The Effect of Intrathecal Baclofen Therapy in Ambulatory MS Patients
Objectives: To characterize the effects of ITBT on ambulation in MS patients with severe spasticity.
Methods: Data was extracted from the medical records of 49 ambulatory patients who received ITBT at our clinic and analyzed retrospectively. Primary outcomes were: ability to ambulate, Timed 25-Foot Walk (T25FW), and assistive device used. Statistical comparisons were made via two-tailed paired two-sample t-test or McNemar’s test.
Results: Our cohort consisted of 31 females and 17 males. Age at ITBT initiation was 48.6±8.4yrs. and duration of MS symptoms was 16.1±8.6yrs. Mean baseline time on the T25FW was 33.3±30.5s, with a mean change of -1.02s (p = 0.72) and 5.99s (p = 0.095) at 6 and 12 months, respectively. 6(20.7%) patients used no assistive device at baseline whereas 23(79.3%) used a unilateral or bilateral assistive device to complete the T25FW. This did not significantly differ at 6 months (no assistance - 3(10.3%); uni/bilateral assistance - 26(89.7%); p=0.18) but there was a significant increase in the proportion of patients using an assistive device at 12 months (no assistance – 2(6.9%); uni/bilateral assistance – 27(93.1%); p=0.045). Of the 49 patients, 36 and 33 remained ambulatory 6 and 12 months later, respectively. Those who remained ambulatory at one year walked faster on the T25FW at baseline than those who lost the ability to ambulate (22.07±18.19s vs. 61.99±38.53s; p=0.004).
Conclusions: Among patients who retained the ability to walk 1 year after initiation of ITBT there was no statistically significant change on the T25FW at 6 or 12 months, though use an assistive device increased significantly at 12 months. A subgroup of patients were unable to walk 25 feet at 6 (23%) and 12 (30%) months, but the potential contribution of ITBT to this functional decline, versus disease progression, remains to be determined. Higher T25FW values (i.e. slower gait) at baseline were associated with a higher likelihood of becoming non-ambulatory 1 year after ITBT initiation. Further research is needed to better understand the effects of ITBT on ambulation in MS patients with severe spasticity.