paratonia
gegenhalten

Another form of hypertonia is paratonia, which is associated with dementia.

Paratonia or gegenhalten is defined as "a form of hypertonia with an involuntary variable resistance during passive movement."

In other words, attempting to move the limb of a person with paratonia will result in that person involuntarily resisting the movement.

There are a range of abnormalities of movement which are typical of catatonia, such as echopraxia, catalepsy, waxy flexibility and paratonia (or gegenhalten).