Infections of the Developing and Mature Nervous System

Question 1

Congenital Infections: What is most important - virulence of organism or age of fetus at time of insult?

Answer 1

Age of fetus at time of insult - typically if insult is within the first 2 trimesters - will result in congenital malformations. If in the 3rd trimester - more of a destructive lesion.

Question 2

What are 2 main routes of infection of a fetus?

Answer 2

1. Bacteria ascend from the cervix to reach the amniotic fluid
2. Transplacental: toxo/syphilis, rubella, CMV, other viruses.

Question 3

What is the most common congenital infection?

Answer 3

CMV - up to 1% of all infnats infected, but 10% of those will be symptomatic. Those that are symptomatic with abnormal imaging will have high rates of neurodevelopmental sequelae: cerebral palsy, epilepsy, developmental delay, mental retardation, vision loss, sensorineural deafness.

Question 4

How to Dx CMV?

Answer 4

urine/saliva with cell cx or PCR - Imaging doesn’t make Dx but can suggest the disease

Question 5

What are imaging findings of CMV?

Answer 5

• Depends on when in utero infection occurred
• Overall findings tend to be:
  
  • Microcephaly (diminished white matter)
  • anterior temporal lobe cysts
  • astrogliosis
  • cerebral calcifications
  • delayed myelin maturation/dysmyelination
  • More severe cases:
    
    • cortical malformations
    • cerebellar hypoplasia

Question 6

Lenticulostriate vasculopathy can be found in what diseases?

Answer 6

AKA: minteralizing vasculopathy

• Very nonspecific
• Multiple infections
• Trisomy 13, 21
• Drug exposure, or other toxins
• CHD

Question 7

Do imaging findings in CMV correlate with timing of infection?

Answer 7

Yes: if Infected in first half of the second trimester:

• Cortical malformations
  
  • Agyria, lissencephaly, cerebellar hypoplasia
  • marked ventriculomegaly
  • significant periventricular calcification
  • germinal zone/anterior temporal cysts

Question 8

If CMV infection after first half of 2nd trimester, what sort of imaging findings?

Answer 8

• Mild ventricular dilation
• less consistent cerebellar hypoplasia
• Less conspiculous cortical malformations (subtle polymicrogyria)
• Still periventricular calcifications

Question 9

CMV infection near the end of gestation may result in what?

Answer 9

• More subtle abnormalities.
• periventricular calcs
• mild prominence of ventricles/sulci

Question 10

What is this?

Answer 10

Congenital CMV: Lenticulostriate vasculopathy, with periventricular calcs and parenchymal calcls. NOTE: These findings are highly suggestive of CMV although nonspecific and can be seen with other insults.

Question 11

What is this?

Answer 11

Highly suggestive of CMV (ventriculomegaly, parenchymal/periventricular calcs) - 2 different patients.

Question 12

What is this?

Answer 12

Congenital CMV

• Parenchymal calcs
• Germinal Zone Cysts
• Also basal ganglia/intraparenchymal calcs (different patient)

Question 13

What is this?

Answer 13

Congenital CMV

• Associated with anterior temporal lobe cyts
• Also associated with cerebellar hypoplasia when more severe

Question 14

What is this?

Answer 14

CMV

• Likely later infection
• mild volume loss (ventricular/sulcal prominence)
• Mild encephalomalacia