Cerebrospinal fluid analysis

Condition	Pressure	WBCs (cells/μL)	Predominant Cell	Protein	Glucose	Pathognomonic Finding / Key Differentiator
Normal	Normal (6-20)	< 5	Lymphs	Normal	Normal	-
Bacterial Meningitis	↑↑↑	>1,000	PMNs	↑↑	↓↓	Neutrophils dominate with very low glucose.
Viral Meningitis	N / ↑	< 1,000	Lymphs	N / ↑	Normal	Normal glucose with a lymphocytic pleocytosis.
Fungal / TB	N / ↑	< 500	Lymphs	↑	↓	Low glucose with a lymphocytic pleocytosis.
SAH	↑	High RBCs	RBCs	↑	Normal	Xanthochromia (yellow supernatant); differentiates bleed from traumatic tap.
Guillain-Barré	N	Normal	Lymphs	↑↑↑	Normal	Albuminocytologic dissociation (high protein, normal WBC).
Multiple Sclerosis	N	N / <50	Lymphs	N / ↑	Normal	Oligoclonal bands of IgG unique to CSF.