肠道病毒71感染手足口病合并急性弛缓性麻痹的脊髓MRI表现及肌力的2年随访研究

A 2 Years Follow up Study of the Spinal Cord MR Findings and Muscle Strength in Acute Flaccid Paralysis Patients Associated with Enterovirus 71 Infected Hand Foot Mouth Disease

目的探讨肠道病毒71型(EV71)感染手足口病合并急性弛缓性麻痹(AFP)的起病及恢复期的脊髓MRI特点,并观察影像学和肌力变化之间的相互关系。资料与方法搜集2008年6至10月EV71感染手足口病合并AFP患儿8例,对其脊髓MRI表现及肌力进行2年随访观察。结果本组8例,单侧下肢无力4例,双侧下肢无力2例,单侧上肢无力和双侧上肢无力各1例,合并脑干脑炎4例。MRI病变特异性累及脊髓前角,上肢无力累及颈膨大,下肢无力累及腰膨大,T2WI高信号。单侧肢体无力5例,其中2例为单侧脊髓前角受累,3例表现为双侧受累,患侧病变范围大,信号强度高。双侧肢体无力3例,脊髓前角病变范围大的一侧肌力下降明显。2年后复查,8例均表现脊髓前角病变范围减小,肌力提高者10肢,肌力下降1肢,新出现肌力下降者1肢。T2WI呈高信号及稍高信号6例,肌力均达4级以上,呈脑脊液信号2例,肌力未达4级。结论脊髓MRI是诊断和随诊EV71感染手足口病合并AFP的最佳影像学检查方法。起病时病变累及脊髓前角区,单侧或双侧受累,以一侧为主多见。恢复期病变范围均有不同程度吸收,多数病变T2WI信号减低。起病时病变范围与肌力下降程度相一致,恢复期T2WI病变区仍呈脑脊液信号者肌力恢复较差。脊髓MRI对EV71感染手足口病合并AFP的临床预后评估具有一定的价值。

Objective To investigate the MR imaging characteristics of the spinal cord in the onset and recovery stages of the acute flaccid paralysis（AFP） patients associated with EV71 infected Hand Foot Mouth disease（HFMD）,and to observe the relationship between the imaging appearance and muscle strength.Materials and Methods 8 cases of AFP associated with EV71 infected HFMD were collected from June to October in 2008.The MRI findings of spinal cord and the muscle strength were followed up for 2 years.Results 4 of 8 patients had unilateral lower limb weakness,2 of 8 patients had bilateral lower limb weakness.Unilateral and bilateral upper limbs were weakness in 1 case respectively.4 of 8 patients combined brainstem encephalitis.All lesions appeared as hyperintensity signal on T2WI,which involved anterior horns of the spinal cord.Cervical enlargement was involved in the patients with upper limbs weakness and lumbar enlargement was involved in the patient with lower limbs weakness.Unilateral limb weakness in 5 cases,but only 2 of them appeared as unilateral anterior horn involvement.Bilateral anterior horns were involved in the other 3 and the range of the lesions was larger and the signal intensity was higher in the ipsilateral side.Two years later,8 patients showed decreased range of the lesions.Muscle strength was increased in 10 limbs,decreased in 1 limb and 1 new limb was involved.Muscle strength of the limbs were more than 4 degrees in the 6 patients with hyper or slightly hyperintensity signal on T2WI.Muscle strength of the limbs less than 4 degrees in 2 patients showed cerebrospinal fluid signals on T2WI.Conclusion Spinal MRI is the best method in diagnosing and following up the AFP associated with EV71 infected HFMD.The lesions commonly involve unilateral or bilateral anterior horn of the spinal cord in initial stage.Lesions are absorbed in various degrees,most of them show signal decreased on T2WI in recovery stage.The sizes of lesions reveal on T2WI are consistent with the decreasing of muscle strength in initial stage,however,in recovery stage,muscle strength of limbs of the patients with cerebrospinal fluid signal on T2WI imaging is worse than those with hyperintensity signal on T2WI imaging.Spinal MRI may be helpful in evaluating the prognosis of the AFP associated with EV71 infected HFMD.