Should computed tomography scanning replace lumbar puncture in the diagnostic process in suspected subarachnoid hemorrhage?

The role of lumbar puncture and computed tomography scanning for initial diagnosis of subarachnoid hemorrhage has been evaluated in a retrospective survey of 283 consecutive cases. The material has been divided into early-and late-diagnosed cases with 72 hours after bleeding as the demarcation line between groups. The early-diagnosed cases have been further subdivided into patients exhibiting contraindications for lumbar puncture, patients with a typical history of apoplectic headache, and patients presenting with a diffuse noncharacteristic history. Four initially alert patients suffered neurological deterioration associated with the performance of lumbar puncture, which corresponds to a complication rate of 2.2%. It is concluded that all cases of suspected intracranial hemorrhage in the pediatric age group should be immediately investigated by computed tomography. In old age, individual factors determining the patient's operability overshadows all other aspects. In the intermediate age group lumbar puncture is preferable to diagnose subarachnoid hemorrhage in cases first seen in a late stage, due to both the high rate of falsely suspected cases as well as the poor visualization of degenerating blood in the cerebrospinal fluid by computed tomography. In patients suffering severe apoplectic headache with nuchal rigidity, lumbar puncture is without question superfluous. If neck stiffness is not considered, 4.68 computed tomography investigations per 100,000 individuals would be performed yearly in falsely suspected cases, a diminishingly small cost corresponding to less than 1% of all cranial computed tomography scans performed in this region. Early-diagnosed patients with a diffuse atypical history constitute a small, low risk group for lumbar puncture. It may be acceptable in such patients to diagnose subarachnoid hemorrhage either by means of computed tomography or lumbar puncture, depending on the availability of local computed tomography resources.