Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous
Abstract Background Chemical intolerance (CI) is a chronic condition characterized by recurring and severe symptoms triggered by exposure to low levels of odorous or pungent substances. The etiology of CI has been a controversial subject for a long time. The aim of this review is to summarize findin...
Main Authors: | , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
BMC
2019-10-01
|
Series: | Environmental Health and Preventive Medicine |
Subjects: | |
Online Access: | http://link.springer.com/article/10.1186/s12199-019-0816-6 |
id |
doaj-9ed5212788244df8ad382ae9bae41a6c |
---|---|
record_format |
Article |
spelling |
doaj-9ed5212788244df8ad382ae9bae41a6c2020-11-25T03:40:44ZengBMCEnvironmental Health and Preventive Medicine1342-078X1347-47152019-10-0124111110.1186/s12199-019-0816-6Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardousKenichi Azuma0Iwao Uchiyama1Mari Tanigawa2Ikuko Bamba3Michiyo Azuma4Hirohisa Takano5Toshikazu Yoshikawa6Kou Sakabe7Department of Environmental Medicine and Behavioral Science, Kindai University Faculty of MedicineSick-house Medical Science Laboratory, Division of Basic Research, Louis Pasteur Center for Medical ResearchOutpatient Department of Sick-house Syndrome, Hyakumanben ClinicFaculty of Education, Home Economics, Tokyo Gakugei UniversityDepartment of Human Environmental Design, Faculty of Health Science, Kio UniversityDepartment of Environmental Engineering, Graduate School of Engineering, Kyoto UniversitySick-house Medical Science Laboratory, Division of Basic Research, Louis Pasteur Center for Medical ResearchDepartment of Anatomy and Cellular Biology, Tokai University School of MedicineAbstract Background Chemical intolerance (CI) is a chronic condition characterized by recurring and severe symptoms triggered by exposure to low levels of odorous or pungent substances. The etiology of CI has been a controversial subject for a long time. The aim of this review is to summarize findings on the neurological processing of sensory information during and after exposure to low levels of odorous or pungent substances in individuals with CI, focusing on the brain function and networks. Methods Scientific studies on CI published between 2000 and 2019 in academic peer-reviewed journals were systematically searched using medical and scientific literature databases. Only peer-reviewed articles reporting original research from experimental human studies directly associated with CI, and involving related neurological responses or brain imaging after exposure to odorous or pungent substances (i.e., in chemical provocation tests), were considered. Results Forty-seven studies were found to be eligible for a full-text review. Twenty-three studies met the selection criteria and were included in this review. Evidence indicated that differences between subjects with CI and healthy controls were observed by brain imaging during and after exposure to odorous or pungent substances. Differences in brain imaging were also observed between initial exposure and after exposure to these substances. Neurological processing of sensory information after exposure to extrinsic stimuli in the limbic system and related cortices were altered in subjects with CI. A previous documentable exposure event was likely to be involved in this alteration. Conclusions This review documents consistent evidence for the altered neurological processing of sensory information in individuals with CI. Further neurophysiological research exploring the processing of extrinsic stimuli and cognition of sensation through the limbic system and related cortices in CI, and the appearance of symptoms in individuals with CI, are required.http://link.springer.com/article/10.1186/s12199-019-0816-6Brain imagingChemical intoleranceExposure eventLimbic systemMultiple chemical sensitivityOdor processing |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Kenichi Azuma Iwao Uchiyama Mari Tanigawa Ikuko Bamba Michiyo Azuma Hirohisa Takano Toshikazu Yoshikawa Kou Sakabe |
spellingShingle |
Kenichi Azuma Iwao Uchiyama Mari Tanigawa Ikuko Bamba Michiyo Azuma Hirohisa Takano Toshikazu Yoshikawa Kou Sakabe Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous Environmental Health and Preventive Medicine Brain imaging Chemical intolerance Exposure event Limbic system Multiple chemical sensitivity Odor processing |
author_facet |
Kenichi Azuma Iwao Uchiyama Mari Tanigawa Ikuko Bamba Michiyo Azuma Hirohisa Takano Toshikazu Yoshikawa Kou Sakabe |
author_sort |
Kenichi Azuma |
title |
Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous |
title_short |
Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous |
title_full |
Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous |
title_fullStr |
Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous |
title_full_unstemmed |
Chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous |
title_sort |
chemical intolerance: involvement of brain function and networks after exposure to extrinsic stimuli perceived as hazardous |
publisher |
BMC |
series |
Environmental Health and Preventive Medicine |
issn |
1342-078X 1347-4715 |
publishDate |
2019-10-01 |
description |
Abstract Background Chemical intolerance (CI) is a chronic condition characterized by recurring and severe symptoms triggered by exposure to low levels of odorous or pungent substances. The etiology of CI has been a controversial subject for a long time. The aim of this review is to summarize findings on the neurological processing of sensory information during and after exposure to low levels of odorous or pungent substances in individuals with CI, focusing on the brain function and networks. Methods Scientific studies on CI published between 2000 and 2019 in academic peer-reviewed journals were systematically searched using medical and scientific literature databases. Only peer-reviewed articles reporting original research from experimental human studies directly associated with CI, and involving related neurological responses or brain imaging after exposure to odorous or pungent substances (i.e., in chemical provocation tests), were considered. Results Forty-seven studies were found to be eligible for a full-text review. Twenty-three studies met the selection criteria and were included in this review. Evidence indicated that differences between subjects with CI and healthy controls were observed by brain imaging during and after exposure to odorous or pungent substances. Differences in brain imaging were also observed between initial exposure and after exposure to these substances. Neurological processing of sensory information after exposure to extrinsic stimuli in the limbic system and related cortices were altered in subjects with CI. A previous documentable exposure event was likely to be involved in this alteration. Conclusions This review documents consistent evidence for the altered neurological processing of sensory information in individuals with CI. Further neurophysiological research exploring the processing of extrinsic stimuli and cognition of sensation through the limbic system and related cortices in CI, and the appearance of symptoms in individuals with CI, are required. |
topic |
Brain imaging Chemical intolerance Exposure event Limbic system Multiple chemical sensitivity Odor processing |
url |
http://link.springer.com/article/10.1186/s12199-019-0816-6 |
work_keys_str_mv |
AT kenichiazuma chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous AT iwaouchiyama chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous AT maritanigawa chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous AT ikukobamba chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous AT michiyoazuma chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous AT hirohisatakano chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous AT toshikazuyoshikawa chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous AT kousakabe chemicalintoleranceinvolvementofbrainfunctionandnetworksafterexposuretoextrinsicstimuliperceivedashazardous |
_version_ |
1724533118498504704 |