How do neuropsychological tests work?

Neuropsychological tests are usually paper and pencil, verbal response or motor tests. Patients are asked to remember, assemble, copy, focus attention or perform other tests that reflect neurocognitive qualities. The neurocognitive qualities measured could be described as general intelligence, processing ability, language ability, perceptual organizational skill, verbal memory, nonverbal memory, executive functioning, motor functioning, and emotional condition. By responding to certain test sequences, these qualities can be measured. By applying the measurement to known cognitive disorders a diagnosis may be formulated and recommendations made.

How is an individual’s score determined?

All neurocognitive tests are measures of central tendency. A measure of central tendency is a measurement that changes as it moves further and further away from average. For example, IQ is arbitrarily set at an average or ‘mean’ of 100. Deviation from this mean occurs in ‘standard deviation’ units of 15. So, at 115 (15 points above the mean), a person is functioning at the 84th percentile; at 85 (15 points below the mean), a person functioning at the 16th percentile. If we go 2 standard deviations from the mean (100 + 15 + 15, or 130) a person is functioning at the 98th percentile; at 2 standard deviations below the mean (or 70), a person is functioning at the 2nd percentile. All neurocognitive measures use this type of deviation from central tendency in order to determine whether a person is functioning within normal limits.

Couldn't it affect the diagnosis if someone is simply having a bad day?

There are two ways in which transient situations, such as a person’s level of fatigue, poor ‘fit’ with a specific test or some other incidental situation is remedied. The first is that neurocognitive tests are not interpreted until they are well out of the average range. For example, if an individual has intelligence in the normal range - say the 50th percentile - but scored at the 30th percentile on a test of memory; that would not be interpreted as a deficit.

The second factor is that neurocognitive findings are generally interpreted in patterns. There is a pattern of findings associated with Alzheimer’s Disease, Stroke, Traumatic Brain Injury, and most other neurological conditions. By analyzing the pattern of deficits, the patient’s weaknesses, if present, tend to either conform or fail to conform to the expected pattern. Random situations, such as an individual’s fatigue or poor ability to understand the instructions of a specific test, and so forth, rarely cause the type of finding pattern which results in a spurious diagnosis.

How much does neurocognitive examination cost?

Neurocognitive evaluation costs change depending upon the procedure. A full fee schedule is available upon request. Neurocognitive evaluations are accepted by all major insurance companies.

How long does a neurocognitive examination take?

A neurocognitive examination can vary in length from an hour or two to several hours, depending on the specific type of testing done and the tests which must be included in order to rule out certain conditions.

Who can perform a Neurocognitive Examination?

Neurocognitive examinations should only be performed by specially trained professionals. Technically, neurocognitive examination can be legally performed by any individual who holds a license as a psychologist in the state of California. This is also true of medicine, in that any licensed physician in the state of California may provide any specialized medical service. As with medicine, however, it is considered ethical to provide only services for which you have acquired any specialized training necessary. It requires years of extra education and training to perform neuropsychological examinations accurately and safely. The surest sign of competence in neuropsychology is certification by the American Board of Clinical Neuropsychology (ABCN) sanctioned by the American Board of Professional Psychology (ABPP). This is the board that sanctions all of the primary board certifications in the field of professional psychology. The ABCN Board is a non-profit board set up in order to ensure neurocognitive competence. It includes a rigorous evaluation process that requires approximately two years in order to be certified. First, the prospective neuropsychologist must document that they have received appropriate education and training at the pre and post doctoral levels. If admitted to the process, the applicant must pass a comprehensive written examination. This is followed by a work sample examination, and finally, by an oral examination which is held twice yearly at the Rush Presbyterian Medical Center in Chicago. As of 2011 there are 80 ABCN certified neuropsychologists practicing in the state of California, of approximately 720 practicing world wide.