title: Functional Brain Activity Relates to 0-3 and 3-8 Hz Force Oscillations in Essential Tremor.
abstract: It is well-established that during goal-directed motor tasks, patients with essential tremor have increased oscillations in the 0-3 and 3-8 Hz bands. It remains unclear if these increased oscillations relate to activity in specific brain regions. This study used task-based functional magnetic resonance imaging to compare the brain activity associated with oscillations in grip force output between patients with essential tremor, patients with Parkinson's disease who had clinically evident tremor, and healthy controls. The findings demonstrate that patients with essential tremor have increased brain activity in the motor cortex and supplementary motor area compared with controls, and this activity correlated positively with 3-8 Hz force oscillations. Brain activity in cerebellar lobules I-V was reduced in essential tremor compared with controls and correlated negatively with 0-3 Hz force oscillations. Widespread differences in brain activity were observed between essential tremor and Parkinson's disease. Using functional connectivity analyses during the task evidenced reduced cerebellar-cortical functional connectivity in patients with essential tremor compared with controls and Parkinson's disease. This study provides new evidence that in essential tremor 3-8 Hz force oscillations relate to hyperactivity in motor cortex, 0-3 Hz force oscillations relate to the hypoactivity in the cerebellum, and cerebellar-cortical functional connectivity is impaired.
authors: Department of Kinesiology, The Pennsylvania State University, State College, PA, USA.
authors: Kristina A
authors: KA
authors: Neely
authors: Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA.
authors: Ajay S
authors: AS
authors: Kurani
authors: Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
authors: Priyank
authors: P
authors: Shukla
authors: Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
authors: Peggy J
authors: PJ
authors: Planetta
authors: Department of Neurology and Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, FL, USA.
authors: Aparna
authors: A
authors: Wagle Shukla
authors: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA.
authors: Jennifer G
authors: JG
authors: Goldman
authors: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA Department of Physical Therapy and Human Movement Sciences, Northwestern University, Evanston, IL, USA.
authors: Daniel M
authors: DM
authors: Corcos
authors: Department of Neurology and Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, FL, USA.
authors: Michael S
authors: MS
authors: Okun
authors: Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA Department of Neurology and Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, FL, USA Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
authors: David E
authors: DE
authors: Vaillancourt
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D020329:Essential Tremor / Q000473:pathology*; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000473:pathology
chemical_list: D010100:Oxygen
keywords: Parkinson's disease; cerebellum; essential tremor; fMRI; grip force; motor control