Reconnecting the Hand and Arm to the Brain: Efficacy of Neural Interfaces for Sensorimotor Restoration after Tetraplegia.

Background: Paralysis after spinal cord injury involves damage to pathways that connect neurons in the brain to peripheral nerves in the limbs. Re-establishing this communication using neural interfaces has the potential to bridge the gap and restore upper extremity function to people with high tetraplegia. Objective: We report a novel approach for restoring upper extremity function using selective peripheral nerve stimulation controlled by intracortical microelectrode recordings from sensorimotor networks, along with restoration of tactile sensation of the hand using intracortical microstimulation. Methods: A right-handed man with motor-complete C3-C4 tetraplegia was enrolled into the clinical trial. Six 64-channel intracortical microelectrode arrays were implanted into left hemisphere regions involved in upper extremity function, including primary motor and sensory cortices, inferior frontal gyrus, and anterior intraparietal area. Nine 16-channel extraneural peripheral nerve electrodes were implanted to allow targeted stimulation of right median, ulnar (2), radial, axillary, musculocutaneous, suprascapular, lateral pectoral, and long thoracic nerves, to produce selective muscle contractions on demand. Proof-of-concept studies were performed to demonstrate feasibility of a bidirectional brain-machine interface to restore function of the participant's own arm and hand. Results: Multi-unit neural activity that correlated with intended motor action was successfully recorded from intracortical arrays. Microstimulation of electrodes in somatosensory cortex produced repeatable sensory percepts of individual fingers for restoration of touch sensation. Selective electrical activation of peripheral nerves produced antigravity muscle contractions. The system was well tolerated with no operative complications. Conclusion: The combination of implanted cortical electrodes and nerve cuff electrodes has the potential to allow restoration of motor and sensory functions of the arm and hand after neurological injury.

Utility of Stereoelectroencephalography in Children with Dysembryoplastic Neuroepithelial Tumor and Cortical Malformation.

BACKGROUND: Uncontrolled seizures in children can contribute to irreversible cognitive impairment and developmental delay, in addition to placing them at risk for sudden unexplained death in epileptic patients (SUDEP). Since its introduction at Saint Ann Hospital in Paris in the 1960s, stereoelectroencephalography (SEEG) is increasingly being utilized at epilepsy centers in the United States as an invasive tool to help localize the seizure focus in drug-resistant focal epilepsy. INDICATIONS: Children with symptomatic epilepsy, commonly due to cortical dysplasia and dysembryoplastic neuroepithelial tumor (DNET), may benefit from SEEG investigation. The arrangement of SEEG electrodes is individually tailored based on the suspected location of the epileptogenic zone (EZ). The implanted depth electrodes are used to electrically stimulate the corresponding cortices to obtain information about the topography of eloquent cortex and EZ. Morbidity: Surgical morbidity in these children undergoing SEEG investigation is low, but not negligible. The number of electrodes directly correlates with the risk of intraoperative complication. Thus a risk and benefit analysis needs to be carefully considered for each patient. Neurodiagnostic technology: Both during and after the SEEG electrode implantation, the intraoperative monitoring and EEG technologists play a vital role in the successful monitoring of the patient. CONCLUSION: SEEG is an important tool in the process of epilepsy surgery in children with symptomatic epilepsy, commonly due to cortical dysplasia and DNET.

Modern technology calls for a modern approach to classification of epileptic seizures and the epilepsies.

In the last 10-15 years the ILAE Commission on Classification and Terminology has been presenting proposals to modernize the current ILAE Classification of Epileptic Seizures and Epilepsies. These proposals were discussed extensively in a series of articles published recently in Epilepsia and Epilepsy Currents. There is almost universal consensus that the availability of new diagnostic techniques as also of a modern understanding of epilepsy calls for a complete revision of the Classification of Epileptic Seizures and Epilepsies. Unfortunately, however, the Commission is still not prepared to take a bold step ahead and completely revisit our approach to classification of epileptic seizures and epilepsies. In this manuscript we critically analyze the current proposals of the Commission and make suggestions for a classification system that reflects modern diagnostic techniques and our current understanding of epilepsy.