RN/Thomson AHC Home Study Program CE CENTER

CE credit is no longer available for this article. (Expired November 2007)

Originally posted November 2005

By Vanessa C. Kramasz RN, MSN, APRN

Vanessa Kramasz is on the nursing faculty at Gateway Technical College in Burlington, WI, and a certified family nurse practitioner with Aurora Healthcare, a health services provider in Milwaukee. The author has no financial relationships to disclose.

Decades after being infected with the poliovirus, survivors may come to you with disturbingly familiar symptoms. Will you know what to do?

When my mother was in her early 50s, she started complaining of muscle weakness and pain in her legs, arms, and back. Her family doctor couldn't find anything wrong, and with no definitive diagnosis, I attributed her symptoms to aging or arthritis.

Ever persistent, Mom did some research, spoke with another physician, and joined a support group for people who were having similar ailments. What they had in common was that they all had contracted poliomyelitis decades before, and unlike thousands of other victims of this crippling, deadly disease, they had survived to live normal lives. Some years later, though, they developed the sneaking suspicion that their disease had returned.

Like a bad dream they couldn't shake, these polio survivors began to notice physical weakening and fatigue that were disturbingly familiar; it seemed they were experiencing the same symptoms that appeared when they'd first contracted polio. Fortunately for my mother, the second physician she consulted was well aware of something about which even I, as a nurse practitioner, hadn't a clue: a neuromuscular disorder called post-polio syndrome (PPS), marked by the recurrence of motor symptoms some 10 – 40 years after recovery from a polio infection.¹

The potential ramifications of this syndrome are significant. There are about 1.6 million polio survivors in the United States, and it's predicted that many of them will suffer some degree of PPS.² As these survivors age and seek care for acute and chronic disorders, there's a chance you'll come into contact with some of them. It's important to understand that these patients may be having great difficulty adjusting to this second, unexpected occurrence of symptoms. And, because polio is now considered a conquered disease in this country and is largely forgotten, patients may encounter a general lack of knowledge among nurses and physicians about the disease and its late consequences.³

Coming to terms with polio's after-effects

The last reported outbreak of polio in this country was in 1979. At presstime, however, poliovirus infection had been identified in four children in Minnesota. The Minnesota Department of Health reported that the youngsters had been exposed to a strain of virus found in the live oral polio vaccine, no longer used here, most likely from someone immunized outside the United States.

Elsewhere, there were more than 1,300 confirmed cases from January 2004 to March 2005.⁴ The World Health Organization is aggressively working toward vaccinating populations at highest risk, mostly in Africa and Asia. The goal is global eradication of this contagious virus, which attacks motor nerve cells of the spinal cord and brain stem and can cause severe and often permanent paralysis.³

My mother contracted the virus in 1951, during one of the worst polio epidemics in the United States.³ This was before a vaccine discovered by Jonas Salk was made available to the public in April 1955. Mother was 19 when she presented with fever and pain throughout her body, the worst of it in her back and neck. Admitted to a hospital that was filled with polio patients, she was treated for two weeks with steamed wool blankets for her severe back pain.

She was later moved to a rehabilitation hospital, where physical therapy to loosen her stiffened body was, as she describes it, "horrific" and "excruciating." There, she slowly regained muscle strength and was able to walk again. She thought she had escaped the worst, and for a long while that was true.

Then, in the late 1970s and beyond, polio survivors—my mother among them—began reporting new and sometimes disabling symptoms: overwhelming fatigue, muscle weakness and joint pain, sleep disorders, heightened sensitivity to anesthetics, cold intolerance, and difficulty swallowing and breathing.⁵ At first, other disorders were diagnosed. Then, at an international symposium in 1984, the late effects of poliomyelitis were defined and given a name: post-polio syndrome.

Interestingly, PPS is not a recurrence of the virus. In addition, it's not usually life-threatening, though patients who were left with severe respiratory difficulty after their first bout with polio may experience new severe respiratory impairment as part of PPS.¹

The causes of PPS are not thoroughly understood. Researchers believe that its symptoms result, at least in part, from the unusual stress placed on surviving nerve cells. During polio's initial attack, some motor neurons are damaged or destroyed. Without impulses from these nerve cells, muscles can't function. Fortunately, many other motor neurons usually survive the polio attack and establish new nerve connections to the orphaned muscle cells, in an attempt to take over the function of the destroyed nerve cells. This process of remodeling enables a person to regain at least some use of the affected muscles. But many years later, the overburdened nerve cells may begin to fail, resulting in new muscle weakness.³

PPS usually progresses slowly and is marked by long periods of stability. The severity of the condition depends on the degree of residual weakness and disability caused by the polio attack.¹ With rehabilitation, some PPS patients return to their previous level of functioning; others may need braces, crutches, canes, or wheelchairs.

There is no definitive diagnostic test for PPS. Diagnosis is based on symptomatology, a past history of poliomyelitis, and the exclusion of other disorders, such as osteoarthritis, fibromyalgia, depression, and a number of neurological conditions. Diagnosis, then, hinges on a nurse or doctor who's knowledgeable about PPS and can recognize it in a patient.⁶

Nurses need to know what to look for

As PPS patients age and seek care for other chronic illnesses, you'll need to know how to identify and address their special needs and symptomatology. A PPS patient may frequent the ED with aspiration pneumonia, for example, or be evaluated for frequent falls because of muscle weakness and atrophy.

The following nursing diagnoses will help you implement interventions in the care of PPS patients:⁷

Pain. The patient experiences burning, cramping, aching, or a "tired" feeling in the neck, back, legs, and arms and may develop spasms from the overuse of muscles.⁶ Having fought a debilitating disease, polio survivors are used to pushing themselves. For instance, a patient who can't lift her arm will use her shoulder instead; contracting the shoulder muscles on a regular basis can lead to pain and spasms.

Weakness and fatigue. About 75% of PPS patients report mental and physical fatigue and new muscle weakness.⁸ While the pathophysiology of the fatigue isn't clear, weakness is associated with atrophy of the muscles that were involved during the polio infection. This may contribute to fatigue when functions such as breathing, walking, and swallowing are compromised. Sometimes, muscles that appeared to be unaffected by the poliovirus may also develop this new progressive weakness. These muscles had subclinical involvement at the time of the acute poliomyelitis.⁹

Memory problems. Difficulty with word-finding is a common symptom of post-polio fatigue. The memory lapse is thought to be caused by a decreased level of dopamine that's been found in polio survivors' brains and affected by physical and emotional stress.¹⁰

Breathing problems. Difficulty breathing, hypoventilation, and hypercapnia are common. Early signs of respiratory dysfunction include headaches, fatigue, nightmares, restless sleep, difficulty sleeping while supine, poor concentration, anxiety, inability to speak loudly, breathlessness, and frequent respiratory infections.⁶

Sleep disturbances. Sleep apnea is common in PPS patients and may be caused by weakened musculature or brain dysfunction.^2,10 Patients may be kept up at night by such movement disorders as generalized random myoclonus—twitching and contraction of various muscles—or restless legs syndrome.¹⁰ The movement interrupts the REM cycle of sleep, causing poor sleep patterns and daytime fatigue. Many patients aren't aware of such movement until it's documented during a sleep study.

Impaired swallowing. Swallowing difficulty, or dysphagia, is common in polio survivors who had bulbar involvement—weakening of muscles innervated by cranial nerves—when first infected. Dysphagia puts patients at risk for aspiration. Early signs of swallowing difficulty are coughing, choking, and frequent clearing of the throat.

Cold intolerance. Polio survivors may find that their limbs become more sensitive to pain when it's cold. Many have reported that their feet have always been cold to the touch, with the problem worsening as they age.⁹

During infection, the poliovirus may have attacked the sympathetic motor nerves in the spinal cord, as well as other areas of the brain that regulate peripheral vasoconstriction.⁹ Because the capillaries do not contract, warm blood flows to the surface of the skin, resulting in excessive loss of heat and cooling of the limbs, sometimes causing severe shivering. The skin may become pale and cyanotic. Impaired vasoconstriction increases the risk of postural hypotension, especially if the patient takes vasodilators.

Urinary problems. These include retention, incomplete emptying of the bladder, incontinence, nocturia, and hesitancy. They may occur because the pelvic floor and bladder detrusor muscles have been paralyzed by the poliovirus.^2,9

Emotional stress. When polio survivors realize they're losing muscle strength and function, they understandably become fearful and even depressed. The resurfacing of symptoms can cause painful memories, and patients are likely to have difficulty accepting and adjusting to this unexpected recurrence.^2,9

Treating the symptoms may lessen the pain

There currently is no treatment specifically for PPS, but symptoms can be managed, sometimes quite successfully. Outcome studies at the Post-Polio Institute in Englewood, NJ, for example, make it clear that PPS symptoms need not progress.

A month after completing a six-week rehabilitation program at the institute, PPS patients' muscle weakness, pain, and fatigue can decrease by as much as 22%.⁵ This is accomplished through individualized treatment that includes physical and occupational therapy, stress management, and dietary counseling, using a "conserve to preserve" strategy: Essentially, if any activity causes fatigue, weakness, or pain, those with PPS shouldn't do it.⁵

While polio survivors may have engaged in an intense exercise regime to recover from the initial illness, doing so can be detrimental for PPS patients. My mother, for example, has benefited from knowing her limitations. She lives a healthy lifestyle and has learned not to overexert herself if she wants to avoid pain.

Pain management for PPS may include biofeedback, hot- or cold-pack application, relaxation, massage, and medication. Patients may need higher than normal doses of analgesics for longer periods of time to achieve adequate pain relief.²

Moderate exercise or physical therapy may help in the management of weakness and fatigue.⁸ Swimming is excellent exercise for PPS patients; the water counters the effects of gravity. Exercise programs should be designed and supervised by healthcare providers familiar with PPS and the risks that excessive exercise poses to them.¹¹ Patients can reduce muscle stress and mental fatigue by pacing their activities, allowing for adequate rest, and using braces, walkers, or mobility chairs.

Respiratory dysfunction can be managed with proper positioning, adequate fluid intake, and the monitoring of breath sounds and secretions. Interventions may include incentive spirometry to mobilize secretions and open up the lungs; bi-level positive airway pressure (BiPAP), delivered through a mask worn during sleep; and other forms of noninvasive, positive-pressure ventilation.²

Because hypercapnia may be present, use oxygen cautiously with PPS patients. Even as little as one to two liters per minute may cause a sudden rise in carbon dioxide levels; the oxygen blunts the respiratory drive, which may result in apnea.⁹ To reduce carbon dioxide retention, monitor for apnea and implement other measures to decrease hypoventilation, such as pain relief, adequate rest periods, and noninvasive, positive-pressure ventilation at night.²

A speech therapist can best address swallowing difficulties. She will likely encourage the patient to consume pureed foods and thickened liquids—like liquid yogurt—when possible, swallow twice for every mouthful, and rest before eating.

If vasoconstriction has been impaired and shivering is a problem, you can raise the patient's temperature with heated blankets. Be sure to monitor for hypotension, which may occur as the patient gets warmer.

A patient with urinary problems may benefit from one or more of the following: incontinence studies, medication, exercises to strengthen pelvic floor muscles, bladder retraining, or intermittent catheterization.²

To relieve stress and depression, support groups, therapy, and education are all helpful. You can listen to PPS patients and be an advocate for their needs. Adequate discharge planning, with the proper referrals, is a necessity.

Awareness is key to patient safety

PPS presents some challenges for patients already taking certain medications. For example, antihistamines, benzodiazepines, opiates, narcotics, and amitriptyline (Elavil, Endep) and some other antidepressants may have a greater sedating effect on a PPS patient; even a normal dose can cause sedation.^9,10

In addition, antibiotics, chemotherapy, and megadoses of vitamin B₆ can cause nerve damage to already weakened nerve cells. Other medications, including quinine, quinidine, procainamide (Procan, Pronestyl), beta-blockers, calcium channel blockers, steroids (when used long-term), and the antihyperlipidemic drugs known as the statins may increase weakness and fatigue.^9,10 Advise your PPS patient to inform the prescribing healthcare provider of her condition and report any new onset of weakness and fatigue.

Anesthesia and surgery pose another challenge. Polio survivors are easily anesthetized and take longer to wake up from anesthesia. This may happen because the poliovirus has damaged the reticular activating system of the brain, which is responsible for keeping the brain awake.⁵

Gaseous and IV anesthesia may cause trouble with breathing and swallowing; even local anesthetics can cause problems. A polio survivor should, therefore, have lung function tests before receiving a general anesthetic.

Before surgery, polio patients must inform the surgeon and anesthesiologist of any preexisting breathing, coughing, or swallowing problems.⁵ PPS patients are at greater risk for postop vomiting and aspiration, so positioning and suctioning are crucial.¹² Administering anti-nausea medications may also help.

Overall, communication among members of the healthcare team and the patient is imperative. Polio survivors are driven and accomplished people; they have overcome great pain and suffering to live normal lives. By educating ourselves and learning how to recognize and manage PPS, we can form a partnership with our patients to prevent further disability and help prolong their lives.

REFERENCES

Diagnosing PPS

For PPS to be diagnosed, a patient must have:

Although these criteria are the accepted medical standard, PPS has recently been diagnosed in patients with a history of non-paralytic polio. And there are peo le who may be susceptible to PPS even if they experienced only a very mild case of polio that was undiagnosed at the time.

Source: March of Dimes. "Post-polio syndrome: Identifying best practices in diagnosis & care." 2001. www.marchofdimes.com/files/PPSreport.pdf (18 Aug. 2005).

The future for polio survivors

The National Institute of Neurological Disorders and Stroke (NINDS) is sponsoring a clinical trial to determine whether modafinil (Provigil) can reduce fatigue in patients who have post-polio syndrome (PPS). Physicians treating PPS patients have begun prescribing modafinil, approved for narcolepsy and other conditions, to those with profound fatigue.

Another NINDS study, started in 2004, will assess the integrity of central motor pathways in polio survivors with and without PPS and investigate differences in the intracortical mechanisms for controlling muscles affected by poliomyelitis and those unaffected by it. In addition, Post-Polio Health International has awarded a grant to researchers from Johns Hopkins University. They hope to determine whether early use of noninvasive, positive-pressure ventilation prolongs survival in patients with amyotrophic lateral sclerosis and whether their findings relate to other neuromuscular conditions, including polio and its late effects.

Sources: 1. U.S. National Institutes of Health. "Modafinil to treat fatigue in post-polio syndrome." 2005. http://clinicaltrials.gov/ct/show/NCT00067496?order=1 (18 Aug. 2005). 2. U.S. National Institutes of Health. "Brain physiology in polio survivors," 2005. http://clinicaltrials.gov/ct/show/NCT00080600?order=4 (18 Aug. 2005). 3. Post-Polio Health International. "PHI grant awarded to Johns Hopkins team to study early use of noninvasive ventilation." 2004. www.post-polio.org/ivun/val_18-4a.html#phi (18 Aug. 2005).

WEB EXCLUSIVE

The long reach of the poliovirus

The poliovirus enters the body through the mouth and replicates in the pharynx and other areas of the GI tract. The virus invades local lymphoid tissue, enters the blood stream, and then may infect cells of the central nervous system. Replication of the poliovirus in motor neurons of the anterior horn and brain stem results in cell destruction and causes the typical manifestations of poliomyelitis.

The incubation period for poliomyelitis is six to 20 days. Infected patients without symptoms shed the virus in the stool and usually transmit it to others via the fecal-oral route, although the oral-oral route may account for some cases. The most infectious period is from seven to 10 days before and after the onset of symptoms, but the virus may be present in the stool for three to six weeks.

According to the Centers for Disease Control and Prevention, up to 95% of all polio infections are asymptomatic. Approximately 4% – 8% of polio infections consist of a minor, nonspecific illness, such as a respiratory infection, without clinical or laboratory evidence of central nervous system invasion. Less than 1% of all polio infections result in flaccid paralysis. In most people with poliomyelitis, muscle function returns to some degree. In fact, many people recover completely. Weakness or paralysis that's still present 12 months after onset is usually permanent.

Sources: 1. Centers for Disease Control and Prevention. "Poliomyelitis." www.cdc.gov/nip/publications/pink/polio.pdf (7 Oct. 2005). 2. Silver, J.K. (2001). Post-polio: A guide for polio survivors and their families. New Haven: Yale University Press. 3. March of Dimes. "Post-polio syndrome: Identifying best practices in diagnosis & care," (2001) www.marchofdimes.com/files/PPSreport.pdf (18 Aug. 2005).

To take the test, return to the top of the page and click the "Take the Test Now" button.