Historical reflections on neurosyphilis based on the 1826 treatise on general paralysis in demented patients by Louis Florentin Calmeil (1798-1895)

General paralysis is a neurological symptom of tertiary syphilis that was first identified in asylums as paralytic madness. The enlightened discussion of 60 clinicopathological cases provided by Louis Florentin Calmeil in his 1826 treatise greatly improved our knowledge of general paralysis. However, Calmeil was unable to relate this symptom to syphilis, although the latter was quite widespread at that time. Following a detailed reanalysis of Calmeil's observations with special attention to his clinical and demographic data, we conclude that this eminent clinician was unable to define the cause of general paralysis because his early 19th century mind was still under the influence of traditional knowledge and moral prejudices. For Calmeil, general paralysis belonged entirely to the realm of psychiatry.