Headache following a lumbar puncture （post-lumbar-puncture headache,PLPH）is a common and often debilitating syndrome, which was reported to occur in about 40% patients who received lumbar puncture. Now there lacks of effective approaches in the prophylaxis of PLPH, although some physicians consider bed rest for at least 6 hours to be a useful methods (Some recent meta-analysis found no benefit of bed rest for any hours in the prevention of PLPH). Studies have found that P substances and its receptor (Neurokinin-1 receptor, NK-1R)have played an important role in the pathogenesis of PLPH. Thus, we hypothesize that use of NK-1R inhibitor (aprepitant) 1 hour before lumbar puncture may decrease the incidence of PLPH and lower the severity of PLPH.

Headache following a lumbar puncture （post-lumbar-puncture headache,PLPH）is a common and often debilitating syndrome, which was reported to occur in about 40% patients who received lumbar puncture. Now there lacks of effective approaches in the prophylaxis of PLPH, although some physicians consider bed rest for at least 6 hours to be a useful methods (Some recent meta-analysis found no benefit of bed rest for any hours in the prevention of PLPH). Studies have found that P substances and its receptor (Neurokinin-1 receptor, NK-1R)have played an important role in the pathogenesis of PLPH. Thus, we hypothesize that use of NK-1R inhibitor (aprepitant) 1 hour before lumbar puncture may decrease the incidence of PLPH and lower the severity of PLPH.

Inclusion Criteria:

• Patients diagnosed as acute leukemia, or lymphoma
• Patients will received repeated lumbar puncture (at least 2 times, and at least 2 weeks apart) and intrathecal treatment
• Without CNS involvement
• Without headache for at least 1 week before the day of lumbar puncture
• The platelet count was at least 30×10e9/L

Exclusion Criteria:

• With CNS involvement of disease
• With headache before lumbar puncture
• Needs lumbar puncture more than once a week