Lesson 42

METHODS OF METHODS OF NEUROLOGICAL NEUROLOGICAL

ASSESSMENTASSESSMENT

Lecture 42Lecture 42

WHAT IS A NEUROLOGICAL WHAT IS A NEUROLOGICAL ASSESSMENT?ASSESSMENT?

Neurological assessment was traditionally carried Neurological assessment was traditionally carried out to assess the extent of impairment to a particular out to assess the extent of impairment to a particular skill and to attempt to locate an area of the brain skill and to attempt to locate an area of the brain which may have been damaged after brain injury or which may have been damaged after brain injury or neurological illness .neurological illness .

Miller outlined three broad goals of neurological Miller outlined three broad goals of neurological assessment.assessment.

Firstly, diagnosis, to determine the nature of the Firstly, diagnosis, to determine the nature of the underlying problem. underlying problem.

Secondly, to understand the nature of any brain Secondly, to understand the nature of any brain injury or resulting cognitive problem and its impact injury or resulting cognitive problem and its impact on the individual, on the individual,

And lastly, assessments may be undertaken to And lastly, assessments may be undertaken to measure change in functioning over time.measure change in functioning over time.

DefinitionDefinition

““Neuropsychology is the study of brain-Neuropsychology is the study of brain-behavior relationships”. behavior relationships”.

Assessment may be carried for a Assessment may be carried for a variety of reasonsvariety of reasons, , such as: Clinical evaluation, to understand the pattern such as: Clinical evaluation, to understand the pattern of cognitive strengths as well as any difficulties a of cognitive strengths as well as any difficulties a person may have, and to aid decision making for use person may have, and to aid decision making for use in a medical or rehabilitation environment. in a medical or rehabilitation environment.

The objectives of neuropsychological assessment in The objectives of neuropsychological assessment in clinical practice are to assess and diagnose clinical practice are to assess and diagnose disturbances of mentation and behavior and to relate disturbances of mentation and behavior and to relate these findings to their neurological implications and to these findings to their neurological implications and to the issues of clinical treatment and prognosis.the issues of clinical treatment and prognosis.

The clinical neuro-psychologist offers a variety of The clinical neuro-psychologist offers a variety of services, including the assessment of the services, including the assessment of the psychological-behavioral effects of real or suspected psychological-behavioral effects of real or suspected brain lesions, the diagnosis of organic brain brain lesions, the diagnosis of organic brain conditions, and the planning and implementation of conditions, and the planning and implementation of rehabilitation programs for brain injured patients.rehabilitation programs for brain injured patients.

Historically, the field of neuropsychology evolved from a Historically, the field of neuropsychology evolved from a lesion localization model.lesion localization model.

The neuropsychologist endeavors to assess different The neuropsychologist endeavors to assess different domains of functioning (e.g., attention, memory, domains of functioning (e.g., attention, memory, problem solving) in order to generate a profile of problem solving) in order to generate a profile of strengths and weaknesses that can inform treatment strengths and weaknesses that can inform treatment planning and adaptation in daily life. planning and adaptation in daily life.

A neuropsychological assessment typically evaluates A neuropsychological assessment typically evaluates multiple areas of functioning. Such as: multiple areas of functioning. Such as:

• Sensory perceptual and motor functions, Sensory perceptual and motor functions, Attention, Memory, Attention, Memory,

• Auditory and visual processing, Language, Auditory and visual processing, Language, • Concept formation and problem solving, Concept formation and problem solving, • Planning and organization, Speed of Processing, Planning and organization, Speed of Processing, • Intelligence, Academic skills, Intelligence, Academic skills, • Behavior, emotions, and personalityBehavior, emotions, and personality

WHAT INFORMATION DOES THE WHAT INFORMATION DOES THE NEUROPSYCHOLOGICAL ASSESSMENT NEUROPSYCHOLOGICAL ASSESSMENT PROVIDE?PROVIDE?

A comprehensive assessment can yield information to A comprehensive assessment can yield information to assist in distinguishing one disorder from another as assist in distinguishing one disorder from another as well as better clarifying its nature.well as better clarifying its nature.

In addition, based on knowledge of brain-behavior In addition, based on knowledge of brain-behavior relationships, evidence for dysfunction in one region of relationships, evidence for dysfunction in one region of the brain may tell us something about other difficulties the brain may tell us something about other difficulties that might be present.that might be present.

In this regard, knowing more about the In this regard, knowing more about the individual’s individual’s strengths and weaknessesstrengths and weaknesses can assist in interpreting can assist in interpreting their behaviors and guiding program/treatment their behaviors and guiding program/treatment planning.planning.

Finally, a written report should be provided following Finally, a written report should be provided following completion of the assessment that can be shared with completion of the assessment that can be shared with those involved in the individual’s care.those involved in the individual’s care.

APPROACHES TO THE NEUROLOGICAL APPROACHES TO THE NEUROLOGICAL EVALUATIONEVALUATION

Neuropsychologist make inferences regarding an Neuropsychologist make inferences regarding an individual’s neurological functioning based on individual’s neurological functioning based on measures of behavior (neuropsychological test measures of behavior (neuropsychological test performance).performance).

Another very important conceptual issue in the Another very important conceptual issue in the neuropsychological examination has to do with the neuropsychological examination has to do with the pre-morbid level of functioningpre-morbid level of functioning..

Lezak (1976) discusses 2 methodsLezak (1976) discusses 2 methods The first is based on the assumption that certain well The first is based on the assumption that certain well

established abilities, such as vocabulary skills and established abilities, such as vocabulary skills and fund of general information, are frequently preserved fund of general information, are frequently preserved in individuals with brain injury, while other skills are in individuals with brain injury, while other skills are impaired.impaired.

The second method assumes that the The second method assumes that the individual’s best current performance “provides individual’s best current performance “provides the closest approximation to his original ability the closest approximation to his original ability level;” hence the clinician simply looks for the level;” hence the clinician simply looks for the highest scores or set of scores.highest scores or set of scores.

Again, caution is warranted, since some Again, caution is warranted, since some patients are so severely impaired that all test patients are so severely impaired that all test scores are depressed. scores are depressed.

Lezak warns that a single high test score on a Lezak warns that a single high test score on a memory task may not be a good estimate of memory task may not be a good estimate of pre-morbid level of functioning, since memory is pre-morbid level of functioning, since memory is the least reliable indicator of general intellectual the least reliable indicator of general intellectual ability of all intellectual functions.ability of all intellectual functions.

Other Methodological Other Methodological ApproachesApproaches

There are several other methodological There are several other methodological approaches that neuropsychologists use in approaches that neuropsychologists use in evaluating and interpreting a given patient’s evaluating and interpreting a given patient’s performance. No single approach is itself performance. No single approach is itself satisfactory, but when they are used in concert satisfactory, but when they are used in concert each approach supplements the other. each approach supplements the other.

The more common approaches are:The more common approaches are:

Level Of Performance, Pattern Analysis, Patho-Level Of Performance, Pattern Analysis, Patho-gnomonic Signs, and Right-left Differences. gnomonic Signs, and Right-left Differences.

Each is described more fully below.Each is described more fully below.

LEVEL OF PERFORMANCELEVEL OF PERFORMANCE In the level of performance approach, the patient is In the level of performance approach, the patient is

administered tests that are sensitive to cerebral administered tests that are sensitive to cerebral impairment.impairment.

The patient’s scores on such tests are compared to The patient’s scores on such tests are compared to normative levels.normative levels.

In the past, many psychologists used the In the past, many psychologists used the Bender Bender GestaltGestalt as a single measure of organicity. as a single measure of organicity.

It is by no means sufficient, because it provides just It is by no means sufficient, because it provides just one bit of data about the patient.one bit of data about the patient.

Another problem with the level of performance Another problem with the level of performance approach particularly when a single test is used is that approach particularly when a single test is used is that a patient may do well on this test despite having a patient may do well on this test despite having significant deficits in other areas of higher cortical significant deficits in other areas of higher cortical functioning.functioning.

PATTERN ANALYSISPATTERN ANALYSIS:: Pattern analysis means that the patient is given Pattern analysis means that the patient is given

a battery of tests with known association to a battery of tests with known association to higher cortical functioning; and the higher cortical functioning; and the neuropsychologist then looks at the pattern of neuropsychologist then looks at the pattern of test performance—on which tests did the test performance—on which tests did the patient perform relatively poorly, and on which patient perform relatively poorly, and on which tests did the patient perform well?tests did the patient perform well?

The problem with pattern analysis approach is The problem with pattern analysis approach is that a person could have a low score on a given that a person could have a low score on a given test for numerous reasons, and the simple test for numerous reasons, and the simple presence of the low score does not necessarily.presence of the low score does not necessarily.

RIGHT-LEFT DIFFERENCES:RIGHT-LEFT DIFFERENCES: To use the right-left difference approach, the clinician To use the right-left difference approach, the clinician

examines the test scores of patient on the tasks that examines the test scores of patient on the tasks that require performance or participation of both sides of the require performance or participation of both sides of the body.body.

A number of tests on the Halstead Battery involve having A number of tests on the Halstead Battery involve having the patient perform a given task with his or her dominant the patient perform a given task with his or her dominant hand and then perform the same task with the non-hand and then perform the same task with the non-dominant hand. dominant hand.

For example, to give another example on the For example, to give another example on the Tactual Tactual Performance TestPerformance Test, a right handed patient who takes a , a right handed patient who takes a significantly longer time for block placement with the left significantly longer time for block placement with the left hand than for the right might suggest a lesion in the hand than for the right might suggest a lesion in the parietal area of the right hemisphere. parietal area of the right hemisphere.

One problem with this approach is that measuring right-left One problem with this approach is that measuring right-left differences typically means measuring motor and sensory-differences typically means measuring motor and sensory-motor deficit, so the number of tests in this category is motor deficit, so the number of tests in this category is limited.limited.

PATHOGNOMONIC SIGNS:PATHOGNOMONIC SIGNS: A pathognomonic sign is a problem that a patient A pathognomonic sign is a problem that a patient

manifests that is an absolute indication of organic manifests that is an absolute indication of organic brain disorder. A pathognomonic sign is present the brain disorder. A pathognomonic sign is present the patient is, by definition, suffering from an organic patient is, by definition, suffering from an organic neurological disorder.neurological disorder.

Examples of pathognomonic signs are visual field Examples of pathognomonic signs are visual field deficits, spatial inattention or neglect, aprexia and deficits, spatial inattention or neglect, aprexia and alexia.alexia.

The major advantage of the pathognomonic sign The major advantage of the pathognomonic sign approach is that if the sign is present, the patient approach is that if the sign is present, the patient definitely has organic impairment.definitely has organic impairment.

The major disadvantage, however, is that absolute The major disadvantage, however, is that absolute pathognomonic signs are seen rather infrequently on pathognomonic signs are seen rather infrequently on neuropsychological evaluation. neuropsychological evaluation.

USES OF CLINICAL NEURO-USES OF CLINICAL NEURO-PSYCHOLOGICAL ASSESSMENT:PSYCHOLOGICAL ASSESSMENT:

1. DIAGNOSTIC CLARIFICATION1. DIAGNOSTIC CLARIFICATIONIn confusing or complex cases, neuropsychological In confusing or complex cases, neuropsychological assessment can be useful for testing out the relative assessment can be useful for testing out the relative contributions of contributions of

• neurological conditions (e.g., cellular degeneration, neurological conditions (e.g., cellular degeneration, neuro-chemical disruption), neuro-chemical disruption),

• emotional states (e.g., anxiety, depression), andemotional states (e.g., anxiety, depression), and• psychiatric illnesses (e.g., personality disorder, psychiatric illnesses (e.g., personality disorder,

psychoses). psychoses). Neuro-psychological assessment can be used to help Neuro-psychological assessment can be used to help

localize brain damage. localize brain damage.

2. MEASURING CHANGE:2. MEASURING CHANGE:Repeat assessment can be valuable in charting Repeat assessment can be valuable in charting progress (e.g., recovery from cerebrovascular progress (e.g., recovery from cerebrovascular accident or closed head injury) as well as for accident or closed head injury) as well as for recognizing a decline in mental status recognizing a decline in mental status

(e.g., following the course of various dementias, (e.g., following the course of various dementias, identifying unexpected declines in patients undergoing identifying unexpected declines in patients undergoing various treatments or during the process of recovery).various treatments or during the process of recovery).

3. EVALUATING COGNITIVE AND 3. EVALUATING COGNITIVE AND FUNCTIONAL STATUS:FUNCTIONAL STATUS:Neuropsychological testing is able to delineate an Neuropsychological testing is able to delineate an individual's pattern of cognitive strengths and individual's pattern of cognitive strengths and weaknesses relative to his or her own ability as well as weaknesses relative to his or her own ability as well as compared to normative samples of age-matched compared to normative samples of age-matched peers (Ideally, norms should be matched for age, peers (Ideally, norms should be matched for age, education, gender, and race if each variable has been education, gender, and race if each variable has been shown to affect test performance). shown to affect test performance).

Applications Of Neuro-psychological Applications Of Neuro-psychological Assessment:Assessment:

1. VOCATIONAL INTERVENTIONS:1. VOCATIONAL INTERVENTIONS:With the input of the neuropsychologist, a patient's With the input of the neuropsychologist, a patient's ability to rejoin the work force can be evaluated and ability to rejoin the work force can be evaluated and efforts toward re-entry can be facilitated (e.g., develop efforts toward re-entry can be facilitated (e.g., develop specific routines that are tailored to the patient's specific routines that are tailored to the patient's existing strengths and that anticipate the impact of his existing strengths and that anticipate the impact of his or her limitations). or her limitations).

Aspects of neuropsychological testing can be Aspects of neuropsychological testing can be integrated with organizational psychology in order to integrated with organizational psychology in order to enhance the quality of vocational assessment.enhance the quality of vocational assessment.

2. ACADEMIC INTERVENTIONS:2. ACADEMIC INTERVENTIONS:As with vocational interventions, results of a As with vocational interventions, results of a neuropsychological assessment may be used to plan neuropsychological assessment may be used to plan a special educational program to better meet the a special educational program to better meet the needs of an individual. This may be useful with needs of an individual. This may be useful with developmental disorders as well as with patients developmental disorders as well as with patients recovering from illness or injury.recovering from illness or injury.

3. FAMILY INTERVENTIONS:3. FAMILY INTERVENTIONS:Accurate knowledge about a patient's functional status Accurate knowledge about a patient's functional status may assist him or her to adjust their role within a may assist him or her to adjust their role within a family system. Neuropsychological information may family system. Neuropsychological information may enable family members to recognize the need for enable family members to recognize the need for changes and accommodations within their changes and accommodations within their relationships, highlight the need for environmental relationships, highlight the need for environmental changes to accommodate patient deficits, and provide changes to accommodate patient deficits, and provide an opportunity for emotional processing and eventual an opportunity for emotional processing and eventual acceptance of the patient's limitations.acceptance of the patient's limitations.

4. COMPETENCY ISSUES:4. COMPETENCY ISSUES:Neuropsychological status plays an important Neuropsychological status plays an important role in determining a patient's overall role in determining a patient's overall competency. competency.

Questions typically involve one's ability to Questions typically involve one's ability to exercise rational judgment, make competent exercise rational judgment, make competent decisions, and live in an independent fashion. decisions, and live in an independent fashion.

In addition to cognitive status, assessment of In addition to cognitive status, assessment of the patient's awareness of their limitations is the patient's awareness of their limitations is also important in establishing ability for also important in establishing ability for independent functioning.independent functioning.

Methods of Neuro-Psychological Methods of Neuro-Psychological Assessment:Assessment:

1. MEDICAL HISTORY:1. MEDICAL HISTORY:All relevant medical records, especially results All relevant medical records, especially results of neurological examination, imaging studies, of neurological examination, imaging studies, and electrophysiological (EEG) results.and electrophysiological (EEG) results.

2. CLINICAL INTERVIEW:2. CLINICAL INTERVIEW:Includes review of cognitive, sensorimotor, and Includes review of cognitive, sensorimotor, and neurovegetative complaints as well as medical, neurovegetative complaints as well as medical, psychiatric, and substance abuse history. psychiatric, and substance abuse history. Family members may be interviewed when Family members may be interviewed when necessary.necessary.

3. PSYCHOMETRIC TESTS:3. PSYCHOMETRIC TESTS:

These may be "paper and pencil" tasks or These may be "paper and pencil" tasks or measures requiring performance of a relevant measures requiring performance of a relevant skill (e.g., assembly of blocks or puzzles, skill (e.g., assembly of blocks or puzzles, reaction time tasks). reaction time tasks).

Major cognitive domains typically assessed Major cognitive domains typically assessed include: include:

Attention, Memory, Intelligence, Visual-Spatial-Attention, Memory, Intelligence, Visual-Spatial-Perceptual functions, Psychosensory and Motor Perceptual functions, Psychosensory and Motor abilities, "Executive" or "Frontal Lobe" abilities, "Executive" or "Frontal Lobe" functions, and Personality or Emotional functions, and Personality or Emotional Functioning.Functioning.

4. INTERPRETATION OF RESULTS:4. INTERPRETATION OF RESULTS:Deficit patterns occurring across neuropsychological Deficit patterns occurring across neuropsychological tests can be suggestive of various sites of cerebral tests can be suggestive of various sites of cerebral dysfunction and neurological processes underlying the dysfunction and neurological processes underlying the deficit pattern. deficit pattern.

An effort is made by the neuropsychologist to integrate An effort is made by the neuropsychologist to integrate test data, history, clinical interview, behavioral test data, history, clinical interview, behavioral observations, and available laboratory and radiological observations, and available laboratory and radiological evidence into one cohesive summary report that evidence into one cohesive summary report that arrives at a neurobehavioral diagnosis, discusses the arrives at a neurobehavioral diagnosis, discusses the neurological implications (e.g., localization, course, neurological implications (e.g., localization, course, prognosis), and can be used in the process of prognosis), and can be used in the process of treatment planning.treatment planning.

INTERPRETATION OF NEURO-INTERPRETATION OF NEURO-PSYCHOLOGICAL TEST RESULTS:PSYCHOLOGICAL TEST RESULTS:

First, a patient’s First, a patient’s level of performance level of performance may be may be interpreted in the context of normative data.interpreted in the context of normative data.

Second, some calculate difference scores between Second, some calculate difference scores between two tests for a patient; certain level of difference two tests for a patient; certain level of difference suggests impairment.suggests impairment.

Third, Third, pathognomonic analysis pathognomonic analysis of scores on tests has of scores on tests has been reliably associated with specific neurological been reliably associated with specific neurological injuries or impairments.injuries or impairments.

Finally, a number of statistical formulas that weight Finally, a number of statistical formulas that weight test scores differently may be available for certain test scores differently may be available for certain diagnostic decisions.diagnostic decisions.

NEURODIAGNOSTIC PROCEDURESNEURODIAGNOSTIC PROCEDURES The medical field has a variety of neurodiagnostic The medical field has a variety of neurodiagnostic

procedures. they include the tradition neurological procedures. they include the tradition neurological examination performed by the neurologist, spinal taps, examination performed by the neurologist, spinal taps, X rays, electroencephalograms (EEGs), computerized X rays, electroencephalograms (EEGs), computerized axial tomography (CAT) scans, positron emission axial tomography (CAT) scans, positron emission tomography (PET) scans, and the more recent nuclear tomography (PET) scans, and the more recent nuclear magnetic resonance imaging (NMR or MRI) technique.magnetic resonance imaging (NMR or MRI) technique.

Many of these neurodiagnostic procedures are quite Many of these neurodiagnostic procedures are quite expensive, and some are invasive. Therefore, it may expensive, and some are invasive. Therefore, it may be helpful to use neuropsychological tests as be helpful to use neuropsychological tests as screening measures, the results of which may indicate screening measures, the results of which may indicate whether more expensive neurodiagnostic tests are whether more expensive neurodiagnostic tests are indicated.indicated.

TESTING AREAS OF COGNITIVE TESTING AREAS OF COGNITIVE FUNCTIOINGFUNCTIOING

A. INTELLECTUAL FUNCTIONING:A. INTELLECTUAL FUNCTIONING:

A number of techniques have been used over to A number of techniques have been used over to assess levels of intellectual functioning. assess levels of intellectual functioning.

To estimate level of intellectual ability, many To estimate level of intellectual ability, many neuropsychologists use the WAIS -3 and subtests neuropsychologists use the WAIS -3 and subtests from a modified version of the WAIS-R called the from a modified version of the WAIS-R called the WAIS-R-NI (Kaplan, 1991). WAIS-R-NI (Kaplan, 1991).

The modifications include, for example, changes in The modifications include, for example, changes in administration (such as allowing the patient to administration (such as allowing the patient to continue on a subtest despite consecutive incorrect continue on a subtest despite consecutive incorrect answers) and additional subtest items.answers) and additional subtest items.

Because of these modifications, it is believed that the Because of these modifications, it is believed that the WAIS-R-NI provides more information regarding the WAIS-R-NI provides more information regarding the patient's cognitive strategies.patient's cognitive strategies.

B. ABSTRACT REASONING:B. ABSTRACT REASONING:

Some of the more commonly used tests to assess Some of the more commonly used tests to assess abstract reasoning abilities include the Similarities abstract reasoning abilities include the Similarities subtest of the WAIS-3 and the Wisconsin Card Sorting subtest of the WAIS-3 and the Wisconsin Card Sorting Test, or WCST (Heaton, 1981). Test, or WCST (Heaton, 1981).

The Similarities subtest requires the patient to produce The Similarities subtest requires the patient to produce a description of how 2 objects are alike. The WCST a description of how 2 objects are alike. The WCST consists of decks of cards that differ according to the consists of decks of cards that differ according to the shapes imprinted, the colors of the shapes, and the shapes imprinted, the colors of the shapes, and the number of shapes on each card. number of shapes on each card.

The patient is asked to place each card under the The patient is asked to place each card under the appropriate stimulus card according to a principle appropriate stimulus card according to a principle (same color, same shapes, same number of shapes) (same color, same shapes, same number of shapes) deduced from the examiner's feedback ('that's right' deduced from the examiner's feedback ('that's right' and 'that's wrong'). and 'that's wrong').

C. MEMORY:C. MEMORY:Brain injury is often marked by memory loss. To test Brain injury is often marked by memory loss. To test for such loss, Wechsler (1945) developed the for such loss, Wechsler (1945) developed the Wechsler Memory Scale, or WMS. The Wechsler Wechsler Memory Scale, or WMS. The Wechsler Memory Scale-3 is the most recent revision of the Memory Scale-3 is the most recent revision of the WMS. WMS.

WMS-3 subtest scores are combined into 8 primary WMS-3 subtest scores are combined into 8 primary indexes that assess a range of memory functioning: indexes that assess a range of memory functioning: Auditory Immediate, Visual Immediate, Immediate Auditory Immediate, Visual Immediate, Immediate Memory, Auditory Delayed, Visual Delayed, Auditory Memory, Auditory Delayed, Visual Delayed, Auditory Recognition Delayed, General Memory and Working Recognition Delayed, General Memory and Working Memory. Memory.

Four supplementary Auditory Process Composites can Four supplementary Auditory Process Composites can also be calculated. These are used to assess memory also be calculated. These are used to assess memory processes when stimuli are presented auditorily.processes when stimuli are presented auditorily.

D. VISUAL-PERCEPTUAL PROCESSING:D. VISUAL-PERCEPTUAL PROCESSING:

Visual-spatial skills are necessary for a broad range of Visual-spatial skills are necessary for a broad range of activities, including reading a map, parallel parking a activities, including reading a map, parallel parking a car, a throwing a baseball from the outfield to a base. car, a throwing a baseball from the outfield to a base.

In addition to the In addition to the Rey-Osterrieth Complex Figure Rey-Osterrieth Complex Figure TestTest, many neuropsychologists seeking to assess , many neuropsychologists seeking to assess visual-spatial skills examine performance on certain visual-spatial skills examine performance on certain WAIS-3 subtests, such as the WAIS-3 subtests, such as the Block Design subtestBlock Design subtest. .

Several specialized tests of these skills are also Several specialized tests of these skills are also available. For example, the judgment of available. For example, the judgment of Line Line Orientation TestOrientation Test requires examinees to indicate the requires examinees to indicate the pair of lines on a response card that 'match' the 2 lines pair of lines on a response card that 'match' the 2 lines on the stimulus card.on the stimulus card.

E. LANGUAGE FUNCTIONING:E. LANGUAGE FUNCTIONING:

Various forms of brain injury or trauma can affect Various forms of brain injury or trauma can affect either the production or comprehension of language. either the production or comprehension of language.

Tests that require patients to repeat words, phrases, Tests that require patients to repeat words, phrases, and sentences can assess articulation difficulties and and sentences can assess articulation difficulties and paraphasias (word substitutions); naming tests can paraphasias (word substitutions); naming tests can help diagnose anomias (impaired naming). help diagnose anomias (impaired naming).

Language comprehension can be assessed using the Language comprehension can be assessed using the Receptive Speech Scale of the Luria-Nebraska. This Receptive Speech Scale of the Luria-Nebraska. This subtest requires patients to respond to verbal subtest requires patients to respond to verbal commands. Speech and language pathologists do an commands. Speech and language pathologists do an excellent job of comprehensively assessing language excellent job of comprehensively assessing language dysfunction, and the neuropsychologist may choose to dysfunction, and the neuropsychologist may choose to refer patients to these health professionals if a refer patients to these health professionals if a screening test indicates suspected problems in screening test indicates suspected problems in language production or comprehension. language production or comprehension.