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.
In most cases, the cause of motor neuron diseases is not known; however, a small percentage of cases are inherited. Some motor neuron diseases, such as ALS, are ultimately fatal, while others, such as PLS, impact bodily functions and quality of life, but do not necessarily result in death.otor neuron diseases (MNDs) are a group of neurological conditions that progressively destroy motor neuron cells.