ABSTRACT
BACKGROUND AND PURPOSE: Complications from lumbar puncture (LP) include headache; mild puncture-site pain; and, rarely, subdural, epidural, or subarachnoid hemorrhage. In infants, asymptomatic leakage of CSF documented with ultrasound is common. We report the MR imaging findings and clinical course of 25 symptomatic patients with spinal epidural collections after LP. MATERIALS AND METHODS: MR imaging and clinical records of 25 children with new symptoms following LP were retrospectively reviewed. RESULTS: All patients had abnormal dorsal spinal epidural collections. Signal-intensity characteristics of the collections were most commonly isointense to CSF on all pulse sequences. Significant anterior displacement of the dura with effacement of the subarachnoid space was frequently noted. All patients had fluid surrounding small foci of epidural fat, elevating them from their native interspinous fossa, resulting in a "floating" appearance. Eighteen collections involved the thoracic and lumbar spine; 4 involved the thoracic, lumbar, and sacral spine; 2 extended from the lumbar to the cervical level; and 1 was isolated to the lumbar spine. Five patients had follow-up MR imaging showing complete resolution of collections. The size of the collections was not directly related to the number of puncture attempts. Clinical symptoms resolved with time in all patients with conservative management. CONCLUSION: Symptomatic epidural fluid collections after LP are often extensive and may compromise the thecal sac. These collections are not usually the result of a difficult LP and have signal intensity characteristics most consistent with CSF leak rather than hemorrhage. Signs and symptoms typically resolve with time, without treatment and with no serious sequelae.
