Brain injuries which lead to impaired cognitive function remain the least explored area for active neurological intervention. Several clinical observations suggest that mechanisms of plasticity are available to the brain that might be harnessed for therapeutic advantage for treating cognitive disorders. A significant percentage, roughly 20%, of patients who suffer severe brain damage remain conscious with preserved capacity for memory, attention, intention, and awareness. In many cases, these patients fluctuate dramatically (e.g., the well-known case of Gary Dockery, the brain-injured police officer who “woke up” and interacted with his family for nearly twenty-four hours after seven years of minimal responsiveness—Chicago Tribune Jan. 29, 1997 “After Miracle Coma Patient Has Way to Go”).
There has been a striking lack of therapeutic options for these patients, despite evidence of their capacity to further optimize their brain function; this capacity is evident in the spontaneous fluctuations of functional level in many patients and the induced functional changes in some patients following sensory stimulation or patient initiated behaviors. The significance of developing a therapeutic intervention for patients having impaired cognitive function, especially those who remain conscious with preserved capacity for memory, attention, intention, and awareness lies in both the devastating reduction in quality of life they suffer and the economic burden these patients place on the health care system. These costs include full-time care in nursing and chronic rehabilitation facilities. Moreover, head trauma accounts for the largest percentage of these patients and most patients having impaired function caused by head trauma are under 40 years of age. Such patients represent a disproportionate economic cost in terms of both the loss of their expected productivity and the attendant costs of very long-term full-time care based on their young age.
Vestibular stimulation has been shown to reverse cognitive impairments. Schiff, et al., “Does Vestibular Stimulation Activate Thalamocortical Mechanisms That Reintegrate Impaired Cortical Regions?,” Proc. R. Soc. Land. B. 266:421-23 (1999). However, improved procedures for controlling such stimulation is needed.
The present invention is directed to overcoming this deficiency.