CNS Infections- Mass Lesions & Neurocysticercosis Flashcards Preview

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Flashcards in CNS Infections- Mass Lesions & Neurocysticercosis Deck (15)
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1
Q

Mass lesions AKA contrast/ring-enhancing lesions caused by Infectious abscesses and common parasitic diseases of the CNS via:

A

Neurocysticercosis (NCC) and Toxoplasma gondii/Toxoplasmosis

2
Q

Mass lesions manifest as

A

Fever, Severe headaches, Seizures

3
Q

Mass lesions due to abscesses are usually caused by procaryotic organisms, the most common pathogen being:

A

S. aureus

  • Mixed anaerobic infections account for 1/2 of all cases
  • Mostly Gram-negative rods and Gram-positive cocci
4
Q

Other causes of mass lesions due to abscess are

A
  • L. monocytogenes or M. tuberculosis are also causes

- Fungi agents include Coccidioides immitis, Candida albicans

5
Q

Neurocysticercosis (NCC) is caused by

A

Taenia solium metacestodes

Most common parasitic CNS disease

6
Q

Neurocysticercosis (NCC) is the most common cause of _________ in the world

A

epilepsy

7
Q

Parenchymal cysts are mature, living cysticerci are viable for 2→10y, during which time they _________ and the host is usually ________.

A

suppress the host immune response

asymptomatic (with a few cysts); 6→10 or more can be symptomatic

8
Q

As cysticercus begins to die, they ________ causing an intense inflammatory response (with perilesional edema) & fibroblast form capsule around cyst. This causes the host to show signs and symptoms. Cyst degeneration takes 6→18 months. Rarely, parenchymal cysts growth causing _________.

A

leak antigens

mass effect on brain parenchyma

9
Q

Extraparenchymal Cysts: A few (@10%) oncospheres lodge in __________ and develop into atypical cysts (greatly enlarged) → obstruction of CSF pathway → may cause ___________.

A
  • ventricles, subarachnoid space or meninges

- focal neurological signs or increased cranial pressure (hydrocephalus), and headaches

10
Q

Symptoms usually only occur if ________ are seen on an MRI

A

calcified lesions

11
Q

Differential for mass lesion

A
  1. Neurocysticercosis (Taenia solium)
  2. Cystic Echinococcosis-hydatid cyst (Echinococcus granulosus or multilocularis)
  3. Raccoon Round Worm Encephalitis/Baylisascariasis (Baylisascaris procyonis)
  4. Toxocaria (Toxocaria cannis or cati)
  5. Toxoplasmosis (Toxoplasma gondii).
  6. Abscess:
    - Bacteria: S. aureus, anaerobes, L. monocytogenes, M. tuberculosis.
    - Chronic fungi: C. immitis or Candida albicans
12
Q

T confirm diagnosis with Neurocysticercosis you must have 1 of the following 3:

A
  1. Histological demonstration of parasite from biopsy of brain or spinal chord.
  2. Cystic lesion showing the scolex on CT scan or MRI.
  3. Direct visualization of retinal parasites by fundoscopic exam.
  • Live cysts are none contrast-enchancing but dying-dead cysts are contrast-enchancing
  • If pt doesn’t have at least 1, can use imaging to confirm diagnosis
13
Q

Imaging/other tests used to confirm diagnosis with NCC

A
  1. **Positive serum enzyme-linked immunoelectrotransfer blot (EITB) for detection of anticysticercal antibodies has a sensitivity and specificity of more than 98% and is the serologic assay of choice for the detection of cysticercosis.
  2. **CSF WBC with differential reveals an eosinophilia as high as 15%.
  3. **Patient signs and symptoms.
  4. EEG changes (focal discharge, sharp spike, slow wave) indicate active seizure focus.
  5. History of travel, employment, living in an endemic area.
  6. Documented familial infestation.
  7. Resolution of cysts after treatment.
  8. documented extra-CNS cysticercosis
14
Q

IN CSF WILL SEE

A

eosinophilia

15
Q

Treatment

A

Niclosamide, Praziquantel, Albendazole
all destroys VIABLE cyst in CNS

-anticonvulsants, corticosteroids, surgery