Motor-related Cortical Potential in Patients With Essential Tremor
Condition: Essential Tremor; Movement-related Cortical Potentials
MeSH terms: Tremor; Essential Tremor
Study type: Interventional

Summary: 
      In this proposal, in addition to the conventional MRCP recording, the dipoles and sources of
      the different subcomponents of MRCP will also be analyzed with the brain electric source
      analysis (BESA) to evaluate the difference in the solutions and source strength underlying
      the MRCP between normal controls and patients with ET.
    

Detailed description: 
      Essential tremor (ET) is a common disorder with unknown etiology and pathogenesis. Typically
      described as a postural tremor, ET often has a marked kinetic component suggesting cerebellar
      involvement in the pathogenesis of the tremor. The assumption has been illustrated by both
      positron emission tomography and functional magnetic resonance imaging studies, which
      revealed that blood flow and activity of the cerebellum were increased in ET patients as
      compared to the normal controls. In contrast to the cumulative body of imaging evidence, the
      physiological bases to link the ET and cerebellar functional alternation are scarce. Studies
      with tandem gait analysis have revealed 25% abnormality of ET patients and surface
      electromyographic study has found a delay in the second agonist burst during rapid wrist
      movements suggesting the possible role of cerebellar functional alternation in the generation
      of ET. In addition, since the tremor of ET tends to appear in the movement ignition or during
      postural maintenance, it is conceivable that this sort of tremor might exert certain impact
      on the programming and preparation of the limb movement. Thus it would be appropriate to
      adopt a tool, which can concomitantly assess the cerebellar function and movement
      preparation, to investigate the patients with ET. In this proposal, we will record
      movement-related cortical potentials (MRCP) in ET patients. MRCP is a slow negative shift
      starting 1-1.5 sec before volitional movement. It consists of at least 3 subcomponents, the
      Bereitschaftspotential, the negative slope, and the motor potential. The generators crucial
      for the generation of MRCP include cerebellum, motor and motor association cortex. Thus MRCP
      seems to be an appropriate tool to assess the patients with ET, in whom the trivial
      cerebellar functional alternation could be responsible for the tremor generation and motor
      preparation might be hampered concomitantly. In this proposal, in addition to the
      conventional MRCP recording, the dipoles and sources of the different subcomponents of MRCP
      will also be analyzed with the brain electric source analysis (BESA) to evaluate the
      difference in the solutions and source strength underlying the MRCP between normal controls
      and patients with ET.
    

Intervention name(s): Motor-related cortical potential (Procedure)
Intervention type(s): Procedure
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic