Experience with external pump trial prior to implantation for intrathecal baclofen in ambulatory patients with spastic cerebral palsy

Abstract

Objectives: To evaluate effectiveness and safety of intrathecal baclofen administration (ITB) testing with continuous infusion via an external pump before the implantation of an internal one in ambulatory spastic patients with cerebral palsy (CP).

Patients and methods: Seven CP patients (3 diplegic, 4 quadriplegic - 18.4+/-7.0 years) with a progressive decrease in walking ability were included. Assessments included: Ashworth's scale, Observational Gait Scale (OGS), and GMFM-66.

Results: During the ITB test (45-150 microg/24h), spasticity decreased by more than two points on Ashworth's scale (p<0.001) and walking ability improved (median OGS increased from 7 to 9, p<or=0.05). After implantation of an internal Synchromed pump (dosage 66-160 microg/24h), mean GMFM-66 increased from 49.9+/-7.3 to 54.5+/-7.7 (p<0.05) and median OGS from 7 to 10 (p<0.05). Two nonambulatory patients recovered some walking ability following implantation of the pump. Adverse effects included one case of chemical meningitis during the test and two temporary CSF leaks.

Conclusions: Tests of ITB using a continuous infusion by an external pump allowed precise evaluation of the effects of different ITB doses on walking ability, enabling prediction of how the patient would respond to an internal pump. All patients showed ambulatory improvement with ITB.