Introduction:

Acute disseminated encephalomyelitis (ADEM) and Guillain-Barré Syndrome (GBS) are commonly recognized as separated entities. Both are hypothesized to be related to a viral-induced autoimmune response. There are only few reports of concomitant ADEM and GBS.

Case report: A 2-years-old boy began with vomiting, irritability, and three days later with eyelid and scrotal edema. There was no history of recent fever or infection. Forty days before, he received anti-polio and tetravalent vaccines. Scrotal echography showed edematous infiltration. No other laboratorial alterations occurred. After 72 hours, irritability worse and somnolence was noted. He developed flaccid paraplegia, distal weakness of inferior limbs, absence of reflexes, sphincter dysfunction, and paralyses of the right sixth nerve. CNS MRI showed multiple cerebral and cerebellar lesions on the white matter, hyperintense on T2 and flair sequences. No medullar lesion occurred. CSF showed 30 leukocytes with mononuclear predominance, glucose 68, total proteins 95, negative for viruses. He received pulse therapy with methyl-prednisolone with partial improvement. One week later, MRI showed improvement of cerebral lesions and enhancement of spinal roots.  He received immunoglobulin. Control CSF had protein-cytology dissociation. Electromyography showed intense sensitive-motor polyneuropathy. Visual evoked potential was normal, and auditive was abnormal on right side. Hands strength and axial tonus improved. Three weeks after, immunoglobulin was repeated, with improvement of sphincter function, but still with paraplegia. He was discharged with motor physiotherapy and oral prednisolone.

 Conclusion: The occurrence of these 2 entities, simultaneously or sequentially during a short period, is not well understood and is probably underdiagnosed.