If you’ve ever played with a young baby, perhaps you’ve noticed that uncanny ability they have to grasp onto your fingers. They even have enough grip strength to hang on while they’re pulled from their backs up to a sitting position. Many proud parents have uttered the words, “Wow, my baby is so strong!”
And they are right! The palmar grasp reflex is a primitive skill that is left over from our early days on the evolutionary timeline- when we had to hang on tight to our mothers’ backs while they swung from limb to limb. It serves a purpose even now that we’ve evolved into more sophisticated creatures, although any exact scientific explanation is really just a best guess. The palmar grasp reflex teaches us, as infants, how to use our hands to hold things, which is a precursor to feeding ourselves. That’s a pretty important function.
But after a few months of infancy, as our cortical brain tissue develops and specializes, we learn to override the reflex and grasp and let go of things as we please. This is normal development.
In neurodegenerative diseases, cortical brain tissue shrinks and our brains can no longer override those reflexes. The palmar grasp reflex reappears, but is misinterpreted as a volitional action of defiance. A person who won’t release the grab bar, or the walker, or your forearm may just be displaying a reflexive movement that is not easy to overcome. This is not an adverse behavior. This is neurodegeneration.
People who have trouble releasing things or who grasp tightly to the edge of their blankets, or armrests, or any object are at risk of developing contractures- a tight fist that is not easily opened. Contracted hands are a beast to care for, and painful for the patient as well.
Remember that the grasp reflex is closely tied to the tendency to feed ourselves, so you might even see more objects in the hands going toward the mouth. This isn’t hunger, it’s reflex.
To prevent this sort of outcome, make sure to get folks engaged in open handed, object-releasing activities throughout the early and middle stages of dementia. Once the person is showing signs of palmar reflex (death grip) use demonstration to cue them to open it themselves. Prying their hands open will only cue the reflex to kick in more- imagine trying to pry a baby monkey off his mother’s back if he perceives a threat. He’s only going to grab hold more tightly.