Pathology

Question 1

What’s the difference between leptomeningitis and pachymeningitis?

Answer 1

leptomeningitis: term for the arachnoid and pia matter combined. This describes an inflammatory process localized to these meningial layers.

Pachymeningitis referes to inflammation of the dura, usually the consequence of contiguous infection.

Question 2

What are the associations between age and bacterial infections leading to meningitis?

Answer 2

Neonates: E.Coli, Group B strep, Listeria

Non vaccinated children: H. influenza

Military barracks, teenagers: N. meningitidis

Adults and Elderly: Strep. pneumonia

Question 3

What are the most characteristic cells seen in bacterial meningitis to make a diagnosis, how does this change for TB? How are they obtained? What else will you observe?

Answer 3

PMNs in CSF.

TB, viral, and fungal =lymphocytes

Lumbar punture L4-L5

decreased CSF glucose; gram stain and culture

Question 4

What are the classic clinical symptoms of meningitis? What tests would you perform in the clinic?

Answer 4

Triad of headache, nuchal rigidiy, and fever. vomiting and convulsions in children is common. If untreated it will lead to death.

Kernig and Brudzinski signs

K-pain in knee when hip is flexed (strait leg rasing test)

B-flex the neck and watch the knees and hips flex as well

Question 5

Pott’s disease?

Answer 5

TB of the spine (Pott’s disease) produces an epidural granulomatous mass that frequently causes destruction of the spine with spinal cord compression.

Question 6

What are the most common causative agents of viral meningitis?

Answer 6

Enteroviruses including Coxsackie B

    - Mumps virus
    - Epstein-Barr Virus (Infectious Mono)
    - Echovirus
    - Herpesvirus

Question 7

Viral meningitis

Answer 7

Most common viral disease of CNS

CSF excess lymphocytes no decrease in glucose

AKA aseptic meningitis

Question 8

TB meningitis is characterized by what?

Tuberculoma?

Answer 8

Granulomas in the meninges

Localizes aroung the base of the brain

Cause meningeal fibrosis leading to communicating hydrocephalus (decreased CSF absorption and increasing intercranial pressure)

arteritis and parenchymal infartions

Tuberculoma

**mass full of caseous necrosis, allows the bacteria to gain access to the brain my hematogenous spreading. **

Question 9

How do you contract Cryptococcus Neoformans and what does it lead to?

Answer 9

Found in immunocompromised

enter via inhalation of contaminated particles: bird shit

histology-widespread lesions, white nodules

Question 10

What is a cerebral abscess?

Answer 10

Abscess in the cerebral cortex white matter, which contains a rich capillary bed. Bacteria get lodged there and cause infection. (similar to osteomyelitis in epiphysial plate)

Acture inflammation=cerebritis: converts lesion to abscess

Question 11

Viral encephalitis is indentified histologically how?

Answer 11

Hallmark-Perivascular cuffs of lymphocytes involving small arteries

Diagnostic feature-Intranuclear or cytoplasmic inclusion bodies (in some)

Question 12

Which viruses have inclusion bodies? Which are cytoplasmic vs intranuclear?

Answer 12

1. H. simplex and zoster: intranuclear inclusions.
   
   2. Rabies: Cytoplasmic “Negri bodies”.
   3. CMV: intranuclear inclusions.
   4. Subacute Sclerosing Panencephalitis (SSPE): intranuclear inclusions (lethal caused by measles)
   5. Progressive Multifocal Leukoencephalopathy (PML): intranuclear inclusions

Question 13

What does CMV have cytoplasmic or intranuclear inclusion bodies? Can you identify it

Answer 13