Intrathecal Baclofen for spasticity-related pain in amyotrophic lateral sclerosis

Apr 17 2007

An estimated 5,600 people in the United States are diagnosed every year with Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease, and as many as 30,000 Americans have the disease at any given time.

Unfortunately, there is no cure for ALS, and it leads to death most typically two to five years after diagnosis. One of the side effects of ALS is spasticity, a condition resulting from excess motor neuron excitation due to lesions in the upper motor neuron pathway that lead to the absence of inhibition of alpha and/or gamma motor neurons. Spasticity can cause uncontrollable and often painful muscle contractions. Although the pain associated with spasticity can usually be controlled with medication and physical therapy, some patients are unresponsive to this treatment.

Researchers at the University of Minnesota Medical School and the Cleveland Clinic explored the efficacy of treating ALS patients with intractable spasm-related pain with an intrathecal baclofen (ITB) pump. Eight patients were implanted with the ITB pump between January 2003 and December 2005 at the Cleveland Clinic.

The results of this study, Intrathecal Baclofen for Spasticity-Related Pain in Amyotrophic Lateral Sclerosis: Efficacy and Factors Associated with Pain Relief, will be presented by Shearwood McClelland III, MD, 3:57 to 4:09 p.m. on Tuesday, April 17, 2007, during the 75th Annual Meeting of the American Association of Neurological Surgeons in Washington, D.C. Co-authors are Francois A. Bethoux MD, Matthew H. Sutliff, PT, Darlene K. Stough RN, Kathleen M. Schwetz, RN, Danuta M. Gogol, RN, Michelle Harrison, PT, Erik P. Pioro, MD, PhD, and Nicholas M. Boulis, MD.

Patients were selected by the operating surgeon and neurologists specializing in the treatment of ALS on the basis of a history of longstanding ALS-associated spasticity, despite optimal medication management. Following successful test injection, patients were referred to the Cleveland Clinic Center for Neurological Restoration for programmable ITB implantation.

• The eight patients ranged in age from 33 to 77, with a mean age of 43.8 at surgery.
• The duration of the patients' ALS symptoms ranged from 14 to 108 months, with an average of 47.4 months at surgery.
• Both pre- and postoperative pain was quantified using a 0-10 scale, with 0 representing no pain and 10 representing maximum pain.
• The mean modified preoperative pain score was 7.69, ranging from 6 to 10.

Following surgery, patients were transferred to an inpatient rehabilitation unit before eventually returning home with continuing outpatient or in-home rehabilitation. Patients were subsequently followed by the ALS and related disorders team at the Cleveland Clinic for ITB pump adjustments and refills. Mean follow-up was 9.8 months.

The following outcomes were noted:

• Following ITB pump placement, the average pain score was 3.56 (range = 0 to 8), a reduction of 54 percent from preoperative scores.
• No patients experienced neurological morbidity or mortality.
• Six patients (75 percent) experienced pain relief, of which three received complete pain relief (postoperative pain score of 0).

“The degree of pain relief following preoperative ITB test injection correlated with the degree of postoperative pain relief following ITB implantation,” stated Dr. McClelland. The two patients who did not experience pain relief from implantation were the same patients who failed to experience pain relief from preoperative ITB test injection. The three patients who experienced complete pain relief also experienced complete pain relief following preoperative ITB.

“These results support ITB as a treatment modality for pain associated with refractory spastic ALS, and underscore the importance of pain documentation following preoperative ITB test injection. In appropriately selected ALS patients with spasticity, ITB implantation can offer a significant quality of life improvement for an incurable and often painful condition,” concluded Dr. McClelland.

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 6,800 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system, including the spinal column, spinal cord, brain and peripheral nerves.

http://www.aans.org/