Injuries can sometimes involve damage to the nerves. This can cause increased sensitivity (which we refer to as hypersensitivity) loss of sensation or a significant change in how you perceive your sensation e.g. pins and needles. It is important to address these problems and learn how to regain sensation, re-learn ‘normal’ and reduce the hypersensitivity. We have a large area of the brain that represents the sensation of the hand in an area called the Sensory Homunculus. The reason it is so large is that the hands, particularly the fingertips, have many more nerve endings compared to the rest of the upper limb. This means when we injure our fingers, it can be more painful. Interestingly pain can only be interpreted in the brain. Injury to the body has to involve a signal going from the limb up to the brain and then a response is sent back to the limb with instruction.
Nerves are able to regenerate, meaning if they are cut or crushed, they can regrow. However, when nerves regrow, they repair first at the site of injury and then regrow down towards the tips of the fingers. Nerves can regrow at a rate of 2mm per day. Depending how far away from the finger tips the injury is, will determine the recovery time. After initial injury the nerve can take up to a month to begin regenerating. Symptoms that indicate you may have a nerve injury can include numbness, burning, shooting, pins and needles.
Assessment of your sensation is important to establish as a baseline. We use Sensory Monofilaments, which is a standardised assessment. This can determine if you have protective sensation and how it may impact your functional use of your hands. Protective sensation is the reflex that automatically pulls your hand (body part) away from hot or sharp items without the requirement of the feedback from the brain. Treatment works to build up tolerance to different textures, temperature and increasing your functional use. There is no limit of time to relearn and for the nerve to regenerate. Studies have shown cases of sensation return after 20 years.