Pls just effects UMN. It causes slow progression of weakness and spasticity. Can move quickly or take 20 years to full disability. It does not cause the breathing issues therefore is not considered terminal, it does however cause bulbar symptoms eventually taking the ability to talk and eat, so not easy. Pls can turn into ALS at anytime, that's a good and bad thing. It certainly makes you enjoy each day to the full and not take anything for granted.