509 - A Silent Leak: Intrathecal Baclofen (ITB) Pump Pocket Pseudomeningocele Masked by Oral Therapy (A Case Report)

A 26-year-old male with cerebral palsy was managed with ITB pump therapy (1500mcg/day) for 12 years with functional independence. After prior baclofen withdrawal and catheter malfunction requiring elective catheter replacement, he later wished to discontinue pump therapy. His dose was reduced to 1000 mcg/day, and oral baclofen 20mg PO TID was initiated with no associated withdrawal symptoms. Several weeks later, he presented to the ED with postural headaches. Abdominal radiographs revealed catheter disconnection distally from the pump, and physical exam revealed a large expanding fluid collection at the pump pocket. Emergent pump explantation revealed a large collection of CSF within the pump pocket and the catheter was tied to prevent further CSF leakage. Oral baclofen dose was escalated, symptoms resolved, and the patient has maintained stable functional mobility (modified independence for ambulation with rolling walker, supervision to independent for dressing) for over two years.

Discussions: Pseudomeningocele, an extradural CSF collection often secondary to catheter malfunction, is a recognized complication of ITB therapy, reported in up to 44% in young adults and 25% in pediatric patients. Among pediatric cases, 72% with CSF leak experienced headaches, typically managed conservatively or with an epidural blood patch.  While relatively common, this case underscores the risk of withdrawal symptom masking when oral baclofen is used adjunctively, potentially delaying recognition of pseudomeningocele necessitating emergent intervention.

Conclusions: Pseudomeningocele formation from ITB pump catheter failure is well documented, and timely recognition with surgical management is critical to prevent further morbidity. This case highlights that concurrent oral baclofen may obscure withdrawal symptoms in the setting of catheter malfunction and pseudomeningocele formation. Although oral baclofen mitigates acute withdrawal, vigilant monitoring of the pump pocket and patient symptoms during dose titration remains essential to ensure safe outcomes.