Intrathecal Baclofen for Amyotrophic Lateral Sclerosis-Associated Spasticity: Analysis of Long-Term Outcomes and Predictors of Treatment Response

Shearwood McClelland III M.D.¹, Francois A. Bethoux M.D.², Matthew H. Sutliff P.T.², Darlene K. Stough R.N.², Kathleen M. Schwetz R.N.², Danuta M. Gogol R.N.², Michelle Harrison P.T.², Erik P. Pioro M.D., Ph.D.², Nicholas M. Boulis M.D.³

¹Department of Neurosurgery, University of Minnesota Medical School, Minneapolis, MN; ²Department of Neurology, The Cleveland Clinic Foundation, Cleveland, OH; ³Department of Neurosurgery, The Cleveland Clinic Foundation, Cleveland, OH.

Introduction:

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting upper and lower motor neurons. Patients with significant upper motor neuron degeneration often experience spasticity, manifesting as involuntary muscle contraction that causes stiffness interfering with movement and locomotion. Although most spasticity patients are adequately controlled with medication and physical therapy, some patients remain refractory to treatment. For this subpopulation, intrathecal baclofen (ITB) may provide adequate relief for an otherwise untreatable condition. We detail our experience with the largest reported series of patients receiving ITB for intractable ALS-associated spasticity.

Methods:

From 2003-2005, ten patients (6M/4F) with intractable ALS-associated spasticity underwent ITB placement at our institution. Mean age at surgery was 46.6 years (range=33-77), and average ALS duration was 51 months (range=13-120). All patients responded positively to preoperative ITB test injections (25-50 mcg), and subsequently underwent programmable intrathecal infusion system implantation. Postoperative response was quantified using the modified Ashworth scale. Mean follow-up was 11 months (range=1-29).

Results:

Following ITB placement, the mean Ashworth score reduction was 1.7 (range=0-2.9), with no neurologic morbidity/mortality. Neither age over 40 (p=0.849) nor duration of ALS longer than 3 years (p=0.846) impacted postoperative response (t-test).

Conclusion:

In the largest reported series of ITB for ALS patients, ITB provides effective treatment of intractable ALS-associated spasticity without neurologic morbidity/mortality. Careful patient selection, surgical technique and management are key to optimal results. Surgical intervention should not be withheld until patients are severely disabled (nonambulatory), since ITB in ALS patients with early-onset refractory spasticity may help preserve quality of life throughout the disease course.

Keywords:

Spasticity, Amyotrophic Lateral Sclerosis, Intrathecal Baclofen, Ashworth Scale