The Medical Work-up of the Environmentally Ill Patient

[Guest guest]

I want to thank our silent sister for all the

information she's been sending our way! . . . - Rogene

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The Medical Work-up of the Environmentally Ill Patient

Gunnar Heuser, M.D., Ph.D.

" Good morning; guten Morgen; bonjour, " began Dr.

Heuser, adding that it was " a pleasure to be here with

such a distinguished audience. "

Saying that he was approaching MCS from the point of

view of a clinical toxicologist, Dr. Heuser said that

he sees patients from near and far who have been

exposed to chemicals. Despite having already seen

numerous doctors who could find nothing wrong, these

patients still feel that they are sick. " We listen,

and have a test for most symptoms. We take a protocol

approach and do a thorough work-up. Almost every one

of them has something wrong. "

The potential for chemical injury is acknowledged if

the concentration of a given chemical is in excess of

government-regulated limits for a specific time

interval. However, Dr. Heuser said that although fewer

people believe that one can get sick with lower levels

of exposure, he does believe in chemical sensitivity

and believes that MCS has a physical base. He said

that he selected two concepts to cover in the 30

minutes allotted—mast cells and the limbic system.

Both affect multiple organs and can manifest in

multiple systems complaints.

Dr. Heuser recalled the history of one patient who

came to him after repeated admissions to the emergency

department at UCLA following exposure to very small

amounts of chemicals. Despite testing and avoiding

known triggers, she still suffered from very serious

reactions. Upon questioning her, Dr. Heuser learned

that she had a flushing sensation and a metallic taste

in her mouth at the time of her reaction, both of

which he knew may be symptoms of a mast cell disorder.

Her history of exposure went back to an exposure to

pesticides in the 1970s, and she was experiencing

multisystem symptoms. A skin biopsy confirmed nests of

mast cells in higher than normal concentrations.

Suspecting that her son might also be affected, Dr.

Heuser tested him as well. He too was positive, and

proved to be " exquisitely sensitive to chemicals. "

Suspecting that there might be a connection between

MCS and a mast cell disorder, Dr. Heuser contacted

experts and support groups. The first issue he read of

the Mastocytosis Chronicles described the triggers of

a young boy with mastocytosis, triggers that sounded

very similar to those for MCS. Communication by phone

with many mastocytosis patients showed that more than

half complained of sensitivity to small doses of

chemicals (fumes, perfumes, others). Symptoms of

mastocytosis include flushing and many dysfunctions of

the central nervous system, and have a very similar

symptom complex to that of MCS.

Dr. Heuser showed a slide entitled " Mast Cell

Mediators and their Role in Interstitial Cystitis. " He

said that elevated levels of one of the prestored

mediators, tryptase, supports a diagnosis of mast cell

disease. The diagnosis of both mast cell disorder and

MCS has been confirmed by means of skin biopsies for

close to 20 patients, a number that Dr. Heuser said

was significant. When he attended a support group for

those suffering from mastocytosis, Dr. Heuser said he

noticed a button on display advocating a perfume-free

environment, and was struck by how chemically

sensitive mast cell patients are.

Dr. Heuser, who received his Ph.D. in Montreal under

Dr. Hans Selye, author of a textbook on mast cells,

said that he has now come full circle in his research.

He urged others to allow for the possibility that

those with MCS may in fact have mastocytosis, or at

least a mast cell disorder.

The limbic system provides easy access to the brain

when chemicals are inhaled. When one inhales through

the nose, the little nerves in the roof of the

nose—which Heuser described as " dangling in the

wind " —pick up the chemical and, if the protective

detoxification function of the mucosa fails, that

chemical has easy access to the brain. The message

will go through the olfactory bulb, which provides a

pathway to the limbic system.

Dr. Heuser said the University of California at Irvine

(UCI) has developed a baseline of over 60 normal PET

(positron emission tomography) scans, answering the

need for a control group. Twenty of Dr. Heuser’s

patients have had PET scans at their own expense, and

all were shown to be " exquisitely sensitive to

chemicals. " The scans he showed depicted abnormalities

in colour. Blue showed a decreased metabolism and

uptake of glucose and was present in the cortical

areas. Yellow and red indicated an increased uptake of

glucose. The slides showed a decreased metabolism in

the periphery and an increased metabolism (or " hot "

area) in the limbic and brain stem areas. Tests on the

most severe patients showed a " striking imbalance

between hot and cold. "

All of this shows that the amygdala (part of the

limbic system) is hot, and not normal, commented Dr.

Heuser. Olfactory stimuli from the olfactory bulb

travel to the extended amygdala complex (EAC), which

functions as a way station to other structures,

including the hypothalamus. Visual, auditory,

somatosensory, and other sensory inputs acquire

emotional significance by being interpreted in the

EAC, which controls reactions of fear and other strong

emotions. Dr. Heuser said that a number of his

patients " fall apart, " and have a dramatic reaction

when exposed to chemicals. He recounted that in an

experiment, a patient with epilepsy had a seizure

triggered by a discharge from the amygdala and

displayed a panic reaction. He suggested that perhaps

the reason that some patients with MCS are so

emotional is that their emotional reactions are linked

to a discharge deep down in the amygdala.

The EAC is one of the most easily kindled structures

in the brain, and once kindled, the resultant changes

in EAC function are long term. Experiments with

animals showed that when given low-level electrical

shocks there was no reaction at first. After close to

20 doses, some animals react with grand mal seizures

after the same low-level electrical shock. That is

kindling, a process that can take place with

chemicals, as well. EAC function has been shown to

play a significant role in kindling in animals exposed

to pesticides, xylene, and other chemicals.

In summary, Dr. Heuser said that mast cells and/or the

limbic system and its connections appear to play a

significant role in patients with MCS. Although their

potential interaction remains to be studied, he said

he was confident that one day it will be.

Dr. Heuser said that as he is in private practice he

receives no grants for his research and can only

acknowledge his patients. He expressed a debt of

gratitude to his wife, Sylvia, who helped to put this

presentation together. " Merci beaucoup. C’était un

grand plaisir d’être ici aujourd’hui, " he said in

conclusion.

Questions and Comments

Saying that he wanted to turn his attention to

neurodiagnostic imaging, a doctor asked if it had been

validated. He also asked about the baseline, and

suggested that findings were concurrent with that of

an anxiety disorder. He asked if there was a control

group.

Dr. Heuser replied that UCI is one of the few centres

with a control population.

Dr. Ross noted that Dr. Simon will discuss control

groups later on at this conference.

Last Modified: 2004-02-10