Siderophages in differentiation of blood in cerebrospinal fluid.

This paper evaluates demonstration of siderophages as a method of differentiating blood in CSF. Of 1147 CSF samples, 125 were selected which had been obtained by lumbar puncture from patients with proven intracranial haemorrhage (spontaneous or traumatic) after an exactly known interval since the onset of clinical phenomena (haemorrhage or accident). No siderophages were found within 24 hours; in a few cases they were found on the second or the third day, and after that time they were found in the majority of cases. This is a pathognomonic finding. Collection of CSF in successive portions, qualification of the tap by the clinician as 'traumatic' or 'atraumatic', and demonstration of crenated red cells, were found to be unreliable methods. A modified apparatus for sedimentation is described.