Bayle's Disease

a mental disease, caused by syphilis, of the central nervous system. Bayle’s disease was first described in 1822 by the French psychiatrist A. L. J. Bayle. Its relationship with syphilis was established in 1913 by the Japanese bacteriologist H. Noguchi, who discovered spirochetes in the brain of those afflicted with the disease.

A comparatively rare disease nowadays, Bayle’s disease develops five to 15 years after infection, generally as a result of inadequate treatment. It was widespread at the turn of the 20th century. Progress in the control of syphilis has tended to decrease morbidity; less than 0.3 percent of the patients in psychiatric hospitals have Bayle’s disease.

Bayle’s disease is manifested by the progressive deterioration of the mind to the point of severe dementia, which is accompanied by somatic and neurological disorders. In the initial stage of the disease, symptoms of neurasthenia predominate, including fatigue, irritability, and decreased efficiency. In addition, personality changes occur; patients become rude and tactless and their baser tendencies surface. At other times, the patient can have a placid disposition. Memory and judgment become increasingly impaired and previous habits and knowledge are lost. As dementia progresses, megalomania, elevated or depressed moods, hypochondria, and alternating states of depression and maniacal excitement are observed. Epileptiform attacks and speech, motor, and writing disorders are possible symptoms. Characteristic neurological symptoms include the nonuniformity of the pupils and their inability to react to light, paresis of the ocular muscles, an increase in tendon reflexes, and trembling of the hands and tongue. The disease culminates with a state of marasmus.

A diagnosis of Bayle’s disease is confirmed by laboratory tests, such as the Wassermann reaction. Treatment includes the administration of antibiotics and other antisyphilitics. Pyrotherapy arrests the development of the disease, which accounts for the rarity of severe forms of Bayle’s disease.