An autopsy case of amyotrophic lateral sclerosis accompanied by syndrome of inappropriate secretion of antidiuretic hormone.

We report an autopsy-confirmed case of amyotrophic lateral sclerosis (ALS) accompanied by syndrome of inappropriate secretion of antidiuretic hormone (SIADH). A 67-year-old man was admitted to our hospital with muscle weakness, dysarthria and dysphagia. During hospitalization, respiratory insufficiency was ingravescent, and hyponatremia, hypo-osmolarity, elevated osmotic pressure of urine, and elevated urinary sodium excretion were noted. Based on these findings we diagnosed ALS with SIADH, and treatment with infusion of concentrated NaCl was started. However, the patient died of respiratory failure on day 50. We assumed that severely restrictive ventilatory impairment was the cause of SIADH in this case.