Effect of intrathecal baclofen on sleep and respiratory function in patients with spasticity

Objective: To prospectively evaluate the effect of pump-infused intrathecal baclofen infusion (ITB) in therapeutic doses on sleep quality and on daytime and nighttime respiratory function in patients with severe spasticity. Methods: We prospectively evaluated 20 consecutive patients (mean ± SD age 45 ± 13 years). We assessed spasticity and obtained polysomnography, pulmonary function tests, and resting energy expenditure measurements 1 week before and at least 8 days after pump implantation. Patients stopped oral baclofen upon pump implantation but continued other medications unchanged. We report descriptive statistics as means ± SD. Results: Most of the patients had multiple sclerosis (n = 9) or spinal cord injury (n = 8); there was one case each of cerebral palsy, hereditary spastic paraplegia, and Friedreich ataxia. Before and after ITB initiation, mean Ashworth scores were 2.75 ± 0.85 and 1.15 ± 0.36, and mean spasm scores were 3.75 ± 0.55 and 1.00 ± 0.56. ITB improved total sleep time ( p = 0.05) and sleep efficiency ( p = 0.01) and reduced periodic leg movements ( p = 0.02). ITB did not modify sleep-related respiratory events, lung function tests, CO 2 rebreathing response, or resting energy expenditure. Conclusion: Compared with oral baclofen, intrathecal baclofen infusion did not affect respiratory function and improved sleep continuity. Intrathecal baclofen infusion in therapeutic doses may act at the spinal level rather than at the supraspinal level.