Many acute inflammatory diseases of the CNS are characterized by a mild to moderate increase in total protein concentration caused either by an increased capillary permeability of the blood-CSF barrier (purulent meningitis), by disturbed elimination of CSF at the spinal radices (Guillain-Barré syndrome polyradiculitis, Lyme Neuroborreliosis) or by mechanic disturbance of CSF bulk flow (spinal canal stenosis).

Purulent meningitis is an example of severe increase of total protein (>1,000 mg/lL). Acute Lyme disease (borreliosis) and the Guillain-Barré syndrome polyradiculitis are examples for moderate (750–1,000 mg/L), and viral meningitis and polyneuropathies examples for mild abnormal elevations (500–750 mg/L).

Interpretation of total protein will be described in detail in chapters on CSF in clinical syndromes.