The first reaction to bacteria or their toxins is

Info icon This preview shows pages 497–509. Sign up to view the full content.

. The first reaction to bacteria or their toxins is hypermia of meningeal venules and capillaries and an increased permeability of these vessels. . This leads to exudation of purulent fluid in the subarachnoid space. 497
Image of page 497

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

If the infection is controlled at an early stage the exudated fluid may disappear. . But if the infection becomes chronic the purulent fluid undergoes organization and fibrosis. . Thus, if the infection becomes chronic, there is fibrous overgrowth of the meninges resulting in thickened, cloudy, or opaque arachnoid and often adhesions between the pia and arachnoid and even between arachnoid and dura. . The production of exudative fluid is responsible for hydrocephalus in meningitis. 498
Image of page 498
In acute cases large amount of fibrinopurulent fluid may collect somewhere in the pathway of C.S.F. and block the flow of C.S.F. This leads to hydrocephalus. . Hydrocephalus may occur in acute cases but it is more common in chronic cases. . In chronic cases the exudative fluid undergoes fibrosis and produces subarachnoid adhesions which are an important factor in producing hydrocephalus. 499
Image of page 499

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

So make it clear, that as any meningitis becomes more chronic the pia arachnoid exudates tends to accumulate around the base of brain and obstruct the flow of the C.S.F. giving rise to hydrocephalus. . The fibrosed exudates are also responsible for increased cranial nerve involvement in chronic cases of meningitis. . Though the cranial nerves and spinal cords are surrounded by purluent exudate from the beginning of the infection, the perineural sheath surrounding them become infiltrated by inflammatory cells only after several days. Thus the cranial nerve and spinal nerve involvement are far more common in chronic meningitis. 500
Image of page 500
501
Image of page 501

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

502
Image of page 502
Q) Patient with fever had a lumbar puncture done as part of workup for fever. The CSF revealed high proteins with normal sugar and marked increase in lymphocytes. The diagnosis is likely to be - a) Tubercular meningitis (PGI Dec 01) b) Bacterial meningitis c) Viral meningitis d) Partially treated pyogenic infection e) Neurocysticercosis 503
Image of page 503

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

504
Image of page 504
Q) The CSF findings in TB meningitis are all the following except - (AI 95) a) Raised protein b) Low sugar c) Low chloride d) High RBC count D 505
Image of page 505

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

CSF picture in viral meningitis (PG1 Dec 03) a) Lymphocytic pleocytosis b) WBC count>1500/mL c) Sugar is normal d) Sugar is very low e) Protein is elevated 506
Image of page 506
507
Image of page 507

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

In meningitis there is invariable involvement of the subarachnoid vessels. , This unusual involvement of the vessels is related to their anatomic peculiarity. . The adventitia of the subarachnoid vessels, both of arterioles and venules in actually formed by an investment of the arachnoid membrane, which is involved by the infection process is meningitis.
Image of page 508
Image of page 509
This is the end of the preview. Sign up to access the rest of the document.
  • Winter '16
  • jean grey

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern