This is based on the findings of the CSF analysis, determining the stage of disease. To determine the medicine of choice, the disease is divided into two stages: early and late stage}<b>Early (first) stage</b>: yy CSF is normal yy Lymphocytes <5 cells/mm3 yy Total protein <37 mg/dl (by dye-binding protein assay) or < 25 mg/dl (by Double Standard & Centrifuge Method) yy Absence of trypanosomes (by Double Standard and Centrifuge Method)}<b>Late (second) stage</b>: yy Lymphocytes > 5 cell/ mm3 And/or yy Presence of trypanosomes