Publications by authors named "Christopher R Conner"

Deep brain stimulation (DBS) targeting the ventral intermediate (Vim) nucleus of the thalamus is an effective treatment for essential tremor (ET). We studied 15 ​ET patients undergoing DBS to a major input/output tract of the Vim, the dentato-rubro-thalamic tract (DRTt), using resting state functional MRI (rsfMRI) to evaluate connectivity differences between DBS ON and OFF and elucidate significant regions most influential in impacting tremor control and/or concomitant gait ataxia. Anatomical/functional 1.

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Quantum communication test beds provide a useful resource for experimentally investigating a variety of communication protocols. Here we demonstrate a superconducting circuit test bed with bidirectional multiphoton state transfer capability using time-domain shaped wave packets. The system we use to achieve this comprises two remote nodes, each including a tunable superconducting transmon qubit and a tunable microwave-frequency resonator, linked by a 2 m-long superconducting coplanar waveguide, which serves as a transmission line.

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Essential tremor DBS targeting the ventral intermediate nucleus (Vim) of the thalamus and its input, the dentato-rubro-thalamic tract (DRTt), has proven to be an effective treatment strategy. We examined thalamo-cortical evoked potentials (TCEPs) and cortical dynamics during stimulation of the DRTt. We recorded TCEPs in primary motor cortex during clinical and supra-clinical stimulation of the DRTt in ten essential tremor patients.

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Article Synopsis
  • Deep brain stimulation (DBS) is a recognized treatment for various neurological and psychiatric disorders, but disparities in access to this procedure exist based on demographic factors.
  • The study analyzed 104,356 DBS cases from 1993 to 2017 using the National Inpatient Sample to identify trends and predictors affecting procedure utilization among different patient groups.
  • Findings indicate significant disparities in DBS access, especially concerning age, sex, and race, with noticeable variations in these factors depending on the specific indication for treatment.
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Objective: The use of magnetic resonance-guided focused ultrasound (MRgFUS) for the treatment of tremor-related disorders and other novel indications has been limited by guidelines advocating treatment of patients with a skull density ratio (SDR) above 0.45 ± 0.05 despite reports of successful outcomes in patients with a low SDR (LSDR).

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Objective: Temporary drainage of CSF with lumbar puncture or lumbar drainage has a high predictive value for identifying patients with suspected idiopathic normal pressure hydrocephalus (iNPH) who may benefit from ventriculoperitoneal shunt insertion. However, it is unclear what differentiates responders from nonresponders. The authors hypothesized that nonresponders to temporary CSF drainage would have patterns of reduced regional gray matter volume (GMV) as compared with those of responders.

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Background: The surgical treatment of insular lesions has been historically associated with high morbidity. Laser interstitial thermal therapy (LITT) has been increasingly used in the treatment of insular lesions, commonly neoplastic or epileptogenic. Stereotaxis is used to guide laser probes to the insula where real-time magnetic resonance thermometry defines lesion creation.

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Deep brain stimulation (DBS) to the superolateral branch of the medial forebrain bundle is an efficacious therapy for treatment-resistant depression, providing rapid antidepressant effects. In this study, we use F-fluorodeoxyglucose-positron emission tomography (PET) to identify brain metabolic changes over 12 months post-DBS implantation in ten of our patients, compared to baseline. The primary outcome measure was a 50% reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) score, which was interpreted as a response.

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Objective: Reimbursement trends for common procedures have persistently declined over the past 2 decades. Spinal instrumentational and fusion procedures are increasingly utilized and have increased in clinical complexity, yet longitudinal inflation-adjusted data for Medicare reimbursements of these procedures have not been evaluated.

Methods: The Centers for Medicare and Medicaid Services (CMS) Physician Fee Schedule Look-Up Tool was used to extract Medicare reimbursements for the 5 most common spinal procedures and associated instrumentations from 2000-2020.

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Article Synopsis
  • Deep brain stimulation (DBS) targeting the medial forebrain bundle shows promise as a treatment for therapy-resistant depression, with effects lasting up to 5 years in some patients.
  • The study tracked 10 patients, assessing improvements using the Montgomery-Åsberg Depression Rating Scale, with significant reductions in scores post-stimulation.
  • Key recommendations for future studies include extending the sham stimulation phase and integrating functional imaging to better understand treatment effects.
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High-fidelity quantum entanglement is a key resource for quantum communication and distributed quantum computing, enabling quantum state teleportation, dense coding, and quantum encryption. Any sources of decoherence in the communication channel, however, degrade entanglement fidelity, thereby increasing the error rates of entangled state protocols. Entanglement purification provides a method to alleviate these nonidealities by distilling impure states into higher-fidelity entangled states.

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For most people, recalling information about familiar items in a visual scene is an effortless task, but it is one that depends on coordinated interactions of multiple, distributed neural components. We leveraged the high spatiotemporal resolution of direct intracranial recordings to better delineate the network dynamics underpinning visual scene recognition. We present a dataset of recordings from a large cohort of humans while they identified images of famous landmarks (50 individuals, 52 recording sessions, 6,775 electrodes, 6,541 trials).

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Background: Methodological approaches to deep brain stimulation (DBS) continue to evolve from awake frame-based to asleep frameless procedures with robotic assistance, primarily directed to optimize operative efficiency, lead accuracy, and patient comfort. Comparison between the 2 is scarce.

Objective: To analyze the impacts of methodological differences on operative efficiency and stereotactic accuracy using a frame compared with a frameless robotic platform while maintaining the awake state and use of multiple microelectrode recording (MER) trajectories.

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In 2019, we implemented a pill-based, opioid-minimizing pain protocol and protocolized moderate sedation for dressing changes in order to decrease opioid exposure in burn patients. We hypothesized that these interventions would reduce inpatient opioid exposure without increasing acute pain scores. Two groups of consecutive patients admitted to the burn service were compared: Pre-group (from January 1, 2018 to July 31, 2019) and Post-group (from January 1, 2020 to June 30, 2020) from before and after the implementation of the protocols (from August 1, 2019 to December 31, 2019).

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Importance: Motor vehicle crashes (MVCs) are an important public health concern. Recent trends suggest that introducing rideshare services has decreased the incidence of MVCs. However, detailed analyses linking rideshare volume, convictions for impaired driving, and nonfatal MVC traumas remain inconclusive.

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Background: Parathyroid carcinoma (PC) is an exceedingly rare, slow-growing but progressive endocrine malignancy that represents a diagnostic and therapeutic challenge. Vertebral metastasis of PC is remarkable, with only 3 prior cases of spinal metastasis reported in the literature.

Case Description: A 62-year-old woman presented with 1 week of neck pain radiating down her right arm.

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Objective: A high rate of cerebral aneurysm recurrence following endovascular coiling has prompted the use of digital subtraction angiography (DSA) for interval follow-up. However, the utility of skull x-rays as an alternative screening method for aneurysm recurrence is unproperly characterized.

Methods: Retrospective review of a prospective registry of ruptured and unruptured cerebral aneurysms.

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The generation of high-fidelity distributed multi-qubit entanglement is a challenging task for large-scale quantum communication and computational networks. The deterministic entanglement of two remote qubits has recently been demonstrated with both photons and phonons. However, the deterministic generation and transmission of multi-qubit entanglement has not been demonstrated, primarily owing to limited state-transfer fidelities.

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Neurosurgery is male dominated with women representing only 12% of residents and 5% of practicing neurosurgeons. The conflicting demands of training versus pregnancy and motherhood are significant deterrents to women entering the field. We examined pregnancy incidence and timing, perinatal complications, and the perceived career impact of motherhood on female neurosurgeons using an anonymous survey of 643 training, practicing, and retired female neurosurgeons from the United States.

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Background: Postoperative cerebral edema around a deep brain stimulation (DBS) electrode is an uncommonly reported complication of DBS surgery. The etiology of this remains unknown, and the presentation is highly variable; however, the patients generally report a good outcome.

Case Description: Here, we report an unusual presentation of postoperative edema in a 66-year-old female who has bilateral dentatorubrothalamic tract (specifically, the ventral intermediate nucleus) DBS for a mixed type tremor disorder.

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A carotid-cavernous fistula (CCF) is an abnormal connection between the carotid circulation and the cavernous sinus. Treatment of CCFs often consists of obliteration of the fistula by a transarterial or transvenous endovascular approach using embolic agents. However, fistula embolization is often halted due to the potential embolic complications that may arise from the retrograde flow of the embolic agents into the arterial circulation, which often leads to the development of fistula recurrence.

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Background: Epidural hematomas (EDHs) involving the venous sinuses are uncommon and carry the risk of hemorrhage or venous infarction. We report the largest case series for superior sagittal sinus- and transverse sinus-related EDHs including surgical and nonsurgical management. We compare our findings to the relevant literature.

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Current models of word-production in Broca's area (i.e. left ventro-lateral prefrontal cortex, VLPFC) posit that sequential and staggered semantic, lexical, phonological and articulatory processes precede articulation.

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Background: Blood blister-like aneurysms (BBAs) are an uncommon group of arterial aneurysms with a high risk of rupture, progression, and repeat rupture. The best intervention is unclear; however, their clinical behavior typically requires urgent intervention. We describe a BBA managed conservatively with complete resolution found at follow-up.

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Semantic memory underpins our understanding of objects, people, places, and ideas. Anomia, a disruption of semantic memory access, is the most common residual language disturbance and is seen in dementia and following injury to temporal cortex. While such anomia has been well characterized by lesion symptom mapping studies, its pathophysiology is not well understood.

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