This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'CSF examination of a severely ill patient shows albumino-cytologic dissociation. It occurs in cases of: \nSelect and explain. \nA. Guillain Barre syndrome, B. TBM, C. Motor neurone disease, D. Demyelinating disorder', 'role': 'user'}, {'content': "Answer: A \nExplanation: The cerebrospinal fluid (CSF) often shows a characteristic abnormality, termed cytoalbuminologic dissociation, with an elevated CSF protein level without accompanying pleocytosis. The CSF is often normal when symptoms have been present for 48 h; by the end of the first week, the level of protein is usually elevated. Ref: Amato A.A., Hauser S.L. (2012). Chapter 385. Guillain-Barre Syndrome and Other Immune-Mediated Neuropathies. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.", 'role': 'assistant'}]