BMJ Case Reports 2017; doi:10.1136/bcr-2017-219721

Syndrome of inappropriate antidiuretic hormone accompanied by bilateral hypothalamic and anterior thalamic lesions with serum antiaquaporin 4 antibody

  1. Jun Saito1
  1. 1 Endocrinology and Diabetes Center, Yokohama Rosai Hospital, Yokohama City, Japan
  2. 2 Department of Neurology, Division of Neuromuscular Diseases, Yokohama Rosai Hospital, Yokohama, Japan
  1. Correspondence to Dr Kosuke Inoue, kosuke.inoue1989{at}, bluebird_si{at}
  • Received 10 February 2017
  • Revised 28 March 2017
  • Accepted 3 April 2017
  • Published 20 April 2017


We described a rare case of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and severe unconsciousness accompanied by bilateral hypothalamic and anterior thalamic lesions with positive serum antiaquaporin 4 (AQP4) antibody. A 29-year-old man was admitted to our hospital due to the subacute progression of an unconscious state. He was observed to be hyponatraemic secondary to SIADH. Brain MRI showed bilateral hypothalamic and anterior thalamic lesions. Anti-AQP4 antibody was detected in his serum. After the administration of intravenous methylprednisolone pulse therapy, his symptoms improved with complete recovery from SIADH and regression of the hypothalamic and anterior thalamic lesions. The patient was transferred to another hospital for rehabilitation with 20 mg/day of oral prednisolone 127 days after admission. This case highlights the importance of testing for anti-AQP4 antibody in patients with unexplainable SIADH, subacute progressive unconsciousness and bilateral hypothalamic and anterior thalamic lesions.


  • Contributors KI mainly treated the patient and wrote this manuscript. TN and AK edited the manuscript from the perspective of neurology. JS gave a helpful advice for the treatment of the patient and finally reviewed the manuscript.

  • Competing interests None declared.

  • Patient consent Obtained from guardian.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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