Homo means same. hetero means opposite
Nerves that detect deep pressure are called Pacinian corpuscles.
Pacinian corpuscles are microscopic onion-shaped nerve structures that are situated in the dermis and hypodermis. Pacinian corpuscles detect deep pressure and vibration. This nerve has a myelinated nerve ending in the middle of its structure and the external layer contains flattened cells, a lymph-like fluid and collagen fibers. The structure of pacinian corpuscles provides a fast response and rapid recovery by transmitting fast events. This make them sensitive to pressure and vibration.
Likely he will be diagnosed by the hospital as seen as a risk constantly for violence with others. This isn't uncommon in people with drug abuse, or someone who has come from an abusive household. It's quite likely he has faced abuse and may suffer from an emotional mental health disorder. (IE manic depressive disorder, anger issues, or purely a sociopath)
An exposure to sarin or sarin like chemical will caused the sarcoplasmic reticulum to be continuously stimulated by the continual electrical signal. This will open the calcium channels and allows the calcium ions to bind continuously with troponin. Sarin is an organophosphorus chemical which is highly poisonous. It is used as a chemical weapon of destruction.