Neuropsychological Assessment

Roots in Neurology
The branch of medicine that focuses on the nervous system and its disorders.

Neuropsychology:
The branch of psychology that focuses on the relationship between brain functioning and behavior.

Formerly a specialty area within clinical psychology.

Psychologists screen for signs and symptoms of a neurological deficit during:

  • History Taking.
  • Interviewing.
  • Test-taking.
  • Intelligence Tests.
  • Other Tests.

The Nervous System and Behavior
Damage to certain parts of the brain will be reflected as behavior deficits.

For example, damage to the temporal lobe may affect:

  • sound discrimination.
  • sound recognition.
  • voice recognition.
  • visual memory storage.

The Neuropsychological Examination:
Tests and procedures employed in a neuropsychological examination vary as a function of:
  • Purpose of examination.
  • Neurological intactness of the examinee.
  • Thoroughness of the examination.

For a neuropsychological examination a battery of tests administered should include, at a minimum:

  • Intelligence Tests.
  • Personality Tests.
  • Perceptual-Motor / Memory Tests.
If impairment is discovered, the examinee will be referred for further and more detailed tests.

History Taking
The typical neuropsychological exam begins with a careful history taking. Areas of interest include:

  • Medical history of patient.
  • Medical history of patient's family.
  • Presence of absence of developmental milestones.
  • Psychosocial history.
  • Character, severity, and progress of any history of complaints.

The Neuropsychological Mental Status Exam
The MSE deals with questions concerning the addressee's

  • Consciousness.
  • Emotional State.
  • Thought Content and Clarity.
  • Memory.
  • Sensory Perception.
  • Performance of Action.
  • Language.
  • Speech.
  • Handwriting.
  • Handedness.

Neuropsychological Tests
Tests and assessment procedures assess various aspects of functioning including aspects of:

  • Perceptual functioning.
  • Motor functioning.
  • Verbal functioning.
  • Memory Functioning.
  • Cognitive Functioning.

These tests are also used in screening for deficits and in adjunct to medical examinations.

The tests can be helpful in the assessment of:

  • Change in mental status.
  • Abnormalities in function before abnormalities in structure can be detected.
  • Strengths and weaknesses of patient.
  • Ability of individual to stand trial.
  • Changes in disease process over time.

Specialized Interviews and Rating Scales
A number of structured interviews and rating forms are available as aids in the screening and evaluation process:

  • Short Portable Mental Status Questionnaire.
  • Neuropsychological Impairment Scale.
  • Patient's Assessment of Own Functioning.
  • Structured Interview for the Diagnosis of Dementia.

Intellectual Ability Testing in Neuropsychology
The Wechsler Scales are often used as a diagnostic tool:

  • The varied nature of the tasks or the scales and the wide variety of the response may provide some clue to the existence of a deficit.
  • A wide gap in verbal and performance scores may also indicate a deficit.

Memory Tests
Formal testing for memory may involve the use of instruments such as the Wechsler Memory Scale-Revised:

  • The task is to recall stories and other verbal stimuli.
  • The test is appropriate for people within the ages of 16-74.

Verbal memory is assessed through the presentation of stimuli such as these that must then be recalled:

  • words.
  • digits.
  • nonsense syllables.
  • Sentences.

Verbal memory can also be assessed through a variety of existing tests including:

  • California Verbal Learning Test.
  • Rey Auditory Verbal Learning Test.
  • Selective Reminding Test.

Nonverbal memory can be assessed through such tests as:

  • Benton Test of Visual Retention-Revised.
  • Memory for Designs Test.
  • Rey-O Complex Figure

These tests provide a measure of the test takers ability to perceive and retain images of visually presented geometric figures.

Recently, an effort has been made to make tests more "ecologically valid", or "real world" in nature.

This is accomplished by using tasks that people must perform each day such as:

  • Remembering names and faces when meeting new people.
  • remembering lists.

Tests of Cognitive Functioning
Difficulty in thinking abstractly is a relatively common consequence of brain injury.

One popular measure of verbal abstraction ability is the Wechsler Similarities Subtest:

The task is to identify how two objects are alike.

Proverb interpretation is another way to assess ability to think abstractly.

Nonverbal tests of abstraction include sorting tests:

  • Wisconsin Card Sorting Test - test of problem solving and ability to develop and test hypostheses
  • Category Test.
  • Stroop Test - test of cognitive flexibility

Brain damage may result in deficits with respect to organizing and planning abilities, as well as reasoning ability.

Common to many types of neurological impairment disorder of orientation is a lack of awareness of one's relationship to one's surroundings.

Awareness of deficits (anosagnosia)

Tests of Verbal Functioning
Aphasia-the loss of the ability to express oneself and/or to understand spoken or written language because of some neurological deficit.

Tests of Verbal Functioning

  • Controlled Word Association Test:
    • The examiner says a letter of the alphabet and the subjects task is to think of as many words as possible beginning with that letter.
  • Reitan-Indiana Aphasia Screening Test:
    • Contains a variety of items using language, including naming common objects, following verbal, and writing familiar words.

Perceptual and Motor Tests
Letter Cancellation Tests/Field of Search Test is useful in uncovering deficits in visual scanning ability.

  • Auditory Discrimination Test:
    • The task is to discriminate between short words such as muss and much.
  • Finger Tapping, Strength of Grip
  • Purdue Pegboard Test:
    • A measure of manual dexterity where the object is to insert pegs into holes using one hand, then the other hand, and then both hands.
  • Bender Visual-Motor Gestalt Test
    • The test consists of nine cards, on each of which is printed one design believed to assess perceptual maturation and neurological impairment.
    • The test taker is shown each of the cards in turn and instructed to, "Copy it as best you can."
    • After all nine designs have been copied, the test taker is given a fresh sheet of paper with the instructions, " Now please draw all of the designs you can remember."
    • Evidence in support of the use of the Bender-Gestalt to assess personality is tenuous.:Early reviews on the validity were favorable, but they were found to include inappropriate subject selection procedures.
    • A high false negative rate was associated with the Bender.
    • Also, the Bender was associated with a high rate of false positives.

Neuropsychological Test Batteries

The Flexible Battery:
Definition: Specific tests chosen for some purpose relevant to the unique aspects of the patient and the presenting problem.

With this commonly used battery, the clinician hand-picks the test to be included in the battery as opposed to a prepackaged group of test.

Problems with this include:

  • The burden of integrating the findings from each individual test.
  • The tests frequently overlap, wasting testing and scoring time.

The Prepackaged Battery:
Definition: Designed to comprehensively sample the patient's neuropsychological functioning.

Especially appealing to clinicians new to neuropsychological assessment, because it tends to be less demanding in many ways.

Halstead-Reitan Neuropsychological Battery

  • The battery consists of 7 subtests:
  • Category-Measure of abstracting ability.
  • Tactual Performance-Measures memory and localization.
  • Rhythm-Task is to discriminate between like and unlike pairs of musical beats.
  • Speech Sounds Perception-Task is to discriminate spoken syllables.
  • Finger Tapping-Measure of manual dexterity.
  • Time Sense-Task of reproducing movement from sight as well as ability to estimate time span.
  • Trails A & B-Measures Psycho-Motor speed and flexibility.
  • Administration requires a highly trained examiner.
  • The battery requires a full day to complete.
  • Interpretation requires a trained neuropsychologist.
  • High degree of clinical and psychometric reliability for most of the tests in the battery.

Luria-Nebraska Neuropsychological Battery

  • The LNNB has 11 scales on Form 1, and 12 scales on Form 2.
  • The scales assess cognitive processes and functions.
  • The LNNB is appealing because it takes about 1/3 the time of the Halstead-Reitan and can be administered at bedside.
  • The psychometric soundness has been challenged; it is presumed to be overly dependent on language and to yield a high rate of false negative findings.

Other Neuropsychological Batteries
Many published and unpublished neuropsychological test batteries are designed to probe deeply into one area of neuropsychological functioning instead of surveying for possible behavioral deficit in a variety of areas.

Batteries can focus on any specific aspect of brain-behavior functioning.

Beyond physically locating areas of damage and deficit, there is a great need to understand cognitive strengths and weaknesses and to put that understanding to work in prevention, treatment, and rehabilitation efforts.