meningitis

Question 1

what is meningitis and the difference between viral and bacterial

Answer 1

inflamation of the meninges surrounding the brain and spinal cord

Bacterial meningitis is fatal unless treated. Bacteria that enter the bloodstream and travel to the brain and spinal cord cause bacterial meningitis.

Viral meningitis is usually mild and often clears on its own.

Question 2

what causes meningitis

Answer 2

For the inflammation of the meningitis to occur there needs to be a trigger. could be an autoimmune disease, where the body attacks itself, like lupus, or the body having an adverse reaction to some medication, which can happen with intrathecal therapy

But, by far, infection is the most common trigger for meningitis across all age groups, like with the Neisseria meningitidis bacteria or herpes simplex virus for example.

Question 3

what is the patho of meningitis infection

Answer 3

there are 2 main routes of infection that can reach the CSF and the LEPTOMENINGES
- The first way is direct spread, which is when a pathogen gets inside the skull or spinal column, and then penetrates the meninges, eventually ending up in the CSF
Sometimes the pathogen will have come through the overlying skin or up through the nose, but it’s more likely that there’s an anatomical defect to blame. for example a defect to spina bifida or skull fracture.

• The second way is hematogenous spread, which is when a pathogen enters the bloodstream and moves through the endothelial cells in the blood vessels making up the blood-brain barrier and gets into the CSF
  pathogens typically bind to surface receptors on the endothelial cells to get across, otherwise areas of damage or more vulnerable spots.

The immune system responds to the antigen by flooding the subarachnoid space with white blood cells, which, release chemokines - and create inflammation

Question 4

what are causes of viral meningitis

Answer 4

In viral meningitis there is a predominantly lymphocytic
inflammatory CSF reaction without pus formation, polymorphs or adhesions

more common viruses include: enteroviruses, herpes simplex and HIV
also: Mumps, Varicella zoster

Question 5

what are the causes of bacterial meningitis

Answer 5

Bacterial - the pia-arachnoid is congested with polymorphs. A layer of pus forms. This may organize to form adhesions, causing cranial nerve palsies and
hydrocephalus.
- most common strains of baceteria that cause meningitis are: (Explaining Big Hot Neck Stiffness)
E.coli, group B streptococcus (infants
Haemophilus influenzae (older infants, kids)
Neisseria meningitidis (young adults)
Streptococcus pneumoniae (elderly)

Question 6

what are the clinical features of mengitis

Answer 6

NEONATES and CHILDREN - fever, lethargy, irritability, vomiting, poor feeding.
ADULTS - classic triad - headache, fever, nuchal rigidity.
- photophobia, confusion, vomiting, papilledema
- brudzinski sign
- kernigs sign - resistance to knee extension when hip flexed 90 degrees
- jolt accentuation of headache
- meningococcal meningitis

Question 7

what are the clinical features of meningitis

Answer 7

In acute bacterial infection there is usually intense malaise, fever, rigors, severe headache, photophobia and vomiting, developing within hours or minutes.

the patient is irritable and prefers to lie still. Neck stiffness and positive Kernig’s sign usually appear within hours.
In less severe cases (e.g. many viral meningitides), there are less prominent meningitic signs

Question 8

how is meningitis diagnosed and treated

Answer 8

meningeal irritation test - kernigs and brudzinzki test
lumbar puncture - analyze white blood cells, protein and glucose
PCR - look for underlying cause

bacterial - steroids then antibiotics
drugs - antivirals, antibacterials,
vaccnine - Neisseria meningiditis