05-07-2012, 01:59 PM
Brain-Computer Interface
Brain-Computer Interface.doc (Size: 28.5 KB / Downloads: 30)
History
This 38-year-old man had a 10-year history of progressive, spastic quadriplegia from a factor-Q deficiency. At evaluation, he was able to communicate only through eye blinks and head nods under specific circumstances with a communication board. Although able to breathe on his own, he was unable to speak and frequently had pulmonary problems. A percutaneous gastrostomy tube had been inserted for his nutrition and medications. He required 24-hour nursing care and resided in a convalescent home. Both a living will and power of attorney had been established. He had heard about investigational procedures that attempt to improve communication in patients who lack the ability to communicate by normal means. He had a great deal of familiarity with computers and was quite interested to participate in this program.
Examination
After initial evaluation, it was decided not to proceed with surgery because of marked atrophy in the primary motor and parietal areas (Figure 1) and an apparent inability to communicate adequately with the patient. On appeal, it was emphasized that communication during the initial evaluation had been suboptimal due to technical problems, and that on the fMR image he did demonstrate increased signal in what was presumably the arm area during imagined arm movements. On further review, it was clear that the patient's communication skills were better than previously assessed. On this basis, surgery was performed.
Operation
A right frontal craniectomy was performed over the hand area of the motor cortex as identified on fMR imaging by using Stealth imaging guidance. Two neurotrophic electrodes and transmitters were implanted. It was noted that the cortex was very gliotic. To provide adequate space for the transmitters, one device was placed on the left, and the outer cortical bone and dipole were removed bilaterally beneath the transmitters with a high-speed drill. Cranioplasty was used to secure the connectors and electronics as well as to provide a layer of protection over the top of them. There were no intraoperative complications and the patient was taken to the intensive care unit after surgery.
Postoperative Course
There was some difficulty with the extubation due to the patient's long-standing respiratory insufficiency, but he was successfully extubated on post operative Day 1. Postoperative x-ray films demonstrated bibasilar atelectasis, which was managed with aggressive pulmonary toilet. Physical therapy, nutritional consultation, and speech therapy were performed during the postoperative recovery period. On postoperative Day 4, the patient was discharged in stable condition. Prophylactic antibiotic drugs were used for 10 days and the remainder of the postoperative course was uneventful.
Brain-Computer Interface
Although signals could be obtained from the neurotrophic electrodes, the number and characteristics were abnormal compared with previous patients. The ability of this patient to control the signals was minimal. Because he was not able to interface with the computer successfully, intracranial local field potentials were obtained that allowed computer interactions.[17] The patient's local field potential signals were transmitted wirelessly to a receiver and translated by computer software in to computer cursor movement for a virtual keyboard. This was useful but very limited in its capabilities.
Brain-Computer Interface.doc (Size: 28.5 KB / Downloads: 30)
History
This 38-year-old man had a 10-year history of progressive, spastic quadriplegia from a factor-Q deficiency. At evaluation, he was able to communicate only through eye blinks and head nods under specific circumstances with a communication board. Although able to breathe on his own, he was unable to speak and frequently had pulmonary problems. A percutaneous gastrostomy tube had been inserted for his nutrition and medications. He required 24-hour nursing care and resided in a convalescent home. Both a living will and power of attorney had been established. He had heard about investigational procedures that attempt to improve communication in patients who lack the ability to communicate by normal means. He had a great deal of familiarity with computers and was quite interested to participate in this program.
Examination
After initial evaluation, it was decided not to proceed with surgery because of marked atrophy in the primary motor and parietal areas (Figure 1) and an apparent inability to communicate adequately with the patient. On appeal, it was emphasized that communication during the initial evaluation had been suboptimal due to technical problems, and that on the fMR image he did demonstrate increased signal in what was presumably the arm area during imagined arm movements. On further review, it was clear that the patient's communication skills were better than previously assessed. On this basis, surgery was performed.
Operation
A right frontal craniectomy was performed over the hand area of the motor cortex as identified on fMR imaging by using Stealth imaging guidance. Two neurotrophic electrodes and transmitters were implanted. It was noted that the cortex was very gliotic. To provide adequate space for the transmitters, one device was placed on the left, and the outer cortical bone and dipole were removed bilaterally beneath the transmitters with a high-speed drill. Cranioplasty was used to secure the connectors and electronics as well as to provide a layer of protection over the top of them. There were no intraoperative complications and the patient was taken to the intensive care unit after surgery.
Postoperative Course
There was some difficulty with the extubation due to the patient's long-standing respiratory insufficiency, but he was successfully extubated on post operative Day 1. Postoperative x-ray films demonstrated bibasilar atelectasis, which was managed with aggressive pulmonary toilet. Physical therapy, nutritional consultation, and speech therapy were performed during the postoperative recovery period. On postoperative Day 4, the patient was discharged in stable condition. Prophylactic antibiotic drugs were used for 10 days and the remainder of the postoperative course was uneventful.
Brain-Computer Interface
Although signals could be obtained from the neurotrophic electrodes, the number and characteristics were abnormal compared with previous patients. The ability of this patient to control the signals was minimal. Because he was not able to interface with the computer successfully, intracranial local field potentials were obtained that allowed computer interactions.[17] The patient's local field potential signals were transmitted wirelessly to a receiver and translated by computer software in to computer cursor movement for a virtual keyboard. This was useful but very limited in its capabilities.