Objective: To investgate the use of the lumber puncture and CT in diagnosis of primary SAH. Methods: Clincal data and lumbar puncture and CT of 60 patients with primary SAH
1 patient with cerebral lobar hemorrhage and 1 patient with Jackson
s epilepsis were analysed. Both cases were wrong erraneously diagnosed as primary SAH. Results:The postive rate of CSF is 100% in 10 days
89% in 11 to 15 days
45% in 21 to 30 days after coming on of primary SAH.The positive rate of CT is 100% in 48 hours
80% in 3 to 5 days and is very lower after 5 days coming on of primary SAH. Conclusion: Either lumbar puncture or CT has advantage and deficiency in diagnosis of primary SAH. The combination of lumbar puncture and CT can increase correctness and decrease wrong diagnosis.