SPECT Scans Demonstrate Brain Abnormalities in Chemically Sensitive Patients
Several percent of the US population is believed to have heighted sensitivity to low level exposure to common chemicals such as 2nd hand tobacco smoke, pesticides, perfumes/colognes, cleaning chemicals and formaldehyde from carpets and building materials. Sensitivity to many common chemical exposures is sometimes called multiple chemical sensitivity or MCS. When exposed to low-level chemical exposures, MCS patients often experience many diverse health problems such as chronic fatigue, muscle and joint pain, asthma, sinus problems, headaches, digestive problems, dizziness and concentration/ memory problems. Chemical sensitivity usually develops after either a short heavy exposure to chemicals (such as a fire or chemical spill) and/or long term low level exposure (such as exposure to pesticides and cleaning chemicals in a poorly ventilated building).
Problems with memory, concentration and mental abilities are often particularly difficult for MCS patients. Chemically sensitive patients often report feeling “spacey” after low level chemical exposure. Recently, a Spanish study measured brain blood flow in 8 chemically sensitive (who met criteria for MCS) patients and 8 controls by the use of brain SPECT. SPECT or Single Photon Emission Computer Tomography is a way to measure the flow of blood in various parts of the body. SPECT scans were given both before and after moderate level exposure to a petroleum based paint in a booth. The MCS patients and controls were also given various “neuropsychiatric” tests of memory, attention, intelligence and motor skills both before and after the exposure to the paint
The MCS subjects had similar mental skills on the neuropsychiatric tests compared to the controls before the paint exposure, however, following the paint exposure the MCS patients had significantly lower scores on many neuropsychiatric tests of attention, memory and executive function as compared to the controls. Following the paint exposure, the MCS patients showed significant hypoperfusion (less blood flow) to many areas of the brain including the olfactory regions (which control smell), the right and left limbic system (hippocampus, parahippocampus, amygdala), the right thalamus (which plays a key role in vision and hearing), and the right temporal (side of brain) regions. The limbic system of the brain plays a key role in many important body processes such as emotions, memory, attention and autonomic functions such as breathing and balance.
This lack of blood flow to many critical areas of the brain may play a major role in causing the problems with attention, memory and general intelligence often seen in MCS patients who are exposed to low levels of chemicals. The authors concluded that “… it seems unlikely that the objective changes in the brain SPECT in our study could have been produced by a placebo mechanism”. It others words, the mental problems seen in MCS patients following chemical exposure appear to be due to the toxic nature of the chemicals themselves and not due to the worry or apprehension of smelling chemicals.
This SPECT research was published by Orriols et al and is now in Press in the Journal of the Neurological Sciences.
Martin Pall, PhD. of Washington State University has received written an excellent review of recent research on chemical sensitivity. His review was published in General and Applied Toxicology, 3rd Edition (John Wiley and Sons). This review explains how many different chemical exposures such as pesticides, solvents, formaldehyde, molds, tobacco smoke and many other chemicals can cause the wide range of symptoms seen in chemically sensitive patients. This review explains in great detail how many toxic chemicals can overstimulate the NMDA (N-methyl-D-aspartate) receptors in the brain. Overstimulation of the NMDA brain receptors can then cause disregulation of the bodies system of regulating nitric oxide (NO) and ONOO- (pronounced “Oh, No”). This disregulation of the nitric oxide system can then cause many health problems throughout the body. I encourage interested readers to read Dr. Pall’s interesting review of MCS.
Readers who want free pdf. copies of these 2 important papers on chemical sensitivity are welcome to contact me at LukeTCurtis@aol.com.