title: Neuroimaging findings in primary insomnia.
abstract: State-of-the-art neuroimaging techniques have accelerated progress in the study and understanding of sleep in humans. Neuroimaging studies in primary insomnia remain relatively few, considering the important prevalence of this disorder in the general population. This review examines the contribution of functional and structural neuroimaging to our current understanding of primary insomnia. Functional studies during sleep provided support for the hyperarousal theory of insomnia. Functional neuroimaging also revealed abnormalities in cognitive and emotional processing in primary insomnia. Results from structural studies suggest neuroanatomical alterations in primary insomnia, mostly in the hippocampus, anterior cingulate cortex and orbitofrontal cortex. However, these results are not well replicated across studies. A few magnetic resonance spectroscopy studies revealed abnormalities in neurotransmitter concentrations and bioenergetics in primary insomnia. The inconsistencies among neuroimaging findings on insomnia are likely due to clinical heterogeneity, differences in imaging and overall diversity of techniques and designs employed. Larger samples, replication, as well as innovative methodologies are necessary for the progression of this perplexing, yet promising area of research.
authors.affiliation: Department of Exercise Science, Concordia University, 7141 Sherbrooke St W, Montreal, Quebec, H4B 1R6 Canada; Center for Studies in Behavioral Neurobiology, Concordia University, 7141 Sherbrooke St W, Montreal, Quebec, H4B 1R6 Canada.
authors.forename: J N
authors.initials: JN
authors.lastname: O'Byrne
authors.affiliation: Department of Psychology, Concordia University, 7141 Sherbrooke St W, Montreal, Quebec, H4B 1R6 Canada.
authors.forename: M
authors.initials: M
authors.lastname: Berman Rosa
authors.affiliation: Department of Psychology, Concordia University, 7141 Sherbrooke St W, Montreal, Quebec, H4B 1R6 Canada.
authors.forename: J-P
authors.initials: JP
authors.lastname: Gouin
authors.affiliation: Department of Exercise Science, Concordia University, 7141 Sherbrooke St W, Montreal, Quebec, H4B 1R6 Canada; Center for Studies in Behavioral Neurobiology, Concordia University, 7141 Sherbrooke St W, Montreal, Quebec, H4B 1R6 Canada; Institut Universitaire de Gériatrie de Montréal, Université de Montréal, 4565, chemin Queen-Mary, Montreal, Quebec, H3W 1W5 Canada. Electronic address: tt.dangvu@concordia.ca.
authors.forename: T T
authors.initials: TT
authors.lastname: Dang-Vu
mesh_terms: D000342:Affective Symptoms / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D001143:Arousal / Q000502:physiology; D002540:Cerebral Cortex / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D015897:Comorbidity; D006624:Hippocampus / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008959:Models, Neurological; D059906:Neuroimaging / Q000379:methods; D009929:Organ Size; D009928:Organ Specificity; D010725:Phosphocreatine / Q000032:analysis; D049268:Positron-Emission Tomography; D007319:Sleep Initiation and Maintenance Disorders / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon; D066127:White Matter / Q000473:pathology; D005680:gamma-Aminobutyric Acid / Q000032:analysis
chemical_list: D010725:Phosphocreatine; D005680:gamma-Aminobutyric Acid
keywords: Hyperactivation; Hyperarousal; Imagerie par résonance magnétique; Insomnia; Insomnie; Magnetic resonance imaging; Magnetic resonance spectroscopy; Neuroimagerie; Neuroimaging; Positron emission tomography; Single-photon emission computed tomography; Sleep; Sleep disorder; Sommeil; Spectroscopie en résonance magnétique nucléaire; Tomographie d’émission monophotonique; Tomographie par émission de positrons; Troubles du sommeil