Amyotrophic Lateral Sclerosis (ALS) in Physical Medicine and Rehabilitation 

Amyotrophic lateral sclerosis (ALS) is the most common type of adult-onset motor neuron disease. Adult-onset motor neuron diseases are a group of neurologic disorders that present in adult life and are characterized primarily by progressive degeneration and loss of motor neurons. ALS involves upper and lower motor neurons and presents as an idiopathic, progressive degeneration of anterior horn cells and their associated neurons, resulting in progressive muscle weakness, atrophy, and fasciculations.^{[1, 2]}

The disease was first described in 1869 and is commonly called Lou Gehrig disease, after the professional baseball player who died of ALS in 1941.

Other diseases classified as adult-onset motor neuron diseases have more restricted presentations and can evolve into idiopathic ALS if the patient is tracked for a long period. These diseases include the following:

• Progressive bulbar palsy - Pure bulbar involvement
• Progressive muscular atrophy - Pure lower motor neuron degeneration
• Primary lateral sclerosis - Pure upper motor neuron degeneration
• Adult-onset spinal muscular atrophy - Includes a broad range of primary motor neuron diseases classified by pattern of inheritance, distribution of weakness, or age of onset

Respiratory complications

All deaths directly caused by ALS result from respiratory complications. This occurs primarily from the patient's inability to ventilate as respiratory muscle weakness progresses. In patients with bulbar weakness, aspiration of secretions or food may occur and precipitate pneumonia, resulting in further respiratory compromise; therefore, aggressive respiratory management is necessary in the comprehensive care of patients with ALS.

Routinely measure vital capacity in the sitting and recumbent positions. Most often, the recumbent measurement declines prior to the sitting measurement. Gravity assists in lowering the diaphragm as the patient's angle of inclination is increased. As respiratory weakness progresses, patients have increasing difficulty with diaphragmatic movement when supine because of the elimination of this effect from gravity. This results in alveolar hypoventilation and ultimate oxyhemoglobin desaturation.

Difficulty sleeping may be the first symptom of hypoventilation. Patients should be questioned routinely regarding sleep habits, and if a sleep disturbance develops, measure vital capacities sitting and supine. In addition, perform overnight oxygen saturation monitoring to assess for nocturnal hypoxemia and the need for nocturnal noninvasive intermittent positive pressure ventilation (IPPV).

Special concerns

An attorney should be consulted regarding a "living will" and power of attorney should be established prior to the terminal phase of this ultimately fatal disease.

Also see the following:

• Emergent Treatment of Amyotrophic Lateral Sclerosis (ALS)
• Amyotrophic Lateral Sclerosis
• Primary Lateral Sclerosis

Physical therapists should instruct proper stretching and daily range-of-motion (ROM) exercises to the patient with amyotrophic lateral sclerosis (ALS) and his/her caregivers. Therapists should try to anticipate the patient's future needs and introduce assistive devices in a timely manner. Lightweight ankle-foot orthoses can be provided to minimize foot drop and stabilize weak quadriceps muscles to prevent falls.

The physical therapist should also emphasize energy conservation and teach patients and caregivers methods for performing safe, efficient transfers. Therapists also can provide instruction for strengthening exercise programs, but exercises should be performed at submaximal levels in muscles without marked weakness and should be prescribed only for patients with slowly progressive disease.

In one study, individualized, moderate-intensity, endurance-type exercises for the trunk and limbs performed 15 minutes twice daily was shown to significantly reduce spasticity as measured by the Ashworth scale.

When making wheelchair recommendations, the therapist should try to anticipate the patient's future needs. Wheelchairs should be introduced while the patient is still ambulatory in order to enhance energy conservation. Initially, a lightweight wheelchair should be rented, with plans to purchase a heavier, more expensive chair when the patient is no longer able to ambulate. Recommend modifications to the patient's wheelchair in a timely manner and in accordance with the patient's tolerance for gadgets.

Occupational therapists should focus on teaching energy conservation techniques to the patient with amyotrophic lateral sclerosis (ALS) and his/her caregivers. Adaptive equipment should be introduced early and in synchronization with the patient's progressing needs.

Upper extremity bracing can be used in cases where weakness may alter joint biomechanics. Patients with poor grasp can be provided with a universal cuff, and patients with hand weakness can be braced in 20-25° of extension to improve grip strength. For patients with proximal upper extremity weakness, a balanced forearm orthosis (ie, deltoid aid) may be beneficial to enhance upper extremity movement by eliminating the effects of gravity. When shoulder girdle weakness progresses to advanced stages, slings can be used to decrease pain by limiting traction on the associated ligaments, nerves, and vessels.

For patients with severe limb involvement, introduce environmental control units (ECUs) that utilize oral-motor movements. In patients with severe bulbar involvement, extraocular movements are usually preserved so ECUs incorporating eye gaze technology can be used.

Speech therapists can teach patients with amyotrophic lateral sclerosis (ALS) with bulbar involvement to slow their speech and exaggerate articulation to improve comprehension for caregivers. For patients with respiratory insufficiency, the therapist can teach phrasing to promote energy conservation. Submaximal tongue strengthening exercises and diaphragmatic exercises also should be taught, to help improve articulation and voice projection.

As the patient's voice becomes more strained, the caregiver can be fitted with a hearing aid to promote communication with the patient. This also provides the patient with an "interpreter" who can assist in communicating with others. If the patient and caregiver already have their own form of communication (ie, gestures) that works well for them, encourage them to continue using their existing system as long as it is effective.

Monitor patients, and, as their speech declines, introduce augmentative communication devices, such as writing implements, communication boards, or computer-assistive technology. For patients with severe bulbar and limb involvement, eye gaze and blink generally are preserved. Therefore, the speech therapist can take advantage of these preserved functions by introducing blink-controlled voice synthesizers, communication boards, and computer assistive devices that utilize eye gaze techniques.

In patients with bulbar involvement, the speech therapist can perform an oropharyngeal assessment to evaluate for clinical signs of dysphagia. In many cases, a videofluoroscopic swallowing evaluation is necessary to identify specific problems during the various phases of swallowing. Speech therapists can provide interventions, such as alterations in the consistency, taste, or temperatures of foods, to improve oral intake and prevent aspiration. Straws may be used to encourage the recommended chin-tuck position for swallowing thin liquids. Enforce upright positioning at all meals, and, in patients with neck extensor weakness, recommend a soft cervical collar to improve positioning during meals.

Patients with ALS who predominantly have limb and respiratory weakness, accompanied by limited bulbar involvement, may prevent respiratory complications and placement of permanent tracheostomy through aggressive pulmonary care. Respiratory therapists can play a critical role in the management of these patients.^[3]

Recommend that patients perform routine measures of assisted peak cough flows to evaluate bulbar muscle function. Continued attainment of adequate peak cough flow is the most important goal for preventing serious pulmonary complications.

Routinely measure vital capacity in sitting and recumbent positions. Usually, recumbent vital capacity is the first to decline, resulting in nocturnal hypoventilation.

Oxyhemoglobin saturations (SaO₂) should be monitored, especially at night in patients complaining of nocturnal awakenings or sleep difficulties. Decreased overnight SaO₂ indicates nocturnal hypoventilation and the need for noninvasive IPPV at night. Despite low SaO₂, do not administer oxygen without invasive ventilation. In patients without invasive ventilation, oxygen administration decreases the respiratory drive and may thereby result in exacerbation of hypercapnia.

Respiratory therapists also are involved in educating patient and caregiver. They can instruct caregivers on proper performance of assisted cough techniques and teach submaximal respiratory strengthening exercises to the patient. Respiratory therapists also can provide instruction for proper use of expiratory muscle aids, such as the intermittent abdominal pressure ventilator and mechanical insufflator-exsufflator. In addition, they can teach patients and caregivers to use and manipulate inspiratory muscle aids, including noninvasive and invasive ventilation.

Finally, respiratory therapists can teach patients glossopharyngeal breathing. This involves gulping boluses of air into the lungs to add to the user's deep breath and can be useful in patients with nonbulbar ALS who do not have a tracheostomy. One glossopharyngeal breath contains 6-9 gulps and can provide the patient with weak inspiratory muscles and no vital capacity a safe way to breathe if, for any reason, a ventilator cannot be used or there is sudden ventilator failure.

Noninvasive intermittent positive pressure ventilation

Noninvasive IPPV is a form of mechanical ventilation that does not require placement of a tracheal tube. It can be delivered by mouth, oral-nasally, or nasally. The amount of bulbar involvement and the personal preference of the patient determine the type of interface used.

Mouthpiece IPPV most commonly is used in patients with nonbulbar ALS and is effective for 24-hour use. Lip-seal retention can be added to increase efficacy while the patient is sleeping. Nasal interfaces can be used in patients with bulbar involvement or for nocturnal ventilation. Some prefer nasal interfaces for daytime use as well, because they leave the mouth free for other activities. Custom-molded nasal interfaces or oral-nasal shells also can be made to increase efficacy and/or comfort. Increased risk of death is associated with intolerance to noninvasive IPPV, and increased survival has been documented in patients who can tolerate this form of ventilation.

Intermittent abdominal pressure ventilation

Another type of respiratory muscle aid is the intermittent abdominal pressure ventilator. This device assists expiratory muscles and provides daytime ventilatory support. The intermittent abdominal pressure ventilator uses an elastic air sac, which intermittently inflates to aid in expiration. The air sac is contained in a corset, which can be concealed under clothing. This device should not be used in patients with significant scoliosis or obesity. Some patients prefer its use to that of the mouthpiece intermittent positive pressure ventilator, as it leaves the mouth free for mouthstick and other activities.

Oxygen administration

Oxygen administration depresses the respiratory drive as in chronic obstructive pulmonary disease (COPD). The underlying reason for the patient's hypoxemia is not lack of perfusion but rather lack of adequate ventilation. Oxygen administration can lead to worsening hypercapnia; therefore, hypoxia in these patients initially should be treated by increasing ventilation, either noninvasively or invasively.

Reserve oxygen administration for patients whose hypoxemia is not reversed with ventilatory support. In such patients, usually an underlying process, such as pneumonia, has resulted in decreased pulmonary perfusion. This situation necessitates oxygen administration, but oxygen should be given only once the airway has been secured and the patient is invasively ventilated. Invasive ventilation in this instance should be temporary until the secondary process has been treated. Following adequate treatment, the patient should be able to return to his or her previous respiratory management.

Peak cough flows

As mentioned earlier, assisted peak cough flows should be performed regularly and used to monitor bulbar functioning. Once peak cough flows drop below 160 L/min, flows likely are inadequate to clear debris, thereby resulting in mucous plugging. Risk of mucous plugging is significantly increased during periods of intercurrent respiratory infection and can result in acute respiratory distress necessitating placement of an endotracheal tube. Patients with peak cough flows below this level may require permanent tracheostomy tube placement to allow suctioning and invasive ventilation when needed.

Suctioning alternative

An alternative (or adjunct) to suctioning can be provided with a mechanical insufflator-exsufflator. This respiratory aid assists in clearing debris by providing deep insufflation, immediately followed by a forced exsufflation to create artificially about 10 L/sec of expiratory flow (a normal cough expels air at approximately 16 L/sec). This can be administered directly via a tracheostomy tube with the cuff inflated or via an oral nasal mask.

The mechanical insufflator-exsufflator can be used acutely to relieve mucous plugs, but it also may be used routinely to provide assisted coughs and maintain clear airways. When used in combination with other respiratory muscle aids, it can avert tracheostomy tube placement, maintain quality of life, and prolong survival.

Weight loss is another common symptom in amyotrophic lateral sclerosis (ALS) and usually relates to the progression of dysphagia, which results in the patient's inability to maintain adequate caloric intake with oral feedings alone. Weight loss also may develop in patients with and without bulbar involvement because of generalized fatigue, poor appetite, and associated depression. Malnutrition is a poor prognosticating factor and correlates with increased risk of death; therefore, once a patient has lost 5-10% of normal body weight, consider enteric feeding and discuss options with the patient and caregivers.

Consult a gastroenterologist early so that placement of feeding tube is not delayed while weight loss progresses. Placement is preferred while the patient still is able to eat by mouth. In this situation, enteric feeding can be presented as a positive option, because it allows the patient to eat for enjoyment, rather than simply for nutritional necessity. This prevents the fatigue and frustration associated with mealtimes experienced by some of these patients.

Initially, nasogastric or orogastric feeding may be an option, but these methods can lead to traumatic irritation of the mucosa with prolonged use. For long-term feeding, options include standard gastrostomy, percutaneous endoscopic gastrostomy (PEG), and jejunostomy. Preferred intervention is usually PEG tube placement, because other types of long-term feeding tubes require placement under general anesthesia, while a PEG tube can be placed under local anesthesia.^[4]

Increased risk of regurgitation is associated with gastrostomy/PEG tubes; therefore, some may prefer placement of a jejunostomy tube, which decreases the risk of aspiration.

Spasticity occurs from loss of inhibition from upper motor neurons. Baclofen acts as a gamma amino butyric acid (GABA) agonist and is the drug of choice for the treatment of spasticity in patients with amyotrophic lateral sclerosis (ALS). Alpha-adrenergic agonists, such as tizanidine and clonidine, also may be effective, but hypotension is a potential side effect that may limit their use.

Dantrolene interferes with excitation-contraction coupling and usually is used as an adjunct agent. Dantrolene does have potential for hepatotoxicity; therefore, monitor liver function tests closely in patients treated with this medication. Benzodiazepines facilitate GABA in the central nervous system (CNS) and are effective in the treatment of spasticity.

Use these medications with extreme caution in patients with ALS because of their adverse effect of respiratory depression. Patients may already be compromised from a respiratory standpoint, and this class of medications may worsen residual respiratory function.

Carefully monitor the use of antispasticity agents, because they can cause sedation, dizziness, increased weakness, or other adverse effects that may be potentially harmful to the patient.

Pain can occur for many reasons, but in these patients, it is usually musculoskeletal in origin. Pain may be caused by muscle spasms, contractures, or altered joint biomechanics. First-line treatment for pain is with nonsteroidal anti-inflammatory drugs (NSAIDs). If the patient is intolerant to these medications, use acetaminophen. Muscle cramps occur frequently. Traditional treatment was with quinine, but this drug is no longer recommended because of its side-effect profile.

NSAIDs may provide some benefit, but antispasticity medications discussed above are currently recommended for treatment of muscle cramps and usually are effective. In some instances, pain may be neuropathic in origin, and anticonvulsant medications may be beneficial. Tricyclic antidepressants also are indicated for this type of pain and may be tried. For severe pain, unresponsive to the above treatments, narcotics are indicated. Use them with caution, however, as they too can cause respiratory depression, especially at higher doses.

Fasciculations can be troublesome, or even embarrassing, for some patients. Avoiding caffeine and nicotine can reduce them, but in those patients with severe symptoms, benzodiazepines can be effective. Use these medications with caution because of their side-effect profile.

Sialorrhea (drooling) is a problem for almost all patients with bulbar involvement. Treatment includes the use of direct cholinergic inhibitors or medications such as tricyclic antidepressants that have anticholinergic side effects. CNS stimulants, such as methylphenidate, also have been used and are effective in some patients. Upright positioning is essential, and, for those with labial incompetence, intermittent mechanical suctioning can be beneficial.

Psychologic symptoms are common and are indirectly related to the disease and its progression. Patients with amyotrophic lateral sclerosis (ALS) generally have preserved cognitive functioning with a progressive loss of control over their disease process and daily functioning. This can be very distressing to the patient and his/her caregivers, and symptoms of fear, anxiety, and depression may manifest. If left untreated, these symptoms may result in a decline in the patient's functioning out of proportion to disease severity.^{[1, 5]}

Early recognition of psychologic disorders is important. This allows appropriate interventions to be made to provide support to the patient and caregivers. Interventions can be provided through individual and family psychotherapy, as well as through psychoactive medications. Selective serotonin re-uptake inhibitors (SSRIs) most commonly are used for the treatment of depression. Tricyclic antidepressants usually are used as second-line treatments. In some patients with anxiety, SSRIs also may be beneficial, but in patients with severe anxiety that limits function, benzodiazepines are indicated.

Assistance of a psychologist is recommended early on to help identify and treat clinical symptoms. Psychotherapy and counseling can be used alone or in combination with medications, but treatment with medications alone is not recommended. Symptoms such as anxiety and fear can be treated through role-playing and relaxation techniques. Other potential problems, such as caregiver burnout and patient loss of control, also may be identified and treated through the assistance of a psychologist. In addition, psychologists can aid the patient in developing advance directives, addressing financial concerns, and assisting in planning for total care.

Incidence of suicide is surprisingly rare in patients with ALS. This may be attributed to the fact that in the early stages of the disease, the patient either denies or does not fully comprehend the impact of the disease. Once the patient realizes fully the devastation caused by his or her illness, the individual may be too weak to perform the act of suicide.

One study looked at attitudes of patients with amyotrophic lateral sclerosis and their primary caregivers toward physician-assisted suicide. Among the patients studied, mean duration of illness was 4 years from onset of symptoms. Researchers found that 56% percent of ALS patients studied were willing to consider assisted suicide. Of these patients, 79% felt that, if physician-assisted suicide were legal, they would request a lethal prescription from a physician. Most said they probably would keep the prescription available for potential use in the future, although only 1 patient expressed readiness to request the prescription with the intent of taking it to cause death in the next month. Of the caregivers studied, 73% had attitudes toward assisted suicide similar to those of the patients, and 76% were able to predict accurately the patient's willingness to consider taking a lethal dose of medication.

Surprisingly, incidence of depression was not associated with the patient's willingness or unwillingness to consider assisted suicide. Patients who were willing to consider assisted suicide tended to be male, had more years of education, had higher scores of hopelessness, and rated their quality of life (QOL) as lower than did those who opposed assisted suicide. Patients and caregivers who would consider assisted suicide were less likely to be religious on all measures.

This has strong implications for physicians, multidisciplinary team members, and caregivers who work closely with these patients. In the above study, as stated, most caregivers were able to predict whether patients would consider assisted suicide if it were offered to them. Discussing these matters with the patient and his/her primary caregiver is important. By recognizing signs of hopelessness and diminished QOL in these patients, physicians can institute cognitive therapies and other interventions in an effort to help the patient find meaning in the future, reduce fears, and avoid focusing on the worst outcomes.

Should surgical management fail, patients with amyotrophic lateral sclerosis (ALS) who have respiratory failure due to bulbar and respiratory muscle involvement may need a permanent tracheostomy. Severe bulbar involvement may also preclude oral feeding due to significant aspiration and, therefore, a PEG feeding tube may be necessary for adequate nutritional support.

Patients with amyotrophic lateral sclerosis (ALS) who have severe, generalized spasticity resulting in pain or impaired function may initially be given oral medications discussed previously; however, if these medications are ineffective or poorly tolerated at higher doses, consider referral for placement of an intrathecal baclofen pump.

Patients with severe spasticity limited to specific muscle groups may be treated with isolated nerve or motor point blocks, using phenol or botulinum toxin. The type of block generally used is based on the size of the muscle groups involved, risk of paresthesias with phenol injections, cost, and physician preference.

An inpatient stay in the acute care setting may be necessary at onset of symptoms if the diagnosis of amyotrophic lateral sclerosis (ALS) is uncertain and a full diagnostic workup is indicated to rule out diseases that may mimic ALS.

Once a diagnosis has been made, inpatient stays in an acute care hospital may be necessary in times of acute decompensation related to intercurrent illnesses, such as pneumonia.

Additionally, an acute stay may be indicated as respiratory function declines and appropriate ventilatory options are explored and implemented.

Rehabilitation Hospitalization

The patient's rehabilitation program may be initiated in the inpatient setting, at the time of diagnosis, or at a follow-up outpatient visit with a physiatrist.

An inpatient rehabilitation stay is indicated when the patient has had a significant decline in function and appropriate resources or equipment have not been set up in the patient's home yet to provide for current needs.

An inpatient stay also may be necessary after noninvasive or invasive ventilation has been initiated to monitor the patient and allow time to educate the patient and caregivers on the appropriate use of equipment while the ventilator and other respiratory aids are being set up in the home.

Outpatient Care

Coordinate care in the outpatient setting with a multidisciplinary team to provide the patient with amyotrophic lateral sclerosis (ALS) with timely interventions appropriate for his or her current and upcoming needs.

Visits with the physiatrist should include a thorough history and repeat clinical examination to monitor the patient's disease progression.

At each visit, discuss code status, as studies have shown that patient preferences regarding code status may change within a 6-month period because of changes in physical functioning and increased medical needs.

Patient Education

Provide patient education at the time of diagnosis and throughout the course of disease. There are many resources available to patients with amyotrophic lateral sclerosis (ALS) and their families. Provide the names and numbers of local support groups as soon as the diagnosis has been confirmed. Some excellent online resources for physicians and patients include the ALS Association, World Federation of Neurology - Amyotrophic Lateral Sclerosis, and American Academy of Neurology.

For patient education information, see the Dementia Center and the Brain and Nervous System Center, as well as Amyotrophic Lateral Sclerosis (Lou Gehrig’s Disease), and Dementia in Amyotrophic Lateral Sclerosis (Lou Gehrig’s Disease).