Q: What is the characteristic finding in CSF in Guillain–Barré syndrome (GBS)?

Answer: Albumino-cytological dissociation

In Guillain–Barré syndrome, cerebrospinal fluid (CSF) shows characteristic finding of albumino-cytological dissociation. In contrast to infectious causes, there is an elevated protein level (100–1000 mg/dl), without pleocytosis. An increased white blood cell count may indicate an alternative diagnosis, probably an infection.