Last year, the Centers for Disease Control as well as Prevention estimated which between 14,000 as well as 15,000 Americans have A.L.S., which makes This particular sound like a rare disease, however only because life expectancy is actually so short. A.L.S. occurs throughout the earth, as well as This particular is actually probably far more common than generally thought.
Over the course of a lifetime, one person in about 400 is actually likely to develop This particular, a risk not unlike which of multiple sclerosis. however with the rare exception of an outlier like the brilliant physicist Stephen Hawking, who has had A.L.S. for more than 50 years, This particular usually kills so quickly which many people do not know anyone living with This particular disease. Only one person in 10 that has a.L.S. is actually likely to live for a decade or longer.
The disease is actually most commonly diagnosed in middle age, among people in their 50s or 60s, though This particular sometimes afflicts young adults. Dr. Hawking was found to have This particular at age 21.
Early symptoms can be very subtle as well as so are often overlooked or attributed to a minor problem like lack of sleep, undue stress, overwork or poor diet. However, the underlying damage can start long before the symptoms are noticed. Given the redundancy built into the brain, about a third of motor neurons are destroyed before signs of muscle loss become apparent.
Initial symptoms depend on which group of motor neurons are affected first. In about 70 percent of people, the first symptoms involve muscle weakness inside the legs or arms which can result in frequent tripping, instability, stiffness, difficulty walking or inability to open a jar or turn a key. About one-quarter of cases start with muscle loss inside the face, mouth as well as throat, resulting in slurring of speech as well as swallowing difficulties, as well as in 5 percent, the muscles of the trunk are first affected. However, in most people the disease soon spreads to affect nearly all voluntary movements.
Patients usually retain control over bladder as well as bowel function as well as eye movement until very late inside the disease. In fact, after losing the ability to speak or write, many learn to communicate by looking at letters or words on a computer as well as using a voice synthesizer.
Sensory nerves as well as the autonomic nervous system are usually spared in order which most with the disease can hear, see, touch, smell as well as taste. however as patients lose the ability to swallow, oral feeding creates a choking hazard — some, in fact, choke on their own saliva — as well as tube feeding becomes the only option for maintaining nutrition.
Half or more of patients remain mentally sharp, bearing painful witness to their physical decline, although mild cognitive as well as behavioral modifications are fairly common, as well as 10 percent to 15 percent of patients develop symptoms of frontotemporal dementia. They may become withdrawn, apathetic, uninhibited, distractible as well as repeat words or gestures.
The cause or causes of A.L.S. are unknown in 0 percent to 95 percent of cases. The remaining cases are inherited by a parent who carries a mutation in one or more genes. Researchers are studying these genes in patients as well as engineered mice in hopes of developing drugs or stem cells which slow, stop or even reverse progression of the disease.
For example, a recent study published online in JAMA Neurology by researchers at Methodist Neurological Institute in Houston suggests which reducing inflammation by modifying certain abnormal immune cells may prove helpful to patients, especially if the treatment could be applied early inside the disease.
some other recent studies in mice, yeast as well as fruit flies by researchers at Stanford University School of Medicine suggest which suppressing a certain protein called ataxin-2 may foster resistance to A.L.S. In mice genetically engineered to have A.L.S., Lindsay Becker, a graduate student, found which completely removing ataxin-2 enabled some of the animals to live “hundreds as well as hundreds of days,” instead of only a month.
Another promising avenue of research involves the abnormal behavior of an enzyme called RIPK1, which can damage neurons by disrupting the production of the myelin sheath which insulates axons, the neuron extensions which transmit signals by one cell to the next. Researchers at Harvard Medical School showed which in genetically engineered mice that has a.L.S., a substance called necrostatin-1 not only restored the myelin sheath as well as stopped axon damage however also prevented limb weakness.
Currently, only two drugs have been approved for treating A.L.S. One is actually Rilutek (riluzole), which counters the elevated levels of the neurotransmitter glutamate which arise inside the brains as well as spinal fluid of A.L.S. patients. Its limited effect on life span — an extension of a few months — suggests which excess glutamate is actually hardly the only noxious factor involved inside the disease. The Food as well as Drug Administration just approved a second drug, Radicava (edaravone), said to slow progression of the disease in a six-month study in Japan, though its effects on survival are not yet known. This particular must be administered intravenously for 10 days every two weeks at a cost of more than $145,000 a year for the medication alone.
Aside by genetically transmitted familial cases, potential risk factors for A.L.S. include traumatic brain injury as well as exposure to toxic substances like lead as well as certain pesticides. The risk is actually higher than expected among military veterans, professional football players as well as athletes who took dietary supplements containing branched-chain amino acids. The Department of Veterans Affairs recognizes A.L.S. as a service-connected disease.
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