CSF abnormalities in multiple sclerosis – Medicine MCQ

All of the following are true regarding CSF abnormalities in multiple sclerosis except?
A. CSF protein concentration is more than 100 mg/dl
B. CSF IgG index express ratio of IgG to albumin in CSF divided by the same ration in serum
C. Oligoclonal bands may be absent at onset of multiple sclerosis
D. Number of oligoclonal bands increase with time

Correct answer: A. CSF protein concentration is more than 100 mg/dl

Explanation:

The following CSF parameters point against a diagnosis of multiple sclerosis:
Pleocytosis of more than 75 cells/μl.
Presence of polymorphonuclear lymphocytes.
Protein concentration more than 100 mg/dl.

Reference: Harrison’s Principles of Internal Medicine, 19th edition, p2665