A 28-year-old woman with a single clinical demyelinating episode has a normal brain MRI. Cerebrospinal fluid analysis is performed to support a diagnosis of multiple sclerosis. Which pattern is most supportive?
- A CSF neutrophil pleocytosis with elevated protein
- B Identical oligoclonal bands in serum and CSF
- C Two or more oligoclonal bands present in CSF and absent in paired serum ✓
- D Low CSF glucose with lymphocytic pleocytosis
Correct answer: C. Two or more oligoclonal bands present in CSF and absent in paired serum
Explanation
Intrathecal synthesis of IgG produces oligoclonal bands restricted to the CSF and absent from serum, found in about 85 percent of MS patients and included in the McDonald criteria as supportive evidence when imaging is equivocal. Bands identical in serum and CSF reflect a systemic immune response such as infection or paraproteinemia and carry no localizing value. Neutrophils and low glucose point toward bacterial infection rather than demyelination.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.