Symptom Awareness
Weakness
Weakness is a common symptom associated with MS. When caused by MS, weakness is a result of damage to the nerves of the Central Nervous System (CNS), which includes the brain and spinal cord. As the protective covering (known as myelin) of these nerves becomes inflamed and eventually damaged, the swift flow of nerve impulses is interrupted, preventing instructions from adequately reaching the extremities. This type of weakness in MS is often caused by demyelination within the spinal cord, although demyelination within the brain can also be at fault.
Weakness may also arise as a complication of other factors. For example, a number of other MS symptoms, such as fatigue, spasticity, and balance problems, can lead to weakness. Additional issues, such as stress, overexertion, and inactivity, may result in weakness as well.
The symptom of weakness is frequently perceived as one leg feeling heavy and being difficult to lift, especially at the end of the day. This may be particularly evident when stepping up onto a stair or curb. Although less common, some may experience similar sensations of heaviness or clumsiness in one or both of their arms and hands. Losing the ability to grip, push, or lift can be very frustrating.
Physical Therapist Brian Hutchinson, MS, PT explains, "The amount of weakness is not necessarily associated with the duration of one's MS. In fact, weakness can be a 'presenting,' or initial symptom. A common presentation is that one will experience weakness in one extremity, and at a later time, a second extremity could become affected."
Treating Weakness
Weakness, as with any MS symptom, may be temporary, subsiding as inflammation from an exacerbation decreases. Treatment for weakness in this type of situation may involve steroids to reduce inflammation, in an attempt to lessen the intensity of the flare-up and accelerate recovery.
An assistant therapist demonstrates how to improve balance with a physioball. By improving balance, less strength is required to sit or stand upright, and this can help reduce weakness. (All photos on pages 44-51 are reprinted from the Winter 2004 issue of The Motivator, "The Benefits of Rehabilitation" article.)
"Getting plenty of rest is important while recovering from an exacerbation," Hutchinson points out, "but resting the muscles too much may have a negative impact. Specific exercises should be prescribed by a physical or occupational therapist, or a physician who specializes in neurological conditions, to keep muscles moving. This helps to reduce muscle stiffness, decrease atrophy, and maximize function."
Hutchinson warns, "When weakness continues beyond an exacerbation, the patient should be re-evaluated by a professional. Strategies should be developed to avoid overuse of the affected limb, while keeping the muscle active."
He goes on to explain, "No medications are available at this time to specifically treat weakness. Treating related symptoms — such as using an anti-spasticity medication to reduce muscle tightness and spasms, will have a secondary effect of reducing weakness. A new drug is on the horizon, however, but is not yet approved. Fampridine-SR may help individuals with both relapsing as well as progressive forms of MS to walk faster and to have an increase in leg strength."
Acorda Therapeutics' Fampridine-SR works by blocking areas where damaged myelin has exposed portions of the nerve membrane. The drug helps to keep nerve impulses on track so they may pass through areas of damage. Following the announcement in September 2006 of positive results from its phase III clinical trial, Acorda plans to meet with the United States Food and Drug Administration (FDA) to discuss the next steps toward approval of the drug.
Fampridine-SR is a sustained-release tablet formulation of the investigational drug fampridine (4-aminopyridine, or 4-AP). Adverse events include an increased risk of seizures that appears to be dose related (meaning that the risk increases as the dose increases). For more information on Fampridine-SR, readers may visit Acorda Therapeutics' website at www.acorda.com. Readers may also call Acorda Therapeutics' patient information line at (877) 223-5212.
Sometimes assistive devices, such as a cane or brace, are used to remove some of the pressure on a weak limb. People who are moderately to severely weak are often reluctant to use a wheelchair or scooter, but using these devices can be very helpful. By conserving energy, a wheelchair or scooter enables an individual to be more active over a longer period of time.
If desired, the use of assistive devices may be reserved just for times of extra activity. Using a cane will not make someone more dependent on others, but rather increases independence by providing added support, so he or she may have the strength to continue with activities longer.
Parallel bars are used to help regain strength and balance.
Individuals using or planning to use any assistive device should always do so under the direction of a physical or occupational therapist, or a physician who specializes in neurological conditions. These professionals can make sure that the device is properly fitted, and a professional will also provide specific instruction for correct use of the device.
Planning ahead is particularly valuable for dealing with weakness. When traveling or involved in a prolonged activity, arranging for a wheelchair in advance to cover long distances can save time and energy. Being aware of limitations while organizing one's schedule may help to avoid late-day weakness. Taking care of more difficult tasks early on is also a good strategy; it allows for easier tasks to be done later, when one might have less strength.
Many thanks go to Brian Hutchinson and Valerie Gibson for their assistance with this article. Hutchinson works as a physical therapist for The Heuga Center, located in Edwards, Colorado, which specializes in education and wellness for individuals with MS. Readers may visit The Heuga Center's website at www.heuga.org; the center may also be contacted by calling (800) 367-3101.
Gibson is a physical therapist and founder of Advanced Physical Therapy and Rehabilitation Center, LLC in Vienna, Virginia, specializing in neurorehabilitation. Readers may visit the center's website by going to www.aptrehab.com; the center may also be contacted by calling (703) 749-0223.
For more information and resources on weakness, assistive devices, or physical therapy, readers may contact MSAA's Helpline at (800) 532-7667.
References
MSAA booklet, Multiple Sclerosis, Managing Symptoms, third edition, 2002.
Burks JS, Johnson KP, Multiple Sclerosis — Diagnosis, Medical Management, and Rehabilitation, Demos Medical Publishing, New York, 2000.
Schapiro, RT, Managing the Symptoms of Multiple Sclerosis, fourth edition, Demos Medical Publishing, New York, 2003.
As with all of MSAA's articles, the information provided is for patient education only. Readers are strongly advised to consult their treating physician or other medical professional before making any changes to their treatment, diet, and exercise regimens, as well as to their activities and/or lifestyle.
