Especially frequent during menstruation is hemicrania. Sometimes hemicrania may begin a day or two before menstruation, as a prodromal sign, and may accompany its whole course, becoming, however, less severe toward the end of the flow. Hysteria most commonly manifests itself in association with menstruation by a depressed emotional state, by tearfulness, by complaints made without sufficient grounds, by globus hystericus or clavus hystericus; sometimes also by paroxysms of muscular spasm; very rarely by hystero-epileptic seizures. Epilepsy may occur either by day or by night. Nocturnal seizures usually occur without any apparent external cause, as a result of the central stimulus; diurnal attacks, on the other hand, have usually some external exciting cause. Often, however, years may elapse without any attack of major epilepsy occurring, the disease manifesting itself in one or more of the many varieties of the minor form (_petit mal_), as transient absences of mind, attacks of vertigo, etc. The nervous disturbance in a menstruating woman may be so great as to lead to the production of psychoses. The question of the existence of a menstrual insanity _sui generis_ has been answered by many alienists in the affirmative; by others, however, who see in the alleged cases nothing specific, it has been answered in the negative. The relation of menstruation to the mental disorder may be a double one: 1, menstruation may occur repeatedly in the course of an already established mental disorder; 2, menstruation and its morbid variations may favor the occurrence of psychoses that exist already in a latent form, and may lead to the origination of psychoses to which the organism is predisposed.