Multiple Chemical Sensitivity (MCS) is a chronic acquired disorder of unknown pathogenesis. The aim of this study was to ascertain whether MCS patients present brain single photon emission computed tomography (SPECT) and psychometric scale changes after a chemical challenge.
This procedure was performed with chemical products at non-toxic concentrations in 8 patients diagnosed with MCS and in their healthy controls.
• In comparison to controls, cases presented basal brain SPECT hypoperfusion [reduced blood flow] in small cortical areas of the right parietal and both temporal and fronto-orbital lobes.
• After chemical challenge, cases showed hypoperfusion [increased blood flow] in the olfactory, right and left hippocampus, right parahippocampus, right amygdala, right thalamus, right and left Rolandic and right temporal cortex regions.
• By contrast, controls showed hyperperfusion in the cingulus, right parahippocampus, left thalamus and some cortex regions.
• The clustered deactivation pattern in cases was stronger than in controls (p=0.012)
• And the clustered activation pattern in controls was higher than in cases (p=0.012).
In comparison to controls, cases presented:
• Poorer quality of life and neurocognitive function at baseline,
• And neurocognitive worsening after chemical exposure.
Chemical exposure caused neurocognitive impairment, and SPECT brain dysfunction particularly in odor-processing areas, thereby suggesting a neurogenic origin of MCS. [Neurogenic – “starting with or having to do with the nerves of the central nervous system.”]
Source: Journal of the Neurological Sciences, Oct 2, 2009. PMID: 19801154, by Orriols R, Costa R, Cuberas G, Jacas C, Castell J, Sunyer J. Servei de Pneumologia, Hospital Universitari Vall d' Hebron, Barcelona, Catalonia, Spain; CIBER Enfermedades Respiratorias (CIBERES), Spain. [E-mail: firstname.lastname@example.org]