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.
A brief description of the symptoms of some of the more common MNDs follows. Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease or classical motor neuron disease, is a progressive, ultimately fatal disorder that disrupts signals to all voluntary muscles.pinal muscular atrophy (SMA) is a hereditary disease affecting the lower motor neurons. It is an autosomal recessive disorder caused by defects in the gene SMN1, which makes a protein that is important for the survival of motor neurons (SMN protein).