Gastric perforation and critical illness polyneuropathy after steroid treatment in a patient with encephalitis/encephalopathy with transient splenial lesion.

The outcome of mild encephalitis/encephalopathy with reversible splenial lesion (MERS) is favorable whether or not specific treatment is performed. We report a patient with MERS treated with methylprednisolone, complicated by gastric perforation followed by critical illness polyneuropathy. The patient was a 14-year-old male with mildly impaired consciousness and hyponatremia who was treated with methylprednisolone pulse therapy. High fever appeared after methylprednisolone pulse therapy and free air was recognized on an abdomen roentgenogram. Gastric perforation was recognized on emergent endoscopic surgery and omental implantation repair was performed. His consciousness was fully recovered after surgery, whereas he was noted to have motor and sensory impairment of the lower extremities and vesico-rectal disturbance. Nerve conduction studies revealed decreased compound muscle action potentials with preserved motor conduction velocity and decreased sensory nerve action potentials. He was diagnosed as having critical illness polyneuropathy, and bedside physical rehabilitation was initiated. His neurological symptoms resolved within 6months. Our patient highlighted possible serious adverse events associated with steroid treatment for children with MERS.