Weakness

Weakness is a common symptom in MS, resulting from the demyelination of neurons in the brain and spinal cord that control the muscles. It most commonly affects those muscles involved in walking.

Non-Pharmacologic Management

Exercise

An exercise program that involves extensive work with weights is not generally effective in reducing weakness, although a general exercise program prescribed by a physical therapist or other healthcare provider can lessen weakness by improving your overall level of conditioning. It should incorporate passive exercises that include range of motion and stretching, as well as active exercises tailored to the individual. These often include progressive-resistance exercises and aerobic exercises to whatever extent safely and comfortably possible for the individual patient.

Pharmacologic Management

Drugs that reduce spasticity and fatigue may also help to reduce weakness.

Ampyra® (dalfampridine)

The United States' Food and Drug Administration (FDA) approved Ampyra® (dalfampridine) in 2010 to improve walking speed in individuals with MS. This is the first drug to be approved for individuals with MS whose ability to walk has been impacted by the disease. Ampyra is an oral, timed-release medication developed to improve the conduction of impulses between damaged nerves of the central nervous system (CNS). Phase III clinical trials showed that a greater number of individuals with MS experienced improvement in walking speed when taking Ampyra, compared to when taking a placebo.

Ampyra (pronounced "am-PEER-ah") was developed by Acorda Therapeutics and is manufactured by Elan Corporation. Formerly known as Fampridine-SR, Ampyra is a sustained-release version of 4-aminopyridine (4AP). In earlier studies, larger doses of the drug were given and the risk of seizures became a concern. Given in extended-release tablets, the risk of seizures did not differ from the placebo group.

MSAA Chief Medical Officer Jack Burks, MD explains, “Following the instructions for correct dosing is absolutely essential. Taking more than one tablet within 12 hours, or crushing or splitting a tablet, will increase the risk for seizures. Some patients tend to think that taking more of a symptom-management drug will result in greater effectiveness, but this is definitely not the case with this type of medication.”

To read more about this drug and its study results, please see MSAA’s article, “Ampyra Approved to Improve Walking for Individuals with MS.”

Side effects included dizziness, falls, back pain, insomnia, fatigue, nausea, and balance problems.