General Concepts of Neuropsychological Assessment
INDICATIONS AND ADVANTAGES
Neuropsychological assessment is a more “formal” process than mental status testing in the clinic or at the bedside. A neuropsychological assessment requires referral to a testing service, where trained neuropsychologists or psychometricians administer the tests in a standardized manner, minimizing environmental confounding variables. This referral should take place only after the clinician has taken a neurobehavioral history, made behavioral observations, and performed an MSX in the context of the clinical assessment. This clinical examination helps guide the choice of neuropsychological tests and procedures. Compared with most mental status tasks, neuropsychological tests have strong psychometric properties and have undergone both validation, often in different populations, and various forms of reliability testing. These instruments also have age- and education-based normative data, and, depending on the test, there may even be normative data for different sociocultural, linguistic, or ethnic groups.
There are a number of indications for referral for neuropsychological testing. In general, neuropsychological assessment is useful in distinguishing cognitive changes from normal and in characterizing the cognitive profile. Extensive and in-depth neuropsychological testing is best for the evaluation of mild or subtle impairments not detected on the clinic or bedside MSX, including mental status scales and inventories. This is possible because neuropsychological instruments allow for comparing the patient’s performance with others of his or her age and education. A score that is normal for one older or less educated individual may be very abnormal for a younger or more educated person who might have scored at ceiling on mental status screening. Consequently, patients who continue to complain of memory or other cognitive impairment, particularly those of high intellectual background, may need a referral for neuropsychological testing.
There are several other indications for a neuropsychological referral. One is when it is difficult to differentiate the cognitive manifestations of depression, psychosis, or other psychiatric syndromes from an underlying neurodegenerative or other brain disorder. Neuropsychological testing is of further value in quantifying the actual cognitive profile, including the patient’s strengths and weakness and degree of impairment. This information can be useful in addressing recovery, functional interventions, or rehabilitation programs. A comprehensive neuropsychological assessment can help in differential diagnosis when it provides the referring clinician with an analysis of the patient’s cognitive profile and its compatibility with different disorders. Without other clinical information, however, neuropsychological testing by itself cannot diagnose causative diseases or etiology. Finally, there is a role in neuropsychological assessment for capacity and competence assessments and in forensic and legal situations.
LIMITATIONS AND CONCERNS
There are often concerns about the time that it takes to complete and report the results of neuropsychological testing. First, a full assessment cannot be done when the patient is first seen by the referring clinician. Neuropsychological testing requires scheduling an extended period of time in a controlled setting. This testing may require 2 to 7 hours and more than one session, hence it is not practical for screening for mental status impairments. Testing for a prolonged period can be quite challenging for cognitively impaired patients, and there are “state” effects with increasing fatigue and waning cooperation. If the session is too long, this can result in worse performance on later tests. Another drawback to neuropsychological assessment is the delay in generating a report. They require a period of time for scoring and interpretation, which delays the availability of the report and makes it less useful when urgent clinical decision-making is needed. The neuropsychologist must assure the timely availability of the neuropsychological report for patient care and its integration with the referring clinician’s diagnosis and management.
Another area of concern in neuropsychological testing is the effects of demographic variables. The patient’s age, education, sociocultural or ethnic background, and sex can affect test performance. Very old age and very high or low educational levels have highly significant effects on these instruments. There are age-related changes in psychomotor speed, sustained and complex attention, retrieval of information, and other aspects of cognition (see Chapter 6 , Box 6.3). Neuropsychological tests have shown decreased performance on timed scores and “fluid” intelligence with aging, but relative preservation of verbal scores, narrative language, and established skills. After age, education has immense effects on how patients perform on these tests. Differences in test performance between those with grade school versus higher education can be profound, not only from differences in knowledge and familiarity with the content, but also because of differences in comfort in taking paper and pencil (and increasingly computerized) tests. Although normative data adjusted for age and education are a strength of neuropsychological assessment, age and education may still impact on the clinical significance of the testing results. Other variables, such as sex differences, appear negligible for most tests, but sociocultural, linguistic, and ethnic differences can be substantive. Neuropsychologists have attempted to construct “culture-fair” tests as much as possible and, for the most part, are aware of these variables in interpreting the test results.
A final concern is establishing the presence of change from a prior level of cognitive functioning. The interpretation of the results of these tests depends on an estimation of the patient’s estimated premorbid capabilities. Most often there are no prior or premorbid tests of cognition for comparison. The neuropsychologist must then estimate premorbid levels of functioning using patient characteristics, demographic formulas, or performance on select measures such as the North American Adult Reading Test (NAART). Most commonly, an estimate of premorbid status is derived from the patient’s prior educational and occupational attainment. Other measures of premorbid cognition include demographic formulas, such as the Barona Index, or formulas that combine demographic information with vocabulary or word pronunciation tests, such as the Vanderploeg equation. These formulas can generate a wide range of potential premorbid estimates, and a preferred method to assess premorbid cognitive level is the ability to read aloud and pronounce irregular words. The NAART consists of 50 irregular words of decreasing frequency, for example, “island” or “cellist,” whose pronunciation cannot be read aloud correctly using common phonemic rules and require familiarity and past educational exposure. The NAART, however, is based on language, a cognitive domain that is sensitive to brain injury, and estimates of premorbid cognitive ability from word reading ability may be unreliable in patients with dementia or other brain disorders.
Neuropsychological Batteries and Testing
There are many neuropsychological tests that are available (see Lezak et al, 2012), some of which are clearly similar or the source of mental status tasks described in prior chapters. The neuropsychological assessment usually groups tests into a battery that targets the major domains of cognition. Multiple cognitive functions can affect performance on each test, which increases the value of a battery approach with neuropsychological interpretation of the entire profile. There is no single, best neuropsychological battery of tests, but all batteries should aim to cover mental control/attention, language, memory, visuospatial skills, executive abilities, and other major cognitive domains ( Table 17.1 ). Batteries can be predominantly “fixed” or predetermined, or they may be “flexible,” with the neuropsychologist choosing the appropriate tests based on the clinical question and the features of the patient. Often, the battery has a fixed core of tests with additional flexible choices as deemed indicated.
| Domain | Neuropsychological Test |
|---|---|
| Attention and Fundamental Functions | WAIS subtests—Digit Span within Working Memory Index Trail Making-A and the Processing Speed Index (also executive) (Continuous Performance Test, Digit Vigilance Test, Paced Auditory Serval Attention Test, others) |
| Language and Speech | Boston Naming Test Controlled Oral Word Association Test (“F-A-S”); semantic verbal fluency Aphasia Test (e.g., Boston Diagnostic Aphasia Examination, Multilingual Aphasia Examination, Wechsler Test of Adult Reading, others) |
| Memory and Semantic Knowledge | Wechsler Memory Scale versions California Verbal Learning Test (and other supraspan word learning tests such as the Rey Auditory Verbal Learning Test, Hopkins Verbal Learning Test Rey-Osterrieth Complex Figure Test Delayed Recall (Rivermead Behavioral Memory Test, Test of Memory Malingering, others) |
| Constructional, Perceptual, and Spatial Abilities | Rey-Osterrieth Complex Figure Test Copy WAIS subtests—Block Design within Perceptual Reasoning Index (Hooper Visual Organization Test, Bender Visual Motor Gestalt Test, others) |
| Praxis and Related Cortical Movement Abnormalities | Halstead-Reitan Neuropsychological Battery (HRNB) subtests (e.g., such as finger oscillation (tapping), grooved pegboard, tactile performance) |
| Calculations and Related Functions | WAIS subtests—Arithmetic within Working Memory Index |
| Executive Operations and Attributes | Wisconsin Card Sort Test Trail Making-B Controlled Oral Word Association Test (i.e., “F-A-S”) (Range of other available tests include the Stroop Test discussed in Chapter 13 , Delis-Kaplan Executive Functions System, HRNB Category Subtest, Tower of London, Figural Fluency Tests, others) |
| Behavior (emotion/personality/psychopathology) | Minnesota Multiphasic Personality Inventory-2 (Milton Clinical Multiaxial Inventory, Thematic Apperception Test, others) |
| General | (Wide Range Achievement Test, Shipley Institute of Living Scale) |
Historically, the two best-known fixed batteries for brain disease are the Halstead-Reitan Neuropsychological Battery (HRNB) and the Luria‐Nebraska Neuropsychological Battery (LNNB). In addition to the trademark category test (discerning the principle embedded in arrangements of figures and shapes), the HRNB includes many “neurophysiological” tests that are not traditional paper and pencil tests. Among these are the tactual performance test (placing different shaped blocks without vision), seashore rhythm test (judging the similarity of auditory rhythmic pattern), speech sound perception test (identifying spoken nonsense syllables), finger oscillation (tapping) test (tapping a mechanic counter as fast as possible with index finger), sensory perceptual and lateral dominance examinations, and the frequent addition of the grooved pegboard test and hand grip strength on a dynamometer. The entire HRNB is not based on current knowledge of the organization of behavior in the brain and is not a sensitive battery for the detection of mild cognitive deficits or for brain-behavior localization. Nevertheless, some of these HRNB subtests have proven useful and may be incorporated in flexible batteries. The 2- to 3-hour LNNB was a product of brain-behavior observations made by Alexander Luria and consists of 269 brief items that assess motor, rhythm, tactile, visual, oral language, writing, reading, arithmetic, memory, and intellectual functions. An additional scale consists of the items drawn from the other scales found to be maximally sensitive to brain dysfunction, and there are right and left hemisphere scales. The LNNB is open to errors of omission, issues of reliability and validity, and lack of normative data, and is only used by a small group of neuropsychologists.
Most commonly used batteries have a core base on the Wechsler Adult Intelligence Scale (WAIS) plus a number of other popular tests that cover the major cognitive domains, including some subtests of the HRNB. The current version of the WAIS (WAIS-IV; WAIS 5 pending) has 10 core subtests, which yield the Full Scale IQ, and five supplemental subtests. The WAIS-IV has four indices: verbal comprehension (information, similarities, vocabulary), working memory (arithmetic, digit span), perceptual reasoning (block design, matrix reasoning, visual puzzles), and processing speed (digit-symbol coding, symbol search). Although the WAIS was not original designed for the assessment of cognitive disorders, the extensive experience and large normative data with the WAIS provides a basis for interpreting the subtests in relation to cognitive changes. The pattern of performance on subtest scores can be informative as to the type of disturbance. Furthermore, the verbal comprehension and perceptual reasoning indices yield a General Ability Index, which is a measure of cognitive abilities that is less vulnerable to impairments of processing speed and working memory.
To the WAIS core, neuropsychologists can complete the battery from a large array of available neuropsychological tests ( Table 17.2 ). Although there are likely regional variations, by and large, there is some consistency in the choice of additional tests. For coverage of the cognitive domains of memory and language, among the most popular are the Wechsler Memory Scale-III (WMS-III), California Verbal Learning Test (CVLT), Boston Naming Test (BNT), and Controlled Oral Word Association Test (COWAT). The WMS-III includes 18 subtests, such as paired-associate learning and logical memory, and yields information about various kinds of memory and learning processes. The WMS-III provides a comprehensive assessment of memory with subtest scores and summary memory index, but it may take an hour to administer. The CVLT is a supraspan auditory learning test that measures recent verbal memory and new learning (see another supraspan test, Chapter 9 , Tables 9.1 and 9.2). A list of 16 or 9 words (depending on CVLT version) that are repeatedly rehearsed by the patient is followed by an interference task. After a 20-minute delay, the patient must recall the words freely and through multiple choice. The BNT is a sensitive confrontational naming test, which presents a series of 60 line drawings of increasing naming difficulty. Because patients may misname the line drawings due to visuospatial patterns, the BNT test includes conceptual and phonemic cueing trials. The COWAT asks the patient to say as many words as they can think of in 1 minute that begin with a given letter of the alphabet (usually “F”, “A”, and “S” in English), excluding proper nouns, numbers, and the same word with a different suffix, for example, shout, shouted, shouting. The score is the total number of words generated in all categories and stratified by age and years of education ( Table 17.3 ). Related category fluency asks the patient to say as many words as they can think of in 1 minute for a given category, for example, animals, vegetables, or tools.
| Test Name | Description |
|---|---|
| Bender Visual Motor Gestalt Test | Classic test of visual-perceptual and visual-motor functioning |
| Boston Diagnostic Aphasia Examination | Extensive assessment of language functions |
| Boston Naming Test | 60-item confrontational naming test (“mini” version has 15 items) |
| California Verbal Learning Test | Supraspan auditory learning test described in text |
| Continuous Performance Test | Test of sustained attention |
| Controlled Oral Word Association Test | Verbal fluency based on number of words that start with a certain letter (“F-A-S”) |
| Delis-Kaplan Executive Function System | Series of tests that assess a number of executive functions, such as abstraction and deductive reasoning |
| Digit Vigilance Test | Attention measured by visual tracking |
| Figural Fluency Tests | Generation of as many figures as possible within time and spatial constraints |
| Finger Oscillation Test | HRNB finger tapping test for motor speed and agility |
| Grooved Pegboard | This test involves putting grooved pins in pegboard for fine motor ability |
| HRNB Category Test | Executive task that involves discerning the principle embedded in arrangements of figures and shapes |
| Halstead-Reitan Neuropsychological Battery (HRNB) | Original neuropsychological battery for brain disease, described in text |
| Hooper Visual Organization Test | Visual integration of “cut up” pictures, like a visual puzzle |
| Luria‐Nebraska Neuropsychological Battery (LNNB) | Alternate neuropsychological battery for brain disease, described in text |
| Minnesota Multiphasic Personality Inventory-2 (MMPI-2) | Assesses personality and psychopathology with validity scales for effort and malingering |
| Millon Clinical Multiaxial Inventory | Alternative to MMPI-2 |
| Multilingual Aphasia Examination | Alternative to Boston Diagnostic Aphasia Examination |
| North American Reading Test (NAART) | Irregular word reading test, described in text |
| Paced Auditory Serial Attention Test | Difficult serial addition tasks for testing attention and concentration |
| Repeated Battery for the Assessment of Neuropsychological Status (RBANS) | Brief screening and monitoring battery composed of five domains and multiple subtests, described in text |
| Rey Auditory Verbal Learning Test | Original supraspan verbal learning task and an alternative to the California Verbal Learning Test |
| Rey-Osterrieth Complex Figure Test | Complex figure copy and delayed recall, described in text |
| Rivermead Behavioral Memory Test | Excellent memory test for everyday real-life memory |
| Shipley Institute of Living Scale | General abilities tested by vocabulary knowledge and abstract sequential patterns |
| Stroop Test | Word, color, and color-word reading for response interference |
| Tactual Performance | Tests tactile perception, spatial memory, and speed of motor performance |
| Test of Memory Malingering | Visual recognition test to detect malingering in memory |
| Thematic Apperception Test | Projective test for assessing personality and emotions |
| Tower of London | Assesses strategy in alternate ring placements on pegs, an executive task |
| Trail Making Tests A and B | Visual sequencing tests, described in text |
| Semantic (Word) Fluency Test | Verbal fluency for categories, such as animals, vegetables, or tools |
| Wechsler Adult Intelligence Scale-III | The WAIS-III is a common core test for most neuropsychiatric batteries. The subtests are very informative. The WAIS-III is described in text |
| Wechsler Memory Scale-III | Comprehensive memory test with highly informative subtests, described in text |
| Wechsler Test of Adult Reading | Reading test estimates of premorbid cognitive ability, alternative to NAART |
| Wide Range Achievement Test | General assessment in multiple areas reflective of premorbid achievement, also an alternative to NAART |
| Wisconsin Card Sort Test | Executive set shifting test, described in text |
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
