amyotrophic lateral sclerosis

amyotrophic lateral sclerosis
/ay'muy euh trof"ik, -troh"fik, ay muy'euh-/, Pathol.
an incurable disease of unknown cause in which progressive degeneration of motor neurons in the brain stem and spinal cord leads to atrophy and eventually complete paralysis of the voluntary muscles. Abbr.: ALS Also called Lou Gehrig's disease.
[1885-90; A-6 + MYO- + -TROPHIC]

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, also called  Lou Gehrig disease  

      degenerative neurological disorder that causes muscle atrophy and paralysis. The disease usually occurs after the age of 40; it affects men more often than women. ALS is frequently called Lou Gehrig disease in memory of the famous baseball player Lou Gehrig, who died from the disease in 1941.

      ALS affects the motor neurons—i.e., those neurons that control muscular movements. The muscles innervated by the degenerating neurons become weak and eventually atrophy. Symptoms include muscle weakness, frequent falls, breathing difficulty, persistent fatigue, spasticity, and twitching. Death generally results from atrophy of the respiratory muscles. There is no cure or treatment for ALS.

      Progressive muscular atrophy is a variety of ALS in which the neuron degeneration is most pronounced in the spinal cord. Symptoms are similar to ALS, though spasticity is absent and muscle weakness is less severe. Individuals with progressive muscular atrophy generally survive longer than those suffering from ALS.

      Progressive bulbar palsy is another variety of ALS caused by degeneration of the cranial nerves and brainstem. Chewing, talking, and swallowing are difficult, and involuntary emotional outbursts of laughing and tongue twitching and atrophy are common. The prognosis is especially grave in this form of ALS.

      Approximately 10 percent of ALS cases are hereditary. A defect in the gene that produces the enzyme superoxide dismutase, which eliminates free radicals (radical) from the body's cells, is responsible for the hereditary form of ALS. Free radicals are molecular by-products of normal cell metabolism that can accumulate in and destroy cells. The genetic defect causes ineffective production of superoxide dismutase in neutralizing free radicals, which subsequently destroy motor neurons. Genetic screening can determine potential carriers of the gene in families with a history of ALS.

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Universalium. 2010.

Look at other dictionaries:

  • amyotrophic lateral sclerosis — n a rare fatal progressive degenerative disease that affects pyramidal motor neurons, usu. begins in middle age, and is characterized esp. by increasing and spreading muscular weakness abbr. ALS called also Lou Gehrig s disease * * * a motor… …   Medical dictionary

  • amyotrophic lateral sclerosis — by 1881, from French, first word from Gk. a , privative prefix, + mys, myos muscle (see MUSCLE (Cf. muscle)) + trophikos feeding, from trophe nourishment (see TROPHY (Cf. trophy)). Often known in U.S. as Lou Gehrig s disease, after the New York… …   Etymology dictionary

  • amyotrophic lateral sclerosis — [ā΄mī΄ō träf′ik, ā΄mī΄ōtrō′fik] n. [< ModL amyotrophia, muscular atrophy < Gr a , not + myos (see MYO ) + trophia, TROPHY + IC] a degenerative disease of the nerve cells that control muscular movement; Lou Gehrig s disease …   English World dictionary

  • Amyotrophic lateral sclerosis — This article is about progressive Motor Neuron Disease (MND) affecting both the upper motor neurons and lower motor neurons. For MND affecting either but not necessarily both, see Motor neurone disease. ALS redirects here. For other uses, see ALS …   Wikipedia

  • amyotrophic lateral sclerosis — noun thickening of tissue in the motor tracts of the lateral columns and anterior horns of the spinal cord; results in progressive muscle atrophy that starts in the limbs • Syn: ↑ALS, ↑Lou Gehrig s disease • Hypernyms: ↑nervous disorder,… …   Useful english dictionary

  • amyotrophic lateral sclerosis — noun Etymology: 2a + my + trophic Date: 1886 a rare progressive degenerative fatal disease affecting the motor neurons, usually beginning in middle age, and characterized especially by increasing and spreading muscular weakness and …   New Collegiate Dictionary

  • amyotrophic lateral sclerosis — (= Lou Gehrig&’s disease; motor neuron disease) Progressive degenerative disease of motor neurons in the brain stem and spinal cord that leads to weakening of the voluntary muscles …   Dictionary of molecular biology

  • amyotrophic lateral sclerosis — noun A chronic, progressive disease characterized by degeneration of the central nervous system and the loss of voluntary muscle control. Syn: Lou Gehrigs disease See Also: motor neurone disease …   Wiktionary

  • Amyotrophic Lateral Sclerosis — n. (Medicine) ALS, Lou Gehrig s disease, incurable progressive disease of the motor nerve cells in the brain and spinal cord that causes their degeneration and muscle degeneration …   English contemporary dictionary

  • amyotrophic lateral sclerosis — noun a form of motor neuron disease …   English new terms dictionary