Within minutes of the stroke – either due to a blockage of the blood supply or bleeding – the neurons in the affected area begin to die due to a lack of oxygen and nutrients if we are unable to restore the blood supply to the area. Neurons and other cells continue to die at a rate of 32,000 neurons per second. At the same time, at-risk neighbouring areas begin to swell due to ongoing blood leakage, inflammation, or both. This continues in the next 24-72 hours. Afterwards, swelling begins to reduce towards the end of the week. Within two weeks and two months, the brain clears dead cells; as a result, some gaps appear. These recovery efforts continue for three months. Then it slows down.
Within hours of the stroke, the at-risk neighbouring neurons and other cells begin repair work. They start creating new connections (“synapses”), new dendrites, and sprout axons. This rapid repair occurs between the first week and the third month, then slows down.