Jean-Martin Charcot's contributions to the interface between neurology and psychiatry

Jean-Martin Charcot: the polymath

Jean-Martin Charcot, widely regarded as a leading founder of modern neurology, made substantial contributions to the understanding and characterization of numerous medical conditions. His initial focus was on internal medicine, later expanding to include neuropathology, general neurology, and eventually emerging fields such as neuropsychology and neuropsychiatry. Furthermore, Charcot's intellectual pursuits extended beyond medicine, encompassing research in art history, medical iconography, sociology, religious studies, and the arts, solidifying his status as a polymath.

Abrupt treatments of hysteria during World War I, 1914-18

Case reports of the abrupt recovery of hysterical disorders during World War I (1914-18), though undoubtedly subject to publication bias, raise both aetiological and treatment issues regarding pseudo-neurological conversion symptoms. Published clinical anecdotes report circumstantial, psychotherapeutic, hypnotic, persuasive (and coercive) methods seemingly inducing recovery, and also responses to fright and alterations of consciousness. The ethics of modern medical practice would not allow many of these techniques, which were reported to be effective, even in the chronic cases.

A neurological bias in the history of hysteria: from the womb to the nervous system and Charcot

Hysteria conceptions, from ancient Egypt until the 19th century Parisian hospital based studies, are presented from gynaecological and demonological theories to neurological ones. The hysteria protean behavioral disorders based on nervous origin was proposed at the beginning, mainly in Great Britain, by the "enlightenment nerve doctors". The following personages are highlighted: Galen, William, Sydenham, Cullen, Briquet, and Charcot with his School. Charcot who had hysteria and hypnotism probably as his most important long term work, developed his conceptions, initially, based on the same methodology he applied to studies of other neurological disorder. Some of his associates followed him in his hysteria theories, mainly Paul Richer and Gilles de La Tourette who produced, with the master's support, expressive books on Salpêtrière School view on hysteria.

Hysterical conversion and brain function

Hysterical conversion disorders represent "functional" or unexplained neurological deficits such as paralysis or somatosensory losses that are not explained by organic lesions in the nervous system, but arise in the context of "psychogenic" stress or emotional conflicts. After more than a century of both clinical and theoretical interest, the exact nature of such emotional disorders responsible for hysterical symptoms, and their functional consequences on neural systems in the brain, still remain largely unknown. However, several recent studies have used functional brain imaging techniques (such as EEG, fMRI, PET, or SPECT) in the attempt to identify specific neural correlates associated with hysterical conversion symptoms. This article presents a general overview of these findings and of previous neuropsychologically based accounts of hysteria. Functional neuroimaging has revealed selective decreases in the activity of frontal and subcortical circuits involved in motor control during hysterical paralysis, decreases in somatosensory cortices during hysterical anesthesia, or decreases in visual cortex during hysterical blindness. Such changes are usually not accompanied by any significant changes in elementary stages of sensory or motor processing as measured by evoked potentials, although some changes in later stages of integration (such as P300 responses) have been reported. On the other hand, several neuroimaging results have shown increased activation in limbic regions, such as cingulate or orbitofrontal cortex during conversion symptoms affecting different sensory or motor modalities. Taken together, these data generally do not support previous proposals that hysteria might involve an exclusion of sensorimotor representations from awareness through attentional processes. They rather seem to point to a modulation of such representations by primary affective or stress-related factors, perhaps involving primitive reflexive mechanisms of protection and alertness that are partly independent of conscious control, and mediated by dynamic modulatory interactions between limbic and sensorimotor networks. A better understanding of the neuropsychobiological bases of hysterical conversion disorder might therefore be obtained by future imaging studies that compare different conversion symptoms and employ functional connectivity analyses. This should not only lead to improve clinical management of these patients, but also provide new insights on the brain mechanisms of self-awareness.

Conversion motor paralysis disorder: overview and rehabilitation model

It is important to consider a differential diagnosis between paralysis on an organic basis and paralysis and disability due to psychological mechanisms in people with physical impairment secondary to trauma, without evidence of organic etiology. We review the most dramatic type of conversion disorder (CD)-'Conversion Motor Paralysis'. Recent important medical literature concerning the accepted treatment and rehabilitation management will be reviewed and discussed. The inter-disciplinary in-patient team management approach in a rehabilitation setting offers the benefits of a comprehensive assessment and treatment. The diagnosis is temporary and conditional, since there may be a long delay until the appearance of organic findings. A complete medical assessment is essential in order to rule out any possibility of an organic etiology. In as many as 25% to 50% of patients diagnosed as conversion, an organic medical diagnosis was found.