This syndrome followed the use of a commercial salt substitute containing lithium chloride, citric acid and potassium iodide. The changes which occurred were profound and severe, yet transient, and the patient made a rapid and complete recovery. The signal symptoms and signs as they successively occurred over a period of a week included anorexia, rapid change in personality, lethargy, dysphagia and pain on swallowing, bradycardia, cutaneous hyperesthesia and hyperalgesia, muscular hyperirritability, profound general and multiple myoclonus and mental obfuscation. REPORT OF CASE The patient was an 82 year old man previously rather vigorous and alert. He was hospitalized January 9 at the Cedars of Lebanon Hospital, Los Angeles, on arrival from another locale for further convalescence. Immediate previous diagnoses included: (1) simple fractures, right fourth, fifth and sixth ribs incurred Dec. 11, 1948; (2) rectal prolapse; (3) urinary bladder retention and infection; (4) bronchopneumonia with onset on Dec. 27, 1948,