GENERAL PARALYSIS OF THE INSANE is a disease marked by definite pathological changes in the central nervous system, chiefly in the cortex of the brain, but which may extend to any part of the cerebro-spinal tract or to the sympathetic ganglia and cranial and spinal nerves. Its constant symptoms are—(1) vaso-motor disturbance ending in vaso-motor paresis; (2) mental impairment, which makes progress, for the most part unevenly, to complete terminal dementia or extinction of mind; (3) impaired muscular control, which advances more or less uniformly to almost entire paresis or nearly total paralysis. Expansive delusions, the delirium of grandeur, megalomania (which may change suddenly to micromania), or simply a feeling of elation, happiness, self-satisfaction, or undue complacency, are found, but often not until or near the end. The other symptoms vary in individual cases within a wide range, so as to simulate almost every form of insanity; and it is quite possible that they include what a more exact pathology will hereafter recognize as several distinct diseases. SYNONYMS.—General paralysis is also known as general paresis, progressive paralysis of the insane, paretic dementia, paralytic dementia, cirrhosis of the brain, paralysie-générale, folie paralytique, démence paralytique, periencephalite chronique diffuse, meningo-myélo-encephalite chronique interstitielle diffuse, encephalite généralisée, periencephalite chronique diffuse, encephalite interstitielle diffuse, encephalite avec proliferation sclereuse interstitielle, Allgemeine Paralyse, progressive Paralyse der Irren, chronische progressive parenchymatöse Encephalitis der Rindensubstanz, pericerebritis, periencephalo-meningitis diffusa chronica, periencephalo-myelitis chronica diffusa, encephalitis interstitialis corticalis, paralytische Blödsinn, primäre Encephalitis interstitialis mit Ausgang in Sclerose. Griesinger placed general paralysis among the complications of insanity. It is popularly known as softening of the brain (Gehirnerweichung). HISTORY.—The combination of the two series of symptoms, paralysis and dementia, was recognized by Haslam, and at the beginning of this century by French writers, who also knew their fatal import. Esquirol describes a typical case of general paralysis of the insane under the head of monomania in his _Maladies mentales_. His pupils, especially Bayle and Calmeil, have studied and described general paralysis. At the time of his first visit to England, forty years ago, the late Luther Bell had never recognized a case, and there can be no doubt of the fact that it has {177} rapidly increased, particularly in the last dozen or twenty years, with the rapid increase in the aggregation of the population.