Neuropsychological Testing in Occupational Medicine When is a referral appropriate and what will neuropsychological testing offer? Nancy Fiedler, Ph.D. Rutgers, The State University of New Jersey
Objectives Determine when to make a referral for a neuropsychological evaluation Structure a relevant referral question for neuropsychological evaluations Interpret typical neuropsychological reports Recognize the strengths and weaknesses of neuropsychological testing Distinguish psychiatric from neuropsychological testing protocols and how these domains interact to affect job performance
Neuropsychological Tests: observable and quantifiable behaviors Domains of cognitive and sensory function Attention Working memory Motor and Processing speed Verbal and visual memory Perceptual organization Executive function GENERAL INTELLIGENCE
Psychiatric Testing: self and other report Structured and clinical interviews (self report) Personality testing (MMPI, CPI) Acute symptom reports (e.g., SCL-90, Beck depression)
When to refer for neuropsychological testing: Employee with a pattern of compromised performance not attributable to organizational issues such as lack of training or poor supervision Baseline testing of cognitive performance to monitor progression of disease or disability Differentiation of compromised cognition from stress-related cognitive complaints
The Referral Question Employee X has exhibited a sustained pattern of poor performance as indicated by the following: Attendance Documentation of supervisor ratings of job duties observable behaviors at work Is this employee capable of performing the following job duties: Job duties of concern Job description with behavioral indicators
Psychiatric and/or neuropsychological deficits Common referral question: I want a neuropsychological evaluation of this employee Employee exhibiting bizarre behavior at work: inappropriate with supervisors and students Reporting that others are discriminating against her No clear evidence of any physical illness or injury preceding these episodes
Neuropsychological testing is not a substitute for appropriate employee supervision, training, and documentation of work performance
Why Neuropsychological Tests? Indicators of functional impairment at exposure levels below those that produce overt tissue or organ damage Simple, noninvasive methods to monitor effects of exposure or disease Functional correlates of central nervous system Standardized, behavioral evaluation of specific cognitive skills Performance compared to normative standard Indicator of impaired behavior that could compromise safety on the job
Ecological Validity Are the decrements observed clinically meaningful? What critical functions do they predict?
What is Clinical Impairment?
When does a neuropsychological decrement compromise safety? Tasks to be performed require vigilance and working memory (e.g., monitor complex operational systems) Driving or operating vehicles (analogy to ETOH) Fine motor coordination and steadiness required to perform operations (machinery, discharge a weapon, surgery) It depends...
Interpretation of Neuropsychological data must incorporate patient history and mental status Psychiatric & Medical History - ETOH & Drug Use - Head Injuries - Neurologic Disorders - Major Medical Illness Current Mental Status - Thought Disorder - Oriented to Person, Place, & Time - Use of Prescription & Over-the-Counter Medication, Caffeine, Alcohol
Patient Characterization Sensory Function - Vision - Hearing - Tactile Perception - Estimate of Premorbid Intellectual Function - school performance
When to refer for neuropsychological testing: brain injury due to accident 32 year old, single, Caucasian police officer College education Traumatic brain injury in MVA Coma for one month subarachnoid hemorrhage, subdural hematoma Cognitive rehabilitation for 2 years SSRI antidepressant treatment for one year Can this employee perform his job?
Fitness for Duty: Police Duties 1. Confronting subject prior to arrest: A. Must be able to effectively communicate, sometimes in a commanding manner, to instruct a suspect or criminal 2. Must possess and carry a service weapon at all times 3 Must possess the ability to determine when deadly force shall and shall not be used 4. Observe, record, recall and report incidents and information on police matters 5. Maintain high mental alertness and readiness to act even during extended period of calm and inactivity 6. Understand and follow orders, policies and procedures
Fitness for Duty: Police Duties (Cont d) 7. Withstand and deal appropriately with high levels of stress inherent in police work without presenting any risk to oneself or others 8. Must have the ability to organize and remember critical facts concerning the investigation 9. Must be capable of managing people in distress 10. Must be able to effectively interview/communicate with victims, suspects, witnesses and informants 11. Communication skills to verbally direct and control victims, crowds, and other emergency response personnel in any crisis to ensure the safety and preservation of life and property (loud and soft tones of voice) 12. Writing skills to depict events of police investigation
2002 Test Administration
Perceptual Motor & Attention/Concentration Psychomotor Reaction time, vigilance, digit symbol Concentration & Information Processing Digit span, mental arithmetic
Psychomotor Skills Neuropsychological motor speed, Testing in eye Occupational hand Medicine coordination Finger Tapping Grooved Peg Board
2002 Administration Age & Education Corrected T-Scores Average 80 70 60 50 40 30 20 10 0 Dominant Finger Tapping Non-Dominant Grooved Peg
Monitor Progression of Cognitive Skills in Rehabilitation: One-year follow-up after cognitive rehabilitation
2003 Administration Age & Education Corrected T-Scores Average 80 70 60 50 40 30 20 10 0 Finger Tapping Dominant Non-Dominant Grooved Peg
Job duties and cognitive rehabilitation Capacity to carry and use a weapon Ability to remember details of incidents Make judgments of when force is required Slowed motor speed Memory function within average range Processing speed and working memory within average range Comprehension and problem solving within normal range
Deterioration of Work Performance 58 year old, married, Caucasian male Master s degree in social work 20 year history of alcohol abuse: dependence and blackouts 11 year history of anxiety and depression Stable SSRI treatment
Job Performance: interaction of psychiatric and neuropsychological deficits Memory loss at work forgetting conversations; frequent questions Lack of supervisory direction for employees Difficulty completing tasks that were previously routine
Verbal and Visual Memory - The ability to register, store, and retrieve learned information Verbal Memory Word lists or associations: List A (Monday List) drill plums vest parsley grapes paprika sweater wrench chives tangerines chisel jacket nutmeg apricots pliers slacks Short Stories: Story A Anna Thompson / of South / Boston /, employed / as a cook/ in a school / cafeteria /, reported / at the City Hall / Station / that she had been held up / on State Street/ the night before/ and robbed/ of fifty six dollars/.
Job duties vs. neuropsychological results Forgets conversations and work instructions Poor supervision of employees Difficulty completing tasks that were once routine Verbal memory impairment Depression Processing speed is slowed
Progressive Dementia 30 year old, black, single female College graduate in chemical engineering Employed as an environmental engineer Severe headaches caused by cerebral aneurysm Left frontal craniotomy to repair the aneurysm Vocational rehabilitation for one year Hospitalized for paranoid ideation Stelazine, cogentin, tenormin
Work Performance Unclear written correspondence Inaccuracies in work Requires close supervision low mood and poor attitude in response to criticism
80 70 60 50 40 30 20 10 0 WAIS-R Age/Education Corrected T-Score Arithmetic Comprehension Similarities Picture Completion Picture Arrangement Block Design Object Assembly Digit Symbol Verbal Performance Full Scale Vocabulary Digit Span Information Average
Executive Function Ability to think in concepts and to generalize from specific instances; ability to plan and think ahead based on anticipated consequences Proverbs - What does this saying mean? Shallow brooks are noisy Similarities - In what way are an ORANGE and a BANANA alike?
Card Sorting - Executive Function Tower Tests -
Mental Flexibility Age/Education Corrected T-Score Average 80 70 60 50 40 30 20 10 0 Trail Making Test A Trail Making Test B
Verbal Learning and Memory Number Correct Perseverations 18 16 14 12 10 8 6 4 2 0 Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Trial B Free Cued Free Cued List A Immediate Short Delay Long Delay Recog. Hits Peserv.
Matching job duties with neuropsychological results Job title: engineer Written reports contain significant errors Does not notice errors in spite of numerous corrections College education as normative base Complex learning impaired: arithmetic, conceptual problems/abstract thinking High perseverations on verbal learning
Psychiatric vs. Organic Brain Syndrome 46 year old, married, high school educated, Caucasian male Exposed to chlorodifluromethane (Freon 22) in work as a refrigerator mechanic No loss of consciousness but pt. Reported fearing he would die Numerous symptoms including poor concentration, dizziness, depression, fatigue, panic, poor memory
Indices of Poor Effort: Test of Memory Malingering Recognition memory worse than recall of newly learned information Symptoms are inconsistent with injury Performance on easier tasks is worse than on more difficult tests Inconsistent performance
120 100 80 60 40 20 0 Index Score Summary WAIS-III WMS III Working Memory Process. Speed Auditory Immed Visual Immed. Immed. Memory Auditory-Delay Visual-Delay Auditory Recog.-Delay Genrl. Memory Working Memory Percept. Organiz Verbal Comprehen
Test of Memory Malingering Patient Traumatic Brain Injury No Cognitive Impairment Dementia Number of Correct Responses 60 50 40 30 20 10 0 Trial 1
120 110 100 90 80 70 60 50 40 30 MMPI-2 T-Score Depression Hypochondriasis Masculinity/Feminity Paranoia Psychasthenia Schizophrenia Mania Social Introversion Hysteria Average
Continuum of Effects Test Sensitivity in descending order Mood and symptoms Motor speed Psychomotor speed/latency of response Working memory & vigilance Learning and memory Executive function and judgment Intelligence
Conclusions Neuropsychological tests can predict the ability to perform specific job duties, but are best for jobs that require skills similar to what the tests evaluate Questions of fitness for duty need to be accompanied by behavioral descriptions of job duties and evidence of on-thejob employee behavior Behavioral data rather than diagnoses are most informative about the ability to perform a job testing can provide such data