pituitrin and Amyotrophic-Lateral-Sclerosis

A 65-year-old man who had muscle weakness and dysarthria was admitted for investigation of motor neuron disease. He had lost 12 kg of weight in 6 months. Neurological findings disclosed upper and lower motor neuron disturbances with normal sensory nerve function, and needle electromyography showed a neurogenic pattern. Laboratory findings on admission demonstrated dilutional hyponatraemia due to an excessive secretion of antidiuretic hormone (ADH). Based on these findings, the patient was diagnosed as having the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with amyotrophic lateral sclerosis (ALS). During the night of first hospital day, the patient complained of severe dyspnoea, and mechanical ventilation was commenced. Following the mechanical ventilation, plasma ADH levels and serum sodium concentration were normalized. We propose that respiratory failure secondary to the atrophy of respiratory muscle might be responsible for the development of SIADH.

Topics: Aged; Amyotrophic Lateral Sclerosis; Blood Gas Analysis; Diagnosis, Differential; Electromyography; Humans; Inappropriate ADH Syndrome; Male; Respiration, Artificial; Respiratory Insufficiency; Saline Solution, Hypertonic; Sodium; Vasopressins

We report 2 autopsy-proven cases of motor neuron disease/amyotrophic lateral sclerosis (MND/ALS), who developed the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) prior to the respiratory failure. With respect to the underlying mechanisms of SIADH in the cases, we considered two factors; 1) dysfunction of the feedback system in ADH secretion via intrathoracic volume receptors caused by changes in intrathoracic circulation, and 2) primarily functional abnormalities in the limbic system which could influence hypothalamic osmoreceptors. It appears that SIADH can be followed by an exacerbation of respiratory dysfunction in MND/ALS.

Topics: Amyotrophic Lateral Sclerosis; Feedback; Humans; Hypothalamus; Inappropriate ADH Syndrome; Limbic System; Male; Middle Aged; Motor Neuron Disease; Neurologic Examination; Respiratory Insufficiency; Vasopressins; Water-Electrolyte Balance

A 71-year-old female with amyotrophic lateral sclerosis (ALS) developed the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) during respiratory failure due to atrophy of the respiratory muscles. Serum sodium concentration fell to 116 mEq/l and then returned to the normal range after water restriction and respiratory care. This is considered to be the first case report of ALS associated with SIADH.

Topics: Aged; Amyotrophic Lateral Sclerosis; Blood Chemical Analysis; Electromyography; Female; Humans; Inappropriate ADH Syndrome; Respiratory Insufficiency; Sodium; Vasopressins