MRI Findings of Neurological Complications in Hand-Foot-Mouth Disease by Enterovirus 71 Infection

Objective: To explore the imaging characterization of neurological complications associated with the enterovirus 71 (EV71) epidemics. Methods: Thirty-five cases of hand-foot-mouth disease with neurological complications during the recent EV71 outbreaks in Hainan Province, China, from May 2008 to September 2010 were collected. All patients were performed MRI scan. The clinical data and MRI appearance were analyzed. Results: Acute flaccid paralysis associated with EV71 infected hand-foot-mouth diseases was seen in seven cases. The typical MRI appearance was linear long T2 signal intensity in the posterior part of spinal cord. Symmetrical, well-defined hyperintensity lesions in the spinal cord were seen in T2-weighted transverse images. Obvious enhancements of the ventral horns and root were seen in the contrast-enhanced axial T1-weighted image. In 21 cases of pontine encephalitis, long T1 and long T2 signal intensity was seen in the posterior portions of the medulla oblongata, midbrain, and pons. It is nonspecific MRI appearance in seven cases of aseptic meningitis (AM), but subdural effusion, meningeal enhancement, and hydrocephalus can be indirect sign of AM. Conclusion: MRI is an effective modality to investigate neurological complications associated with the EV71 epidemics. Involvements of posterior portions of the medulla oblongata and pons, and bilateral anterior horns of spinal cord are characteristic findings.