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.
For the broader group of diseases, see Motor neuron disease. Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease and motor neurone disease (MND), is a specific disease that causes the death of neurons which control voluntary muscles. Some also use the term motor neuron disease for a group of conditions of which ALS is the most common.