VERTIGO, dizziness, giddiness, or swim ming of the head; a defect, real or seeming, in the equilibration of the body. Though the con dition is sometimes so distressing. as to be considered by the patient a disease, it is essen tially only a symptom. It is believed that the cerebellum is the centre for the co-ordination of muscular movements, and that impressions from the semi-circular canals of the internal ear also influence the movements necessary for maintaining the equilibrium of the body. But the essential nature of vertigo is not yet clearly determined. By some it is believed to be due to disordered cerebral circulation; by others, to result from a disturbance of the central nerve ganglia. The sense of instability and of ap parent rotary movement of the body or of other objects, always present, may be attended by mental confusion or loss of consciousness, or by anguish or terror. There may or may not be present also buzzing in the ears, mist or flashes of light before the eyes, nausea and vomiting, looseness of the bowels and a flow of pale urine. Vertigo may result from functional disorders of the heart or stotnach, from defects in vision, from diseases of the middle ear, from some peripheral irritations (as laryngeal ver tigo), from toxmmias, as in Bright's disease, from organic brain disease and from unrecog nized causes. Grasset classifies vertigo under two heads, acute or accidental and chronic or habitual. Under the first head he places forms of it which attend the onset of acute infec tious diseases, inflamtnations, influenzas and the vertigo which accompanies the stage of ex citation in cerebro-spinal meningitis, that which appears with attacks of indigestion, the vertigo of acute alcoholism and of the first cigar, and the dizziness caused by swinging, dancing, sea sickness or by looking down from a great height. Then there are acute toxic vertigos
caused by digitalis, hemp, opium, belladonna, gelseminum, nicotin, etc., also others caused by heat, the introduction of a bowie, the suppres sion of habitual discharges, the pressure of wax or other accumulations on the drumhead, nasal obstruction and post-nasal catarrh, men tal strain, emotional disturbances, etc. Under the head of chronic vertigos are placed epilep tic vertigo, vertigo dependent upon disturb ances in the sensory nerve-centres, especially auricular vertigo, stomachic and cardiovascular vertigo.
In the treatment of vertigo the main thing is to remove the cause. Vertigo caused by in digestion frequently demands a prompt etnetic or purgative. The tone of the stomach may be restored by tincture of nux vomica or by dilute hydrochloric acid. Smokers' vertigo re quires for relief a complete cessation from smoking, a slight laxative and bitters. For the vertigo of seasickness brcnnide of sodium or amyl nitrite and kola-seeds, ditninishing as much as possible the drinking of liquids and the use of a tightly-drawn ventral bandage seem to be of most service. Ocular vertigo, depend-. ent upon astigmatism, hypermetropia, paralysis of certain of the ocular muscles and various eye-strains may often be relieved by the oculist See BRAIN, DisEasza oF; CEREBELLUM ; EAR.