Clinical and neuroimaging features of enterovirus71 related acute flaccid paralysis in patients with hand-foot-mouth disease

Objective: To investigate clinical and neuroimaging features of enterovirus71 (EV71) related acute flaccid paralysis in patients with hand foot mouth disease. Methods: Nine patients with acute flaccid paralysis met the criterion of EV71 induced hand foot mouth disease underwent spinal and brain MR imaging from May 2008 to Sep 2012. Results: One extremity flaccid was found in four cases (3 with lower limb, 1 with upper limb), two limbs flaccid in three cases (2 with lower limbs, 1 with upper limbs), and four limbs flaccid in two cases. Spinal MRI studies showed lesion with high signal in 12 weighted images (T2WI) and low signal T1-weighted images (T1WI) in the spinal cord of all nine cases, and the lesions were mainly in bilateral and unilateral anterior horn of cervical spinal cord and spinal cord below thoracic 9 (T9) level. In addition, the midbrain, pons, and medulla, which were involved in 3 cases with brainstem encephalitis, demonstrated abnormal signal. Moreover, spinal cord contrast MRI studies showed mild enhancement in corresponding anterior horn of the involved side, and strong enhancement in its ventral root. Conclusions: EV71 related acute flaccid paralysis in patients with hand foot mouth disease mainly affected the anterior horn regions and ventral root of cervical spinal cord and spinal cord below T9 level. MR imaging could efficiently show the characteristic pattern and extent of the lesions which correlated well with the clinical features.