title: Role of altered cerebello-thalamo-cortical network in the neurobiology of essential tremor.
abstract: BACKGROUND
  Essential tremor (ET) is the most common movement disorder among adults. Although ET has been recognized as a mono-symptomatic benign illness, reports of non-motor symptoms and non-tremor motor symptoms have increased its clinical heterogeneity. The neural correlates of ET are not clearly understood. The aim of this study was to understand the neurobiology of ET using resting state fMRI.
  
  
  METHODS
  Resting state functional MR images of 30 patients with ET and 30 age- and gender-matched healthy controls were obtained. The functional connectivity of the two groups was compared using whole-brain seed-to-voxel-based analysis.
  
  
  RESULTS
  The ET group had decreased connectivity of several cortical regions especially of the primary motor cortex and the primary somatosensory cortex with several right cerebellar lobules compared to the controls. The thalamus on both hemispheres had increased connectivity with multiple posterior cerebellar lobules and vermis. Connectivity of several right cerebellar seeds with the cortical and thalamic seeds had significant correlation with an overall score of Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) as well as the subscores for head tremor and limb tremor.
  
  
  CONCLUSIONS
  Seed-to-voxel resting state connectivity analysis revealed significant alterations in the cerebello-thalamo-cortical network in patients with ET. These alterations correlated with the overall FTM scores as well as the subscores for limb tremor and head tremor in patients with ET. These results further support the previous evidence of cerebellar pathology in ET.
authors.affiliation: Department of Neurology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.|Department of Clinical Neurosciences, National Institute of Mental Health & Neurosciences, Bangalore, Karnataka, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Lenka
authors.affiliation: Department of Neurology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.|Department of Clinical Neurosciences, National Institute of Mental Health & Neurosciences, Bangalore, Karnataka, India.
authors.forename: Ketaki Swapnil
authors.initials: KS
authors.lastname: Bhalsing
authors.affiliation: Department of Neuroimaging & Interventional Radiology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.
authors.forename: Rajanikant
authors.initials: R
authors.lastname: Panda
authors.affiliation: Department of Neurology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.|Department of Clinical Neurosciences, National Institute of Mental Health & Neurosciences, Bangalore, Karnataka, India.
authors.forename: Ketan
authors.initials: K
authors.lastname: Jhunjhunwala
authors.affiliation: Department of Neurology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.
authors.forename: Rajini M
authors.initials: RM
authors.lastname: Naduthota
authors.affiliation: Department of Neuroimaging & Interventional Radiology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.
authors.forename: Jitender
authors.initials: J
authors.lastname: Saini
authors.affiliation: Department of Neuroimaging & Interventional Radiology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India. drrosedawn@yahoo.com.
authors.forename: Rose Dawn
authors.initials: RD
authors.lastname: Bharath
authors.affiliation: Department of Neurology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.
authors.forename: Ravi
authors.initials: R
authors.lastname: Yadav
authors.affiliation: Department of Neurology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India. pal.pramod@rediffmail.com.
authors.forename: Pramod Kumar
authors.initials: PK
authors.lastname: Pal
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D002531:Cerebellum / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D020329:Essential Tremor / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011446:Prospective Studies; D013003:Somatosensory Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*
keywords: Essential tremor; Functional connectivity; Resting state; fMRI