DR. ABEL MURILLO

Cramps or Spasticity?

By Alfredo Arango
Medical Editor

The way in which medications are administered and their proper doses are of the utmost importance for treatment to be effective, and to prevent harmful side effects as well. For this reason, some medicines are taken orally, others topically, and others are inhaled or injected. In treating a condition known as muscular spasticity, there is a way of administering drugs via implanted pumps that supply medications in a continuous and calibrated fashion. This offers multiple advantages.

Muscular spasticity is caused by the muscle’s lack of balance in the relaxation-contraction process. In the absence of this balance, generally as a side effect of a stroke or spinal-cord injury, among other conditions, only a contraction occurs without any relaxation. If muscular spasticity is not treated early on, and in some cases preventively, it could worsen or become chronic, or often irreversible, thus causing muscular contraction. Unlike cramps that are slight and temporary muscle contractions, in spasticity and contraction the problem is permanent. In some cases it is not painful; however, extremities —arms or legs— lose their normal function, even for simple activities such as getting dressed, sitting or walking.

“The ideal situation is to administer the least amount possible of medication, to decrease side effects, and at the same time guarantee effective treatment. There are very effective medicines we use to relax muscles, including Baclofen or Dantrolene. Unfortunately, these drugs cause side effects such as drowsiness, dizziness, and nausea, or they are not able to cross the blood brain barrier and enter the nervous system in order to reach the area where the appropriate receptors are located. It is more effective to administer the medication directly into the spinal column. A smaller amount of medication applied to the spinal cord makes it possible to reach a higher concentration than with a larger amount administered by mouth. Side effects are practically minimal,” says Dr. Abel Murillo, who specializes in interventional management of pain, and is affiliated with Kendall Regional Medical Center of Miami.

The amount of medication applied directly into the spinal cord, or intrathecally, is in micrograms, whereas orally it is in milligrams.

However, it would be very uncomfortable and painful to have to constantly go to the doctor’s office to get injections into the spinal cord. For this reason, medical technology has developed small pumps or reservoirs that are implanted in the patient’s body and these pumps deliver medication with greater precision, following the doctor’s orders. According to Medtronics, manufacturer of the Baclofen pump, this system consists of a catheter (a small, flexible tube) and a pump. The pump is a metallic disc, measuring one inch wide and three inches in diameter, that is surgically implanted under the skin at the abdominal level. The implant procedure takes two hours.

The pump holds and releases prescribed amounts of medication through the catheter. The reservoir contains enough medication for about three to six months. When the medicine runs out, the pump can be refilled by injecting more medication through a needle.

Not all patients are candidates for intrathecal pump placement. Medtronics warns that the patients who are candidates for this procedure are those who suffer severe spasticity and cannot tolerate medication administered by mouth.

The manufacturers affirm that this therapy brings about a 97 percent reduction of spasticity in severe cases caused by multiple sclerosis or spinal cord injury, and an 86 percent reduction in cases in which the condition is a consequence of cerebral palsy. Correct selection of the patient by the doctor is crucial to the success of the treatment. When a doctor recommends Baclofen-pump placement, a screening test for intrathecal therapy is always performed first to verify potential effectiveness of the medication applied this way. During the test, a small needle is inserted close to the spinal canal in the lower back. Medication is then injected and the patient is observed for 4–6 hours to determine to what extent the drug has an effect on spasticity. If the muscles do not relax during the first test, a higher dose can be applied the following day to see if it produces the desired effect.

This procedure causes minor discomfort. Muscle weakness might be felt due to the relaxing effect of the medication. This occurs because a large dose is administered during the test. When patients obtain positive results from this test, they can then decide with their doctors whether they will have the pump system implanted.

Dr. Murillo explains that in spite of the increased effectiveness made possible by implantable pumps, it is very important for the patient to undergo physical therapy for rehabilitation. Therapy helps muscles stretch and recover their functionality.

Rehabilitation aids in restoring the connection between nerves and muscles, in order to restore strength and tone to muscles that have been numb and spastic.