title: Reduced functional connectivity of somatosensory network in writer's cramp patients.
abstract: The involvement of motor cortex and sensorimotor integration in patients with writer's cramp (WC) has been well documented. However, the exact neurophysiological profile within the somatosensory system, including primary somatosensory cortex (SI), contralateral (SIIc), and ipsilateral (SIIi) secondary somatosensory areas remains less understood.
  
  
  
  This study investigated the neuromagnetic cortical activities of median nerve stimulation in 10 patients with WC and 10 healthy controls (HC). To comprehensively explore all the aspects of somatosensory functioning, we analyzed our data with the minimum norm estimate (MNE), the time-frequency approach with evoked and induced activities, and functional connectivity between SI and SIIc (SI-SIIc), SI and SIIi (SI-SIIi), and SIIc and SIIi (SIIc-SIIi) from theta to gamma oscillations.
  
  
  
  No significant between-group differences were found in the MNE cortical amplitudes of SI, SIIc, and SIIi. Power strengths of evoked gamma oscillation and induced beta synchronization were also equivalent between WC and HC groups. However, we found significantly reduced theta coherence of SI-SIIi, alpha coherence of SI-SIIi and SIIc-SIIi, as well as beta coherence of SIIc-SIIi in patients with WC.
  
  
  
  Our results suggest the involvement of somatosensory abnormalities, primarily with the form of functional connectivity, in patients with WC.
authors.affiliation: Department of Occupational Therapy Graduate Institute of Behavioral Sciences Chang Gung University Taoyuan Taiwan; Healthy Aging Research Center Chang Gung University Taoyuan Taiwan; Department of Psychiatry Chang Gung Memorial Hospital Taoyuan Taiwan.
authors.forename: Chia-Hsiung
authors.initials: CH
authors.lastname: Cheng
authors.affiliation: Institute of Physiology National Yang-Ming University Taipei Taiwan; Laboratory of Neurophysiology Taipei Veterans General Hospital Taipei Taiwan.
authors.forename: Yi-Jhan
authors.initials: YJ
authors.lastname: Tseng
authors.affiliation: Department of Neurology Chang Gung Memorial Hospital Taoyuan Taiwan; College of Medicine Chang Gung University Taoyuan Taiwan.
authors.forename: Rou-Shayn
authors.initials: RS
authors.lastname: Chen
authors.affiliation: Institute of Physiology National Yang-Ming University Taipei Taiwan; Laboratory of Neurophysiology Taipei Veterans General Hospital Taipei Taiwan; Institute of Brain Science National Yang-Ming University Taipei Taiwan; Department of Neurology Taipei Veterans General Hospital Taipei Taiwan.
authors.forename: Yung-Yang
authors.initials: YY
authors.lastname: Lin
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D063132:Connectome; D020821:Dystonic Disorders / Q000209:etiology* / Q000503:physiopathology*; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D008475:Median Nerve / Q000503:physiopathology*; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology; D013003:Somatosensory Cortex / Q000503:physiopathology
keywords: Coherence; dystonia; magnetoencephalography (MEG); median nerve stimulation; secondary somatosensory cortex (SII)
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