Postdural puncture headache (PDPH) is defined, according to the International Headache Society, as any headache develops within 5 days after a lumbar puncture. It worsens within 15 minutes after sitting or standing and improves within 15 minutes after lying.

For preventing PDPH, there are some uncomfortable practices for patients (fluid supplementation and bed rest) and expensive for hospital (time spend for information and management of fluid intake). Patients are usually advised by nurses. If "bed rest" is not effective in prevention of PDPH, "fluid supplementation" is not an advice based on any evidence but only on routine. By this trial, the investigators want to evaluate the scientific value of this advice, in the standard patient care.

The primary objective of this study is to compare oral hyperhydration (2 liters during 2 hours after lumbar puncture - the most common routine according to an internal pilot survey) versus no advice about the fluid intake to prevent the PDPH.

The second objective is to observe the day of apparition of PDPH, between day 0 and day 5.

Postdural puncture headache (PDPH) is defined, according to the International Headache Society, as any headache develops within 5 days after a lumbar puncture. It worsens within 15 minutes after sitting or standing and improves within 15 minutes after lying.

For preventing PDPH, there are some uncomfortable practices for patients (fluid supplementation and bed rest) and expensive for hospital (time spend for information and management of fluid intake). Patients are usually advised by nurses. If "bed rest" is not effective in prevention of PDPH, "fluid supplementation" is not an advice based on any evidence but only on routine. By this trial, the investigators want to evaluate the scientific value of this advice by non-inferiority study, in the standard patient care.

The primary objective of this study is to compare oral hyperhydration (2 liters during 2 hours after lumbar puncture - the most common routine according to an internal pilot survey) versus no advice about the fluid intake to prevent the PDPH. It will be evaluated on the occurrence of PDPH in both of the two groups The second objective is to observe the day of apparition of PDPH, between day 0 and day 5.

Inclusion Criteria:

• Patient in need of dural puncture for diagnostic.
• Age between 18 and 60 years old.
• Patient willing to participate in the research.

Exclusion Criteria:

• Pregnancy.
• Contraindication for increased oral fluid intake.
• Previous dural puncture within 5 day prior enrollment.
• Parenteral fluid intake superior at 266 ml for 2 hours after dural puncture (1000 ml per day).
• Enteral artificial feeding.
• Patient not in capacity to understand correctly French.
• Patient whose cannot be followed correctly by phone.
• Patient refusing to participate in the study.