Page:The New International Encyclopædia 1st ed. v. 14.djvu/415

NERVAL. 365 NERVOUS SYSTEM AND BRAIN. NERVAL, nfir'val', Gekard de. A French writer. See Gekaku de Xehvai.. NERVE. See Xeuvuls System axd 13raix. NERVE-STRETCHING. A variety of treat- ineiit of sciatica, wliieh is acconiplisliecl by put- ting the patient on his back and Hexing the thigh strongly upon the abdomen, it has been suc- cessful in alleviating the pain in a few cases. See Sciatica. NERVI, ner've. A town in the Province of Genoa, Italy, situated on the seacoast, six miles east of Genoa. It is a favorite winter health resort of the eastern Riviera. Population (com- mune), in 1901, 67CG. NERVII, nPr'vM. An ancient tribe in Gallia Belgicii, nurtli of the Ambiani. In the time of Ca'sar, who first mentions them, they were a war- like people, who prohibited trade with their neighbors, forbade the introduction of luxuries, and attempted to make an alliance of the sur- rounding tribes against the Romans. Ca'sar sub- dued them in B.C. 57. NERVOUS DISEASE. An affection of any part of tile nervous system, either of the brain, spinal cord, sympathetic nerves, or peri- pheral nerves. Diseases of the nervous system are divided into functional and organic. In the latter local anatomical alteration of nerve structure is apparent. There are in reality no such things as functional diseases. While not seen or described, undoubtedly anatomical changes are present in many cases; and in others there are lesions at a distance which constitute the real disease, while the symptoms which oc- cupy the attention are the result of reflex action. It cannot be airirmed that there are no structural changes in ncrve-filires in so-called functional dis- eases of the nervous system, which constitute the bulk of nervous diseases. There are 176 special nervous diseases, classed as follows: peripheral, 87 ; spinal cord, 40 ; brain, 28 ; and functional. 21. Of these there are about 65 which are either very common or extremely important (Dana). In their proper place are found articles on the fol- lowing nervous diseases or conditions: Acrome- galy; Apoplexy; Caisson Disease; Catalepsy; Chorea; Embolism; Epilepsy; Facial Neural- gia; Goitre; Hysteria; Insomnia; Locomotor Ataxia ; Meningitis ; JIyelitis ; Neur.stheni. ; Nei-ralgia; Neuritis; Neurosis (including ocvupation neuroses); Neurotic; Paralysis: Sclerosis; Sleeping Sickness; Thrombosis, etc. There is also an article on Neurology'. In addition there are articles in the domain of psyeliiatry, on Insanity; Mania; Melan- cholia; Monomania; Paranoia; Paresis; Kleptomania; Dip.somani. ; Pyroma.ma; Puer- peral Insanity, etc., as well as on Idiocy and Imbecility. Consult : St;irr, Familiar Forms of Nervous Dis- ease (New York, 1805) ; Charcot, Clinical Lee- lures' on Certain Diseases of the Nerrous f!iis- tem. translated by Hurd (Detroit, 18.S8) ; Ili'rt, The Diseases of the Nervous ftt/stem. translated by Hoch (New York. 1893) ; Gowers, Manual of Diseases of the Nervous System. (London, 1899) ; Beevor. Diseases of the Nervous Sj/stem (Phila- delphia, ISnS) ; Church and Peterson, Nervous and Mental Diseases (ib., 1901); Dana, Text- book of Nervous Diseases (New York, 1901); Oppenlieini, Lthrbuch der Nerrenlcrankheiten (lierlin, 1902). NERVOUSNESS. A condition of unstable nervous eiiuilibrium, which is largely tempera- mental. A person alllicted with nervousness startles easily at sudden sounds, is unduly emo- tional, lacks poise and self-possession. If the condition go beyond these limits, actual disease is prest^it, and the person is a neurasthenic, i.e. a sufferer from nerve fag. This state is char- acterized by unfounded feelings of apprehension, tremor, headache, disordered digestion, insomnia, loss of power of application, and irritabilitj*. Overwork, excesses, and di.sease may cause ner- vousness in normally stable jicople, which disap- pears when the cause is removed. NERVOUS SYSTEM AND BRAIN. His- torical. It is impossible in an article such as the present to do more than touch upon some of the more important investigations which have brought us to our present conception of nervous system structure. To the philosopher Descartes, in the latter part of the sixteenth century, be- longs the honor of the first recorded description which gives any intelligent conception of the structure of the nervous system. His drawings of the brain possess a very fair degree of ac- curacy as regards general shape, though the lobes and convolutions appear nuich distorted. He pictured the nerves as originating in the brain and described their function as the carrying of the 'animal spirits' from the brain to the [jcriphery. For the next two hundred and fifty years little progress was made in the study of the structure of the nervous system, though some work was done upon the gross anatomy of the brain by men wiiose names remain to us in our anatomical nomenclature. Thus, Vesalius, Fal- lopius, and Eustachius were among the earliest. In the seventeenth century we have Willis, whose name we recognize in the circle of Willis, and who described the basal ganglia, the pyramids and the olives; Vieussens, whose name is famil- iar in the valve of Vieussens ; and Duboise. whose medical cognomen of 'Sylvius' marks that promi- nent sulcus of the cerebrum. The results of the labors of these investigators, as well as of those of Van Leeuwenhoek, of Malaearne, of Rolando, of Vico d'Azyr, of Arnold, of Jlonro, and others were collected and summed up in an extensive volume published by Buvdach in 1819. Descartes had discovered the nerve fibre, and the next step forward in the histology of the nervoiis system was not taken until Ehrenberg in IS.'i.'i discov- ered the nerve cell in the spinal ganglia. This discovery was emphasized when four years later Purkinje observed the presence of cells not only in the ganslia. but in the cerebrum and cei-e- bellum. The important fact that the dorsal roots of the spinal nerves are concerned with sensation and the ventral roots with motion was discovered by Sir Charles Bell, an eminent British surgeon and anatomist, and communi- cated by him to the Roy;il Society of London about 1820. In 1834 Een'iak discovered that the cells of the sympathetic ganglia had processes, and that these processes were connected with nerve fibres. The importance of this discovery, confirmed in 1842 bv Helmholtz. was not at the tinu' appreciated. One of the most careful stud- ies of nerve cells and their processes was made by Otto Deiters of Bonn and published after the