What research is being done on ALS?
The National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health, is the Federal Government's leading supporter of biomedical research on ALS. The goals of this research are to find the cause or causes of ALS, understand the mechanisms involved in the progression of the disease, and develop effective treatment.
Scientists are seeking to understand the mechanisms that trigger selective motor neurons to degenerate in ALS and to find effective approaches to halt the processes leading to cell death. This work includes studies in animals to identify the means by which SOD1 mutations lead to the destruction of neurons. The excessive accumulation of free radicals, which has been implicated in a number of neurodegenerative diseases including ALS, is also being closely studied. In addition, researchers are examining how the loss of neurotrophic factors may be involved in ALS. Neurotrophic factors are chemicals found in the brain and spinal cord that play a vital role in the development, specification, maintenance, and protection of neurons. Studying how these factors may be lost and how such a loss may contribute to motor neuron degeneration may lead to a greater understanding of ALS and the development of neuroprotective strategies. By exploring these and other possible factors, researchers hope to find the cause or causes of motor neuron degeneration in ALS and develop therapies to slow the progression of the disease.
Researchers are also conducting investigations to increase their understanding of the role of programmed cell death or apoptosis in ALS. In normal physiological processes, apoptosis acts as a means to rid the body of cells that are no longer needed by prompting the cells to commit "cell suicide." The critical balance between necessary cell death and the maintenance of essential cells is thought to be controlled by trophic factors. In addition to ALS, apoptosis is pervasive in other chronic neurodegenerative conditions such as Parkinson's disease and Alzheimer's disease and is thought to be a major cause of the secondary brain damage seen after stroke and trauma. Discovering what triggers apoptosis may eventually lead to therapeutic interventions for ALS and other neurological diseases.
Scientists have not yet identified a reliable biological marker for ALS -- a biochemical abnormality shared by all patients with the disease. Once such a biomarker is discovered and tests are developed to detect the marker in patients, allowing early detection and diagnosis of ALS, physicians will have a valuable tool to help them follow the effects of new therapies and monitor disease progression.
NINDS-supported researchers are studying families with ALS who lack the SOD1 mutation to locate additional genes that cause the disease. Identification of additional ALS genes will allow genetic testing useful for diagnostic confirmation of ALS and prenatal screening for the disease. This work with familial ALS could lead to a greater understanding of sporadic ALS as well. Because familial ALS is virtually indistinguishable from sporadic ALS clinically, some researchers believe that familial ALS genes may also be involved in the manifestations of the more common sporadic form of ALS. Scientists also hope to identify genetic risk factors that predispose people to sporadic ALS.
Potential therapies for ALS are being investigated in animal models. Some of this work involves experimental treatments with normal SOD1 and other antioxidants. In addition, neurotrophic factors are being studied for their potential to protect motor neurons from pathological degeneration. Investigators are optimistic that these and other basic research studies will eventually lead to treatments for ALS.