MRI findings of spine: acute flaccid paralysis associated with enterovirus 71 infected hand-foot-mouth disease

Objective To investigate the characteristics of spinal MR images in acute flaccid paralysis(AFP) associated with enterevirus 71 infected hand-foot-mouth disease.Methods The spinal MR images of eight infants with AFP and positive EV71 cultures were analyzed during an outbreak of hand-foot-mouth disease in China in 2008.Results Acute paralysis was observed in one lower limb in 4 of the 8 patients,in four limbs in 2 patients,in one upper limb and both lower limbs in 1 patient,2 of the 8 patients also had brain stem encephalitis.Lesions were identified in anterior horn regions of spinal cord with hyperintensity on T2-weighted images and hypointensity on T1-weighted images.Location of the lesions included C3 to C7(1 case),T10 extending to conus medullaris(5 cases)and a combination of the above (2 cases).Five of the 8 patients presented with unilateral paralysis.Two of the 5 cases showed unilateral hyperintense lesions in anterior horn regions and the remaining 3 cases showed bilateral hyperintense lesions in anterior horn regions with a unilateral predominance.One of the 3 patients with bilateral lesions showed slight enhancement of anterior horn with prominent enhancement of ventral roots after intravenous injections of contrast medium.Three of the 8 patients with bilateral paralysis showed bilateral hyperintensity in both anterior horn regions.Conclusion MR is the imaging medality of choice for the detection of radiculomyelitis of AFP associated with EV71 infection.