Pediatric Hashimoto's encephalopathy with peripheral nervous system involvement.

Hashimoto encephalopathy is a syndrome of encephalopathy associated with elevated concentration of circulating serum anti-thyroid antibodies usually responsive to steroid therapy. We report a 13-year-old girl with Hashimoto encephalopathy and peripheral nervous system involvement. The child had experienced high-grade pyrexia, global headache and sleeplessness. After admission she had an ileus with a distended urinary bladder, hallucinations and cognitive impairment. She had reduced deep tendon reflexes and distal sensory deficiency. Anti-thyroglobulin antibodies were raised at 2121 IU/mL (normal, 0-40) and the anti-thyroperoxidase was high at 886 IU/mL (normal, 0-50). Progressive neurological and psychiatric remission was noted after i.v. methylprednisolone. Follow-up magnetic resonance imaging showed complete resolution of the foci of signal abnormality previously yielded. This case report is the first, to the best of our knowledge, to describe peripheral nervous system involvement in a child with a diagnosis of Hashimoto's encephalopathy.