. The diseases of infancy and childhood. ephalus may be acute orchronic. Acute hydrocephalus is secondary to basilar meningitis, which isusually of tuberculous origin. The terms tuberculous meningitis andacute hydrocephalus are sometimes used synonymously. A moderate dis-tention of the ventricles is frequent in all varieties of acute amount of fluid in acute hydrocephalus is not great, there beingrarely more than three or four ounces present. Chronic external hydrocephalus except in its mild form is extremelyrare, and is nearly always a secondary lesion. It may follow meningealh
. The diseases of infancy and childhood. ephalus may be acute orchronic. Acute hydrocephalus is secondary to basilar meningitis, which isusually of tuberculous origin. The terms tuberculous meningitis andacute hydrocephalus are sometimes used synonymously. A moderate dis-tention of the ventricles is frequent in all varieties of acute amount of fluid in acute hydrocephalus is not great, there beingrarely more than three or four ounces present. Chronic external hydrocephalus except in its mild form is extremelyrare, and is nearly always a secondary lesion. It may follow meningealhemorrhage, pachymeningitis, or any lesion causing cerebral atrophy. Itis seen in its most marked form associated with congenital malforma- 770 DISEASES OF THE NERVOUS SYSTEM tions of the brain, particularly imperfect development of the hemi-spheres. (See Fig. 103.) On incising the dura mater a few ounces, orsometimes even a pint, of fluid may escape. The convolutions aresomewhat flattened, and may be greatly atrophied. Other lesions are. Fio. 103.—Brain in External Hydrocephalus, Showing Imperfect Developmentof the Hemispheres. Patient three and a half months old; head measured 20/iinches; increase in size, 2 inches in the six weeks before death; symptoms were typicalof ordinary internal hydrocephalus. In the picture the small size of the cerebrum A isbest judged by comparison with the cerebellum B, which is normal. The hemisphereswere rudimentary; the basal ganglia were normal; the cranial cavity containedabout one pint of fluid. found either in the brain or in the dura mater. External hydrocephalusmay cause enlargement of the head and separation of the sutures, andin fact most of the symptoms of the internal variety; but usually it isnot severe enough to give rise to any decided symptoms. CHRONIC INTERNAL HYDROCEPHALUS This is the important variety, and when no qualifying term ismentioned this is the form of hydrocephalus which is always under-stood. Internal hydrocephalus
Size: 1790px × 1395px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1920
