French physician Ernest-Charles Lasègue's name is famous in eating disorder circles for being, with Britain's Sir William Gull, the first to formally describe anorexia nervosa, which Lasègue termed ‘anorexie hystérique’ in his classic 1873 paper Reference Lasègue, Kaufman and Heiman(1).

Over a century later, it is still debated as to who first described anorexia nervosa Reference Vandereycken(2,Reference Silverman3). Lasègue is often contrasted with the flamboyant Gull as the retiring and generally more humble rival. In 1873, Gull asserted his position as the first to describe anorexia nervosa by citing an obscure statement from his 1868 oration and suggested that Lasègue was not aware of this reference Reference Gull, Kaufman and Heiman(4). As editor of the Archives Générales de Médicines, Lasègue swiftly replied that he was indeed unaware of the short reference from Gull's 1868 speech and that Gull himself had not been aware of Lasègue's own report, which had been translated and published in the Medical Times in 1873 Reference Silverman(3). In the true tradition of cross-channel rivalry, Lasègue then impishly added that Gull's 1868 statement was not merely unknown to him in France but probably also unknown to everyone else, including in England. Lasègue then offered to publish Gull's data and analyses if he would send them to Paris, an invitation which Gull did not take up Reference Silverman(3).

Both Lasègue's and Gull's accounts of anorexia nervosa still accurately describe the condition that we encounter today: the emaciation, amenorrhoea, over-exercising, egosyntonic refusal to eat, the patient's contentment with an emaciated state and psychological component of the condition were all observed. Interestingly, neither Lasègue nor Gull mentions body image or fear of gaining weight, which are core psychopathology in the DSM-IV and ICD-10 diagnostic criteria for anorexia nervosa. While Gull Reference Gull, Kaufman and Heiman(4) provided three case reports, describing the current situations of patients and, briefly, their treatment progress, he says nothing of the evolution of the illness before the patients were brought to his attention. In contrast, the description by Lasègue Reference Lasègue, Kaufman and Heiman(1) is more detailed. Lasègue drew on eight cases and described the start of the condition where the patient progressively reduces her food intake and becomes increasingly stricter in her choice of food. He also noted the development of irregular menses followed by amenorrhoea and the progress of anorexia nervosa both physiologically and behaviourally. Many of Lasègue's observations are still valid today, among them the chronicity of the condition, the fact that treatment success routinely alternates with failure and that one ‘frequently only obtain[s] a very insufficient result', the patients' use of excessive condiments to season their meals and the family's dynamics as the illness becomes more severe. However, neither Lasègue nor Gull reported observing relapse, and Lasègue states that he had not known patients to relapse after being cured, nor had he observed death directly resulting from anorexia nervosa.

Yet, Lasègue's claim to fame goes far beyond his description of anorexia nervosa. Lasègue and his colleague Falret were the first to name and describe the shared psychotic disorder folie à deux in 1877 Reference Lasègue and Falret(5), where the delusions of one individual are transferred to and manifest in another. Also known as Lasègue–Falret syndrome, symptoms had already been documented by other French psychiatrists, such as Baillarger in 1860 and Legrand du Saulle in 1871 Reference Shimizu, Kubota, Toichi and Baba(6). However, Lasègue and Falret's 1877 paper is a classic article, which is frequently cited in psychiatry and yet was not translated into English until 1964. Whilst considered comparatively rare, case reports of folie à deux are still routinely published today. Lasègue was also the first to name and describe exhibitionism in 1887 Reference Christoffel(7).

Beyond psychiatry, Lasègue is well known in neurology circles for the eponym ‘Lasègue's sign’ or ‘Lasègue's test' in sciatica, where there is pain when the leg is raised with the knee extended but no pain when the knee is flexed. This sign became a standard test in clinical practice. While Lasègue certainly emphasised its diagnostic importance and its consistent presence in sciatica, the sign was actually described in 1881, by his student, Forst, who attached Lasègue's name to it Reference Wartenberg(8). The mechanism for this test was elucidated by Lazerevic in 1880 Reference Dimitrijevic(9).

A physician, psychiatrist, neurologist and epidemiologist, Lasègue published over 100 papers covering internal medicine, psychiatry, neurology and the history of medicine and has been justifiably dubbed ‘the universal specialist' Reference Vandereycken(2,Reference Wartenberg10). Today, perhaps because of specialisation, clinicians and researchers focus on much narrower fields and it would be unfeasible for them to attempt to contribute significantly to such a wide range of disciplines in the same manner as Lasègue has. Disturbingly, it may also reflect a loss of the art of observation and clinical acumen.