CNS Infections - A. Prunuske

Question 1

Encephalopathy

Answer 1

refers to diffuse cerebral dysfunction _without
inflammation_ usually due totoxinormetabolic dysfunction

not necessarily infection

Question 2

Encephalitis

Answer 2

inflammation of the brain, caused by infection or an allergic reaction

fever, headache, seizures, depressed mental state

Question 3

meninges

Answer 3

the three membranes (the dura mater, arachnoid, and pia mater) that line the skull and vertebral canal and enclose the brain and spinal cord.

Question 4

_______ and _________ are innate immune cells in the CNS

Answer 4

microglia and astrocytes

Question 5

Microbial invasion of brain occurs via which route…

Answer 5

Hematogenous dissemination

Contiguous spread from sinusitis, otitis media, mastoiditis

Trauma or congenital lesions

Retrograde axonal transport—rabies, tetanus

Question 6

Meningitis occurs where?

Answer 6

subarachnoid space

Viral (most common), Bacteria (life-threatening)
Fungi, Protozoa (immunocompromised)

95% have 2 out of headache, fever, nuchal rigidity (stiff neck), and altered mentality

Question 7

Encephalitis occurs where?

Answer 7

diffuse parenchyma

an acute disseminated inflammation of the brain…?

Viral: Enterovirus, Arbovirus, Herpes virus, Rabies
Nonviral: Rickettsia, Mycoplasma, Acute desseminated encephalomyelitis

Empiric treatment with acyclovir until HSV ruled out.

Motor and sensory deficits

Question 8

Brain abscess

Answer 8

focal parenchyma

an acute focal inflammation of the brain…?

Symptoms: Fever, headache, neurologic defects, seizure

Can be caused by a mixture of bacteria: Streptococci (most common), Pseudomonas, Haemophilus, Staphylococcus, Bacteroides

Location specific to infection start:

Otitis media>temporal lobe/cerebellum
** Dental/sinus infection>frontal lobe
Hematogenous>multiple, territory of middle cerebral artery**

Question 9

Myelitis

Answer 9

inflammation of the spinal chord

Polio virus, Coxsackie virus, and West Nile virus can attack anterior horn cells and cause motor paralysis.

Chronic myelopathy is associated with Tropical Spastic Paraparesis caused by Human T-lymphotropic virus (HTLV-1)

Question 10

basilar meningitis

temporal lobe encephalitis

frontal lobe abcess

symptoms?

Answer 10

Question 11

most common cause of viral meningitis and encephalitis,
occur primarily in late summer to fall

Answer 11

Enteroviruses (Coxachee)

Question 12

TORCH infections

Answer 12

Perinatal infections

Mild maternal morbidity, but have serious fetal consequences

Meningitis: Group B strep, E. coli, Listeria

TORCH, which includes Toxoplasmosis, Other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus (CMV), and Herpes infections (HSV-2)

Question 13

Empiric antibiotics if suspect bacterial meningitis covering most likely agents… what are they?

Answer 13

ceftriaxone (+ vancomycin (C. Diff)) (acyclovir)

Question 14

Empiric treatment include 3rd generation cephalosporins

Name some!

Answer 14

Bactericidal, small, lipophilic, low affinity for plasma binding proteins, and not a ligand of the efflux pumps at the blood brain barrier.

ceftriaxone, ceftaxime, ceftazidime

Question 15

How do you treat a brain abcess for the most common causes?

Answer 15

Treatment: Ceftriaxone + Metronidazole (parasites) and may require surgery if Staphylococci (vancomycin) and if Pseudomonas (ceftazidime)

No lumbar puncture- not beneficial and risk of herniation

Streptococci (most common), Pseudomonas, Haemophilus, Staphylococcus, Bacteroides