(Kiosk 4) Posture Dependent Intrathecal Baclofen Pump Malfunction in a Spastic Quadriplegic Cerebral Palsy Patient

Case Diagnosis: Intrathecal baclofen pump malfunction due to postural catheter kink in a spastic and dystonic quadriplegic cerebral palsy patient.

Case Description: A 28-year-old patient with a history of intellectual disability and spastic quadriplegic cerebral palsy presented with her caregiver to establish care with an adult physiatrist. Caregiver expressed concern that the patient’s intrathecal baclofen (ITB) pump was not controlling spasticity and dystonia, and was causing increased pain. On physical exam, there was increased tone and dystonic posturing in the upper and lower extremities.

Discussion: Kinking/occlusion of the ITB pump catheter is a known possible complication although rare. A careful patient history and evaluation can assist the clinician in determining when/if imaging and evaluation of the pump and catheter are necessary. The specific complaint for this patient was worsening dystonia when sitting but improved when laying supine. This history was crucial when diagnostic imaging was performed. No prior case report has described posture related intrathecal baclofen pump kinking to our knowledge.

Setting: Outpatient Transition to Adult Rehabilitation Clinic

Assessment/Results: ITB Shunt-O-gram revealed an issue with the ITB catheter tip with possible erosion that changes with position between supine or sitting, which may have been contributing to lack of ITB pump efficacy. Neurosurgery was unable to withdraw fluid from the ITB side port, further raising suspicion for catheter malfunction. ITB pump replacement procedure revealed a sharply kinked catheter insertion site indicating a site of posture dependent intermittent closure. After the procedure, ITB pump dose was up-titrated with good effect.

Conclusion: Careful history and early consideration for imaging of ITB systems should be considered when evaluating patients who fail to improve after increased doses of baclofen. Further research and new techniques for evaluation of the ITB system should be explored.