Blood oxygenation-level dependent functional MRI in evaluating the selective activation of motor cortexes associated with recovery of motor function in hemiplegic patients with ischemic stroke

摘要

BACKGROUND: Previous studies about blood oxygenation-level dependent (BOLD) functional MRI (fMRI) have indicated that the poststroke recovery of motor function is accompanied by the selective activation of motor cor texes with high correlation.OBJECTIVE: To evaluate the short-term outcomes after rehabilitative interventions with BOLD fMRI in hemi plegic patients with acute stroke, and analyze the correlation of the excitement of brain function in the passive and active movements of the affected limb with the recovery of motor function. DESIGN : A case observation. SETTING: Department of Neurology, Baotou Central Hospital. PARTICIPANTS: Thirty hemiplegic inpatients with ischemic stroke were selected from the Department of Neurology, Baotou Central Hospital from January to December in 2005, including 16 males and 14 females, aging 44-71 years with an average age of (56±5) years, and the disease course ranged from 12 to 72 hours. Inclusive criteria: In accordance with the diagnostic standard of ischemic stroke revised by the Fourth National Academic Meeting for Cerebrovascular Disease; Confirmed by cranial CT or MRI. They were all informed agreed with the detected items.METHODS: ① The Bobath technique was adopted in the rehabilitative interventions of the 30 patients, 30 minutes for each time, twice a day for three weeks continuously. ② The hand motor recovery of the stroke patients was graded by the Brunnstrom,stages ( Ⅰ -Ⅵ), and be able to grasp various objects and extend for the whole range was taken as grade Ⅵ. ③ The patients were examined with fMRI BOLD before rehabilitation and 3 weeks after rehabilitation. All the patients were trained with finger movements, the distracting thoughts should be eliminated as much as possible especially during the movement phase, the patients should highly concentrate on the hand movements. The range for the finger movements should be as large as possible with moderate frequency. The hand movements should be 10 s with an interval of 30 s. Te AVANTO 1.5T MRI machine (Siemens Company, Germany) was used for scanning, the 30 s before fMRI BOLD scanning was the adaptation phase for the patients, and the finger movements were alternated for 6-10 times till the end of the scanning.MAIN OUTCOME MEASURES: Differences after rehabilitation evaluated by the activations of different sensorimotor cortex in the hemiplegic patients with acute stroke. RESULTS: ① In passive and active movements of the affected hand, 5 cases of Brunnstrom grade Ⅰ or Ⅱ were manifested by the activation of unilateral sensorimotor cortex (SMC) of the hemiplegic side, and they were Brunnstrom grade Ⅱ after 3-week rehabilitation, and 1 case with activations of bilateral SMC recovered to Brunnstrom grade Ⅲ. ② Among the patients of Brunnstrom grade Ⅲ or Ⅳ, 5 cases were unilaterally activated, and had no changes after 3-week rehabilitation; Whereas of the 9 cases of bilateral activations, 3 recovered to grade Ⅵ and 6 recovered to grade Ⅴ after 3-week rehabilitation. ③ In the passive and active movements of the affected hand, all the cases of Brunnstrom grades Ⅴ and Ⅵ were manifested by the activations of bilateral SMC. After 3-week rehabilitation, 2 of the 4 cases of grade Ⅴ recovered to grade Ⅵ, and the other 2 recovered to normal; Whereas 5 of the 6 cases of grade Ⅵ recovered to normal, and the other 1 was still grade Ⅵ. CONCLUSION: BOLD fMRI showed that the outcomes of short-term rehabilitation in the patients with bilateral activations were obvious, whereas the outcomes were bad in the patients whose ipsilateral cortexes were activated. The activated signal in ipsilateral or bilateral SMC and the activation of supplementary motor area in active movements were greater than those in the passive ones.