Cytological assessment of cerebrospinal fluid in Guillain-Barre Syndrome

Abstract

Present criteria for the diagnosis of Guillain-Barre Syndrome (GBS) include a cerebrospinal fluid (CSF) mononuclear cell count of 10 or less per microlitre (ul.). The standard technique for quantifying cellularity has been the counting chamber (CC) in a volume of approximately 50 ul. In reviewing cytospin (CS) preparations of CSF samples (500ul/preparation) from 39 patients with GBS we noted that cells were present in 23. In 11 of these cellularity was markedly increased. Therefore, to determine if the CS method is more accurate than the CC in detecting and quantifying cells in CSF, we retrospectively compared the cell yields by each technique in the 23 samples. In 17, a discrepancy was noted. In several, no cells had been detected in the CC while the CS preparations showed cellularity. In 4, the two techniques were equivocal. In 2, a CC yield was not recorded in the patient notes. We then performed chamber counts on specimens of known cell concentration (30, 40, 80 and 200 cells/ul in glucose nutrient solution). Eight counts were performed at each concentration. No cells were detected in 7 out of a possible 32 instances. These data suggest that the CC may underestimate CSF cell content and that the present criterion of less than 10 cells /ul. for the diagnosis of GBS may require revision. The CS method also follows an accurate differential cell count and the detection of atypical cells.