The purpose of this study is to evaluate the long term effects of the ganglion sphenopalatine block (GSP block) on postdural puncture headache.

Adult patients with postdural puncture headache was enrolled in main study (NCT03652714). In the main study the patients was randomised to receive a ganglion sphenopalatine block (GSP-block) with either local anesthetic (lidocaine + ropivacaine) or placebo (isotone NaCl).

Following inclusion in the main study all participants are sent a follow-up questionnaire.

Primary outcome is disability due to headache defined as moderate to severe disability measured with Migraine Disability Assessment Test (MIDAS) in the 3 months following initial block and average pain score in the 3 months following the initial block on a 0-10 pain intensity scale.

Secondary outcome is disability due to headache defined as moderate to severe disability measured with Migraine Disability Assessment Test (MIDAS) in the 3 previous months as well as average pain scores in the previous 3 months, days with headache and long and short term side effects of the block.

Patients who where included in main study and had the following eligibility criteria:

Inclusion Criteria:

• Age > 18 years
• Patients with postdural puncture headache defined as moderate to severe postural headache (VAS >= 30mm) after lumbar puncture or accidental dural puncture during epidural insertion with an onset within 3 days following the puncture.
• Lack of headache remission within 1 day after dural puncture and after treatment with fluids, caffeine and paracetamol
• Patients who have given their written informed consent for participation in the study after fully understanding the protocol content and limitations.

Exclusion Criteria:

• Patients who cannot cooperate to the study
• Patients who does not understand or speak Danish
• Allergy to the drugs used in the study
• Has taken opioids within 12 hours prior to intervention

Patients who were included in main study NCT03652714