Multiple System Atrophy with Syndrome of Inappropriate Antidiuretic Hormone

Abstract

Multiple System Atrophy (MSA) is a rare neurodegenerative disease which mainly affects extrapyramidal system, cerebellum and autonomic nervous system as well as hypothalamus. Hypothalamic disturbances can lead to the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) and resultant hyponatremia. MSA with SIADH is rarely reported. We reported a 71-year-old woman was admitted to our hospital because of fever for two months. She was diagnosed with probable multiple system atrophy based on poorly L-Dopa responsive parkinsonism, urinary incontinence and orthostatic hypotension. Hyponatremia, and the urine sodium and osmolality increased indicating that she had SIADH at the same time. Hyponatremia was corrected after water restriction and sodium supplementation. In this report, we describe the clinical characteristics and treatment in regard to MSA with SIADH.