Acute Flaccid Myelitis (AFM) Associated with Enterovirus: A Distinct Clinical Entity?
26 April 2017 (online)
We report three cases of acute flaccid paralysis resembling a neuronopathic picture. Enteroviral infection was present in these patients. Clinically, the symptoms presented as (encephalo)-myelitis including flaccid paresis of arms and/or legs. Cerebrospinal fluid (CSF) showed signs of inflammation (elevated protein and pleocytosis). MRI showed inflammatory changes in the corresponding anterior horn of the cervical spinal cord in one patient. In two children, enterovirus 71 was found, as seen by Ooi et al. Another child with suspected encephalomyelitis presented with bilateral proximal and left sided accentuated flaccid paresis and paresis of the left diaphragm. In this case, enterovirus D 68 was found.
In the United States, 202 cases of “Acute Flaccid Myelitis” (AFM) were reported between 2012 and 2015. There was a relation to local outbreaks of respiratory infections due to enterovirus D 68. Diagnosis of AFM was made when acute flaccid paresis of arms and/or legs was associated with MRI signs of anterior myelitis. Neurophysiology showed lesions of lower motoneuron in many cases. Epidemiological data strongly support an association with enterovirus D 68 (Messacar et al). An increasing number of such cases were seen during the last years. During the last year, we admitted several patients to our Department of Neuropediatric Rehabilitation given with the (wrong?) diagnosis “transverse myelitis.” They also presented with flaccid (mostly asymmetric) paralysis. It is unclear if immunomodulatory treatment in AFM may be efficient or necessary. Up to now clear evidence is missing. AFM seems to be an important clinical entity in the “post-polio-era” and should be considered in the differential diagnosis of acute flaccid paralysis in children.
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- Ooi MH, Wong SC, Lewthwaite P, Cardosa MJ, Solomon T. Clinical features, diagnosis, and management of enterovirus 71. Lancet Neurol 2010; 9 (11) 1097-1105