Neurospect Findings in Patients Exposed to Neurotoxic Chemicals

Abstract

Exposures to neurotoxic chemicals such as pesticides, glues, solvents, etc. are known to induce neurologic and psychiatric symptomatology. We report on 41 patients 16 young patients (6 males, 10 females, age 34 8 yrs.) and 25 elderly patients (9 males, 16 females, age 55 7 yrs). Fifteen of them were exposed to pesticides, and 29 to solvents. They were studied with quantitative and qualitative analysis of regional cerebral bood flow (rCBF), performed with 30 mCi of Xe-133 by inhalation, followed by 30 mCi of Tc-HMPAO given intravenously. Imaging was performed with a brain dedicated system, distribution of rCBF was assessed with automatic ROI definition, and HMPAO was normalized to maximal pixel activity in the brain. Results of Xe rCBF are expressed as mean and S.D. in ml/min/100g, and HMPAO as mean and S.D. uptake per ROI, and compared with age-matched controls 10 young and 20 elderly individuals. Neurotoxics HMPAO Uptake Young Elderly R. Orbital frontal R. Dorsal frontal .70 .66 p < 0.05 R. Temporal .64 p < 0.001 R. Parietal .66 .66 We conclude that patients exposed to chemicals present with diminished CBF, worse in the right hemisphere, with random presentation of areas of hypoperfusion, more prevalent in the dorsal frontal and parietal lobes. These findings are significantly different from observations in patients with chronic fatigue and depression, suggesting primary cortical effect, possibly due to a vasculitis process.

Italian Expert Consensus on Clinical and Therapeutic Management of Multiple Chemical Sensitivity (MCS)

“…Despite MCS patients often displaying a normal neurological exam, environmental exposures may negatively modulate the nervous system (spatial disorientation, short-term memory loss, tinnitus, tremors, convulsions) in susceptible subjects [ 1 ]. Thus, the neurological armamentarium may also include the following clinical and instrumental tests: Pupillography [ 75 ]; Simple and choice reaction time tasks [ 76 ]; Balance tests [ 77 ]; Visual contrast tests [ 78 , 79 , 80 , 81 ]; Visual color tests [ 82 ]; Tests of the perception of vibrations [ 77 ]; Electroencephalography (EEG) [ 82 ]; Single-photon emission computed tomography (SPECT) [ 83 , 84 , 85 , 86 ]. …”

Colour vision defects in occupational chronic solvent encephalopathy

“…8 In addition, SPECT studies have revealed possible frontal and parietal hypoperfusion. 9 However, the pathological brain tissue findings have not been localized to any specific brain region or tissue compartment, although the neuropsychological findings have suggested possible frontal dysfunction. 10 So far, the toxic effects of industrial solvents have remained unknown, and the diagnosis of solvent encephalopathy is achieved only by costly clinical investigations.…”