Brief Overview of Neuropsychological Assessment

Nancy K. Madigan

Sara J. Hoffschmidt

▪ INTRODUCTION

The field of clinical neuropsychology is a specialization within clinical psychology that emphasizes study of the brain/behavior relationships and assessment of cognitive functioning. By providing objective, quantifiable data regarding a patient’s deficits, evaluation results are often a critical component of diagnosis and treatment planning. Patients appropriate for neuropsychological evaluation vary greatly in functional level and present with a wide variety of medical, neurological, and psychiatric problems. At the core of the neuropsychological evaluation are empirically developed assessment tools that have been standardized on neurologically intact individuals. The patient’s performance on tests is compared to age- and education-matched norms to obtain a profile of his or her intellectual, cognitive, and affective/personality functioning. In addition to clinical interview and formal testing, key components of neuropsychological assessment include diagnostic formulation and communicating recommendations to both the patient and referring clinician.

▪ INDICATIONS FOR TESTING

There are several reasons why a neuropsychological assessment may be of use to the clinician, including assistance with differential diagnosis, treatment planning, and documentation of cognitive deficits to aid in eligibility for services. In addition, characterization of the client’s cognitive strengths and weaknesses can be reassuring and therapeutic for the patient, especially for the “worried well” or those who may have an undiagnosed learning disorder. The referring clinician should understand the kinds of questions that may be realistically addressed by neuropsychological testing. Table 12.1 provides a summary of indications for testing and several examples of referral questions.

Although neuropsychological evaluation may be useful in addressing such referral questions, one often-cited limitation relates to ecological validity, or the degree to which test performance predicts real-life behavior and functioning. For example, a patient’s adaptive or compensatory behavior in daily living may exceed what might be expected on the basis of the patient’s test deficits. Further, neuropsychological assessment can provide an accurate picture of current functioning, but it may not be as useful for problems in which ongoing assessment is needed for the most accurate diagnosis (e.g., complex, emerging psychiatric disorders). Finally, sociocultural factors can affect or limit the validity of testing, including English as a second language, limited educational opportunity (which often correlates with neuropsychological performance), lack of normative data for a particular ethnic population, and cultural differences in symptom presentation.

TABLE 12.1 INDICATIONS FOR TESTING AND EXAMPLE REFERRAL QUESTIONS

INDICATIONS FOR TESTING	EXAMPLES
Differential diagnosis	Progressive dementia versus depression in the elderly Dementia subtype (e.g., frontal temporal, vascular, Lewy body disease, Alzheimer’s) Mild cognitive impairment versus normal aging Objective assessment of attention deficit hyperactivity disorder and learning disorders Evidence of cognitive impairment secondary to medical illness (e.g., seizures, brain injury, demyelinating illnesses, stroke)
Treatment considerations	Aid in determining appropriate medications, as well as medication efficacy and toxicity Appropriateness for cognitive remediation Use and application of relevant compensatory strategies Formal academic or workplace accommodations
Baseline testing and prognosis	Improvement in acute conditions (e.g., head injury, stroke) Decline in deteriorating conditions (e.g., dementia)
Issues of capacity	Objective evidence of cognitive dysfunction to aid in determining competency Eligibility for services (e.g., documentation of mental retardation, disability evaluations, educational accommodations) Safety considerations in those with dementia
Forensic evaluation	Objective assessment of suboptimal performance (e.g., malingering, possible embellishment of cognitive deficits) via symptom validity measures Evidence of cognitive dysfunction in traumatic brain injury

▪ FUNDAMENTALS OF THE NEUROPSYCHOLOGICAL EVALUATION

Assessment Process

Diagnostic Interview

This important component of the evaluation involves obtaining pertinent medical, educational, social, and psychiatric history. Essential to the diagnostic formulation is historical information, which provides the context for examining the patient’s test performance. In addition to interviewing the patient, the neuropsychologist makes efforts to obtain collateral information from a family member, as well as pertinent patient records (e.g., medical evaluations, school reports, and work assessments).

Behavioral Observations

Notes regarding patient behavior are made and incorporated into the final evaluation report. In addition to general physical appearance, aspects of speech, movement/activity, mood, interpersonal comportment, judgment, and insight are described. Behavioral observations also include an assessment of the validity of test results based on the patient’s level of effort, motivation, and cooperation.

Formal Testing

Outpatient evaluations typically are a minimum of 3 to 4 hours in duration, although briefer assessments are common for bedside evaluations. In addition to tests directly administered by the examiner to the patient, the evaluation also may include paper-and-pencil and computer-based measures.

Cognitive Abilities and Domains Assessed

Once the referral question and the goals of the evaluation are identified, the battery of measures to be administered is determined. Neuropsychological tests must meet criteria for adequate psychometric (e.g., reliability, validity, sensitivity) and normative properties. Historically, there have been two primary approaches to neuropsychological testing. In the “fixed battery” approach, a standard set of tests is administered to all patients. The chief advantages of the fixed battery method include a rigorous, quantitative foundation and increased reliability; critiques of this approach focus on its lengthiness and its potential for limiting more individualized, in-depth assessment of specific areas of concern. Contrasting with the fixed battery approach is the “Boston process” approach, in which a qualitative, hypothesis-driven emphasis allows the clinician to select different measures over the course of the evaluation. This method may provide greater understanding of the individual’s specific complaints, with a focus on application of results to life circumstances. In practice, most contemporary neuropsychologists elect to use a “flexible battery” approach, in which core measures are administered and additional tests are added based on clinical observation and the patient’s initial performance.

Only gold members can continue reading. Log In or Register to continue