It has been known for over a hundred years that after a stroke, the brain enters a state of shock, called diaschisis, which means “shocked throughout”.
The “shock” occurs because in a stroke, after neurons die, chemicals leak out of some cells, harming others, inflammation is very active, and interruptions in blood flow occur around the dead tissue. All these events disrupt functioning not just where the stroke occurred but throughout the brain. In addition, immediately after an injury the brain undergoes an “energy crisis” because it has to consume so much glucose to deal with the injury. (Even when healthy, the brain has a huge energy requirement. Though it accounts for only 2 percent of the weight of the body, it consumes 20 percent of its energy.) The period of diaschisis typically lasts about six weeks, during which an injured brain is especially vulnerable because its energy to deal with additional harm is so low.
A stroke patient tries repeatedly, during this period, to move the paralysed arm, and cannot, they will “learn” it doesn’t work and so they’ll start using only their non-affected limb.
Dr. Shimon Rochkind, a neurosurgeon at Tel Aviv University has shown that applying soft lasers to peripheral nerves can help them heal, and that the light improves nerve-cell metabolism, increases sprouting of new connections between nerves, enhances the growth of new nerve axons (which conduct electrical signals) and of myelin (the fatty covering around the nerves that allows them to send faster signals), and decreases scar tissue.
Soft lasers helped damaged nerves stop degenerating and start regenerating themselves.
Another unique aspect of soft laser is that it preferentially affects damaged cells, or cells that are struggling to function and need energy the most. Cells that are chronically inflamed, or that have only a limited blood supply and oxygen due to poor circulation, or that are multiplying (as happens when tissues are trying to heal themselves) are more sensitive to red and near-infrared low-intensity lasers than are well-functioning cells.