Survival of individuals with cerebral palsy receiving continuous intrathecal baclofen treatment: a matched-cohort study

Aim To determine whether intrathecal baclofen (ITB) changes mortality risk in persons with cerebral palsy (CP). Method Records were reviewed for all persons with CP who were managed with ITB for hypertonicity at a specialty hospital in Minnesota between May 1993 and August 2007. A comparison cohort was randomly selected from clients of the California Department of Developmental Services who were initially evaluated between 1987 and 1990 and were matched to those with ITB for age, sex, Gross Motor Function Classification System (GMFCS) level, presence or absence of epilepsy, and feeding-tube use. Survival probabilities were estimated using the Kaplan-Meier method, and differences were tested via log-rank. Results Three hundred and fifty-nine persons with CP (202 males, 157 females) receiving ITB for hypertonicity (mean age 12y 8mo, SD 7y 9mo, range 3y 1mo to 39y 9mo) were matched to 349 persons without ITB pumps (195 males, 154 females; mean age 12y 7mo, SD 8y 4mo, range 2y 7mo to 40y). The proportion of patients at different GMFCS levels in the ITB and in the non-ITB cohorts, respectively, was as follows: level II 3% and 3%, level III 16% and 16%, level IV 38% and 37%, and level V 43% and 44%. Survival at 8 years of follow-up was 92% (SD 1.9%) in the ITB cohort and 82% (SD 2.4%) in the non-ITB cohort (p < 0.001). After adjustment to account for recent trends in improved survival in CP, 8-year survival in the non-ITB cohort was 88%, which was not significantly different from the ITB cohort (p=0.073). Interpretation ITB therapy does not increase mortality in individuals with CP and may suggest an increase in life expectancy.