Jean-Martin Charcot
Encyclopedia
Jean-Martin Charcot was a French neurologist
and professor of anatomical pathology
. He is known as "the founder of modern neurology" and is "associated with at least 15 medical eponym
s", including Charcot-Marie-Tooth disease
and amyotrophic lateral sclerosis
(motor neurone disease). Charcot has been referred to as "the father of French neurology and one of the world's pioneers of neurology".
His work greatly influenced the developing fields of neurology and psychology
. He was the "foremost neurologist of late nineteenth-century France" and has been called "the Napoleon of the neuroses".
"He married a rich widow, Madame Durvis, in 1862 and had two children, Jeanne and Jean-Baptiste, the latter becoming both a doctor and a famous polar explorer".
. Summarizing previous reports and adding his own clinical and pathological observations, Charcot called the disease sclerose en plaques. The three signs of Multiple sclerosis now known as Charcot's triad 1 are nystagmus, intention tremor
, and telegraphic speech
, though these are not unique to MS. Charcot also observed cognition changes, describing his patients as having a "marked enfeeblement of the memory" and "conceptions that formed slowly". He was also the first to describe a disorder known as Charcot joint or Charcot arthropathy, a degeneration of joint surfaces resulting from loss of proprioception
. He researched the functions of different parts of the brain and the role of arteries in cerebral hemorrhage.
Charcot was among the first to describe Charcot-Marie-Tooth disease
(CMT). The announcement was made simultaneously with Pierre Marie of France (his resident) and Howard Henry Tooth
of England. The disease is also sometimes called peroneal muscular atrophy.
Charcot's studies between 1868 and 1881 were a landmark in the understanding of Parkinson's disease
. Among other advances he made the distinction between rigidity, weakness and bradykinesia. He also led the disease, which was formerly named paralysis agitans (shaking palsy), to be re-named on behalf of James Parkinson
.
and hysteria
. He believed that hysteria was a neurological disorder for which patients were pre-disposed by hereditary features of their nervous system. Charcot's interest in hysteria and hypnotism "developed at a time when the general public was fascinated in 'animal magnetism' and mesmerization' ... Charcot and his school considered the ability to be hypnotized as a clinical feature of hysteria ... For the members of the Salpêtrière School, susceptibility to hypnotism was synonymous with disease, i.e. hysteria, although they later recognized ... that grand hypnotisme (in hysterics) should be differentiated from petit hypnotisme, which corresponded to the hypnosis of ordinary people".
The Salpêtrière School's position on hypnosis were sharply criticized by Hippolyte Bernheim
, a leading neurologist of the time. Charcot himself long had concerns about the use of hypnosis in treatment and about its effect on patients. He also was concerned that the sensationalism hypnosis attracted had robbed it of its scientific interest, and that the quarrel with Bernheim, further mostly by his pupil Georges Gilles de la Tourette
, had "damaged" hypnotism.
Charcot is just as famous for his students: Sigmund Freud
, Joseph Babinski
, Pierre Janet
, William James
, Pierre Marie, Albert Londe
, Charles-Joseph Bouchard
, Georges Gilles de la Tourette
, Alfred Binet
, and Albert Pitres
. Charcot bestowed the eponym
for Tourette syndrome
in honor of his student, Georges Gilles de la Tourette.
Although by the 1870s, Charcot was France's best known physician, according to Edward Shorter, his ideas in psychiatry were refuted, and France did not recover for decades. Shorter wrote in his A History of Psychiatry that Charcot himself understood "almost nothing" about major psychiatric illness, and that he was "quite lacking in common sense and grandiosely sure of his own judgement". However, this perspective overlooks that Charcot never claimed to be practicing psychiatry or to be a psychiatrist, a field that was separately organized from neurology within France's educational and public health systems. After his death, the illness "hysteria
" that Charcot described was claimed to be nothing more than an "artifact of suggestion".
However, the negative judgment of Charcot's work on hysteria is influenced by a significant shift in diagnostic criteria and conception of hysteria which occurred in the decades following his death. The historical perspective on Charcot's work on hysteria has also been distorted by viewing him as a precursor of Freud (whose markedly different conception of hysteria was extensively addressed by feminist historians in the last decades of the 20th century).
In fact, Charcot argued vehemently against the widespread medical and popular prejudice that hysteria was rarely found in men. He taught that due to this prejudice these "cases often went unrecognised, even by distinguished doctors" and could occur in such models of masculinity as railway engineers or soldiers. Charcot's analysis, in particular his view of hysteria as an organic condition which could be caused by trauma, paved the way for understanding neurological symptoms arising from industrial-accident or war-related traumas.
Charcot appears, along with Maria Skłodowska-Curie (Madame Curie) and Charcot's patient "Blanche" (Marie Wittman), in Per Olov Enquist
's 2004 novel The Book about Blanche and Marie (English translation, 2006, ISBN 1-58567-668-3). He also appears in the 2005 novel by Sebastian Faulks
, Human Traces
, and in Axel Munthe
's 1929 autobiographical novel The Story of San Michele
. In a letter to the New York Times Book Review of January 18, 1931, however, Charcot's son wrote that "Dr Munthe never was trained by my father." And in his 2008 biography of Munthe (ISBN 978-1-84511-720-7), Bengt Jangfeldt says that 'Charcot is not mentioned in a single letter of Axel's out of the hundreds that have been preserved from his Paris years.' Distorted views of Charcot as harsh and tyrannical have arisen from some sources that mistakenly identify Munthe as Charcot's assistant and take Munthe's autobiographical novel as a factual memoir. In fact, Munthe was just a medical student among hundreds of others. Munthe's most direct contact with Charcot was when he helped a young female patient "escape" from a ward of the hospital and took her into his home. Charcot threatened to advise the police and ordered that Munthe not be allowed on the wards of the hospital again.
Charcot Island
in Antarctica was discovered by his son, Jean-Baptiste Charcot, who named the Island in honor of his father.
Neurology
Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
and professor of anatomical pathology
Anatomical pathology
Anatomical pathology or Anatomic pathology is a medical specialty that is concerned with the diagnosis of disease based on the gross, microscopic, chemical, immunologic and molecular examination of organs, tissues, and whole bodies...
. He is known as "the founder of modern neurology" and is "associated with at least 15 medical eponym
Eponym
An eponym is the name of a person or thing, whether real or fictitious, after which a particular place, tribe, era, discovery, or other item is named or thought to be named...
s", including Charcot-Marie-Tooth disease
Charcot-Marie-Tooth disease
Charcot–Marie–Tooth disease- , known also as Morbus Charcot-Marie-Tooth, Charcot-Marie-Tooth neuropathy, hereditary motor and sensory neuropathy , hereditary sensorimotor neuropathy , or peroneal muscular atrophy, is an inherited disorder of nerves that takes different forms...
and amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis , also referred to as Lou Gehrig's disease, is a form of motor neuron disease caused by the degeneration of upper and lower neurons, located in the ventral horn of the spinal cord and the cortical neurons that provide their efferent input...
(motor neurone disease). Charcot has been referred to as "the father of French neurology and one of the world's pioneers of neurology".
His work greatly influenced the developing fields of neurology and psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
. He was the "foremost neurologist of late nineteenth-century France" and has been called "the Napoleon of the neuroses".
Personal life
Born in Paris, France, Charcot worked and taught at the famous Salpêtrière Hospital for 33 years. His reputation as an instructor drew students from all over Europe. In 1882, he established a neurology clinic at Salpêtrière, which was the first of its kind in Europe. Charcot was a part of the French neurological tradition and studied under, and greatly revered, Duchenne de Boulogne."He married a rich widow, Madame Durvis, in 1862 and had two children, Jeanne and Jean-Baptiste, the latter becoming both a doctor and a famous polar explorer".
Neurology
Charcot's primary focus was neurology. He named and was the first to describe multiple sclerosisMultiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
. Summarizing previous reports and adding his own clinical and pathological observations, Charcot called the disease sclerose en plaques. The three signs of Multiple sclerosis now known as Charcot's triad 1 are nystagmus, intention tremor
Intention tremor
Intention tremor, also known as cerebellar tremor, is a dyskinetic disorder characterized by a broad, course, and low frequency tremor. The amplitude of an intention tremor increases as an extremity approaches the endpoint of deliberate and visually guided movement...
, and telegraphic speech
Telegraphic speech
Telegraphic speech, according to linguistics and psychology, is speech during the two-word stage of language acquisition in children, which is laconic and efficient....
, though these are not unique to MS. Charcot also observed cognition changes, describing his patients as having a "marked enfeeblement of the memory" and "conceptions that formed slowly". He was also the first to describe a disorder known as Charcot joint or Charcot arthropathy, a degeneration of joint surfaces resulting from loss of proprioception
Proprioception
Proprioception , from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement...
. He researched the functions of different parts of the brain and the role of arteries in cerebral hemorrhage.
Charcot was among the first to describe Charcot-Marie-Tooth disease
Charcot-Marie-Tooth disease
Charcot–Marie–Tooth disease- , known also as Morbus Charcot-Marie-Tooth, Charcot-Marie-Tooth neuropathy, hereditary motor and sensory neuropathy , hereditary sensorimotor neuropathy , or peroneal muscular atrophy, is an inherited disorder of nerves that takes different forms...
(CMT). The announcement was made simultaneously with Pierre Marie of France (his resident) and Howard Henry Tooth
Howard Henry Tooth
Howard Henry Tooth, CMG, CB was a British neurologist and one of the discoverers of Charcot-Marie-Tooth disease.-Early life and education:...
of England. The disease is also sometimes called peroneal muscular atrophy.
Charcot's studies between 1868 and 1881 were a landmark in the understanding of Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
. Among other advances he made the distinction between rigidity, weakness and bradykinesia. He also led the disease, which was formerly named paralysis agitans (shaking palsy), to be re-named on behalf of James Parkinson
James Parkinson
James Parkinson was an English apothecary surgeon, geologist, paleontologist, and political activist. He is most famous for his 1817 work, An Essay on the Shaking Palsy in which he was the first to describe "paralysis agitans", a condition that would later be renamed Parkinson's disease by...
.
Studies on hypnosis and hysteria
Charcot is best known today, outside the community of neurologists, for his work on hypnosisHypnosis
Hypnosis is "a trance state characterized by extreme suggestibility, relaxation and heightened imagination."It is a mental state or imaginative role-enactment . It is usually induced by a procedure known as a hypnotic induction, which is commonly composed of a long series of preliminary...
and hysteria
Hysteria
Hysteria, in its colloquial use, describes unmanageable emotional excesses. People who are "hysterical" often lose self-control due to an overwhelming fear that may be caused by multiple events in one's past that involved some sort of severe conflict; the fear can be centered on a body part, or,...
. He believed that hysteria was a neurological disorder for which patients were pre-disposed by hereditary features of their nervous system. Charcot's interest in hysteria and hypnotism "developed at a time when the general public was fascinated in 'animal magnetism' and mesmerization' ... Charcot and his school considered the ability to be hypnotized as a clinical feature of hysteria ... For the members of the Salpêtrière School, susceptibility to hypnotism was synonymous with disease, i.e. hysteria, although they later recognized ... that grand hypnotisme (in hysterics) should be differentiated from petit hypnotisme, which corresponded to the hypnosis of ordinary people".
The Salpêtrière School's position on hypnosis were sharply criticized by Hippolyte Bernheim
Hippolyte Bernheim
Hippolyte Bernheim was a French physician and neurologist, born at Mülhausen, Alsace. He received his education in his native town and at the University of Strasbourg, where he was graduated as doctor of medicine in 1867...
, a leading neurologist of the time. Charcot himself long had concerns about the use of hypnosis in treatment and about its effect on patients. He also was concerned that the sensationalism hypnosis attracted had robbed it of its scientific interest, and that the quarrel with Bernheim, further mostly by his pupil Georges Gilles de la Tourette
Georges Gilles de la Tourette
Georges Albert Édouard Brutus Gilles de la Tourette was a French neurologist who is the eponym of Tourette syndrome, a neurological condition...
, had "damaged" hypnotism.
Arts
Charcot thought of art as a crucial tool of the clinicoanatomic method. He used extensively photos and drawings, many made by himself or his students, in his classes and conferences. He also drew outside the neurology domain, as a personal hobby. He is considered key in the incorporation of photography to the study of neurological cases.Eponyms
Charcot's name is associated with many diseases and conditions including:- Charcot's artery (lenticulostriate artery)
- Charcot's jointNeuropathic joint diseaseNeuropathic arthropathy , also known as Charcot joint , refers to progressive degeneration of a weight bearing joint, a process marked by bony destruction, bone resorption, and eventual deformity...
(diabetic arthropathyArthropathy-Scope:Arthritis is a form of arthropathy that involves inflammation of one or more joints, while the term arthropathy may be used regardless of whether there is inflammation or not.Spondylarthropathy is any form of arthropathy of the vertebral column....
) - Charcot's disease (amyotrophic lateral sclerosisAmyotrophic lateral sclerosisAmyotrophic lateral sclerosis , also referred to as Lou Gehrig's disease, is a form of motor neuron disease caused by the degeneration of upper and lower neurons, located in the ventral horn of the spinal cord and the cortical neurons that provide their efferent input...
, the most-common subtype of motor neurone diseaseMotor neurone diseaseThe motor neurone diseases are a group of neurological disorders that selectively affect motor neurones, the cells that control voluntary muscle activity including speaking, walking, breathing, swallowing and general movement of the body. They are generally progressive in nature, and can cause...
- also known as Lou Gehrig's disease. - Charcot's douche, a very energetic form of massage with a water jet, offered at many spas, especially popular in eastern Europe.
- Charcot-Marie-Tooth diseaseCharcot-Marie-Tooth diseaseCharcot–Marie–Tooth disease- , known also as Morbus Charcot-Marie-Tooth, Charcot-Marie-Tooth neuropathy, hereditary motor and sensory neuropathy , hereditary sensorimotor neuropathy , or peroneal muscular atrophy, is an inherited disorder of nerves that takes different forms...
(peroneal muscular atrophyAtrophyAtrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations , poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, disuse or lack of exercise or disease intrinsic to the tissue itself...
) - Charcot Wilbrand syndrome (visual agnosiaVisual agnosiaVisual agnosia is the inability of the brain to make sense of or make use of some part of otherwise normal visual stimulus and is typified by the inability to recognize familiar objects or faces...
and loss of ability to revisualise images) - Charcot's intermittent hepatic fever (intermittent pain, intermittent fever, intermittent jaundice, and loss of weight)
- Charcot-Bouchard aneurysmCharcot-Bouchard aneurysmCharcot-Bouchard aneurysms are aneurysms of the brain vasculature which occur in small blood vessels . They should not be confused with saccular aneurysms , which occur in larger-sized blood vessels...
s (tiny aneurysms of the penetrating branches of middle cerebral artery in hypertensives) - Charcot's triadCharcot's triadCharcot's neurologic triad is the combination of nystagmus, intention tremor, and scanning or staccato speech. This triad is associated with multiple sclerosis, where it was first described; however, it is not considered pathognomonic for it. It is named for Jean-Martin Charcot.-See also:*Charcot's...
- Charcot arthropathyCharcot arthropathyCharcot arthropathy is a progressive musculoskeletal condition characterized by joint dislocation, fractures and deformities. It results in progressive destruction of bone and soft tissue of weight-bearing joints, most commonly in the foot and ankle...
- Charcot-Leyden crystalsCharcot-Leyden crystalsCharcot-Leyden crystals are microscopic crystals found in people who have allergic diseases such as asthma or parasitic infections such as parasitic pneumonia or ascariasis.The Charcot-Leyden crystal protein interacts with eosinophil lysophospholipases....
due to eosinophils white blood cells lysis in cases of allergic diseases. - Souques-Charcot geroderma: a variant of Hutchinson-Gilford diseaseProgeriaProgeria is an extremely rare genetic condition wherein symptoms resembling aspects of aging are manifested at an early age. The word progeria comes from the Greek words "pro" , meaning "before", and "géras" , meaning "old age"...
; named with Alexandre-Achille SouquesAlexandre-Achille SouquesAlexandre-Achille Souques was a French neurologist who was a native of Comprégnac in the département Aveyron.Souques studied medicine in Paris, where in 1886 he became an interne and in 1891 earned his medical doctorate. Afterwards he worked as médecin des hôpitaux , and in 1918 became a member of...
.
Legacy
One of Charcot's greatest legacies as a clinician is his contribution to the development of systematic neurological examination, correlating a set of clinical signs with specific lesions. This was made possible by his pioneering long-term studies of patients, coupled with microscopic and anatomic analysis derived from eventual autopsies. This led to the first clear delination of various neurological diseases and classic description of them. For example, amyotrophic lateral sclerosis.Charcot is just as famous for his students: Sigmund Freud
Sigmund Freud
Sigmund Freud , born Sigismund Schlomo Freud , was an Austrian neurologist who founded the discipline of psychoanalysis...
, Joseph Babinski
Joseph Babinski
Joseph Jules François Félix Babinski was a French neurologist of Polish descent. He is best known for his 1896 description of the Babinski sign, a pathological plantar reflex indicative of corticospinal tract damage....
, Pierre Janet
Pierre Janet
Pierre Marie Félix Janet was a pioneering French psychologist, philosopher and psychotherapist in the field of dissociation and traumatic memory....
, William James
William James
William James was a pioneering American psychologist and philosopher who was trained as a physician. He wrote influential books on the young science of psychology, educational psychology, psychology of religious experience and mysticism, and on the philosophy of pragmatism...
, Pierre Marie, Albert Londe
Albert Londe
Albert Londe was an influential French photographer, medical researcher and chronophotographer. He is remembered for his work as a medical photographer at the Salpêtrière Hospital in Paris, funded by the Parisian authorities, as well as being a pioneer in X-ray photography.During his two decades...
, Charles-Joseph Bouchard
Charles-Joseph Bouchard
Charles-Joseph Bouchard was a French pathologist born in Montier-en-Der, a commune the department of Haute-Marne. He studied medicine in Lyon and Paris, where he obtained his doctorate in 1866. In 1874 he became a physician at Bicêtre Hospital, and in 1879 was appointed chair of general pathology...
, Georges Gilles de la Tourette
Georges Gilles de la Tourette
Georges Albert Édouard Brutus Gilles de la Tourette was a French neurologist who is the eponym of Tourette syndrome, a neurological condition...
, Alfred Binet
Alfred Binet
Alfred Binet was a French psychologist who was the inventor of the first usable intelligence test, known at that time as the Binet test and today referred to as the IQ test. His principal goal was to identify students who needed special help in coping with the school curriculum...
, and Albert Pitres
Albert Pitres
Albert Pitres, who was born on 26 August 1848 in Bordeaux and died in 1928, was a French neurological physician. He received his training in Paris where he was the student of Jean Martin Charcot and Jules Dejerine. He was the dean of the Faculty of Medicine of Bordeaux.His name became associated...
. Charcot bestowed the eponym
Eponym
An eponym is the name of a person or thing, whether real or fictitious, after which a particular place, tribe, era, discovery, or other item is named or thought to be named...
for Tourette syndrome
Tourette syndrome
Tourette syndrome is an inherited neuropsychiatric disorder with onset in childhood, characterized by multiple physical tics and at least one vocal tic; these tics characteristically wax and wane...
in honor of his student, Georges Gilles de la Tourette.
Although by the 1870s, Charcot was France's best known physician, according to Edward Shorter, his ideas in psychiatry were refuted, and France did not recover for decades. Shorter wrote in his A History of Psychiatry that Charcot himself understood "almost nothing" about major psychiatric illness, and that he was "quite lacking in common sense and grandiosely sure of his own judgement". However, this perspective overlooks that Charcot never claimed to be practicing psychiatry or to be a psychiatrist, a field that was separately organized from neurology within France's educational and public health systems. After his death, the illness "hysteria
Hysteria
Hysteria, in its colloquial use, describes unmanageable emotional excesses. People who are "hysterical" often lose self-control due to an overwhelming fear that may be caused by multiple events in one's past that involved some sort of severe conflict; the fear can be centered on a body part, or,...
" that Charcot described was claimed to be nothing more than an "artifact of suggestion".
However, the negative judgment of Charcot's work on hysteria is influenced by a significant shift in diagnostic criteria and conception of hysteria which occurred in the decades following his death. The historical perspective on Charcot's work on hysteria has also been distorted by viewing him as a precursor of Freud (whose markedly different conception of hysteria was extensively addressed by feminist historians in the last decades of the 20th century).
In fact, Charcot argued vehemently against the widespread medical and popular prejudice that hysteria was rarely found in men. He taught that due to this prejudice these "cases often went unrecognised, even by distinguished doctors" and could occur in such models of masculinity as railway engineers or soldiers. Charcot's analysis, in particular his view of hysteria as an organic condition which could be caused by trauma, paved the way for understanding neurological symptoms arising from industrial-accident or war-related traumas.
Charcot appears, along with Maria Skłodowska-Curie (Madame Curie) and Charcot's patient "Blanche" (Marie Wittman), in Per Olov Enquist
Per Olov Enquist
Per Olov Enquist, better known as P. O. Enquist, is a Swedish author. He has worked as a journalist, playwright and novelist...
's 2004 novel The Book about Blanche and Marie (English translation, 2006, ISBN 1-58567-668-3). He also appears in the 2005 novel by Sebastian Faulks
Sebastian Faulks
-Early life:Faulks was born on 20 April 1953 in Donnington, Berkshire to Peter Faulks and Pamela . Edward Faulks, Baron Faulks, is his older brother. He was educated at Elstree School, Reading and went on to Wellington College, Berkshire...
, Human Traces
Human Traces
Human Traces is a 2005 novel by Sebastian Faulks, best known as the British author of Birdsong and Charlotte Gray. The novel took Faulks five years to write...
, and in Axel Munthe
Axel Munthe
Axel Martin Fredrik Munthe was a Swedish psychiatrist, best known as the author of The Story of San Michele, an autobiographical account of his life and work....
's 1929 autobiographical novel The Story of San Michele
The Story of San Michele
The Story of San Michele is a book of memoirs by Swedish physician Axel Munthe first published in 1929 by British publisher John Murray. Written in English, it was a best-seller in numerous languages and has been republished constantly in the over seven decades since its original...
. In a letter to the New York Times Book Review of January 18, 1931, however, Charcot's son wrote that "Dr Munthe never was trained by my father." And in his 2008 biography of Munthe (ISBN 978-1-84511-720-7), Bengt Jangfeldt says that 'Charcot is not mentioned in a single letter of Axel's out of the hundreds that have been preserved from his Paris years.' Distorted views of Charcot as harsh and tyrannical have arisen from some sources that mistakenly identify Munthe as Charcot's assistant and take Munthe's autobiographical novel as a factual memoir. In fact, Munthe was just a medical student among hundreds of others. Munthe's most direct contact with Charcot was when he helped a young female patient "escape" from a ward of the hospital and took her into his home. Charcot threatened to advise the police and ordered that Munthe not be allowed on the wards of the hospital again.
Charcot Island
Charcot Island
Charcot Island or Charcot Land is an island of the British Antarctic Territory, long and wide, which is ice covered except for prominent mountains overlooking the north coast, west of Alexander Island.-History:...
in Antarctica was discovered by his son, Jean-Baptiste Charcot, who named the Island in honor of his father.
Further reading
External links
- Biography and bibliography in the Virtual LaboratoryVirtual LaboratoryThe online project Virtual Laboratory. Essays and Resources on the Experimentalization of Life, 1830-1930, located at the Max Planck Institute for the History of Science, is dedicated to research in the history of the experimentalization of life...
of the Max Planck Institute for the History of ScienceMax Planck Institute for the History of ScienceThe Max Planck Institute for the History of Science in Berlin was established in March 1994. Its research is primarily devoted to a theoretically oriented history of science, principally of the natural sciences, but with methodological perspectives drawn from the cognitive sciences and from... - Charcot lectures on diseases of the brain and nervous system