202 



into the ventricles and arachnoid spaces of the brain. The disease 

 is sometimes indicated by a difficulty in controlling voluntary move- 

 ments, coma, etc. When effusion as a result of meningitis is sus- 

 pected, iodide of potassa in 2-dram doses may be given twice a day 

 and a strong blister applied l>ehind the ears. 



TUMORS WITHIN THE CRANIUM. 



Tumors within the cranial cavity and the brain occur not infre- 

 quently, and give rise to a variety of symjitoms, imperfect control of 

 voluntary movement, local paralysis, epilepsj', etc. 



Osseous tumors, growing from the walls of the cranium, are not 

 ver3" uncommon. 



DenUgerous cysts, containing a formation identical to that of a 

 tooth, growing from the temjioral bone, sometimes are found lying 

 loose within the cranium. 



Tumors of the clioro'nl plexus, known as hruin sand, are frequentl}^ 

 met with on post-mortem examinations, but seldom give rise to any 

 appreciable symptoms during life. They are found in horses at all 

 ages, and are of slow development. They are found in one or both 

 of the lateral ventricles, enveloped in the folds of the choroid plexus. 



Melanotic tumors have been found in the brain and meninges in 

 the form of small, black nodules, in gray horses, and in one instance 

 arc believed to have induced the condition known as string-halt. 



Fibrous tumors may develop within or from the meningeal struc- 

 tures of the brain. 



Oliomatous tumor is a variety of sarcoma very rarelj' found in the 

 structure of the cerebellum. 



Treatment for tumors of the brain is beyond our ambition in the 

 present age. 



SPASMS — CRAMPS. 



Causes. — Spasm is a marked symptom in many diseases of the brain 

 and of the spinal cord. S^Dasms may result from irritation of the 

 motor nerves as conductors, or maj^ result from irritation of any part 

 of the sympathetic nervous system, and ih&y usually indicate an 

 excessive action of the reflex-motor centers. Spasms maj' be induced 

 by various medicinal agents given in iDoisonous doses, or by effete 

 materials in the circulation, such as nux vomica or its alkaloid 

 strychnia, lead preiaarations, or an excess of the urea products in the 

 circulation, etc. Spasms ma}' be divided into two classes: tonic 

 spasm, when tlie cramj) is continuous or results in persistent rigidity, 

 as in tetanus; clonic spasm, wlicn the cramping is of short duration, 

 or is alternated with relaxations. Cramps may be distinguished from 

 choleraic movements by the extreme pain or suffering which they 

 induce. Spasms may affect involuntary as well as the voluntary 

 muscles, the muscles of the glottis, intestines, and even the heart. 

 They are always sudden in their development. 



