Cortex Motor Function Reorganization in Stroke Patients
Condition: Ischemic Stroke
MeSH terms: Stroke; Ischemic Stroke
Study type: Observational

Summary: 
      In China, stroke is among the highest morbidity and mortality, especially in senile
      population. Most of those patients had survived with various degrees of cerebral dysfunction;
      among them about 50% were motor deficit. Previous in vitro studies indicated that recovery of
      motor function after stroke were related not only to axonal regeneration or synapse
      reformation, but also functional reorganization of adjacent areas and other functional
      associated areas. The previous fMRI studies shown that the cerebral motor cortex possess the
      natural ability of self compensation and self reorganization in the situation of brain
      damage. It was characterized by equally bilateral activation in acute stage to partial
      ipsilateral activation and major contralateral activation in subacute stage to contralateral
      activation in chronic stage.

      We plan to recruit first-episode acute cerebral infarction patients with single lesion on
      middle cerebral artery supply area and age and sex matched healthy volunteers. All the
      patients are going to assess in three different sessions (V1, 3 days after the onset of
      complaint, V2,30 days after onset of complaint; V3, 90 days after onset of the complaint )
      with both clinical check as well as fMRI scan. The clinical assessment including dynamometer
      and finger tapping test to evaluate the strength and the flexibility of each upper legs and
      it also included the corresponding scales to exclude poststroke dementia and moderate and
      serious poststroke depression. The fMRI is scanned by using bilateral arm motor tasks. Motor
      cortex activation regions, activation of voxel between healthy controls and patients in
      different checkpoint are collected.

      The purpose of this study is to investigate the dynamic process of motor cortical functional
      reorganization after cerebral stoke using functional magnetic resonance imaging combined with
      the behavior assessment. Meanwhile，we also studied the differences of motor function recovery
      and motor cortex compensation between dominant hemisphere and non-dominant hemisphere after
      stroke. Therefore, we could provide a theoretical basis and build up a useful evaluation
      system for rehabilitation after stroke and other arious cerebral injury.
    

Detailed description: 
      The cases derive from patients with acute ischemic stroke hospitalized in Neurology
      Department General Hospital of Guangzhou Military Command of PLA. The diagnosis of ischemic
      stroke is diagnosed using the diagnostic criteria of the International Association of
      Neurological Diseases and Stroke Association in 1982. The classification criteria for
      ischemic stroke are based on the current international TOAST etiological classification
      method.

      The study passed the approval of the ethics committee of General Hospital of Guangzhou
      Military Command of PLA, and all patients or their guardian sign informed consent. According
      to the location and diagnostic criteria, the patients are divided into three groups: left
      hemisphere infarction patients group, right hemisphere infarction patients group and normal
      healthy control group. The subjects performed index finger tapping test, the maximum hand
      grip strength test of both hands, National Institute of Health stroke scale(NIHSS), Barthel
      Index(BI), Hamilton Anxiety Scale(HAMA), Hamilton Anxiety Scale(HAMA) and functional magnetic
      resonance (fMRI) tests at 3 days (V1), 30 days (V2) and 90 days (V3 phase) after the onset of
      cerebral infarction. In the healthy control group, the above examination is performed only 1
      times. All subjects are assessed for clinical behavior by an independent third party.

      Task-state function magnetic resonance design: Using the block design. There are two
      sequences. One sequence is in the way of rest and left hand movement, then repeat 5 times,
      ending at rest. The other is in the way of rest and right hand movement, then repeat 5 times,
      ending at rest. Each sequence lasted 220s, and the total duration of all tests was 440s. At
      the hand movement stage, each participant is at 1HZ Rhythm for the clenched fist movement
      with maximum strength, keep their whole body relaxed at the resting phase, with wrist and
      fingers not moving. participants use visual information to strictly control time and
      frequency of movement. Visual information is written by DMDX software, and accept the work
      instruction then sent to a transparent screen via a computer projector. Participants observed
      the information through a reflector mounted on a head coil.

      Magnetic resonance data acquisition: 1.5 Tesla superconducting magnetic resonance scanner of
      Siemens Sonata company is applied. The standard phased array head coil is the radio frequency
      coil. Gradient field is 40m T/m, and switching rate is 200m T/m/ms. The scanning sequence and
      parameters are as follows:(1) T1 WI scan, obtaining whole brain structure image data: repeat
      time is 683ms, echo time is 11ms, layer thickness is 4mm, layer spacing is 1mm, matrix is
      192x144, field of vision is 230mmx230mm, a total of 28 layers, range including whole brain.
      (2) The blood oxygen level dependent signal of the motor task state and resting state
      functional magnetic resonance imaging: using gradient echo combined with single excitation
      echo plane Imaging technology, the parameters are as follows: repeat time is 2000ms, echo
      time is 49ms, layer thickness is 4mm, layer spacing is 1mm, matrix is 64x64, field of vision
      is 210mmx210mm, a total of 28 layers.
    

Intervention name(s): brain damage
Intervention type(s): Other
Intervention description(s): Have or not have the brain damage and the location of the damage
Observational model: Case-Control
Time perspective: Other
Sampling method: Non-Probability Sample
Study population: 
        We plan to recruite first-episode acute cerebral infarction patients with single lesion on
        middle cerebral artery supply area and age and sex matched healthy volunteers.
      
Keywords: motor cortex reorganization, Ischemic Stroke, fMRI, BOLD