The main cause of ALS is not clear. It may be discovered that mutations in the gene that produces SOD1 enzyme is associated with ALS. This enzyme act as antioxidant that protects body from Damage due to radicals. Free radicals are highly reactive molecules, produced by cells during normal metabolism of body. If not neutralized , these free radicals can accumulate and responsible for damage to DNA and proteins within cells. Yet it is not clear that how SOD1 gene mutation leads to motor neuron degeneration but it has been theorized that accumulation of free radical may result in faulty functioning of this gene.
Studies also foccused that role of Glutamate is also responsible for motor neuron degeneration. Glutamate is neurotransmitter in the brain and in ALS patients glutamate level is higher in serum and spinal fluid and the neurons began to die when they get longer period of exposure to glutamate. Auto immune responses suggest one of the important cause of motor degenerative disorders. Antibodies may directly or indirectly impair the function of motor neurons, interfering with the transmission of signals between the brain and muscles.
Other environmental factors is also responsible such as an exposure to toxic or infectious agents, dietary deficiency or trauma. Other research may show that genetic predisposition are also involved in the development of ALS.
COMPLICATIONS OF ALS–
ALS degenerate the motor neurons and lead to the weakness of the muscles. Some common complications are as follows–
1) Problem in eating–
Patients with ALS, generally choke easily. Because of malnutrition, dehydration and weight loss occurs. These patients may aspirate their food or liquors and can cause pneumonia i.e. infection of the lungs. Due to this infection patient have shortness of breath, coughing, chills and fever. In order to overcome these eating problems, feeding tube is used, which delivers patient’s food right to the stomach.
2) Breathing problems–
In motor neuron disease due to degeneration of motor neurons, the muscles in the chest wall and diaphragm gets affected and leas to breathing problems. Due to this breathing problem, patient requires ventilator to breath properly or sometime surgical procedure like trachestomy in which opening of wind pipe help them to breathe is helpful. Studies show that ALS patients die from respiratory failure within 4-5 years.
ALS patients have increased risk of dementia i.e. from fronto temporal dementia or Alzheimer’s disease. In fronto temporal dementia patients have shrinkage in the parts of temporal or frontal lobe and they find difficulties in writing speaking or in appropriate behavior and in Alzheimer’s disease, patient have memory problem or show withdraw towards society.
4) Inability to care–
As in ALS there is weakness in muscles that makes the patient finds difficulty in walking or climbing. Due to muscle problem tremors, twitching or muscle spasm is also common.