Changes in cerebral haemodynamics in cases of post-lumbar puncture headache: a prospective transcranial Doppler ultrasound study.

We used transcranial Doppler ultrasonography in 45 patients to investigate if changes in haemodynamics in the major arteries of the brain base occurred after lumbar puncture and whether or not patients with or without post-lumbar puncture headache differ with respect to their cerebral haemodynamic parameters before and after lumbar puncture. Before lumbar puncture, patients with post-lumbar puncture headache differed from patients without post-lumbar puncture headache in that they showed significantly higher flow velocities and significant asymmetry of flow velocities with lateralization to the right (p less than or equal to 0.05). Patients without post-lumbar puncture headache, on the other hand, showed non-significant flow velocity lateralization to the left. Forty-eight hours after lumbar puncture, both groups demonstrated symmetrical flow velocities. In addition, only patients with post-lumbar puncture headache showed a significant reduction in the flow velocity of the right middle cerebral artery (p less than or equal to 0.05). These findings suggest that it is not only absolute flow velocity that plays a part in the event of headache, the interhemispheric relation of cerebral haemodynamics also plays a fundamental role.