Acute flaccid paralysis in infants and young children with enterovirus 71 infection: MR imaging findings and clinical correlates

BACKGROUND AND PURPOSE: Enterovirus 71 (EV71) infection is now considered a n important cause of childhood acute flaccid paralysis. The purpose of our study was to determine whether EV71-infection-related acute flaccid paralys is in infants and young children has characteristic MR imaging patterns. METHODS: Seven infants and young children with acute paralysis of the upper or lower extremities and positive EV71 cultures underwent spinal MR studie s during an outbreak of hand-foot-and-mouth disease in Taiwan in 1998. RESULTS: Acute paralysis was observed in one upper extremity in two patient s, in one lower extremity in three patients, and in both lower extremities in two patients. None of the patients had sensory impairment or bulbar pals y. MR studies showed unilateral or bilateral hyperintense lesions in the an terior horn regions of the cord on T2-weighted images in six patients. No a bnormal signal was present in one patient. Two of three patients who receiv ed intravenous injections of contrast material had ventral root enhancement on T1-weighted images. One of them also had enhancement of the unilateral anterior horn cells, At clinical follow-up, both patients with bilateral an terior horn abnormalities had residual motor weakness, whereas only one of the five patients with unilateral involvement had residual weakness. CONCLUSION: EV71 radiculomyelitis tends to be unilateral and to specificall y involve both the anterior horn cells of the cord and the ventral roots. M R imaging allows early detection of spinal cord and root lesions.