title: Can Cerebrospinal Fluid Pressure Detect Catheter Complications in Patients Who Experience Loss of Effectiveness With Intrathecal Baclofen Therapy?
abstract: OBJECTIVE
  The catheter status of patients who presented with loss of intrathecal baclofen (ITB) therapy effectiveness was investigated using measurements of cerebrospinal fluid (CSF) pressure transmitted through the catheter fluid path to the pump. The aim of the study was to estimate the appropriate threshold separating catheter complications from "normal" catheter function, and to compare catheter status based on CSF pressure with the clinical diagnosis.
  
  
  METHODS
  This was a prospective, masked nonsignificant risk, research study. Patients (N = 47) received ITB for the treatment of severe spasticity and presented with symptoms of catheter malfunction. CSF pressure data were recorded using an external sensor connected to a needle inserted into the catheter access port. An algorithm calculated the energy of the variations in CSF pressure caused by respiration and heartbeat within the intrathecal space. These data were evaluated against a threshold that separated normal from abnormal catheter function. Catheter status based on the algorithm was compared with the clinical diagnosis.
  
  
  RESULTS
  Complete data were available for 37 patients. Mean CSF pressure energy was significantly higher (p = 0.025; student t-test) for patients diagnosed with normal catheter function vs. catheters with complications. The CSF pressure algorithm matched the clinical diagnosis in 16 of 18 patients with catheter complications (sensitivity = 89%), and 13 of 19 patients with normal catheter function (specificity = 68%).
  
  
  CONCLUSIONS
  In-clinic CSF pressure data acquisition is technically feasible. Overall, catheter status based on the algorithm demonstrated concordance with the clinical diagnosis in 29 of 37 patients (78.4%).
authors.affiliation: MossRehab, Elkins Park, PA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Saulino
authors.affiliation: Goodman Campbell Brain and Spine, Indianapolis, IN, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Turner
authors.affiliation: Medtronic Neuromodulation, Minneapolis, MN, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Miesel
authors.affiliation: Medtronic Neuromodulation, Minneapolis, MN, USA.
authors.forename: Felicia R
authors.initials: FR
authors.lastname: Cochran
authors.affiliation: Medtronic Neuromodulation, Minneapolis, MN, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Stromberg
authors.affiliation: Medtronic Neuromodulation, Minneapolis, MN, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Fehrmann
authors.affiliation: Medtronic Neuromodulation, Minneapolis, MN, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Markert
authors.affiliation: Medtronic Neuromodulation, Minneapolis, MN, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Spencer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001418:Baclofen / Q000008:administration & dosage*; D002408:Catheters, Indwelling / Q000009:adverse effects; D015170:Cerebrospinal Fluid Pressure / Q000187:drug effects*; D005260:Female; D006801:Humans; D015918:Infusion Pumps, Implantable / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009125:Muscle Relaxants, Central / Q000008:administration & dosage*; D009128:Muscle Spasticity / Q000188:drug therapy; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D014481:United States; D055815:Young Adult
chemical_list: D009125:Muscle Relaxants, Central; D001418:Baclofen
keywords: Catheter; SynchroMed; catheter access port; cerebrospinal fluid; intrathecal baclofen therapy