Mutations in GLEI have been identified in families with foetal motoneuron disease. These effects cause an increase in pudendal motoneuron reflex discharge (PMRD) latency. Upper motoneuron lesions to the face often cause paralysis. Most patients have upper motoneuron issues and autonomic disturbances. A decrease in peak-to-peak H-reflex amplitude suggests a decrease in motoneuron excitability.