title: Role of the sensorimotor cortex in Tourette syndrome using multimodal imaging.
abstract: Tourette syndrome (TS) is a neuropsychiatric disorder characterized by motor and vocal tics. Most patients describe uncomfortable premonitory sensations preceding the tics and a subjective experience of increased sensitivity to tactile stimuli. These reports indicate that a sensory processing disturbance is an important component of TS together with motor phenomena. Thus, we focused our investigation on the role of the sensorimotor cortex (SMC) in TS using multimodal neuroimaging techniques. We measured the gamma-aminobutyric acid (GABA)+/Creatine (Cre) ratio in the SMC using GABA (1) H magnetic resonance spectroscopy. We recorded the baseline beta activity in the SMC using magnetoencephalography and correlated GABA+/Cre ratio with baseline beta band power. Finally, we examined the resting state functional connectivity (FC) pattern of the SMC using functional magnetic resonance imaging (fMRI). GABA+/Cre ratio in the SMC did not differ between patients and controls. Correlation between the baseline beta band power and GABA+/Cre ratio was abnormal in patients. The anterior insula showed increased FC with the SMC in patients. These findings suggest that altered limbic input to the SMC and abnormal GABA-mediated beta oscillations in the SMC may underpin some of the sensorimotor processing disturbances in TS and contribute to tic generation.
authors.affiliation: Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
authors.forename: Sule
authors.initials: S
authors.lastname: Tinaz
authors.forename: Beth A
authors.initials: BA
authors.lastname: Belluscio
authors.forename: Patrick
authors.initials: P
authors.lastname: Malone
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: van der Veen
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
authors.forename: Silvina G
authors.initials: SG
authors.lastname: Horovitz
mesh_terms: D000293:Adolescent; D000328:Adult; D001611:Beta Rhythm; D001931:Brain Mapping; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009434:Neural Pathways / Q000503:physiopathology; D066244:Proton Magnetic Resonance Spectroscopy; D012146:Rest; D066191:Sensorimotor Cortex / Q000503:physiopathology*; D005879:Tourette Syndrome / Q000503:physiopathology*; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D005680:gamma-Aminobutyric Acid; D003401:Creatine
keywords: beta oscillations; functional connectivity; functional magnetic resonance imaging; gamma-aminobutyric acid; magnetic resonance spectroscopy; magnetoencephalography; resting state