Background: There
are reports in the literature of long-term
neurobehavioral dysfunction in persons with pesticide exposure,
primarily in occupational settings. This report presents data
concerning a subject with non-occupational and apparently
single-incident exposure.
A home with open windows and a property were sprayed by helicopter
with a mixture of pesticides, including chlorpyrifos, a carbamate
(carbofuran) and an organophosphate.
Three dogs on the property, fed from separate cans of food, were
vomiting and listless, and were diagnosed by their veterinarian with
pesticide poisoning.
The subject reported initial symptoms of anxiety, itching on face
which spread over her body, dizziness and forgetfulness, with sleep
frequently interrupted around 2-3 AM with symptoms of breathlessness, followed
by numb hands and feet and a feeling of "blacking out".
She continued to reside in the home during the time when the pesticides
were still potent. Her primary symptoms at the time of this examination,
three years later, were disabling chemical sensitivity, along with sleep
apnea-like episodes, and memory problems. ...
Methods: Physical examination
which ruled out other causes of the
symptoms, medical record review, brain MRI and neuropsychological
testing.
Results:
Brain MRI showed diffuse scattered foci of increased
signal
intensity in the subcortical and periventricular white matter tracts.
Organophosphate pesticides are known
to cause degeneration of
the myelin.
From normal or better pre-exposure function, declines in function included
arithmetic (5th %); Digit Symbol and Symbol Search (9th %); visual memory
(BVRT, 11 errors); Embedded Figures (1st %); Paired Associates Learning
(1st %) and logical memory (1st %).
Personality testing showed no personality disorder.
[Note:
Below are several paragraphs from the text of the article
which
describe in more detail the patient's actual loss of cognitive
skills.
Her pre-exposure GPA was 3.7, and she had been a member of
Phi Theta Kappa (National Honor Society) and Sigma Tau Delta
(National English Honor Society). The subject was working at
home at the time of exposure.
Current neurobehavioral testing revealed
a FSIQ at the 25th
percentile; performance IQ at the 18th percentile; processing
speed at the 8th percentile; psychomotor speed at the 9th
percentile; arithmetic at the 5th percentile.
A decline in overall intelligence was detected, along with
specific deficits in arithmetic skills, psychomotor speed,
visual perception (visual detection skills), and incidental
memory. When looking at index scores, deficits can be seen
in perceptual organization and processing speed.
The Benton Visual Retention Test
found strong indication
of acquired impairment of cognitive functioning (11 errors).
An Embedded Figures Test which evaluates the ability to
detect visual figure-ground relationships found performance
below the 1st percentile.
The Expanded Paired Associate Test, which evaluates verbal
learning ability, found deficits in immediate recall (1st %)
and
delayed recall (11th %).
Auditory information processing and tracking was below
the 1st %. Logical memory ability, both immediate and
delayed,
was reduced by half. There was no evidence of psychoses,
distortion or malingering based upon numerous tests of these
variables.]
Conclusion: Doctors
need to be aware that pesticide exposure can lead
to permanent neuropsychological deficits, even with a "single" exposure.
Brain dysfunctions from neurotoxicity can be revealed with appropriate
neuropsychological testing.
Click here
for the entire text Dr. Raymond Singer's
article.
1. Singer, R. (1999, expected).
Neuropsychological evaluation of bystander exposure
to pesticides. The Journal
of Neuropsychiatry and Clinical Neurosciences, 9, 1.
RAYMOND SINGER, PH.D., P.A.
36 Alondra Road / Santa Fe, New Mexico /87505
180 E. 79th Street / Suite 1-C / New York, N.Y. / 10021
Telephone: (505) 466-1100
Fax: (505) 466-1101 /
Email: raysinger@aol.com
Source:
http://members.aol.com/neurosite/pest99.htm
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