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.– It is believed that neuroprosthetic devices may both facilitate recovery from the basic head injury (i.e., to help the brain heal)– as well as synchronize and activate circuits that are deficient or impaired from damage caused by the head injury.– 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., 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. 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. As a parallel to traumatic brain injury, movement disorders treatment has evolved to include a number of regions within the brain, focusing on pathways involved with both motor pattern generation (i.e., basal ganglia in concert with cortical areas involved with generating intent), motor output (i.e., motor cortex), and sensory feedback.– As these areas have been further studied over time, additional subregions have been included as treatment possibilities, for example, the subthalamic nucleus, a new target derived from motor systems analysis in nonhuman primates, but rapidly translated into clinical usefulness.,, There are now at least three interconnected regions that appear to be involved in treatment of abnormal motion and for application of conventional deep brain stimulation (DBS). Interestingly, DBS applied to the three interconnected regions (i.e., globus pallidus, subthalamic nucleus, and ventral intermediate thalamus) provide different types of symptom relief with some overlap. DBS provides essentially a point source of electrical input into the brain (i.e., a 1.5 mm contact point; Figure 18.1) but can affect widespread regions through both direct local neuronal changes but particularly direct stimulation of afferent and efferent axons coursing through each area.– In effect, the point source stimulation that DBS provides can reset nearly the entire brain within a short period of time after activation, showing that dynamic stimulation can have widespread effects (as shown in Figure 18.1). There are multiple efforts ongoing to optimize DBS treatment effects, including improving stimulation patterns, measuring widespread EEG changes (i.e., beta oscillations) and using these as a feedback system to monitor treatment efficacy, and to transform DBS systems into “smart” neuroprosthetic systems, along the lines of brain-machine interface approaches. A natural extension of DBS for movement disorders would then be to optimize both the number of stimulation sites as well as coordinate feedback control, to extend DBS toward a full implementation of brain-machine interface. For example, detecting surrogate signals within the brain (either locally or globally) that might be linked to the movement disorder symptoms (i.e., tremor, rigidity, bradykinesia, etc.), analyzing these signals in real-time, and then altering the DBS output to dynamically route stimulation to both multiple sites and in various patterns to improve the disease symptoms. It is not clear if single or multiple sites of DBS stimulation might be more effective, but more advanced tools are needed for individual patients to assess (in a predictive sense) where to place electrodes and how to stimulate. Similarly, a revolution in epilepsy treatment is ongoing to dynamically record and stimulate seizures, with now a first-generation Neuropace device available (with four recording and four stimulating channels).– The location and predictive efficacy of sites and types of stimulation for both movement disorders and epilepsy is a current strong need, with sufficient brain detail and knowledge of the underlying circuitry to be useful for placing electrodes.