We know that certain environmental substances can trigger autoimmune disease. For example, silica can trigger scleroderma; certain drugs can trigger lupus; and, in some women, pregnancy can trigger an autoimmune disease. For more information: http://www.aarda.org/modules.php.
UPPER MOTOR NEURON DISORDERS (UMN). An upper motor neuron starts in the motor cortex of the brain and terminates within the medulla (another part of the brain) or within the spinal cord.So, an UMN disorder would include injury, disease or disturbance within this pathway from or within the brain and to the spinal cord (Photo 6).PPER MOTOR NEURON DISORDERS (UMN). An upper motor neuron starts in the motor cortex of the brain and terminates within the medulla (another part of the brain) or within the spinal cord.
Amyotrophic lateral sclerosis (ALS): A classic motor neuron disease. Motor neuron diseases are progressive chronic diseases of the nerves that come from the spinal cord responsible for supplying electrical stimulation to the muscles.This stimulation is necessary for the movement of body parts. ALS occurs when specific nerve cells in the brain and spinal cord that control voluntary movement gradually degenerate. The loss of these motor neurons causes the muscles under their control to weaken and waste away, leading to paralysis. The cause of this disease process is still unknown.