Postdural puncture headache in complex regional pain syndrome: a retrospective observational study.

OBJECTIVE To describe the unusual course of postdural puncture headache (PDPH) after pump implantation for intrathecal baclofen (ITB) administration in patients with complex regional pain syndrome (CRPS)-related dystonia. DESIGN Case series based on data collected from 1996 to 2005. Setting. Movement disorders clinic, university hospital. PATIENTS A total of 54 patients with CRPS-related dystonia who were treated with ITB. RESULTS A high incidence (76%) and prolonged course (median 18 days, range 2 days to 36 months) of PDPH was found. Radionuclide studies performed in two patients with long-lasting symptoms (12-16 months) did not reveal cerebrospinal fluid (CSF) leakage. In patients without signs of CSF leakage (N = 38), epidural blood patches administered in 24 patients were effective in 54%, while ketamine infusions administered in six patients were effective in 67%. CONCLUSIONS Our observations may suggest that other mechanisms besides intracranial hypotension play a role in the initiation and maintenance of PDPH in CRPS and stimulate new directions of research on this topic.