Retrospective Analysis on the Ef icacy of Flex Dosing vs Continuous Infusion of Intrathecal Baclofen
Patients who experience chronic pain and spasticity and either do not respond well to oral baclofen or cannot tolerate the side effects at the minimally effective dose are often prime candidates for intrathecal baclofen (ITB) therapy. This treatment method allows for significantly lower drug doses to be directly delivered into the cerebral spinal ftuid (CSF), bypassing the difficulties in drug metabolism and permeability to the blood-brain barrier often associated with oral medications. This also signiftcantly reduces the systemic side efects of baclofen, primarily hypotonia and sedation. One obstacle clinicians face, however, is the inability for baclofen to diffuse uniformly within the CSF, making it difficult to treat patients with both upper and lower limb spasticity. Heetla et al showed that continuous infusion of baclofen in a pig model spread no further than a 5 cm distance from the catheter tip. In order to address this, some clinicians have applied the method of “flex dosing”, or providing intermittent boluses of medication rather than a continuous infusion, with the rational being the quicker rate of ftow allows the pump to push medication further into the CSF and diffuse farther. The objective of this study was to determine if flex dosing does indeed increase the efficacy of baclofen as compared to continuous infusion. This study is a followup to a study entitled “Comparison Between Preimplant Oral and Postimplant Intrathecal Baclofen Dosage for the Treatment of Spasticity” presented at the 2015 North American Neuromodulation Society Annual Scientific Meeting. Patients in this study had diagnoses that included MS, Cerebral Palsy, Friedreich's ataxia, spinal cord injury, cerebral vascular accident, and traumatic brain injury.