Overview

Neuropsychological assessment has become increasingly important in inpatient settings since the expansion of brain injury rehabilitation programs in the 1980s.^84,309 Patients with brain injury or other neurologic conditions (e.g., stroke, multiple sclerosis) now comprise a large segment of the rehabilitation population, as do older adults with nonneurologic impairments who also show cognitive effects of normal aging that should be considered in rehabilitation planning.²¹⁹ Inpatient screening by the rehabilitation psychologist is a standard and important component of the care of these individuals, consistent with best practices guidelines advanced by the U.S. Department of Veterans Affairs³⁷⁸ and endorsed by the American Academy of Physical Medicine and Rehabilitation.³ Outpatient assessments of neuropsychological functioning are also critical for continuing treatment planning, making educational/vocational recommendations, and tracking outcome.³³⁶

Inpatient Neuropsychological Assessment

Early rehabilitation neuropsychology assessments can take different forms, depending on the patient’s mental status. For patients at a low level of consciousness, initial (and serial) assessment with brief screening measures (e.g., Coma/Near Coma scale,³⁰⁰ Orientation Log¹⁸⁰) can identify subtle changes in cognitive functioning that are not apparent from casual observation. Such early information regarding recovery of orientation can also help predict functional outcomes at discharge.⁴¹²

For individuals at Rancho Los Amigos Scale VI and above, neuropsychological testing early in acute rehabilitation provides a baseline against which changes in functioning over time can be documented. Testing during this phase also provides an early indication of patients’ potential for improvement over time. Early cognitive screening can predict later need for supervision¹⁶² and functional outcomes.^98,337 It should also be noted that performance on neuropsychological testing after the resolution of posttraumatic amnesia has been associated with return to productivity (employment or attending school) at 1-year postinjury.^{32,73,178,320} Neuropsychological assessment results during this period more directly predict functional outcomes among individuals with TBI than does injury severity.^51,271 Information from baseline testing can also be incorporated into education for family members to help them understand the sources of certain troubling behaviors (e.g., neglect, impulsivity), and to begin to envision the range of possible outcomes and start to cope with potential long-term sequelae.

Neuropsychological testing of the fully oriented patient can be a vital component of rehabilitation planning and treatment. The resulting data document cognitive strengths and weaknesses that enable the rehabilitation psychologist to suggest useful strategies for promoting learning and fostering participation in rehabilitation, and to call attention to potential barriers to progress.³⁴⁴ Neuropsychological assessments involve the evaluation of fundamental skills (e.g., attention, information encoding), which underlie more complex behaviors that are the goals of other therapies (e.g., learning to use adaptive equipment). Armed with a map of the patient’s “cognitive landscape,” the rehabilitation psychologist can work with the team to develop intervention strategies for maximizing the patient’s success in acquiring the skills that are the goals of therapy.

In inpatient settings, rehabilitation psychologists identify neurobehavioral problems (e.g., depression, irritability, fatigue, restlessness) that are frequently reported after brain injury.³²⁷ These difficulties can impede participation and gains in rehabilitation,²⁹⁴ and they also have long-term functional implications.⁴⁸ Depression can result from neurologic changes,¹²³ adjustment-related issues,³¹⁷ and/or premorbid personality and psychiatric difficulties.²⁹⁴ Depression can significantly limit a patient’s ability to learn new skills in rehabilitation.²⁹⁴ Those experiencing significant depression often evidence greater functional limitations than cognitive test scores alone would predict. When such a discrepancy is uncovered, rehabilitation psychologists can highlight the interplay between psychological issues and functional performance, and assist the team in developing behavioral strategies to minimize this impediment to progress.

For individuals nearing discharge from acute rehabilitation, neuropsychological testing can inform recommendations about important postdischarge issues and complex activities such as the ability to live independently,³⁵⁸ to return to work or school,³⁸ and to resume driving.²²⁹

Many patients for whom brain-related insults are not the primary admission diagnosis might also benefit from neuropsychological testing. For example, approximately half of individuals with SCI have evidence of TBI,⁸⁷ a comorbidity that is seen as a particularly challenging one in rehabilitation,³¹⁰ and one associated with more limited functional gains during rehabilitation²²⁴ and increased costs.³⁹ Because their TBI-related impairments are typically more subtle than those of individuals with a primary TBI diagnosis, neuropsychological testing of individuals with SCI can be more sensitive to their cognitive impairments than are broader screening measures such as the FIM.³⁹

Elderly patients admitted for nonneurologic problems can also benefit from inpatient neuropsychological testing. Research indicates that cognitive deficits occur with equal frequency among elderly individuals admitted for rehabilitation after lower limb fractures and those being treated for stroke.²³⁷ Neuropsychological testing of these individuals can raise awareness of subtle cognitive difficulties that might affect participation in rehabilitation. In addition, dementia appears to be more common in geriatric rehabilitation populations than in elderly individuals living in the community, but it often remains undetected in rehabilitation settings.²¹⁸ Neuropsychological screening is recommended for uncovering cognitive deficits and for identifying priorities for intervention during rehabilitation and in the context of discharge planning.²¹⁹ Assessment of cognitive functioning has also been shown to predict outcomes in elderly individuals admitted to rehabilitation for such conditions as hip fractures.¹⁷⁰

Outpatient Neuropsychological Assessment

Even when assessments have been completed in the inpatient setting, outpatient neuropsychological testing is often a valuable component of follow-up care for rehabilitation populations with neurologic conditions.²⁶⁹ Although inpatient assessments provide valuable baseline data, numerous factors can affect recovery over time,³⁹⁶ and declines in cognitive functioning might even occur in a small portion of individuals. In these situations, follow-up outpatient neuropsychological testing can signal the need for further medical workup. In addition, when compared with inpatient testing results, outpatient neuropsychological assessments allow determination of changes in functioning over time. These are important data, given the observed variability in patients’ recovery patterns.²⁵⁷

Neuropsychological testing can be particularly valuable in deciding whether outpatient rehabilitation services are likely to be helpful for individuals who first present to physiatry clinics later in their recovery. The testing data can aid in decision making about interventions for cognitive deficits, such as the use of neuropharmacologic treatments.⁴¹⁶ As with inpatient evaluations, the rehabilitation psychologist strives to differentiate the relative contributions of neurobehavioral, psychological, and cognitive issues to daily functioning, because this can have direct implications for treatment planning. For example, if poor daily memory functioning is due to emotional distress, psychotherapy for adjustment issues or psychopharmacologic treatment, or both, would be indicated rather than training in compensatory strategies.

Outpatient neuropsychological assessments also play an important role in educating the patient and family about ongoing cognitive and neurobehavioral consequences of the injury or insult, and promoting advocacy for the patient and family. While teaching the patient and family members about the patient’s condition is a primary goal in the inpatient setting and can have positive benefits on patient outcomes,²⁸⁵ families and patients rarely retain all information provided to them. A follow-up consultation after the patient has had real-life experiences of success and failure provides an opportunity for the rehabilitation psychologist to draw connections among the patient’s medical condition, neuropsychological functioning, and daily difficulties. The implications of neuropsychological test performance for daily functioning are discussed. This discussion also takes into account changes secondary to recovery of functioning and development of new compensatory strategies, as well as changes in situational factors. Assessment findings form the basis for specific recommendations regarding adaptation tactics that can be used in patients’ daily lives (e.g., memory notebooks), and for guidance regarding how to achieve or adjust as necessary long-term goals such as returning to work, school, or independent living.²⁹²

For many individuals with persistent cognitive limitations, outpatient neuropsychological testing provides a basis for addressing issues related to disability. In addition to being associated with concurrent levels of productivity,¹¹ outpatient testing at 5 months postinjury predicts return to productivity at 1 year postinjury.¹⁵⁸ While many individuals resume working or attending school, accommodations or assistance might be needed, and test results can help clarify just what special provisions are needed. Not only can neuropsychological testing document cognitive strengths and weaknesses for determinations of eligibility for state services (e.g., vocational rehabilitation), but it can also help guide the nature of the services that are provided. As detailed in subsequent sections, neuropsychological testing can drive recommendations regarding accommodations in the educational realm. For those individuals unable to work because of their neurologic condition, neuropsychological testing is often relied on in determinations of disability by government as well as private organizations.³⁵⁶

Domains Assessed

Primary domains assessed in neuropsychological evaluations include intelligence, academic ability, memory, attention, processing speed, language, visual-spatial skills, executive abilities, sensory-motor functions, behavioral functions, and emotional status.²¹⁷ Box 4-2 shows selected neuropsychological measures grouped by primary cognitive domain. (Virtually all neuropsychological tests are multifactorial, so the groupings in Box 4-2 are based on the presumed major cognitive skill required by the test.) While a deficit in any area can have a significant impact on functional outcomes for a given patient, large-scale studies suggest that memory, attention, and executive functioning have particular relevance for rehabilitation populations, including individuals with TBI.¹⁵¹

Memory impairments are prevalent after acquired neurologic injuries such as TBI²⁴⁴ and stroke,¹² and can be significantly disruptive to the rehabilitation process. Memory problems can interfere with a patients’ ability to learn and retain new skills and/or develop compensatory strategies taught by rehabilitation providers. Memory problems can significantly hamper the achievement of important functional outcomes and productivity.^32,156

Attention is a multifaceted construct that underlies all other cognitive skills and is especially important for intact memory functioning, because information that is not attended to cannot be recalled at a later time. Components of attention include focused attention, sustained attention, selective attention, alternating attention, and divided attention.³⁴⁴ In addition to memory problems, attention deficits are among the most commonly reported difficulties in persons with TBI²⁰⁸ and in those with a history of stroke.²¹⁵ Deficits in attention are also associated with relatively poorer long-term functional outcomes, including diminished likelihood of returning to work and independent living.⁴⁷

Executive functioning is a complex cognitive domain encompassing multiple skills that pervade all aspects of daily life. Neural systems engaged in executive functioning involve interconnections of diverse neuroanatomic regions,¹³⁹ but the frontal lobes are viewed as especially vital. Executive functioning deficits include difficulties with problem solving, reasoning, planning, response inhibition, judgment, and use of feedback to modify one’s performance, as well as behavioral deficits such as problems with self-awareness and poor motivation. Neuropsychological tests typically focus on evaluating cognitive manifestations of executive dysfunction. Behavioral evaluation of executive functioning relies to a great extent on observations in natural settings, but some behaviors might emerge during testing. Several questionnaires are specifically designed to detect these behavioral issues, such as the Frontal Systems Behavior Sale (FrSBe).¹⁵² Deficits in executive functioning predict important outcomes such as poor quality of life¹⁷⁴ and functional outcomes.²¹⁵

Fixed Versus Flexible Batteries

Rehabilitation psychologists must balance the relative costs and benefits of fixed versus flexible assessment batteries in neuropsychological assessments. With fixed batteries, such as the expanded Halstead-Reitan battery,¹⁶⁶ the same set of tests is administered to all patients, regardless of the referral questions, and the normative data for all tests are based on a single population. Because all tests are co-normed, proponents of this approach assert that this allows for more confidence in drawing conclusions about an individual’s strengths and weaknesses, based on variability in performances across tests. Because a wide range of domains is evaluated, the rehabilitation psychologist might also identify strengths and weaknesses that were not anticipated on the basis of the referral questions or other information such as lesion locus.¹⁹¹

Another variant of the fixed testing approach involves the use of a test battery that is population specific¹⁵ and is developed by the rehabilitation psychologist for use with a particular patient cohort (e.g., individuals with a particular diagnosis such as multiple sclerosis).²³ With this type of fixed battery, rehabilitation psychologists can amass their own clinically based normative data sets against which new patients can be compared. This approach also promotes research opportunities, because psychological and neuropsychological factors that influence participation in rehabilitation and outcomes after discharge can be identified and evaluated.

While strengths of these fixed testing approaches are numerous in the rehabilitation setting, there are some disadvantages. For example, fixed batteries can take 4 to 6 hours or longer to administer, rendering them unsuitable where there are time constraints (e.g., in inpatient settings where there is competition from other therapies for patient time) or where patient stamina is limited. The structure of a fixed battery also does not allow for a targeted assessment of difficulties, which can have greater utility for treatment planning.

As a result, the generally preferred alternative is a flexible testing approach, one in which a core set of measures is supplemented with additional tests that are selected depending on the referral question.²⁵⁵ As the evaluation unfolds, measures can be added or subtracted according to early findings, as strengths and weaknesses become apparent. The examiner might elect to probe certain areas in more detail to clarify their therapeutic import. At the core of this approach is the notion that flexible batteries allow for personalization of an assessment based on patient needs.¹⁵ Flexible batteries seem more responsive to the constraints of inpatient rehabilitation settings and are the preferred approach of most neuropsychologists, regardless of work setting.²⁹⁷

Modifying Tests for Special Populations

In rehabilitation settings, perhaps more than in any other, psychologists must be aware of factors that can produce “construct-irrelevant variance”²⁵² in the assessment of persons with disabilities. These influences can cause spurious elevations or depressions in test scores and result in misleading inferences about the patient’s abilities and deficits. Given that most neuropsychological measures were developed for assessment of physically healthy people, the norms might not apply to those with certain disabilities. Scores on most neuropsychological tests can also be skewed by such influences as pain, fatigue, visual difficulties, and motor impairments, problems that are quite common among rehabilitation populations. These effects should be eliminated, or at least minimized, so as not to obscure assessment of the neuropsychological phenomena of interest.

A related sort of distortion can occur with instruments intended to assess personality or emotional status, because phenomena that constitute “symptoms” for nondisabled individuals might not carry the same (or any) psychologically relevant diagnostic meaning for those having disabilities. For example, the Minnesota Multiphasic Personality Inventory–2 (MMPI-2) contains items dealing with bowel function, sensory changes, and other physical phenomena that are typical consequences of SCI. Persons with SCI (or TBI, stroke, or multiple sclerosis, among others) who answer these questions honestly can produce profiles suggesting psychological pathology where there is none.^140,253,359 Related measures such as the Symptom Checklist-90-Revised (SCL-90-R) are subject to similar skewing.⁴⁰¹

Although standardized testing is the foundation on which contemporary psychological assessment is built, there is considerable support in statements of professional organizations, test publishers, and experienced clinicians for “reasonable accommodations” in testing persons with disabilities.⁶⁵ The elderly, who are a rapidly expanding segment of the population, can also require special adaptations in assessment.⁶⁶ For example, the most recent edition of the Wechsler Adult Intelligence Scale (WAIS-N)³⁹⁰ addresses these issues in a section on “suitability and fairness.” The “fairness” issue in particular is a long overdue concept in psychology.^128,144 While devoting most attention to modifications for persons with hearing impairment, the WAIS-IV manual warns evaluators against “attribut(ing) low performance on a cognitive test to low intellectual ability when, in fact, it may be related to physical, language, or sensory difficulties.”³⁹⁰ Alterations or accommodations in the testing procedures should be recorded and taken into account in interpreting the test data. While it is recognized that “some modifications invalidate the use of norms, such testing of limits often provides very valuable qualitative and quantitative information.”³⁹⁰

What else can the psychologist do in such situations to ensure fair, accurate, and informative assessment? One method involves “pruning” of those items on measures designed to assess personality or emotional state that are perceived to be irrelevant to the constructs being assessed. Gass¹⁴¹ identified 14 potentially confounding items that, once the presence of brain injury has been established, can be removed and the protocol rescored to yield a “purified” profile. Gass¹⁴⁰ also identified 21 “stroke symptoms” that can be handled in the same manner. Woessner and Caplan^401,402 used expert consensus to determine that 14 and 19 items, respectively, from the SCL-90-R concerned phenomena that were part of the “natural history” of TBI or stroke. They argued that scores indicating pathology in physically healthy people could hold very different diagnostic significance for persons with acute or chronic medical conditions. Failure to attend to possible scale distortions could lead to misinterpretation, erroneous diagnosis, and subsequent misguided treatment.

Some authors^49,106 have argued against this method, maintaining that important information might be lost if items are deleted from standard measures, or that the psychometric properties of the instrument could be significantly altered. These authors based their position on studies of individuals in litigation, however, where validity is a pervasive concern. Stein et al.³⁵¹ offer a nuanced discussion of the pros and cons of retaining or eliminating “somatic items” in assessment of stroke survivors, pointing out that while these might represent a clinical problem, their mere presence offers no clue to etiology and, therefore, to treatment. The rehabilitation psychologist must analyze these symptoms in light of all available information to determine whether a psychologically treatable problem exists.

In the case of neuropsychological measures, greater ingenuity (and caution) is required to ensure that valid information is obtained from test administration. Although one naturally wants to know the impact of the disabling condition on the individual’s functioning, one does not want to consume time and energy simply to confirm the obvious. It is poor practice to administer a 60-item test of visual processing only to discover that the patient saw only part of the stimulus display because of a neurologically based deficit in attention to and awareness of one side of space (unilateral neglect). Possible strategies range from simply allowing extra time for those with psychomotor slowing or impaired manual dexterity, to actually modifying test materials themselves. Berninger et al.²⁸ adapted certain subtests of the Wechsler Adult Intelligence Scale–Revised for use with persons with speech or motor disabilities. They created multiple-choice alternatives for verbal measures (allowing participants to point to their chosen answer), enlarged visual stimuli, and used materials adapted with Velcro to reduce the impact of motor impairment when manual manipulation is required. Caplan⁶⁰ created a “midline” version of the Raven Coloured Progressive Matrices, a multiple-choice, “fill-in-the-blank” test of visual analysis and reasoning. Response alternatives are arrayed in a single column instead of rows, eliminating the lateral scanning component that limits the performance of patients with unilateral neglect. Patients with neglect performed significantly better on “midline” items than the standard ones, while those without neglect performed equally well on both types of item.

Not all authors support this approach. Lee et al.²¹⁴ cautioned that even minor deviations from standard procedures can produce “significant alterations” in performance. We view this as part of the challenge in practicing what is still the “art” of assessment, an endeavor with a substantial scientific base but one that does not mandate robotic behavior on the part of the examiner.

Factors Affecting Validity

Neuropsychological test findings are considered valid when they accurately reflect the patient’s underlying cognitive abilities. In addition to the potential distortions caused by sensory-motor limitations and medical symptoms discussed above, two other factors that can compromise test validity are practice effects and patient effort.

Interpretation of serial neuropsychological assessments, conducted to monitor functioning over time or determine the efficacy of interventions, can be clouded by practice effects—that is, improvements in test scores resulting from familiarity with the test (or even with the process of testing) rather than real gains in cognitive functioning. Research has indicated that some tests are more susceptible to practice effects, such as those evaluating memory.²⁴² Rehabilitation psychologists take several steps to minimize the impact of practice effects. First, comprehensive retesting evaluations are generally scheduled at sufficiently lengthy intervals (e.g., at least 6 months) to reduce the likelihood that patients can remember the test content. Alternative test forms with different test stimuli can also be used. This is especially important when the retest interval is brief. For example, comparable sets of words can be used for list-learning tasks (e.g., Hopkins Verbal Learning Test–Revised).⁴⁴ There is also growing documentation of the utility of statistical corrections, such as the Reliable Change Index¹⁸¹ and regression-based models³⁶⁰ to determine whether genuine and clinically relevant change has occurred on repeat testing.¹⁶⁷

Although the importance of assessment of patient effort has been recognized for some time,²⁸² there has been an avalanche of reports on “symptom validity” testing during the past decade, in large part because of the increased use of neuropsychological findings in forensic settings.^37,212 Although poor patient effort has been estimated to occur in 15% to 30% of forensic evaluations, the likely frequency in clinical settings remains relatively low at 8%.^260,313 Current standards of practice propose that assessment of symptom validity is a necessary part of all evaluations, although the procedures can vary in different settings.⁵¹ Several aspects of patients’ presentations can be examined for indications of poor or variable effort, including variability of performances across tests measuring similar abilities, and consistency between presenting medical factors (e.g., lesion locus) and test performance. One can ask whether the data exhibit “neuropsychological coherence.” Indices of effort are embedded in some tests that are often standard components of neuropsychological evaluations.²⁵⁴ Measures that rely on normative comparisons or use a forced choice paradigm have also been specifically developed as tests of “motivational impairment.”^29,37,212

Psychological Issues in Rehabilitation Settings

Despite rehabilitation’s historically medical emphasis, multiple psychological factors affect both the rehabilitation process and ultimate outcome. Certain psychological conditions also put persons at greater risk for injuries, affecting the psychological mix of the rehabilitation population. People with primary psychiatric disorders are not immune from injuries or serious medical events that necessitate rehabilitation, and their responses to disability can warrant special consideration.