There are a number of residual issues patients face after experiencing even mild closed head injury, as well as moderate and severe injuries, including changes in memory, attention, cognitive processing, and consciousness.1–3 It is believed that neuroprosthetic devices may both facilitate recovery from the basic head injury (i.e., to help the brain heal)4–6 as well as synchronize and activate circuits that are deficient or impaired from damage caused by the head injury.7–9 We will discuss clinical problems associated with traumatic brain injury, depending on severity, and how brain-machine interface (BMI) approaches may help recovery or function, through a combination of brain recording and stimulation systems. The core concept of a brain-machine interface would be to measure the “intent” of the brain to perform an action, such as memory retrieval, motion, or perhaps focusing on an activity.10,11 Neuroprosthetic devices could then link the measured “intent” to an internal or external cue or device to facilitate the action. The last link in effective brain control systems and brain-machine interface is an automatic feedback to enhance and fine-tune performance on the task. Similar to intrinsic motor function, for example, where “intent” is defined, then a motor plan has to be internally created (i.e., by the basal ganglia and thalamus), then smoothly executed (by motor cortex, cerebellum and associated motor circuitry), and refinement via external vision or sensory input is critical for improving the function.11 We discuss several possible treatment routes relative to each level of severity of head injury, and how a feedback, control circuit might be implemented, and critical approaches now available as well as under development.
