Publications by authors named "David K Su"

Restoring dexterous hand control is critical for people with paralysis. Approaches based on surface or intramuscular stimulation provide limited finger control, generate insufficient force to recover functional movements, and require numerous electrodes. Here, we show that intrafascicular peripheral electrodes could produce functional grasps and sustained forces in three monkeys.

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Vagus nerve stimulation (VNS) has been tested as therapy for several brain disorders and as a means to modulate cortical excitability and brain plasticity. Cortical effects of VNS, manifesting as vagal-evoked potentials (VEPs), are thought to arise from activation of ascending cholinergic and noradrenergic systems. However, it is unknown whether those effects are modulated by brain state at the time of stimulation.

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OBJECT Urgent ventriculostomy placement can be a lifesaving procedure in the setting of hydrocephalus or elevated intracranial pressure. While external ventricular drain (EVD) insertion is common, there remains a high rate of suboptimal drain placement. Here, the authors seek to demonstrate the feasibility of an ultrasound-based guidance system that can be inserted into an existing EVD catheter to provide a linear ultrasound trace that guides the user toward the ventricle.

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Objective: Human voluntary movements are a final product of complex interactions between multiple sensory, cognitive and motor areas of central nervous system. The objective was to investigate temporal sequence of activation of premotor (PM), primary motor (M1) and somatosensory (S1) areas during cued finger movements.

Methods: Electrocorticography (ECoG) was used to measure activation timing in human PM, S1, and M1 neurons in preparation for finger movements in 5 subjects with subdural grids for seizure localization.

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Symptomatic intradural extramedullary arachnoid cysts in children are rare, and of the previously reported pediatric cases in the current literature, none to our knowledge were associated with a spinal cord syrinx. We describe an 8-year-old child who presented with paraparesis and regression of bowel and bladder control. An intradural extramedullary arachnoid cyst was identified on preoperative magnetic resonance imaging, with an associated spinal cord syrinx.

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Leiomyomas are benign smooth muscle tumors commonly found in the genitourinary or gastrointestinal tracts. Rarely, they present as primary intracranial extra-axial brain tumors. Most of these lesions have been described in immunocompromised patients, but have been found very rarely in the immunocompetent patient.

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Objective: Accurate image guidance is an essential component of percutaneous procedures in the head and neck. The combination of preprocedural magnetic resonance imaging (MRI) with cone-beam computed tomography (CBCT) and real-time fluoroscopy (the "triple-overlay" technique) could be useful in image-guided targeting of lesions in the head and neck.

Methods: Three patients underwent percutaneous diagnostic or therapeutic procedures of head and neck lesions (mean, 2.

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