Neurosurgery
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Nonfunctioning pituitary macroadenomas frequently invade the cavernous sinus and many cannot be completely resected without undue risk. Gamma knife radiosurgery (GKRS) is highly effective for treating residual and recurrent adenomas. However, there is no consensus as to whether GKRS should be used early to treat residual adenoma or after a set period of clinical observation during which adenoma growth is demonstrated. Given the high incidence of adenoma progression after subtotal resection over time, the present study examines the potential utility of GKRS performed shortly after transsphenoidal surgery vs expectant management with delayed GKRS treatment. ⋯ Early treatment with GKRS appears to decrease the rate of radiographic and symptomatic progression of subtotally resected nonfunctioning pituitary macroadenomas compared with late GKRS treatment after a period of expectant management. Delaying radiosurgery may place patients at increased risk for adenoma progression and endocrinopathy.
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Direct brain stimulation is thought to produce a temporary lesion effect to the surrounding tissue and the synaptically connected network. In the medial temporal lobe (MTL), application of electrical current has been shown to produce memory impairments, but the nature of this effect is unknown. ⋯ We interpret our findings as support for a rapid contextual change account of stimulation-induced forgetting. Stimulation of the MTL may have disrupted neural activity representing temporal context, and thus impaired the internally generated memory search. Alternatively, an interruption of list item maintenance may explain impaired performance. By continuing to refine the cognitive understanding of forgetting-induced MTL stimulation, future research may lead to selective pruning of unwanted memories.
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Intractable focal epilepsy is a devastating disorder with profound effects on cognition and quality of life. Epilepsy surgery can lead to seizure freedom in patients with focal epilepsy; however, sometimes it fails owing to an incomplete delineation of the epileptogenic zone (EZ). Brain networks in epilepsy can be studied with resting-state functional connectivity (RSFC) analysis, yet previous investigations using functional MRI or electrocorticography have produced inconsistent results. Magnetoencephalography (MEG) allows noninvasive whole-brain recordings, and can be used to study both long-range network disturbances in focal epilepsy and regional connectivity at the EZ. ⋯ Widespread global decreases in functional connectivity are observed in patients with focal epilepsy and may reflect deleterious long-term effects of recurrent seizures. Furthermore, enhanced regional functional connectivity at the area of resection may help predict seizure outcome and aid surgical planning.
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Brain Machine Interface (BMI) systems allow patients with neurological injuries to control assistive devices using cortical signals produced during motor imagery (MI). To improve BMI performance, we sought to enhance cortical signals by training subjects in MI techniques that induce activation of mirror neuron networks (MNN). ⋯ Motor imagery training that activates mirror neuron networks enhances cortical signals during MI and during the performance of corresponding movements in healthy subjects. As MI-based signals are used to operate BMIs, our research suggests that MNN-based MI training may improve BMI performance. Additionally, VR-based imagery training may provide a benefit over AO training to induce bilateral activation of MNNs.
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We showed that, after traumatic spinal cord injury (TSCI), the injured cord is compressed by dura. Here, we show that laminectomy + duroplasty decompress the injured cord more effectively than laminectomy alone. ⋯ After TSCI, laminectomy + duroplasty improves spinal cord radiological and physiological parameters more effectively than laminectomy.