contents for 5 min at room temperature. Read absorbance at 640 nm. Calculate
protein amount in CSF sample as given for pyrogallol red dye method.
34.3 Analysis of CSF Glucose
Glucose determination in CSF is carried out similar to blood glucose estimation.
34.4 Clinical Significance...............................
Normal protein levels in CSF are in range of 15–60 mg/dl. In normal conditions,
albumin is main protein present in CSF, but it may contain globulins also in many
diseases. The increased permeability of capillary endothelial barrier due to bacterial,
viral, or fungal meningitis, multiple sclerosis, and cerebral infarction will increase
CSF proteins. An increase in total CSF proteins is due to breakdown of blood-brain
barrier usually as a consequence of an inflammatory reaction or obstruction inflow
of CSF. In acute meningitis, polyneuritis, and tumors such as acoustic neuroma, the
protein levels in CSF increase up to 0.4 g/dl. CSF/serum albumin index reveals the
intactness and impairment of blood-brain barrier.
CSF=serum albumin index¼CSFalbumin inmg=dl
Serum albumin in g=dlAn index value of <9 is considered with an intact barrier. Value of 9–14 is
interpreted as slight impairment while index of 14–30 as moderate impairment. An
index of above 30–100 indicates severe impairment, while values greater than
100 show complete breakdown of barrier.
Normal CSF glucose range is 45–80 mg/dl. Disease conditions like tuberculosis,
benign lymphocytic chronic meningitis, hypoglycemia, and metastatic tumors of
meningitis cause decrease in CSF glucose levels. In bacterial meningitis, the glucose
levels may disappear completely, and in tuberculosis meningitis it is usually between
10 and 40 mg/dl. Increased CSF glucose is observed in diabetes mellitus, encephali-
tis, brain tumors, and cerebral abscess.
34.4 Clinical Significance 137