Question

A 4-year old presents to the Emergency Room. She is lethargic and says her head hurts. Her temperature is 104˚ F.

The following lab results are obtained:

Blood glucose= 90 mg/dL

CSF results:

Color: Colorless

Clarity: Cloudy

WBC count= 7300 cells/µl

Differential : PMNS = 87%

Lymphs = 6%

                     Monos = 7%

Total protein= 130 mg/dL

Glucose = 32 mg/dL

Lactate = 33 mg/dL    

a. These results are most consistent with what preliminary diagnosis? What results lead to this diagnosis?

b.What would you expect to see on a gram stain?

c.If the gram stain showed no organisms, should the preliminary diagnosis be changed? Why or why not?

d.What physiological mechanism accounts for the CSF protein result?

e.What physiological mechanism accounts for the CSF glucose result?

Answer 1

1. These results clearly show that patient is suffering from bacterial meningitis. High temperature, headache, cloudy appearance of CSF, high CSF protein and low CSF glucose are the ones confirming the same.

2. A gram negative result is expected as the 2 species causing bacterial meningitis for a child below 4 year is found as gram negative.

3. Yes, if gram stain shows no organism. It is likely to be a viral meningitis.

4. During bacterial meningitis, protein is found leaking directly into the subarachnoid space. This happens primarily due to inflammation of meninges leading to poor blood brain barrier. Thus the CSF protein increases.

5. When bacterial meningitis happens, the glucose receptor expression from CSF is found to decrease. This cause less amount of glucose to be carried to the CSF. This the overall CSF glucose decreases.