1. A 35-year-old woman is admitted to the hospital with symptoms of intermittent blurred vision, weakness, and loss of sensation in her legs. A lumbar puncture is performed with the following results:

Appearance: Colorless, clear

WBC count: 35 cells/µ L (90% lymphocytes)

Glucose: 60 mg/dL (plasma: 100 mg/dL)

Protein: 60 mg/dL (serum: 8 g/dL)

Albumin: 40 mg/dL (serum: 6 g/dL)

IgG globulin: 20 mg/dL (serum: 2 g/dL)

a. Name and perform the calculation to determine the integrity of the patient’s blood–brain barrier.

b. Does the patient have an intact barrier?

c. Name and perform the calculation used to determine if IgG is being synthesized within the CNS.

d. What does this result indicate?

e. Considering the patient’s clinical symptoms and the calculation results, what diagnosis is suggested?

f. If immunofixation electrophoresis is performed on the patient’s serum and CSF, what findings would be expected?

g. What substance in the CSF can be measured to monitor this patient? Case Studies and Clinical Situations 3920_Ch09_180-202 23/01/14 10:30 AM Page 201 202 Part Three | Other Body Fluids