"Quincke's puncture" is a somewhat outdated eponym for lumbar puncture, used for the examination of the cerebrospinal fluid in numerous diseases such as meningitis and multiple sclerosis. In 1893 he described what is now known as idiopathic intracranial hypertension, which he labeled "serous meningitis".
"Lumbar puncture," a procedure used to examine cerebrospinal fluid, is sometimes referred to as Quincke's puncture.