Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (796 page)

   Adults: WBC 0–5 cells/mm
³
, RBC 0/mm
₃

   Newborns: WBC 0–30/mm
₃
, RBC 0/mm
₃

TABLE 16–17. Differential Counts for CSF (Mean ± SD)

*Submitted By Liberto Pechet, MD.

   Use

   Examination of CSF is required when CNS involvement by inflammatory, infectious, neoplastic, or neurologic complications are suspected. Up to 20 mL of fluid can be removed in the adult.

   CSF is divided into three sterile tubes:

   Chemistry and immunology studies

   Microbiology examinations

   Cell count, differential, and cytology (if indicated)

   Interpretation

   Increased number or red blood cells: either hemorrhagic tap or subarachnoid hemorrhage

   Increased number of neutrophils: bacterial or early viral CNS infection, early CNS TB, CNS syphilis, fungal infection, contamination with peripheral blood through traumatic tap, CNS hemorrhage

   Increased number of lymphocytes: viral infection of the CNS, CNS TB, acute lymphocytic leukemia or lymphoma of the CNS, cryptococcal infection of the CNS, fungal infection of the CNS, CNS syphilis, parasitic disease infecting the CNS, Guillain-Barré syndrome