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

Abstract

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.

Pediatric NMOSD: A Review and Position Statement on Approach to Work-Up and Diagnosis

“…The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common presentation of AQP4-IgG related NMOSD ( 35 , 36 ). Hypotension, hypersomnia, hypothermia, behavioral changes, amenorrhea galactorrhea syndrome, or narcolepsy, with anterior thalamic and hypothalamic MRI involvement should prompt a serum test for AQP4-IgG.…”

Hyponatremia Associated with Prophylactic Low-Dose Trimethoprim during Systemic Corticosteroid Therapy for AQP4-Positive Optic Neuritis in a Diabetic Patient

“…Immune-mediated damage to the hypothalamus may lead to the dysregulation of antidiuretic hormone secretion. Indeed, recent reports indicate that SIADH can be concomitant with NMO, especially in patients with hypothalamic involvement [26,27]. Furthermore, SIADH can occur, albeit rarely, in patients without hypothalamic abnormalities on magnetic resonance imaging [28].…”

A comparison of pediatric and adult neuromyelitis optica spectrum disorders: A review of clinical manifestation, diagnosis, and treatment

“…It is sometimes relapsing [40], occasionally as a first presentation [41], and is not always associated with AQP4-IgG seropositivity [42]. Inappropriate antidiuretic hormone secretion (SIADH) with NMOSD association is important and AQP4-IgG testing has been suggested in any unexplained SIADH associated with unexplained progressive unconsciousness, especially with bilateral anterior thalamus and hypothalamus brain MRI involvement [43]. Hypotension, hypersomnia, hypothermia, behavioral changes, amenorrhea galactorrhea syndrome [44], and narcolepsy [45].…”