Table 5.15.

Usual CSF findings in normal and in various central nervous system (CNS) infections

Normal	Cell-mm3	protein Mg/dl	CSF/serum glucose ratio %
Normal	0–5 (lymphocytes)	20–40	>50
Bacterial meningitis	100 to 1000 (PMN)	100–500	<0.5
Tuberculosis	30–600 (lymphocytes)a	>100 up to 3 g	<0.5
Viral meningitis	100–2000 (lymphocytes)a	Normal to 200	Normal
Encephalitis	Normal to few hundreds	50–100	Normal
Abscess	10–100 (PMN/lymphocytes	30–200	Normal

PMN polymorphonuclear cells

^aPMN predominate initially with lymphocytes predominating after 48 h