If a stroke or head injury damages but does not destroy brain tissue, the tissue can gradually recover its function. Recovery can take 6 months to several years, but rehabilitation can speed recovery and make it more complete. Brain tissue that is destroyed cannot recover its function, but other parts of the brain sometimes learn to take over some of the duties of the destroyed area. Rehabilitation can help this learning process. The amount and rate of recovery of function cannot be predicted with certainty. Thus, rehabilitation is begun as soon as people are medically stable. Early rehabilitation also helps prevent complications such as shortened muscles (contractures), weakened muscles, and depression.
A detailed evaluation of the person, including psychologic testing, helps the rehabilitation team identify the type and severity of damage. Members of the team then assess which lost functions may benefit from rehabilitation therapy and create a program focusing on the person's specific needs. The success of rehabilitation depends on the person's general condition, range of motion, muscle strength, bowel and bladder function, functional ability before the brain injury, social situation, learning ability, motivation, coping skills, and readiness to participate in a rehabilitation program.
If brain injury results in weakened or paralyzed limbs, therapists move the affected limbs or encourage the person to move them. Moving the affected limbs helps prevent or relieve contractures and maintain the joints’ range of motion. Usually, the unaffected limbs should also be exercised regularly to maintain muscle tone and strength. The person is expected to practice other activities, such as moving in bed, turning, changing position, and sitting up. Being able to get out of bed and transfer to a chair or wheelchair safely and independently is important to a person's physical and mental health.
Coordination exercises may also be needed. Sometimes therapists restrain the unaffected limb (called constraint-induced movement therapy). For example, people with a partially paralyzed arm may wear a mitt or sling on their unaffected arm as they repeatedly practice daily activities, such as eating, washing, grooming, writing, and opening doors. This strategy helps rewire the brain to use the weakened or paralyzed limb.
Some problems due to brain injury require specific therapies—for example, to help with walking (gait or ambulation training), to improve coordination and balance, to reduce spasticity (involuntary contraction of muscles), or to compensate for vision or speech problems. For example, people who are having trouble walking may be taught how to prevent falls. Occupational therapy may improve coordination. Heat or cold therapy may temporarily decrease spasticity in muscles and allow muscles to be stretched. People with one-sided blindness may be taught how to avoid bumping into door frames or other obstacles—for example, by turning the head toward the affected side.
A stroke or another brain injury, especially concussion, can impair the ability to think (cognition). People may have problems with orientation, attention and concentration, perception, comprehension, learning, organization of thought, problem solving, memory, and speech. Which problems people have depends on the injury. Cognitive rehabilitation is a very slow process, has to be tailored to each person's situation, and requires one-on-one treatment. The goals are to retrain the brain and to teach ways to compensate for problems. For example, tasks, such as tying a shoe, are broken down into simple parts and practiced. Verbal, visual, and tactile (touch) cues, such as verbal hints, gestures, and color-coding items, also help people learn and remember how to do the task.