system
Given the following post, respond as if you're commenting on Reddit:
human
If you are paralyzed, can you still move some muscle-
groups. If yes/no, why?

I was thinking about **Steven Hawking** when this question popped up in my head. To be able to communicate he makes use of a tiny IR sensor that lets him twitch his cheek to spell and speak words.

But how is he still able to move his eyes and the cheek for that matter? I may not fully understand the effect of the disease that he bears, but lets take another example just in case.

Let's say that you are paralyzed, top to bottom. Could you still be able to move small muscle-groups at all? Or are there areas around your head that doesn't get affected by something like a paralyzation?

EDIT: Thank you all for your answers. I understand paralyzation, and Stephen Hawking's case a bit better now.
gpt
Paralysis has a cause, and that cause determines what muscles are paralyzed. In cases of spinal cord injury, all muscles whose nerves leave the cord below the injury are lost. That's why some people have leg parlysis, but their arms are fine, etc.   

Hawking has ALS, or Lou Gehrig's disease, which causes the loss of motor neurons, usually from largest to smallest. In ALS, there is nearly always some residual muscle capability. Hawking makes use of his.