Lactate in the liquor

The concentration of lactate in the cerebral spinal fluid (CSF) or liquor correlates with its concentration in blood. Determining the lactate in the CSF is critical in differential diagnosis of bacterial or virus meningitis: in bacterial meningitis the value is always over 3.33 mmol/L, and in viral meningitis is less than 2.78 mmol/L.

Differential Diagnosis
In alphabetical order.

Increased

 * Bacterial Meningitis
 * Brain abscess
 * Brain metastases
 * Brain tumor
 * Fungal meningitis
 * Head trauma
 * Intracranial bleeding
 * Increased intracranial pressure
 * Ischemic insult or reduced perfusion to the brain
 * Multiple sclerosis
 * Seizures
 * Syncope
 * Viral meningitis (but less)