Language Functional Reorganization in Subcortical Infarction Patients
Condition: Subcortical Aphasia; Ischemic Stroke
MeSH terms: Ischemic Stroke; Aphasia; Infarction
Study type: Observational

Summary: 
      Post stroke aphasia (PSA) is one of the most frequently happened deficiency of stoke,
      affecting speaking,comprehension, writing and reading of language. Generally, PSA is commonly
      seen in cortical damage, but in recent years it has been found that subcortical injury is
      also an important cause of PSA, which is called subcortical aphasia. Using fMRI technology,
      the investigators aim to investigate the language function of patients with subcortical
      cerebral infarction at different stages of recovery , and explored the mechanism of
      post-injury language reorganization in the brain.

      The investigators recruited 60 first-episode acute cerebral infarction patients with one-side
      lesion in subcortical white matter (40 with left injury and 20with right injury) and 20
      health volunteers. All participants are right-handed, and screened with MMSE, HAMD and HAMA
      to exclude cases of psychosis, post-stroke dementia and depression. Each participant was
      arranged to have three test sessions at different stages after the infarction (T1:within 3
      days after onset of the stroke ; T2:28 ±3days after onset; T3: 90±3days after onset), with
      fMRI and Western aphasia battery (WAB) in each session.

      The purpose of this study is to explore the pathogenesis of subcortical aphasia, and to
      understand the dynamic reorganization of language network during the recovery of language
      function.
    

Detailed description: 
      The participants were recruited from inpatients with acute ischemic stroke in Department of
      Cerebrovascular disease, The Guangzhou General Hospital of Guangzhou Military Command. The
      diagnose of ischemic stroke was made using the diagnostic criteria of the International
      Association of Neurological Diseases and Stroke Association in 1982. The classification
      criterias for ischemic stroke were 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 , and all participants or their guardian signed informed consent. According
      to the location and diagnostic criteria, the participants were divided into three groups:
      left hemisphere infarction patients group ,right hemisphere infarction patients group and
      normal healthy control group. The participants performed 3 language functional behavior tests
      and functional magnetic resonance (fMRI) tests within3 days,28 ±3days ,90±3days after the
      onset of cerebral infarction. In the healthy control group, the above examination was
      performed only 1 times. Language functional behavioral assessments included the Chinese
      version of Western Aphasia Battery(WAB), spontaneous language frequency test(SLFT) and
      picture naming test(PNT). Examines of fMRI included task-state fMRI , resting-state fMRI and
      diffusion tensor imaging(DTI).

      Task state function magnetic resonance design：Using the block design, each sequence uses the
      "baseline-stimulus-baseline-stimulus-baseline
      -stimulus-baseline-stimulus-baseline-stimulus-baseline-stimulus-baseline-stimulus-baseline"
      model. The first baseline duration is 24s. The following baseline duration and duration of
      stimulus are 18s, each sequence is 240s, a total of three sequences. Scan 12min. From the
      Snodgrass picture database, 54 animal pictures and 54 tool pictures can be accurately
      identified by all subjects. Repeat 6 animal chunk and 6 tool naming chunks, six pictures of
      each block for 18 seconds. Choose the abstract map of all the American skunk as the baseline
      map of the animal name, and select the simple arrow picture as the baseline map of the tool.
      In order to avoid repetition effect after practice, the pictures used in the design of MRI
      are not repeated in speech behavior assessment. At baseline, subjects were asked to identify
      the direction of the arrow image and the tail direction of the skunk by silently speaking
      "upright" or "inverted". The subjects received task familiarization training before testing
      to ensure that there was no meaningless picture naming in baseline tasks, but location
      judgment. The design of language task is based on the design of Damasio. In the task state of
      magnetic resonance scanning, the patient is required to read and name the silent images of
      the visual images. The visual information is written by the DMDX software, the picture is
      projected through the brain functional audio-visual stimulation system (SA-9900) to the
      screen, and the subjects are placed on the head line. The reflector on the circle is
      observed.

      Resting-state fMRI：During the rest-state fMRI scan, no task instruction was given to the
      participates, and the participates were completely relaxing, closing their eyes, breathing
      calmly, keeping their head still, but could not fall asleep, tried to avoid any systematic
      thinking activities, scanning 8min.

      Functional magnetic resonance data acquisition：Cranial scanning was performed using the
      HDX3.0Tesla superconducting magnetic resonance scanner of the US GE company. The 8 channel
      phased array head coil is the receiving coil, and the scanning sequence and parameters are as
      follows：

        1. T1 structure imaging using FSPGR BRAVO sequence. The parameters included: time of
           repetition, 8.86 ms; time of echo, 3.52 ms; field of view, 24×24 cm2; in-plane
           resolution,256×256; slice thickness, 1 mm;interslice gap, 1 mm; and number of slices,
           176.

        2. Echo-Planar Imaging (EPI) was used to acquire task-state fMRI data.The parameters
           included: time of repetition, 3000ms; time of echo, 40 ms; field of view, 24×24 cm2;
           in-plane resolution,64×64; slice thickness, 4 mm; interslice gap, 1 mm; and number of
           slices, 34. Scan a sequence of 240s, a total of 12 min.

        3. Echo-Planar Imaging (EPI) was used to acquire rest-state fMRI data.The parameters
           included: time of repetition, 3000ms; time of echo, 40 ms; field of view, 24×24 cm2;
           in-plane resolution,64×64; slice thickness, 4 mm; interslice gap, 1 mm; and number of
           slices, 34. A total of 8 min.
    

Intervention name(s): ischemic brain damage
Intervention type(s): Other
Intervention description(s): Have or not have the ischemic brain damage and the location of the damage
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        The first onset, the onset time was less than 3 days, the lesion was the left and right
        single subcortical infarct lesion confirmed by head Magnetic Resonance Imaging(MRI).All of
        them are come from Neurology/Cerebrovascular Department General Hospital of Guangzhou
        Military Command of PLA between 2016-2017.
      
Keywords: Aphasia; Functional magnetic resonance imaging; Subcortical aphasia; Post-stroke aphasia; Cortical activation