So the other day we introduced the term “Gegenhalten Tone“. Today, we try to put that knowledge to use.
Theoretically, Gegenhalten Tone is a primitive reflex we all developed in utero. Whenever we, as fetuses, floated up against our mothers’ abdomens, we pushed off the uterine wall. Or so I’ve been told. I can’t find the original source that explains the origin and embryonic purpose of Gegentalten, but it doesn’t really matter anyway.
Gegenhalten Tone is also known as paratonia. When we see paratonia in children and adults, it is usually indicative of frontal lobe damage. In Alzheimer’s, it is considered a frontal release sign.
So from an evaluation perspective, there are a few tools we can use to determine the severity of the tone. The scores from these scales closely correlate to the other tools we use to test the severity of dementia (MMSE, ACLS, GDS…).
I like the Paratonia Asssesment Instrument because it enables professionals to distinguish between paratonia, parkinsonian rigidity, and spastic hemiparesis. All five characteristics must be present to call it paratonia:
• An involuntary variable resistance during passive movement
• There is no clasp-knife phenomenon
• The resistance to passive movement is in any direction
• Resistance must be felt in either one limb in two movement directions or in two
• The degree of resistance correlates with the speed of movement (e.g. a low
resistance to slow movement and a high resistance to fast movement)
The Modified Ashworth scale
0 normal tone, passive movement no problem
1 mild paratonia, slight resistance in passive movement
2 moderate paratonia, enhanced resistance in passive movement
3 severe paratonia, severe resistance in passive movement
4 very severe paratonia, passive movement (almost) impossible
So now that we have a couple of decent assessment tools that both identify the abnormal tone as paratonia and rate it’s severity, what do we do with this information?
We rehabilitate and compensate to the best of our abilities, but first we consider the consequences of doing nothing:
1. If the joints become increasingly resistant to movement, they will become stiff and painful.
2. If they become stiff and painful, then there will be a voluntary resistance to movement (ouch don’t do that!) in addition to the involuntary resistance to movement due to brain damage (paratonia). This only hastens the development of contractures and immobility.
Ok, so let’s turn paratonia on its head.
Theoretically, a person with Gegenhalten tone resists movement. But if he or she is resisting movement in one direction, that means he or she is actively moving in another direction. It’s all related to that reflex in utero when the fetus bumped up against the uterine wall and pushed away (or so I’ve been told).
Passively ranging joints is something all caregivers should do for someone with impaired mobility. In the presence of paratonia, this is more difficult. Joint range of motion is actually achieved by actively eliciting movement in the opposite direction. So if I’m pulling on their arm and trying to straighten the elbow, the person is pulling up away from the direction of the pull. If I push the arm and try to bend the elbow, they will push back. It may not be full joint range or enough to prevent an eventual loss of range, but it achieves more that trying to passively range a joint in the presence of severe paratonia.
So, in a practical situation, if Mrs. Jones is sitting on the edge of the bed and keeps leaning back, and I put my hands on her shoulders and upper back and try to push her forward, she will resist that direction and push even harder into my hands (just like the fetus). Conversely, if I resist her leaning forward by placing my hands on the front of her shoulders and chest, she will push forward into my hands, activate her abdominals and hip flexors, and push forward and over her center of gravity- where she has better balance.
And for the record, passive and active range of motion will not decrease paratonia. The goal would not be to reduce the API or Modified Ashworth Score, but it may serve to maintain joint integrity and stave off contractures that are both painful and barriers to good care.
Read up on paratonia here: Paratonia enlightened, Hans Hobbelen 2010