Laughter, known to mankind as a physiological response to happy and comical events in general, is one of the most inviting guides through human life, but sometimes it may point to various morbid states of mind.
Physiological laughter has been studied by numerous psychologists and philosophers, the pathological part of the subject and compulsive laughter by many physicians, both clinicians and anatomists. Reading through the accessible part of the extensive literature on laughter one realizes that much has not yet been quite elucidated. In recent years we have had an opportunity of following a few most interesting cases of pathological laughter. This essay has been devoted to a review of the psychological, clinical and anatomical studies, and to an analysis of our five cases and their relation to epilepsy.