ALS - Amyotrophic Lateral Sclerosis
Amyotrophic Lateral Sclerosis (ALS), commonly known as Lou Gehrig's disease, is a progressive neuromuscular disease. ALS is characterized by a progressive degeneration of motor nerve cells in the brain (upper motor neurons) and spinal cord (lower motor neurons). When the motor neurons can no longer send impulses to the muscles, the muscles begin to waste away (atrophy), causing increased muscle weakness. ALS does not impair a person's intellectual reasoning, vision, hearing or sense of taste, smell and touch. In most cases, ALS does not affect a person's sexual, bowel or bladder functions.
ALS is often referred to as a syndrome because the disease becomes apparent in various patterns. ALS occurs rarely and spontaneously. Currently, there is no cure for amyotrophic lateral sclerosis.
- Most people who develop ALS are between the ages of 40 and 70, although the disease can occur at a younger age.
- It occurs throughout the world with no racial, ethnic or socioeconomic boundaries.
- It affects as many as 30,000 in the United States, with 5,000 new cases diagnosed each year.
- Estimates suggest that ALS is responsible for as many as five of every 100,000 deaths in people aged 20 or older.
- ALS is most common among persons over age 60.
- The incidence of ALS is five times higher than Huntington's disease and about equal to multiple sclerosis.
Many ALS patients can live longer and more productive lives because of current research into the cause, prevention and cure for the disease. Improvements in medical management, including nutrition and breathing, regularly increase patient survival. Fifty percent of affected patients live at least three or more years after diagnosis; 20 percent live five years or more; and up to 10 percent will survive more than ten years.
Causes of ALS
ALS is a somewhat diverse and decidedly mystifying disease. In more than nine out of every 10 cases diagnosed, no clear identifying cause of the disease is apparent, that is, patients lack an obvious genetic history, complete with affected family members. Also, nothing about the way patients live their lives gives scientists and clinicians clues as to what causes ALS. Nothing in patients’ diet, where they’ve lived, how they’ve lived or what they’ve done with their lives can easily explain why they’ve developed this late onset, fully developed and progressive disease.
However, in about 5 percent of cases, a clear genetic history exists. The disease is classed as autosomal dominant in these patients; that is, that almost half of all family members show a clear history of ALS. Studies in the early 1990s on the genetic form of the disease, including work by one of our scientific advisors, Dr. Robert Brown, revealed that a single gene defect could account for a portion of these familial cases.
Mutations in the gene for the enzymes superoxide dismutase 1 (SOD1) or copper zinc superoxide dismutase have been found in approximately 15-20 percent of the familial cases of ALS. Some quick math shows, then, that approximately 1 to 2 percent of all cases of ALS involve this particular gene mutation.
Still, for the majority of ALS cases, we do not know what causes the disease. Researchers haven’t been idle, however, and several attractive theories exist on what could cause or contribute to the death of motor neurons in ALS. Center scientists are focusing on these pathogenic theories.
What are the Symptoms of ALS?
The following are the most common symptoms of ALS. Each individual, however, may experience symptoms differently. Symptoms may include:
- twitching and cramping of muscles, especially those in the hands and feet
- loss of motor control in the hands and arms
- impaired use of the arms and legs
- weakness and fatigue
- tripping and falling
- dropping things
- uncontrollable periods of laughing or crying
- slurred or thick speech and difficulty in projecting the voice
As the disease progresses, symptoms may include:
- shortness of breath
- difficulty breathing
- difficulty swallowing
The symptoms of ALS may resemble other conditions or medical problems. Consult a physician for diagnosis.
How is ALS Diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for ALS may include:
- laboratory tests - including blood and urine studies and thyroid functioning tests
- muscle and/or nerve biopsy
- cerebral spinal fluid analysis (spinal tap) - a procedure used to make an evaluation or diagnosis by examining the fluid withdrawn from the spinal column.
- magnetic resonance imaging (MRI) - a way to image soft tissues that's noninvasive and that doesn't involve X-rays. MRI produces a sharp, two-dimensional view of the brain and spinal cord.
- electrodiagnostic tests (i.e., electromyography (EMG) and nerve conduction velocity, or NCV) - studies that evaluate and diagnose disorders of the muscles and motor neurons. Electrodes are inserted into the muscle, or placed on the skin overlying a muscle or muscle group, and electrical activity and muscle response are recorded.
How is ALS Medically Classified?
Making a proper diagnosis in ALS is complicated because symptoms can vary in each patient. For greater accuracy, physicians have classified every known form:
Classical ALS - a progressive neurological disease characterized by a deterioration of upper and lower motor neurons (nerve cells). This type of ALS affects more than two-thirds of those with the disease.
Primary Lateral Sclerosis (PLS) - a progressive neurological disease in which the upper motor neurons (nerve cells) deteriorate. If the lower motor neurons are not affected within two years, the disease usually remains a pure upper motor neuron disease. This is the rarest form of ALS.
Progressive Bulbar Palsy (PBP) - a condition that starts with difficulties in speaking, chewing and swallowing due to lower motor neuron (nerve cell) deterioration. This disorder affects about 25% of those with ALS.
Progressive Muscular Atrophy (PMA) - a progressive neurological disease in which the lower motor neurons (nerve cells) deteriorate. If the upper motor neurons are unaffected within two years, the disease usually remains a pure lower motor neuron disease.
Familial - a progressive neurological disease that affects more than one member of the same family. This type of ALS accounts for a very small number of people with ALS in the United States (between five and ten percent).
According to the National Institute on Deafness and Other Communication Disorders, approximately 615,000 people in the United States have Ménière's. The disease can develop at any age, but most commonly appears between the age of 40 and 60 years and normally only affects one ear.
Ménière's disease is caused by a dysfunction in the inner ear. The labyrinth is a system of small fluid-filled channels that send sound and balance signals to the brain. It is an unpredictable disease that requires various types of treatment.
This MNT Knowledge Center article will look at the symptoms, causes, natural and conventional treatments, diet options for reducing symptoms, and the triggers of Ménière's disease.
Here are some key points about Ménière's disease. More detail and supporting information is in the main article.
- Ménière's disease involves dysfunction in the inner ear.
- Attacks can last an average of 2 to 4 hours.
- Symptoms include vertigo, dizziness, nausea, and a progressive loss of hearing.
- The exact causes of Ménière's disease are not known.
Although there is no cure, treatment can help manage some of the symptoms.
There appears to be a link between smoking and tinnitus, so quitting may help to reduce symptoms and soothe the effects.
There are links between Ménière's disease, stress, and anxiety. However, it is not known whether stress and anxiety cause symptoms or whether Ménière's disease leads to stress and anxiety. However, some studies indicate that good stress and anxiety management can help reduce the intensity of symptoms.
Medications for vertigo
Certain medications can ease the symptoms of Meniere's.
These may include:
- motion sickness drugs, such as meclizine (Antivert) or diazepam (Valium). They can help with the spinning sensation, as well as nausea and vomiting.
- drugs for nausea, such Prochlorperazine is effective in the treatment of nausea during a vertigo episode.
- diuretics,for example, a combination of triamterene and hydrochlorothiazide (Dyazide, Maxzide) to reduce fluid retention.
By reducing the amount of fluid the body retains, the fluid volume and pressure in the inner ear may improve, resulting in less severe and less frequent symptoms.
Middle ear injections
Some injections into the middle ear may improve symptoms of vertigo.
They include gentamicin, an antibiotic, and steroids, including dexamethasone.
Surgery may be an option if other treatments have not worked or if symptoms are severe. Surgery options include:
- endolymphatic sac decompression, in which a small portion of bone is removed from over the endolymphatic sac
- labyrinthectomy, where a portion of the inner ear is surgically removed
- vestibular nerve section, in which the vestibular nerve is cut
- vestibular rehabilitation therapy, in which people who have problems with their balance between episodes of vertigo may benefit from exercises and activities aimed at helping the body and the brain regain the ability to process balance data properly
People with hearing loss may benefit from a hearing aid.
Vertigo is one of the most obvious symptoms of Ménière's disease.
Symptoms vary from person to person; they can occur suddenly, and their frequency and duration differ.
They are often referred to as an "attack." These attacks vary in length but are an average of 2 to 4 hours long.
Common symptoms that occur during an attack include:
Vertigo: This is usually the most obvious symptom of Ménières disease, which includes:
- a feeling that you are spinning, even when you are not moving
- irregular heartbeat
An episode of vertigo may last from a few minutes to a number of hours. As it is difficult to predict when a vertigo attack will occur, it is important to have vertigo medication handy at all times. Vertigo can interfere with driving, operating heavy machinery, climbing ladders/scaffolding, and swimming.
Tinnitus: This is a ringing, buzzing, roaring, whistling, or hissing in the ear. People are generally more aware of it during quiet times, or when they are tired.
Hearing loss: Hearing loss can fluctuate, especially early on in the disease. There may also be a sensitivity to loud sounds. Eventually, most people experience some degree of long-term hearing loss.
Ménière's disease develops in three stages.
1) Early: This involves sudden and unpredictable episodes of vertigo. Episodes last from 20 minutes to 24 hours. During episodes, there will be some hearing loss, which returns to normal after it is over. The ear may feel uncomfortable and blocked, with a sense of fullness or pressure. Tinnitus is also common.
2) Middle: Vertigo episodes continue but are usually less severe. Tinnitus and hearing loss get worse. During this stage, some people will experience periods of complete remission where symptoms disappear. These periods of remission can last several months.
3) Late: Vertigo episodes become even less frequent, and in some cases never come back. Balance problems, though, can continue. Individuals will feel especially unsteady when it is dark. Hearing and tinnitus normally get steadily worse.
The following symptoms are also possible. These are known as secondary symptoms:
Anxiety, stress, depression: These can result because Ménière's disease is unpredictable, many individuals become anxious, depressed, and stressed. The disease can have an impact on the individual's work, especially if they have to climb ladders or operate machinery. As hearing gets progressively worse, they may find it more difficult to interact with other people.
Some people cannot drive, further limiting their independence, job prospects, freedom, and access to friends and family. It is important for people who experience stress, anxiety, and depression to tell their doctor.
The biggest problem of Ménière's disease is not knowing when episodes of vertigo will occur. The individual may have to lie down and miss out on social, leisure, work, or family activities. People with Ménière's also have a higher risk of falling, having accidents while driving a vehicle or operating heavy machinery, as well as developing depression or suffering from high levels of anxiety.
Vehicle licensing authorities in many countries state that if you have been diagnosed with Ménière's disease, you must cease driving. Driving is not allowed until symptoms are under control — this will need to be confirmed by a doctor.
There are some dietary changes that can help reduce fluid retention. Generally, the less fluid retention a person experiences, the less severe and frequent the symptoms will be.
These measures are known to help:
Eat smaller meals, more often: Evenly distributing meals throughout the day helps regulate body fluids. Rather than three large meals a day, try six smaller ones.
Eat less salt: The less salt you consume, the less fluid your body will retain. Do not add any salt to meals. Cut out most junk foods, as salt is added to these in processing.
Reduce alcohol intake: Alcohol can affect the volumes of inner ear fluid in harmful ways.
Drink water regularly: Be sure to regularly hydrate during hot weather and intense exercise.
Avoid tyramine: Tyramine is an amino acid contained in a range of foods, including chicken liver, smoked meats, red wine, ripe cheeses, nuts, and yogurts. It has been known to trigger migraines and is best excluded from the diet.
The inner ear has a complex anatomy.
Experts believe Ménière's disease is caused by an abnormality in the structure and/or the amount of fluid in the inner ear.
However, they do not know what factors cause these changes.
In the inner ear, there is a cluster of connected passages and cavities — a labyrinth.
The outer part of the inner ear is home to the bony labyrinth. Inside, there is a soft structure of membrane, which is a smaller version of the bony labyrinth with a similar shape.
The membranous labyrinth contains a fluid called endolymph, and has hair-like sensors that respond to the fluid's movement and send messages to the brain through nerve impulses.
Different parts of the inner ear are involved in various types of sensory perception:
- detecting acceleration in any direction
- rotational motion
- sound is detected by the cochlea
For all of the sensors in the inner ear to work properly, the fluid has to be at the right pressure, volume, and chemical composition.
Certain factors present in Ménière's disease alter the properties of the inner ear fluid, triggering the disorienting effects of the disease.
The symptoms of Ménière's can be set off by certain stresses, emotional disturbances, working for too long, other conditions, and tiredness. These are known as triggers.
Salt in the diet is an additional trigger.
Aside from adjustments to the diet and lifestyle, there are few natural options available to treat Ménière's disease.
Some herbs are said to provide relief for vertigo symptoms, such as cayenne, gingko biloba, ginger root, and turmeric. However, evidence is limited as to how effective these are.
Gingko baloba can interact with anticoagulant medicine to increase the risk of bleeding, and taking gingko baloba and thiazides at the same time may increase blood pressure.
Homeopathy may provide a few solutions. The Internet Journal of Otorhinolaryngology suggests that nux vomica and salicylicum acidum are two options that have been effective, and that a plant called Cocculus indicus was equally as effective for reducing Ménière's disease as betahistine, a conventional treatment for vertigo.
However, caution is advised. Always seek the advice of a medical professional and attempt a conventional course of treatment before relying on natural or alternative medicine, and be aware of possible interactions with drugs you may also be taking.
Unfortunately, no single test exists for a quick diagnosis. The doctor will carry out an interview and physical examination, ask about their medical and family history, and consider the signs and symptoms.
The doctor will ask questions regarding:
- how severe the symptoms are
- how often symptoms occur
- what medications they have been taking
- past ear problems
- general health
- any history of infectious diseases or allergies
- any family history of inner ear problems
Several other diseases and conditions have similar symptoms, which makes it hard to diagnose Ménière's disease.
To establish the extent of hearing loss, a doctor will perform an audiogram.
This exam determines the extent of hearing loss caused by the disease. An audiometer produces tones of varying loudness and pitch. The individual listens with headphones and indicates when they hear a sound, or when a sound is no longer present.
Many people with Ménière's disease have some degree of balance problems, even when their sense of balance appears to return to normal between episodes of vertigo.
Electronystagmography (ENG): Warm and cool water or air is introduced into the ear canal. Involuntary eye movements in response to this simulation are measured. Abnormalities may indicate an inner ear problem.
Rotary-chair testing:The individual sits in a chair in a small, dark booth. Electrodes are placed near the eyes, and a computer-guided chair rotates gently back and forth at varying speeds. The movement stimulates the inner balance system and causes nystagmus, or eye movements, that are recorded by a computer and monitored with an infrared camera.
Vestibular evoked myogenic potentials (VEMP) testing: This test measures the function of certain sensors in the inner ear that detect acceleration.
Posturography: The individual wears a safety harness, stands barefoot on a special platform, and has to keep their balance under various conditions.
A doctor may wish to rule out other possible diseases and conditions, such as a brain tumor or multiple sclerosis. In order to do so, the following tests may be ordered:
- MRI scan
- CT scan
- Auditory brainstem response audiometry: A computerized measure of auditory function using responses produced by the auditory nerve at the brainstem. This test can determine whether a tumor is disrupting the function of the auditory nerves.
Ménière's disease has a complicated range of symptoms and is difficult to treat. Attacks may be frequent or infrequent and cause stress and upset to an individual. The most important thing for someone with Ménière's is to seek support.