CSF xanthochromia is most likely caused by which substance?

CSF xanthochromia is most likely caused by which substance?

• A. Bilirubin
• B. Red blood cells
• C. Bacteria
• D. Radiographic contrast media

Answer: (A)

CSF xanthochromia comes from the breakdown of blood in the CSF. When red blood cells in the cerebrospinal fluid lyse, heme is converted first to biliverdin and then to bilirubin. Biliverdin is greenish, but bilirubin has a yellow color, which gives the CSF its yellowish tint over time. This discoloration signals a hemorrhagic process (such as subarachnoid bleeding) and typically appears after some hours as blood products break down. Fresh blood itself makes the CSF look red or pink, not yellow. Bacteria or contrast media can color CSF in other ways, but not with the bilirubin-driven yellow hue seen in xanthochromia.

CSF xanthochromia comes from the breakdown of blood in the CSF. When red blood cells in the cerebrospinal fluid lyse, heme is converted first to biliverdin and then to bilirubin. Biliverdin is greenish, but bilirubin has a yellow color, which gives the CSF its yellowish tint over time. This discoloration signals a hemorrhagic process (such as subarachnoid bleeding) and typically appears after some hours as blood products break down. Fresh blood itself makes the CSF look red or pink, not yellow. Bacteria or contrast media can color CSF in other ways, but not with the bilirubin-driven yellow hue seen in xanthochromia.