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

Case report: Hyponatremia is an initial presentation of Neuromyelitis optica spectrum disorder

OBJECTIVE

Neuromyelitis optica spectrum disorders (NMOSD) is often misdiagnosed or delayed because of the complex and diverse clinical manifestations, especially the atypical initial presentation. Hyponatremia can be an infrequently isolated initial presentation of NMOSD and is associated with hypothalamus involvement. Awareness of this mechanism will help clinicians to identify NMOSD early, treat it in time and improve the prognosis.

METHODS

We describe a 36-year-old woman who developed repeated hyponatremia and then experienced diplopia. Serum AQP4, MOG, MBP and GFAP antibody were detected, and NMOSD was finally diagnosed.

RESULTS

She responded well to high-dose glucocorticoids. Sequential treatment with mycophenolate mofetil (MMF) was prescribed. Two-month follow-up revealed full recovery. So far, after 10 months, the patient still has no recurrence.

CONCLUSION

For young patients, repeated hyponatremia, with or without slight fever, and no evidence of obvious infection, brain magnetic resonance imaging (MRI) and serum AQP4/MOG antibody detection may be useful to determine whether there is a possibility of NMOSD.

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

Hyponatremia associated with low-dose trimethoprim in patients on concomitant systemic corticosteroid therapy has rarely been reported. Here, we describe a 57-year-old woman with a history of diabetes mellitus and hypertension treated with telmisartan, who presented with progressive visual impairment of the left eye due to anti-aquaporin-4 antibody-positive optic neuritis. The patient received pulsed intravenous methylprednisolone followed by oral prednisolone at 30 mg/day and trimethoprim-sulfamethoxazole prophylaxis (160 mg and 800 mg daily). Her serum sodium level steadily decreased, and the potassium level was slightly elevated despite well-preserved renal function. This state persisted even after telmisartan discontinuation. In addition to hypotonic hyponatremia (125 mEq/L) with natriuresis, hyperkalemic renal tubular acidosis was diagnosed based on normal anion gap metabolic acidosis and hyperkalemia with low urinary potassium excretion. After trimethoprim-sulfamethoxazole cessation, electrolytes and acid-base imbalances swiftly recovered. We can conclude that caution must be exercised when treating such patients, because even low-dose trimethoprim may cause hyponatremia concomitant with hyperkalemic renal tubular acidosis, despite the mineralocorticoid effects of systemic corticosteroids.

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

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) primarily affecting the optic nerves and spinal cord, but also involving other regions of the CNS including the area postrema, periaqueductal gray matter, and hypothalamus. Knowledge related to pediatric manifestations of NMOSD has grown in recent years, particularly in light of newer information regarding the importance of not only antibodies to aquaporin 4 (AQP4-IgG) but also myelin oligodendrocyte glycoprotein (MOG-IgG) in children manifesting clinically with this syndrome. In this review, we describe the current state of the knowledge related to clinical manifestations, diagnosis, and chronic therapies for children with NMOSD, with emphasis on literature that has been published in the last 5 years. Following the review, we propose recommendations for the assessment/follow up clinical care, and treatment of this population.