Opening Pressure and Post-Lumbar Puncture Headache in Children Undergoing Intrathecal Baclofen Trial.

Aims: Post-lumbar puncture headache occurs in 5% to 12% of children. The purpose of this study was to determine the frequency and predictors of post-lumbar puncture headache in children with hypertonia undergoing lumbar puncture for intrathecal baclofen trial. Methods: This was a retrospective single-center review of all 43 children (<18 years) with hypertonia and/or dyskinesia undergoing intrathecal baclofen trial from 2013-2022. Predictors of post-lumbar puncture headache were evaluated via 2-way paired t test and Fisher exact test. Results: Seven subjects (16.3%) developed post-lumbar puncture headache. Of patients who developed post-lumbar puncture headache, 3 required emergency care or hospitalization. One was misdiagnosed with constipation. The 16 patients without opening pressure measured were excluded from subsequent analyses. Of the 27 patients with documented opening pressure, the mean opening pressure was 24.0 cm H₂O (SD 6.5) and 5 (18.5%) had elevated opening pressure (>28 cm H₂O). Mean opening pressure was higher for those with post-lumbar puncture headache (28.6 vs 22.4 cm H₂O, P = .014). Sixty percent of patients with elevated opening pressure developed post-lumbar puncture headache. Baclofen pumps were placed in 4 (80%) patients with elevated opening pressure and 6 (85.7%) with post-lumbar puncture headaches without complications. Interpretation: The risk of post-lumbar puncture headache after intrathecal baclofen trial was higher than reported in the literature, likely because of greater rates of elevated opening pressure. Physicians may use opening pressure to predict risk for post-lumbar puncture headache and should educate families about symptoms. Elevated opening pressure or post-lumbar puncture headache may not preclude baclofen pump placement.