Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. Motor neurons are affected in certain patterns, such as cervical, thoracic, lumbar, and bulbar (facial) regions. Although initial presentations can vary, eventually upper and lower motor neurons are lost in the two types of ALS: familial and sporadic.
About 6000 people in the U.S. are diagnosed with ALS yearly. A French physician, Jean Charcot, identified ALS in 1869; initially, the disease was called “Charcot Disease.” However, in 1939, when the famous New York Yankees baseball player Lou Gehrig was diagnosed with ALS, it became known as “Lou Gehrig’s Disease”. (Gehrig died from ALS in 1941 at age 37.) It is estimated 300,000 Americans live with ALS in 2018. The median age of onset is 55, and disease indicence peaks between ages 70-75. More males are affected than females. Approximately 90% of ALS cases are determined to be sporadic, or accquired, while the remainder are considered familial, or hereditary.
The etiology of ALS is unknown; however, research evidence suggests that generics and environment play a role in development of the disease, and there is new evidence that cigarette smoking may also be a risk factor. ALS affects Caucasian and non-Hispanic populations and males at a higher rate. The U.S. Department of Veterans Affairs considers ALS a service-connected disease because military veterans are at higher risk to develop it. Veterans who served in the Gulf War are twice as likely to develop ALS than veterans of the same period who did not serve in the Gulf War. Exposure to environmental toxins, such as lead and pesticides, appears to be a risk factor.
The name, amyotrophic lateral sclerosis, describes the characteristics of this disorder. Amyotrophic refers to muscle atrophy, weakness, and fasciculations (twitching of muscle fibers) that occur as a result of changes in the lower motor neurons. Lateral sclerosis refers to the stiffness that develops in the lateral columns of the spinal cord, which is observed on autopsy. The result is a progressive disorder that involves degeneration of the upper and lower motor system for which the underlying cause is unknown.
The motor cortex of the brain processes incoming signals and creates the electrical impulses for voluntary muscle movements. Upper motor neurons (UMNs) are the myelinated nerve fibers that descent from the motor cortex to the brainstem and spinal cord. The lower motor neurons (LMNs) are the nerves exiting from the spinal cord that connect to skeletal muscles. Myelin is a fatty substance produced in both the central and peripheral nervous systems. It forms a sheath that wraps around axons, provides vital supporting functions, and increases the rate of nerve conduction to target muscle and organs. The myelin sheath acts as an insulator that protects and facilitated the integrity, speed, and intensity of nerve impulses to the target muscle or muscle group.
ALS is motor neuron degenerative disease, involving the deterioration and death of lower and upper motor neurons, affecting the brain, brainstem, and spinal cord. Lower motor neurons that innervate voluntary muscles in the head, neck, and limbs, as well as upper motor neurons that descend through the pyramidal tract to synapse with the lower motor neurons, are affected. Initially there may be specific functional loss of only upper or lower motor neurons, but eventually both are impacted. If ALS occurs concurrently with frontotemporal dementia, there is additional frontotemporal cortical neuron degeneration and cortical atrophy. When motor neuron dies, denervation and atrophy of the innervated muscle fibers occur. As denervation progresses, the clinical exam and muscle biopsy reflect muscle atrophy changes. This is referred to as amyotrophy. When cortical motor neurons die, there is thinning in the corticospinal tracts that travel to the lateral and anterior white matter columns of the spinal cord. When this occurs, fibers and firmness are lost; this is fibrillary gliosis. This is the basis for the remainder of the disease name, termed lateral sclerosis.
The signs and symptoms of ALS depend on the corresponding somatosensory motor cortex are and affected UMN nerve fibers. Approximately 70% of patients present with upper or lower limb-onset ALS, 25% have bulbar-onset ALS, and the remining 5% have truncal muscle-onset ALS that may involve the respiratory muscles. UMN signs and symptoms can be designated as negative and positive. Negative signs and symptoms include weakness, loss of dexterity, fatigue, and impairment or loss of motor planning and control. Positive signs and symptoms include increased and spastic muscle activity and exaggerated spinal reflexes. Other examples include hyperreflexia, spasticity, spasms, and clonus or involuntary rhythmic muscular contractions and relaxations. LMN signs and symptoms typically present with muscle weakness, muscle atrophy, paralysis, fasciculation, hypotonia, and hyporeflexia. As ALS progresses, it eventually causes severe dysphagia and dyspnea, rendering patients unable to speak above a whisper, swallow, or breathe. Death is usually due to respiratory failure and typically occurs 3-5 years following disease onset.
There is no specific diagnostic test for ALS, thus diagnosis may take 9 to 12 months, and often is made by eliminating diagnoses. Estimates are that 50% to 70% of motor neurons are no longer functional when patients seek a diagnosis for symptoms. Overall diagnosis of ALS is based on clinical findings, but it is important to check diagnostic and laboratory tests for confirmation and differential diagnosis.
The clinical changes associated with ALS are often subtle. The most common initial clinical change is muscle weakness of an arm, leg, neck, or the diaphragm. Other symptoms include muscle cramps; fasciculations – muscle twitching, commonly in the arm, leg, shoulder, or tongue; spasticity – muscle contractions causing stiffness and tightness; clonus – alternating contraction and relaxation of the muscle; slurred and nasal speech; and difficulty chewing or swallowing. A positive Hoffmann’s sign – flicking the nail bed of the third or fourth finger causing the thumb and index finger to flex; clonus -rapidly flexing the foot upward or rapidly pushing the patella toward the toes causing muscle contraction and relaxation sustained for five beats or more; and a positive Babinski reflex – stroking the bottom of the foot causing the great toe to point upward rather than curling down are clinical indicators of nervous system damage.
Genetic testing may be done for familial ALS. Laboratory tests include urine and serum protein electrophoresis, 24- hour urine heavy metal panel, complete blood cell count and differential, vitamin B12 and folate levels, C-reactive protein and erythrocyte sedimentation rate, and thyroid and parathyroid function. Brain computerized tomography and magnetic resonance imaging are used to rule out other disorders, for example, brain tumor or multiple sclerosis. Electrodiagnostic studies for muscle wasting, sensory deficits, muscle weakness, and denervation include electromyography. Nerve conduction velocity studies and sensory studies may still be normal in ALS initially, but with severe muscle atrophy and denervation, conduction studies will be abnormal. Additional tests may include lumbar puncture, muscle and /or nerve biopsies, and myelogram of the cervical spine.
There is no cure for ALs; nor is there a proven therapy that will prevent or reverse the course of the disorder.
There are two FDA-approved medications to treat ALS. A benzothiazole-class drug has been available for many years.
- Riluzole (Rilutek) is believed to decrease the neurotransmitter, glutamate, that sends messages between neurons. Riluzole cannot reverse nerve damage, but it can prolong survival time by several months and can lengthen the time a patient can go without mechanical ventilation. The most common adverse effects to Riluzole are nausea, vomiting, diarrhea, abdominal pain, anorexia, dizziness, and asthenia. Liver function tests must be done periodically because there is a risk of liver damage in 10% of patients.
- Edaravone (Radicava), approved by the FDA in 2017, is the newest of the two primary drugs for ALS. It cannot restore lost function but slows the rate of loss of functioning. It is an antioxidant and free radical scavenger that was initially developed as an I.I. treatment for acute ischemic stroke. Edaravone is given by peripherally inserted central catheter infusion over 60 minutes daily for 14 days followed by 14 days with no infusion, then in cycles of 10 days on and 14 days off. Because it contains sodium bisulfite, there is increased risk of anaphylaxis and allergic reactions, especially in asthmatic patients. The mechanism of action is uncertain. Adverse effects include confusion, headache, and gait disturbances.
Another newer medications, Nuedexta, a combination of dextromethorphan and quinidine, can be utilized to treat pseudobulbar effect, along with other bulbar symptoms, such as difficulty speech, facial muscle control, chewing, and swallowing. An older antipsychotic drug used in schizophrenia and Tourette’s syndrome, Pimozide (Orap), has been shown in early research to help preserve neuromuscular function in ALS. Pimozide works by decreasing dopamine in the brain but causes side effects such as drowsiness, dizziness, dry mouth, blurred vision, tiredness, weakness, extrapyramidal symptoms, and tardive dyskinesia. Phase II clinical trials are underway to document safety and efficacy in ALS treatment. Ancillary medications are used in ALS for symptom management, including pain, depression, constipation, sleep disturbance, excess saliva and sputum, muscle cramps and stiffness, and pseudobulbar affect. These medicines include baclofen and diazepam for muscle spasm and glycopyrrolate to manage drooling saliva.
A multidisciplinary approach to care is important in ALS. Speech therapy and adaptive therapies can help preserve language; patients can respond to yes-no questions with eye movement or other nonverbal methods. Voice banking is a technique that stores the ALS patient’s voice for use in computer based speech synthesizers, when speech is no longer possible. Physical therapy includes exercise that features low-impact and gentle techniques in walking, swimming, and stationary bicycling, which can help keep unaffected muscles strong. Stretching and range of motion exercises help prevent muscle contractures and painful muscles spasticity. Exercise also helps ameliorate fatigue and depression. Occupational therapy can assist with use of braces, walkers, wheelchairs, and ramps. Other healthcare professionals essential to optimal care include social workers, respiratory therapists, psychologists, nutritionists, acute care, home care, and hospice nurses.
Promising treatment for ALS are arising from cellular research focusing on understanding why motor neurons deteriorate and exploration of gene mutations. Autologous stem cell treatment is being investigated, along with research into biomarkers that can help identify the presence, rate of progression, or effectiveness of therapeutic interventions for ALS. Treatment using drug-like compounds, gene therapy, antibodies, and cell-based therapies are being explored. For example, researchers are exploring whether lowering levels of certain brain and spinal cord enzyme in individuals with a specific gene mutation could slow the rate of ALS disease progression.
Nursing management for ALS entails a high degree of compassion and presence, not only for the patient but for the family and caregiving community. Caregivers, including nurses, can pray for the ability to offer hope as ALS progresses. Persons with ALS remain cognitively intact throughout the course of their illness. Caregivers must be especially sensitive to the patient’s spiritual suffering, which may be particularly prominent for patients who remain fully aware of their worsening physical status. A spiritual assessment completed by the nurse, patients, family, social worker, and spiritual advisor, such as a chaplain, pastor, or priest, is invaluable. Not only are these patients’ facing death within an abbreviate time frame, but they watch their physical bodies becoming altered and incapacitated for years before dying (The Locked-in Syndrome- fully conscious but unable to respond in any way). Nurses can offer appropriate spiritual interventions, based on the spiritual assessment. Learn what is most meaningful to the patient. Prayer, readings from the Bible or other sources, music, inspirational recordings, and listening can be helpful interventions. Pastoral care can be offered and initiated by the nurse, whether the patient remains in the home, a long-term care facility, or an acute care facility. Importantly, nurses can be significant active listeners and engage in conversation as the patient and/ or family and caregivers need.
The importance of preserving the dignity of the patient is of the highest priority. The nurse is a primary advocate for the rights and choices of the patient and family. Continually assess the patient’s and family’s support system and coping patterns throughout the ongoing loss of independence. Provide an accepting environment to have honest discussions about their fears and needs. This offers opportunities to relay problems to members of the provider team so that issues can be addressed proactively. Encourage realistic expectations, whenever possible. Refer to appropriate team members, such as counselors and ALS support groups. Financial concerns are a huge problem for ALS patients, as they lose the ability to work. As they deteriorate, accommodations must be made in the home, such as installing an entry ramp and widening doors for wheelchairs. Patients will eventually need a power wheelchair and other assistive devices. For travel, a large van with a life ramp will be needed. Mounting costs add stress to an already painful situation.
Nurses can facilitate better patient care through excellent communication about patients, as they work interprofessionally with the care team, including providers who write medical orders and those who offer support services. Nursing care related to activities of daily living is essential in ALS. Nurses can train and support caregivers in multiple aspects of care. Working with occupational therapists (OTs) and physical therapists (PTs), nurses can assist patient communication, using devices, such as the eye-tracking computer, magic slate drawing boards, and word boards.
Nutrition deficits related to swallowing difficulties may be addressed with OTs, as well as dietitians. It is recommended that ALS patients maintain a high-protein, high-carbohydrate diet, and fluid intake of 3,000 ml daily. By careful patient monitoring, nurses can recognize when the diet needs to change to soft or pureed foods, and eventually to G-tube feedings. The care of oral secretions is a common intervention.
Regarding the integumentary system, nurses should promote repositioning immobile patients every 2 hours to prevent skin breakdown. Maintaining intact skin is critical and is accomplished through careful cleansing of the skin, particularly after elimination, and maintaining skin moisture and hydration. A suitable mattress pad or air mattress that decreases skin breakdown risk can be recommended by the nurse.
Because of muscle atrophy, spasticity, and weakness, nurses can help manage muscular issues by promoting active and passive range-of-motion exercises up to four times daily. For optimal respiratory care, keep the head of the bed elevated at 30 degrees or higher to improve respiratory exchange and digestion. Physical examination of the chest for abnormalities is vital. Encourage deep breathing and coughing every 2 hours while awake. Use of oxygen may be essential, as well as suctioning the airway. The nursing role may include teaching family members how to manage suctioning and encouraging incentive spirometry. Ventilator care may become a significant part of nursing care. To avoid pulmonary embolism, initiate the use of compression stockings for deep vein thrombosis prophylaxis. Monitor the patient’s urinary system, looking for signs of urinary retention and infections. Bowel regimens may also fall under the care of the nurse, to both prevent impaction from constipation and to manage diarrhea from liquid supplements. Many times, nurses may find themselves needing to teach a considerable number of skills to the patient’s family and caregivers. The ALS Association offers excellent, in-depth information on nursing care of ALS patients.
Jeffery, D. & Fish, A. F. (2018) A Journey with Amyotrophic Lateral Sclerosis
Vacca, V. M. (2020) Amyotrophi Lateral Sclerosis: Nursing Care and Considerations