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. Key words: Hand,foot and mouth disease;  Enterovirus infections;  Magnetic resonance imaging