Cerebrospinal Fluid (CSF) Gamma-Glutamyl Transferase (GGT) Activity

What Does This Test Measure?

Gamma-glutamyl transferase (GGT) is an enzyme found in many tissues, including the liver, brain, and kidneys. In the CSF, its presence is usually low unless there is an underlying problem. This test helps assess whether there is abnormal activity or damage in the central nervous system.

Why Might This Test Be Ordered?

Your healthcare provider may order this test if you have symptoms like headaches, neurological issues, or if you’re being evaluated for conditions such as meningitis, encephalitis, brain tumors, or other central nervous system disorders. It can also be part of a broader evaluation for conditions affecting the brain’s blood vessels or membranes.

What Does an Abnormal Result Mean?

Elevated GGT levels in CSF can signal inflammation, infection, bleeding, or structural changes in the brain or spinal cord. However, GGT alone is not diagnostic—it is often used alongside other tests and clinical findings to guide further evaluation.

Common Conditions Linked to Abnormal Results

While GGT in CSF is less commonly elevated than in blood, it may be raised in cases of meningitis, encephalitis, subarachnoid hemorrhage, or certain brain tumors. Low levels are generally not clinically significant unless part of a broader pattern of findings.