Board Review: Meningitis
A 21 y/o F with no significant past medical history arrives to your ED in the care of her boyfriend with a chief complaint of confusion. Per report, the boyfriend found the patient walking around the house at 3am disoriented and confused. She reports a headache and amnesia to last nights events. Her vitals show she is febrile. As a part of her work up, you perform a lumbar puncture to evaluate for meningitis. Which of the following CSF results are consistent with the diagnosis of viral meningitis? (scroll down for the answer)
a) WBC Count: 1221/mm3 Cell Type: PMNs Protein: 373 mg/dL Glucose: 22 mg/dL
b) WBC Count: 85/mm3 Cell Type: lymphs Protein: 127 mg/dL Glucose: 50 mg/dL
c) WBC Count: 253/mm3 Cell Type: lymphs Protein: 212 mg/dL Glucose: 40 mg/dL
d) WBC Count: 427/mm3 Cell Type: lymphs Protein: 275 mg/dL Glucose: 43 mg/dL
e) WBC Count: 3/mm3 Cell Type: lymphs Protein: 37 mg/dL Glucose: 47 mg/dL
The correct answer is b) WBC Count: 85/mm3 Cell Type: lymphs Protein: 127 mg/dL Glucose: 50 mg/dL
In viral meningitis, lymphocytes predominant and WBC count will be elevated but typically to less than 100/mm3. Protein will be elevated and glucose levels can be normal. The values for fungal meningitis and a neoplasm can be similar to viral meningitis. It is important to note that both the WBC count and the protein count will be lower in viral meningitis in comparison. Below are the conditions matching with the above CSF results.
a) Bacterial Meningitis
b) Viral Meningitis
d) Fungal Meningitis
e) Normal CSF
Stapczynski, J. Stephan,, and Judith E. Tintinalli. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York, N.Y.: McGraw-Hill Education LLC., 2011. Page 1192-1193.
Seehusn, D.A. Cerebrospinal Fluid Analysis. Am Fam Physician. 2003 Sep 15;68(6):1103-1109. http://www.aafp.org/afp/2003/0915/p1103.html.