Automated Cell Counting in CSF Diagnostics Revisited-Friend or Foe?

Background/Objectives: The gold standard for cerebrospinal fluid leukocyte counting is manual counting in a Fuchs-Rosenthal chamber. Recent advances in automated body-fluid-counting systems, offering a time- and labor-saving solution, are challenging this dogma. Yet, the equivalence of diagnostic accuracy is still debated in the community. Methods: We compared manual and automated cell counting of cerebrospinal fluid samples of lumbar punctures and extraventricular drains with both low and high leukocyte counts, shedding light on the variability of results between man and machine. Results: Automated and manual cell counting showed a strong correlation across all samples, particularly in the subgroup of patients with fewer than 20 cells/µl, where outliers could become especially clinically relevant. Conclusions: We found the automated counting system to be highly accurate and not lacking in diagnostic sensitivity even at low cell counts, making it a powerful tool when used in the right clinical setting.