Glossary of ALS-Related Medical and Scientific Terms

(Presented by The ALS Association Greater New York Chapter)

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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Select a letter from the list above.

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sclerosis A hardening within the nervous system, especially of the brain and spinal cord, resulting from degeneration of nervous elements such as the myelin sheath.

serotonin An important neurochemical whose effects upon the human brain include mood elevation. Production of serotonin in the brain is increased by ingestion of the amino acid tryptophan (a chemical precursor to serotonin) and the pharmaceutical anti-depressant Prozac (trademarked product of Eli Lilly & Company). In 1997, Marianne Regard and Theodor Landis discovered that humans afflicted with hemorrhagic lesions in the brain (cause of abnormal serotonin activation/production) often became "passionate culinary afficionados."

sialorrhea Drooling

side effect An action or effect of a drug other than that desired. Commonly it is an undesirable effect such as nausea, headache, insomnia, acute toxic reaction or drug interaction.

SOD See superoxide dismutase.

SOD assay Bob Brown at Massachusetts General Hospital is completing this project. The SOD assay uses the mutant SOD gene and a series of drugs that are presented to the SOD cells that attempt to prevent the cells' death. He has screened approximately 400 drugs and has had 14 hits thus far. This assay testing is still in progress.

somatostatin A chemical necessary for communication between nerve cells.

spasm A condition in which a muscle or group of muscles involuntarily contract.

spinal cord Part of the central nervous system extending from the base of the skull through the vertebrae of the spinal column. It is continuous with the brain stem, and like the brain it is encased in a triple sheath of membranes. Thirty-one pairs of spinal nerves arise from the sides of the spinal cord. The spinal cord carries information from the body's nerves to the brain and signals from the brain to the body.

spinal muscular atrophy (SMA) A hereditary neurological disease in which only the lower motor nerve cells are affected.

stem cell transplant Transplantation of stem cells from various sources has provided improvement in animal spinal neurodegenerative disease models such as stroke, epilepsy, Parkinson's and spinal cord injury. Human trials are promising, but not complete.

stem cells Cells that can differentiate into many different cell types when subjected to the right biochemical signals. Stem cells are a promising new therapeutic approach to treating CNS disorder. The most versatile stem cells, called pluripotent stem cells, are present in the first days after an egg is fertilized by sperm. Researchers believe they can coax stem cells to become whatever tissues patients need. Stem cells come from embryos, bone marrow and umbilical chords.

striatum Part of the basal ganglia, it is a large cluster of nerve cells, consisting of the caudate nucleus and the putamen, that controls movement, balance, and walking; the neurons of the striatum require dopamine to function.

stroke Also called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain.

subarachnoid hemorrhage A brain attack that occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull (but not into the brain itself).

substantia nigra A small cluster of black-pigmented nerve cells in the brain that produce dopamine. Messages from the substantia nigra are transmitted to the striatum.

superoxide dismutase An enzyme that destroys superoxide. One form of the enzyme contains manganese and another contains zinc. Superoxide is a highly reactive form of oxygen. For ALS, 20% of the total population of patients have mutations in the gene for copper/zinc superoxide dismutase type SOD1. SOD1 normally breaks down free radicals, but mutant SOD1 is unable to perform this function.

sustention (postural) tremor A limb tremor that increases when the limb is stretched.

synapse A tiny gap between the ends of nerve fibers across which nerve impulses pass from one neuron to another; at the synapse, an impulse causes the release of a neurotransmitter, which diffuses across the gap and triggers an electrical impulse in the next neuron.

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