The other is dystonia.
There are different types & varying degrees of severity of dystonia. The head can even pull backwards.
I knew this young girl who walked around with her head all the way back & looking up. I was used to seeing my father's neck, but had never seen anything so sad as this young girl. It was awful.
They're using Botox in some cases. Dystonia can also cause spasmodic dysphonia of the voice. This is kind of a strangling of the vocal cords and the voice sounds strained & gravily. It's exhausing to speak; my dad has that, too. Now they can inject Botox in the larynx.
I've tried to convince my Dad to get the Botox for his voice, but he'll never do it.
Hope this helps explain dystonia a little.
Take Care,
Jan