|Lou Gehrig’s Disease (ALS)|
ALS is a disorder of the nervous system that causes muscle weakness and interferes with a patient’s ability to function physically; the nerve cells that control movement of muscles gradually die and muscles progressively weaken and atrophy. It was first described in the 1820s and named in 1874. “Amyotrophic” refers to the loss of lower motor neurons (nerve cells that project from the spinal cord to the muscle) and “lateral sclerosis” implies the loss of upper motor neurons (nerve cells that project from the brain to the lateral part of the spinal cord); both upper and lower motor neurons are needed to make muscles contract. If only the lower or upper motor neurons are involved, then the condition is not ALS.
Hear Pastor Kevin Kinchen's inspiring story about his experience as our patient families cope with the monumental challenges posed by amyotrophic lateral sclerosis.
Symptoms of ALS
Muscle weakness is the major symptom of ALS. In early stages, the weakness may present itself as a problem with muscle endurance. Twenty percent of patients may experience a compromise in the ability to speak as the first symptom. A patient may experience a range of symptoms which become progressively worse over time:
- Muscle twitching in arms and legs
- Difficulty in walking
- Muscle weakness in legs, feet or ankles; weakness and clumsiness in hands.
- Hand weakness or clumsiness
- Slurring of speech or trouble swallowing
- Muscle cramps and twitching in arms, shoulders and tongue
- Difficulty holding head up or keeping a good posture
Pain is not a recognized symptom of ALS, but some may occur.
ALS does not usually affect the senses, ability to think, sexual function and bowel or bladder control; it will, however, eventually eliminate the ability to control muscles responsible for moving, speaking, eating and breathing. For example, ALS may affect the respiratory system in several ways as the disease progresses:
- The disease can cause increased secretions in the airways of the lungs which may interfere with the ventilator phase of respiration; this will result in lower oxygen levels and higher levels of carbon dioxide, making the patient breathless and reducing energy levels.
- If ALS causes the mechanical phase of respiration to be degraded, a patient may experience an ineffective cough that can lead to an accumulation of secretions in the bronchial tubes. This accumulation, along with an increased occurrence of food or liquid aspiration, can foster growth of bacteria which can lead to pneumonia.
Causes of ALS
The causes of ALS are unknown at present, but researchers are focusing on several possible theories, including gene mutations, overabundance of the neurotransmitter glutamate (which can be toxic to nerve cells), autoimmune response (in which the body’s immune system attacks normal cells) and the gradual accumulation of abnormal proteins in nerve cells.
ALS may be inherited in 5‒10 percent of cases (familial ALS), but the rest of the patients who contract the disease seem to do so at random (sporadic ALS). Most patients diagnosed with ALS do not have a history of ALS in any of their immediate family members .
- In the case of familial ALS, for 80 percent of cases the gene mutation is not identified; only about 20 percent of people with this form of ALS possess an identifiable mutation on chromosome 21, a defect in the enzyme Cu/Zn superoxide dismutase (SOD1).
- In sporadic ALS, several theories have been proposed to explain the possible cause of motor neuron damage.
- The basis of the theory of excitotoxicity is that when the neurotransmitter glutamate is present in high concentrations, it can damage and destroy motor neurons; whether this is due to overproduction of the substance or an inability to reuptake is not known.
- Tissue studies of sporadic ALS patients have shown a higher concentration of altered proteins and greater production of free radicals from cell mitochondria than in tissues of non-ALS subjects. An increased concentration of these substances can damage all parts of a cell.
- Animal models have demonstrated that subjects with motor neuron conditions show early onset activation of the body’s immune system which can lead to inflammation in motor neurons.
- The role of neurotrophic hormones — proteins that promote growth and regeneration in neurons such as insulin-like growth factor-1 (IGF-1), ciliaryneurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) — is also being examined as a potential factor in the death of motor neurons.
Quite possibly, a "communal" process occurs in sporadic ALS that involves all these mechanisms.
Several different forms of motor neuron disease similar to ALS have been described.
- Spinal muscular atrophy is a lower motor neuron inherited disorder that typically occurs during the first two decades of life; the defect is located on chromosome 5 but the specific abnormality is not defined.
- X-linked spinal and bulbar muscular atrophy (Kennedy's disease) is a lower motor neuron disease linked to the X chromosome that occurs primarily in males and is characterized by limb weakness, speech and swallowing difficulties, enlargement of the breasts and testicular atrophy. Currently, it is not understood as to why this condition causes motor neuron loss.
For most patients with ALS, muscle weakness progresses over a three- to five-year period; a small number of people will see the same progression over a period as short as one year and 20 percent of patients may see the advancement of the disease take more than five years. The reasons for the variations are unknown and the course of the disease is difficult to predict on an individual basis.
One to two people out of every 100,000 will develop this disease a year. ALS affects men more than women in a 2:1 ratio, but after age 60, this rate evens out. The average age symptoms start to appear is between 53 and 57 years; about 80 percent of all cases start between the ages of 40‒70. ALS can occur in people of any race; the incidence of ALS is much higher in Guam, western New Guinea and select areas of the Kii peninsula of Japan.
Other factors that may increase the risk of developing the disease include smoking, exposure to lead and service in the military.
Research and Clinical Trials for ALS
At Houston Methodist, our teams are involved in research efforts and clinical trials in order to help relieve the symptoms of ALS and discover a cure. Our research labs discover more about ALS and motor neuron diseases every day. For example, the Appel lab is studying the importance of immune and inflammatory alterations, as well as increased intracellular calcium and free-radical stress, in ALS.
Our researchers participate in numerous neuromuscular drug trials.
- In the oral fingolimod in patients with ALS trial , the primary objective is to determine the safety and tolerability of daily oral administration of 0.5mg fingolimod versus a matched oral placebo. The four-week study will examine the safety and tolerability of subjects to the drug and to quantify the effect of the treatment on circulating lymphocyte populations.
- The purpose of the pulse steroid therapy study is to learn the efficacy of the glucocorticosteroid dexamethasone on disease progression in ALS (based on glucocorticosteroids’ ability to affect a broad range of conditions such as immune inflammation and oxidative stress).
- The primary objective in the multicenter study for the validation of ALS biomarkers is to identify the factors that contribute to development of ALS in order to build better diagnostic tests for earlier detection and to identify targets for more precise and effective therapies. The resulting tests would be able to identify people with ALS and distinguish them from people with disorders that present with similar symptoms such as carpal tunnel syndrome, radiculopathies or myopathies. In this study, blood (plasma and DNA) and possibly cerebrospinal fluid samples will be collected from a range of participants.
- In the study that examines using pyrimethamine in patients with familial ALS , we will determine if people with the familial, inherited form of ALS who take the drug show a decline in their SOD1 levels in cerebrospinal fluid. (SOD1 is a mutated gene found in patients with familial ALS; in animal studies, suppression of the expression of this gene has been shown to prevent subjects from developing the disease. Pyrimethamine is a drug that reduces SOD1 levels in mice and preliminary trials show similar findings for humans.)
- The purpose of the study on using a subcutaneous IgPro20 pump to treat CIDP (chronic inflammatory demyelinating polyneuropathy) is to compare the effectiveness of two doses of subcutaneous IgPro20 (delivered with a portable pump) with the current treatment of CIDP and to examine the safety and tolerability of these doses. IVIG usually requires hospital or home health IVIG infusion. Click here to learn more about CIDP.
- The study on using CD4+CD25+T Reg cells as potential biomarkers of CIDP (to determine development of the disease, treatments and response to therapies) will explore these T regulatory cells to find out if they can be used to detail the severity and progression of the disease and to decide if improvement is occurring with standard immune therapy.
- In the oral fingolimod in CIDP study , the goal is discover whether the once-daily oral drug fingolimod is safe and has benefits for those with CIDP.
To participate in a neurological clinical trial, a patient must first be evaluated at the Methodist Neurological Institute Neuromuscular Clinical Center.
Visit the MDA/ALS Center at Houston Methodist. The center offers highly focused programs for ALS research and medical management and is a part of the Muscular Dystrophy Association ’s 230 hospital-affiliated clinics across the country. Here, patients can interact with many different health professionals such as neurologists, pulmonary specialists, occupational therapists, physical therapists, speech pathologists, neuropsychologists, dietitians, nurses, respiratory therapists and social workers. Our team of 21 professionals from 11 specialties uses a multidisciplinary approach to help patients with ALS to cope with their disease and applies the latest therapies and proactive symptom management in a positive and caring setting.
The specialists at Muscular Dystrophy Association clinics offer services such as:
- Physical, occupational and respiratory therapy
- Information on ALS and referrals to other specialists
- Exploration of the latest research, including clinical trials
- Connection to ALS support groups for caregivers, friends, patients and their families
These services can help a patient with ALS learn new coping strategies to deal with the emotional, physical and lifestyle changes that ALS brings. ALS changes existing lifestyles and certain ways of coping seem to help with these changes:
- Learning to pace your activities
- Altering your life’s priorities to match your current condition
- Redefining how you think of independence
These methods all try to change the focus from quantity of time to quality of time and on how to conserve energy.
US NEWS: NEUROLOGICAL INSTITUTE RANKED NO. 16 IN THE COUNTRY
Houston Methodist Neurological Institute is ranked #16 in U.S. News and World Report’s 2015 rankings for national hospitals in neurology and neurosurgery, we have reached this level of excellence by combining practiced skills with continuous learning and the cutting-edge research from the Houston Methodist Research Institute.
Our physicians at Houston Methodist specialize in managing Lou Gehrig’s Disease (ALS) at the following convenient locations.