What are your protozoal diseases ___________ that may involve the CNS?
- and trypanosomiasis
What are your rickettsial infections that may also involve the CNS? .
- such as typhus
- and Rocky Mountain spotted fever),
What are your metazoal
diseases that may involve the CNS?
especially cysticercosis and echinococcosis
__________________is another of the opportunistic infections commonly found in the setting
of HIV-associated immunosuppression.
The clinical symptoms of infection of the brain by
Toxoplasma gondii are _____________
- evolving during a 1- or 2-week period,
- and may be both focaland diffuse.
In Cerebral Toxoplasmosis Computed tomography and magnetic resonance imaging studies may show _______________; however, this radiographic appearance is not pathognomonic, since
similar findings may be associated with CNS lymphoma, tuberculosis, and fungal infections.
nonimmunosuppressed hosts, the impact of toxoplasmosis on the brain is most often seen when
It may be followed by a cerebritis in
the fetus, with the production of multifocal cerebral necrotizing lesions that may calcify,
producing severe damage to the developing brain.
primary maternal infection occurs early in the pregnancy.
Toxoplasmosis of the CNS produces brain abscesses, which are found most
often in the ______________ and _______, less often in
the cerebellum and brainstem, and rarely in the spinal cord ( Fig. 28-29 ).
cerebral cortex (near the gray-white junction)
deep gray nuclei,
In Toxoplasmosis, acute lesions
Both free tachyzoites and
encysted bradyzoites ( Fig. 28-29B ) may be found at the periphery of the necrotic foci.
organisms are usually seen on routine H&E or Giemsa stains, but are more easily recognized
by immunocytochemical methods.
- central foci of necrosis,
- petechial hemorrhages surrounded by acute and chronic
- macrophage infiltration,
- and vascular proliferation.
A, Toxoplasma abscesses in the putamen and thalamus.
B, Free tachyzoites demonstrated by immunostaining;
inset: Toxoplasma pseudocyst with bradyzoites highlighted by immunostaining.
In the Toxoplasmosis the blood vessels in the vicinity of these lesions may show
marked intimal proliferation or even frank vasculitis with fibrinoid necrosis and thrombosis.
After treatment of Toxoplasmosis, the lesions consist of_____________-
. Cysts and free tachyzoites can also be found
adjacent to these lesions but may be considerably reduced in number or absent if therapy has been effective.
large, well-demarcated areas of coagulation necrosis
surrounded by lipid-laden macrophages
In Chronic lesions of Toxoplasmosis consist of small_____________ that are surrounded by gliotic brain. Organisms are
difficult to detect in these older lesions.
cystic spaces containing scattered lipidand
A rapidly fatal necrotizing encephalitis occurs with infection with _________
- Naegleria species,
chronic granulomatous meningoencephalitis has been associated with infection with
The amebas may sometimes be difficult to distinguish from ______________ ( Fig. 28-30 ).
Necrotizing amebic meningoencephalitis involving the cerebellum (organism
highlighted by arrow).
Since Amebas are hardly distinguished from macrophage, what stain is used to help in the identification?
Methenamine silver or PAS stains are helpful in visualizing the
organisms, although definitive identification ultimately depends on combined
immunofluorescence studies, morphology, culture, and molecular methods.