Cerebrospinal Fluid (CSF) Hematocrit (Mass Concentration)

What Is CSF Hematocrit Used For?

CSF hematocrit is primarily used to evaluate potential causes of abnormal findings in CSF, such as: - Increased red blood cells (which may indicate bleeding, e.g., from trauma, hemorrhage, or vascular abnormalities). - Infections or inflammatory processes that could alter blood content in the CSF. - Conditions affecting blood-brain barrier integrity or red blood cell survival in the central nervous system.

When Might You Need This Test?

Your healthcare provider may order CSF hematocrit if you have symptoms like: - Severe or persistent headaches, - Neurological symptoms (e.g., vision changes, weakness, confusion), - Signs of infection (e.g., fever, stiff neck), - Or if other CSF tests (e.g., protein, glucose) show abnormal results.

CSF is collected via a procedure called a lumbar puncture (spinal tap), where a needle is inserted into the lower back to draw fluid from the spinal canal. The sample is then analyzed for red blood cell concentration.

The test involves measuring the volume of red blood cells relative to the total CSF volume. This helps determine whether red blood cells are present in excess, which could indicate bleeding or trauma.

Normal results typically show very few red blood cells in CSF (often none or minimal). Elevated levels may suggest bleeding, but further evaluation is needed to identify the cause.

Elevated CSF hematocrit can occur with: - Subarachnoid hemorrhage (bleeding into the brain’s protective space), - Trauma or injury to the spine/back, - Certain infections or inflammatory diseases.