Forensic Evaluation of Neuropsychological Decline Following Solvent Exposure

Forensic Evaluation of Neuropsychological Decline Following Solvent Exposure

Raymond Singer, Ph.D.
Independent Practice
Santa Fe, New Mexico
and
New York, New York
www.neurotox.com
ray.singer@gmail.com
Published until Nov 15 at: http://neurotox.blogspot.com/

Presented at the National Academy of Neuropsychology 28th Annual Meeting, New York City, October 25, 2008.

Objective: Forensic analysis of naphtha-exposed sailor with severe anxiety/depression and personality deterioration. Were his symptoms and illnesses due to acute naphtha workplace exposure?
Case:
Gender: Male
Age at exam: 45
Educational level: 6th grade
Height: 5'9"
Weight: 200
Ethnicity: White
Marital Status: Married but separated
The Chemical Exposure
History of accident: The subject had unloaded 50,000 gallons of naphtha from a tugboat barge the night before the accident, with inhalation exposure. The next day, he was removing the puddles of naphtha from the open tank. Per the first responder Ambulance Report: The subject was found unconscious and unresponsive on a tugboat in a booth in the galley. (The galley is the compartment of a ship, submarine, train or aircraft where food is cooked and prepared).
The crew stated that the patient had unloaded 47,000 barrels of naphtha the night before (from the barge of the tugboat to storage onshore). He had gone to bed, woke in the morning, and started cleaning residue from the hold of the barge. At about 1600 hrs, he went into the galley and told a crew member he felt weak and dizzy, with numbness and tingling of both shoulders. The patient then collapsed.
A crew member stated that he observed that the patient had periods of apnea (cessation of breathing) lasting 11-30 seconds, with breath returning after the crew member shook the patient. When found by the ambulance crew, the patient was unconscious and unresponsive to verbal and painful stimuli.
After an intravenous line was started, the patient complained of shortness of breath and dizziness occurring earlier. The patient stated that he had inhaled much naphtha during cleaning residue from the hold of the barge; that he got some naphtha on his hands; and that he had not worn a respirator.
Neurotoxic hazards of naphtha: Naphtha, AKA petroleum ether, is a well known neurotoxic agent. Acute neurotoxic effects of petroleum ether include anesthesia, euphoria, vertigo, and limb numbness. Note that the subject had all of these acute symptoms (method of clinical diagnosis).
Chronic effects include CNS symptoms of headache, fatigue, poor concentration, emotional instability, impaired memory and other intellectual functions, and impaired psychomotor performance. Neuropsy-chological testing is recommended by medical authorities for this exposure and resulting symptoms.
Medical record review found: Dyspnea, trouble sleeping at night, pulmonary edema due to fumes and vapors, headache, dizziness, and generalized weakness, following his exposure, decreased vital capacity and severe decrease in diffusion capacity of the lungs, probable restricted pulmonary function, organic brain disease, sensory nerve conduction studies of the bilateral trigeminal nerve found bilateral disease; regarding the median nerves, slight abnormality on the left, severe abnormality on the right. Regarding ulnar nerves, slight abnormality on the left, moderate abnormality on the right; lung inflammation; mild restrictive pulmonary function, mildly decreased oxygen level in blood, pulmonary function tests results consistent with restrictive defect, diffuse peripheral neuropathy with axonal degeneration radiculo-neuropathy (bilateral neuropathy of the ulnar nerve across the elbow). He said a hospital diagnosed sleep apnea, but he did not provide those records.
He had never been diagnosed with a psychiatric disorder. He had no prior head or neck injuries, loss of consciousness, chronic headaches or any health problems.
Symptoms: The subject reported: "When I first got hurt, I shut myself up in the rear of my house for a year and a half - I was so depressed, I couldn't get myself off the bed... I shut myself away from everybody for 1- 1.5 years, except for doctors. Everything bothered, annoyed and frustrated me - then I get angry."
"When this first happened, I slept all the time. Now I can't go to sleep. I sleep from 4 - 8 am... If I go to sleep any earlier, I'll awaken in an hour or so and then stay awake."
He now lives in a trailer on grandmother's property- "I don't go nowhere". Prior to his illness, he had renovated his own home, which was on the historical registry. In addition to his home, he owned the property next door, and five properties in Houston - one was commercial. He also owned and managed two taxicab companies, and maintained his own vehicles. He also owned and maintained by himself an antique sports car. When not working, he hunted, fished, swam and danced.
He did not have illnesses before this accident, except pneumonia once, but he kept working anyway.
Since his illness, he lost his cab company, his wife separated from him, and he is a hermit, stating "I don't even go to a picture show... the furthest I go is to a doctor in town, maybe grab a burger and eat on the way home. I live next door to my grandmom, and I rarely go visit her. I get real irritable, I get depressed, with lot of things on my mind, and I don't feel like being around people".
Results: See Appendix 1. Average intelligence was used for comparison purposes. Declines were found in all WAIS-III indices; WMS-III and the SRT found deficits in various memory functions; executive dysfunction was found by declines in word and visual fluency, trailmaking, and visual search and attention test. Emotional function declined with Beck severe anxiety and extremely severe depression. Quick Environmental Exposure and Sensitivity Inventory was highly elevated. Distortion not found, using M-FAST, Boone et al. Dot Counting, Portland Digit Recognition Test, and additional malingering tests. NEO-R found declines in personality, including possible personality disorders (see Appendix 2).
Conclusions: The subject was unaware of his cognitive decline, yet testing showed clear declines from prior levels of neuropsychological function, with emotional and personality deterioration caused by acute naphtha exposure.
Appendix 1: Results
Wechsler Adult Intelligence Scale, Third Edition: WAIS-III:
Age - Adjusted
Scaled Scores Percentile
Verbal Subscales
Vocabulary 6 9%
Similarities 7 16%
Arithmetic 7 16%
Digit Span 5 5%
Information 7 16%
Comprehension 10 50%
Letter-Number
Sequencing 9 37%
Performance Subscales
Picture Completion 6 9%
Digit Symbol - Coding 4 2%
Block Design 8 25%
Matrix Reasoning 7 16%
Picture Arrangement 10 50%
Symbol Search 3 1%
Object Assembly 7 16%
Score Percentile Confidence Interval - 90%
IQ Scores:
Verbal IQ: 82 12% 78 - 87
Performance IQ: 80 9% 76 - 87
Full Scale IQ: 79 8% 76 - 83
Index Scores:
Verbal Comprehension 82 12% 78 - 87
Perceptual Organization 82 12% 77 - 89
Working Memory 82 12% 77 - 89
Processing Speed 68 2% 64 - 79
Interpretation: Deficit in all indexes of cognitive function.
Wechsler Memory Scale, Third Edition (WMS-III):
Primary Subtests Age Scaled Score Percentile
Logical Memory I - Recall 5 5%
Faces I - Recognition 7 16%
Verbal Paired Assoc. I - Recall 7 16%
Family Pictures I - Recall 8 25%
Letter-Number Sequencing 9 37%
Spatial Span 8 25%
Logical Memory II - Recall 7 16%
Faces II - Recognition 9 37%
Verbal Paired Assoc. II - Recall 6 9%
Family Pictures II - Recall 8 25%
Auditory Recognition - Delayed 6 9%
Auditory Process Subtests
Logical Memory I
1st Recall Total 5 5%
Learning Slope 11 63%
Verbal Paired Assoc. I
1st Recall Total 7 16%
Learning Slope 8 25%
Logical Memory II
Percent Retention 9 37%
Verbal Paired Assoc. II
Percent Retention 6 9%
Confidence
Primary Index Scores Index Score Percentile Interval (90%)
Auditory Immediate 77 6% 73 - 84
Visual Immediate 84 14% 78 - 95
Immediate Memory 76 5% 71 - 85
Auditory Delayed 80 9% 75 - 90
Visual Delayed 91 27% 84 - 101
Auditory Recog. Delayed 80 9% 76 - 95
General Memory 81 10% 76 - 89
Working Memory 91 27% 84 - 100
Sum of
Auditory Process Composites Scaled Scores Percentile
Single Trial Learning 12 3%
Learning Slope 19 44%
Retention 15 15%
Retrieval -1 34%
Interpretation: Deficit in auditory and immediate memory.
Comprehensive Trail-Making Test (CTMT)
Trail # Raw Score T-Score Percentile Description
1 70 29 2%
2 96 24 <1%
3 96 25 <1%
4 131 18 <1% *Note: patient made 2 mistakes.
5 112 28 1% *Note: patient made 1 mistake.
Total 124
Composite Index 22 1%
Interpretation: Deficit in executive function.
Controlled Oral Word Association Test
Raw Score Correction Total Percentile Classification
20 +3 23 4% Deficient
Interpretation: Deficit
Perseverations: 0 56% Intact
Embedded Figures Test:
Number detected out of 40 objects: 28 Percentile for age and education: 23% Interpretation: Within normal limits
Grooved Pegboard Test evaluates manual dexterity (the ability to use hands in a sensitive and productive way). Dominant Hand: Right
Dominant Non-dominant
Time for completion: 98" 113"
Percentile: 7% 1%
Interpretation: Deficit Deficit
Neurotoxicity Screening Survey:
Factor Results
Score Classification
Memory and Concentration...... 133 Elevated
Autonomic Nervous System...... 95 Elevated
Vision........................ 30 Elevated
Hearing....................... 14 Elevated
Balance....................... 5 Elevated
Smell-Taste................... 12 Elevated
Peripheral Numbness........... 34 Elevated
Sensory-Motor................. 74 Elevated
Chemical Sensitivity.......... 6 Elevated
Emotionality.................. 77 Elevated
Distortion I.................. 13 Within Normal Limits
Distortion II................. 16 Within Normal Limits
Overall Neurotoxicity Indicator: 480 Elevated
Interpretation: Results consistent with those of patients diagnosed with neurotoxicity.
Paced Auditory Serial Addition Test Note: Patient did not complete because he could not understand the instructions. Interpretation: Deficit
Ruff Figural Fluency Test
Error Education
Raw Ratio Correction Total Percentile Interpretation
Unique Designs 41 +12 53 2.3% Impaired
Perseverations 9 0.2195 -0.03 0.1895 84.1% Low Average
Interpretation: Deficit in executive function.
Selective Reminding Test
Words continuously remembered, summed over trials (CLTR): 33
Expected: 78.9
Percentile rank for gender, age and education: 12%
Interpretation: Deficit
Stroop Color and Word Test evaluates mental flexibility (45 sec administration).
Raw Age/Ed
Score Predicted Residual T-Score Percentile Interpretation
Word reading: 64 87 -23 34 6% Deficit
Color naming: 56 69 -13 39 14% Within normal limits
Color/Word: 22 30 - 8 42 21% Within normal limits
Interference: 22 31 - 9 41 18% Within normal limits
Visual Search and Attention Test
Left Right Total
Score 35 28 63
Percentile 1% 1% 1%
Interpretation: Deficit Deficit Deficit
Wide Range Achievement Test
SS Percentile Grade Equiv. Classification
Reading 62 1% 3rd Grade
Spelling 57 <1% 2nd Grade
Arithmetic 77 6% 5th Grade
Interpretation: Deficit
EMOTIONAL FUNCTION
Beck Anxiety Inventory. Score: 33 Interpretation: Severe anxiety
Beck Depression Inventory. Score: 35. Interpretation: Extremely severe depression
Profile of Mood States
Raw Score T Score %
Tension 30 63 90%
Depression** 40 62 89%
Anger/Hostility 42 78 79%
Vigor 6 42 21%
Fatigue 22 66 95%
Confusion/Bewilderment 15 54 66%
Interpretation: Showed moods of tension, depression, anger, and fatigue.
Psychiatric Diagnostic Interview - Revised screens for Organic Brain Syndrome. Interpretation: Impaired.
Whitaker Inventory of Schizophrenic Thinking Index: 22
Interpretation: Intermediate probability of schizophrenic thinking.
WELL-BEING MEASURES
Alcohol Use Disorders Identification Test (AUDIT) was developed by the World Health Organization to identify alcohol use disorders. Cutoff = 8
Score: 0 Interpretation: Alcohol use problems are unlikely.
Fatigue Severity Scale identifies fatigue with features that are specific to the medically ill. These features are largely independent of depressive symptoms of fatigue.
Mean score: 7 Interpretation: Consistent with medically ill patients
General Well Being Schedule evaluates general well-being compared with the population of the US.
Score: Severe Distress
Human Activity Profile measures levels of physical activity.
Score Percentile
Maximum Activity Score 57 <1%
Adjusted Activity Score 31 <1%
Activity Age 70+
Activity Classification Impaired
Dyspnea Scale 2 52%
Interpretation: Deficit
Quick Environmental Exposure and Sensitivity Inventory, Version 1 (QEESI) identifies health problems respondent may experience in response to various environmental exposures.
Score Interpretation
Chemical Intolerance 66 High
Other Intolerance 33 High
Symptom Severity 85 High
Masking Index 4 Medium
Life Impact 64 High
Interpretation: Very suggestive of multiple chemical intolerance.
DISTORTION AND MALINGERING TESTS
Absurd responding checks for very unusual responses, suggestive of malingering or a psychiatric disorder. Subject passed this test.
Amnesia Questionnaire assesses the subject's possible mis-reporting memory symptoms.
Number correct of 14: 12 Interpretation: Non-malingering
Dot Counting Test detects suspect test-taking efforts in adults. This respondent's answers were compared to the Head Injury normative sample in a medico-legal neuropsychological assessment environment.
Comparison Group: Mild Dementia
E-Score: 10 E-Score Cutoff: 22
Signs of suspect effort
Does mean Grouped time exceed mean Ungrouped time by 1 sec? No
Are there counting errors on Card 6 and/or Card 12? No
Interpretation: Normal Effort
Endorsement of Rare Symptoms. The Neurotoxicity Screening Survey presents 14 symptoms that are rare. If a number of these symptoms are endorsed, the question of distortion is highlighted.
Number endorsed: Distortion I: 2 Distortion II: 3 Interpretation: Non-malingering
Even-Odd Forced Choice Test requires the subject to add two single digit numbers, and determine whether the product is even or odd. If the subject's performance is random, the results will still be approximately the same as the results of someone performing absolutely correctly.
Number correct: 19/20 Interpretation: Non-malingering
Memorization of "16" Items (Iverson & Franzen, 1991) requires the subject to memorize a list of 16 items. Because the 16 items are grouped into four conceptual categories, the task is easier than it looks. A cutoff of 6 is used to suggest malingering.
Number correct: 16/16 Interpretation: Non-malingering
Miller Forensic Assessment of Symptoms Test (M-FAST)
Raw Score
Reported vs. Observed 0
Extreme Symptomatology 1
Rare Combinations 0
Unusual Hallucinations 1
Unusual Symptom Course 0
Negative Image 1
Suggestibility 0
Total 3
Interpretation: Within normal limits
Portland Digit Recognition Test
Percent correct responses (5 sec delay): 5/8
Percent correct responses (15 sec delay): 5/7
Percent correct responses (30 sec delay): 5/5
Interpretation: Non-malingering
Three Word Memory Test Number correct: 13/13 trials Interpretation: Non-malingering
Twenty-one Item Memory Test
Number of words correctly recalled:
Free recall: 3
Forced choice: 11
Interpretation: Non-malingering
Recognition testing: Recognition is an easier task than recall.
Recognition tests*** Results Classification
Logical Memory II
24/30
good or better effort

Verbal Paired Associates II
19/24 word pairs
acceptable effort

Word Lists II (min. 18)
15/24
severe brain damage or poor effort

Visual Reproduction II
43/48
excellent effort

Auditory recognition - Delayed (min 43)
43/48
excellent effort



Appendix 2: NEO Personality Testing
Validity indices are within normal limits.
The subject is experiencing a high level of negative emotion and frequent episodes of psychological distress. He is moody, overly sensitive, and dissatisfied with many aspects of his life. He is low in self-esteem. He is a worrier.
The subject is quite introverted, quiet and reserved regarding group interactions. He rarely experiences joy or excitement. He would be described as reserved, serious, retiring and a loner.
The subject has a strong preference for the familiar and pragmatic. He likes routine, is set in his ways, with little desire for change in himself or his world. His respect for authority and his reluctance to question established values may make him a defender of tradition. He is down to earth, conforming, unadventurous, and conventional.
The subject at times can be antagonistic, brusque, and even possibly rude. He can be described as relatively stubborn and critical.
Apparently since his illness, the subject has a low need for a achievement, lack of self-discipline, is unreliable and careless.
The subject can be described as aloof, reserved, arrogant, cold and unfeeling.
Possible personality disorders: Borderline features or a Borderline Personality Disorder; Antisocial Personality Disorder; Narcissistic Personality Disorder; Avoidant Personality Disorder; and Obsessive-Compulsive Disorder.