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Christen M. O’Neal, Cordell M. Baker, Chad A. Glenn, Andrew K. Conner and Michael E. Sughrue

The history of psychosurgery is filled with tales of researchers pushing the boundaries of science and ethics. These stories often create a dark historical framework for some of the most important medical and surgical advancements. Dr. Robert G. Heath, a board-certified neurologist, psychiatrist, and psychoanalyst, holds a debated position within this framework and is most notably remembered for his research on schizophrenia. Dr. Heath was one of the first physicians to implant electrodes in deep cortical structures as a psychosurgical intervention. He used electrical stimulation in an attempt to cure patients with schizophrenia and as a method of conversion therapy in a homosexual man. This research was highly controversial, even prior to the implementation of current ethics standards for clinical research and often goes unmentioned within the historical narrative of deep brain stimulation (DBS). While distinction between the modern practice of DBS and its controversial origins is necessary, it is important to examine Dr. Heath’s work as it allows for reflection on current neurosurgical practices and questioning the ethical implication of these advancements.

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Andrew K. Conner, Kar-Ming Fung, Jo Elle G. Peterson, Chad A. Glenn and Michael D. Martin

Macroscopic ectopic or heterotopic ganglionic tissue within the cauda equina is a very rare pathological finding and is usually associated with spinal dysraphism. However, it may mimic genuine neoplasms of the cauda equina. The authors describe a 29-year-old woman with a history of back pain, right leg pain, and urinary incontinence in whom imaging demonstrated an enhancing mass located in the cauda equina at the L1–2 interspace. The patient subsequently underwent biopsy and was found to have a focus of ectopic ganglionic tissue that was 1.3 cm in greatest dimension.

To the authors' knowledge, ectopic or heterotopic ganglionic tissue within the cauda equina in a patient without evidence of spinal dysraphism has never been reported. This patient presented with imaging and clinical findings suggestive of a neoplasm, and an open biopsy proved the lesion to be ectopic ganglionic tissue. The authors suggest that ectopic ganglionic tissue be added to the list of differential diagnoses of a space-occupying lesion arising from the cauda equina.

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Phillip A. Bonney, Adrian J. Maurer, Ahmed A. Cheema, Quyen Duong, Chad A. Glenn, Sam Safavi-Abbasi, Julie A. Stoner and Timothy B. Mapstone

OBJECT

The coexistence of Chiari malformation Type I (CM-I) and ventral brainstem compression (VBSC) has been well documented, but the change in VBSC after posterior fossa decompression (PFD) has undergone little investigation. In this study the authors evaluated VBSC in patients with CM-I and determined the change in VBSC after PFD, correlating changes in VBSC with clinical status and the need for further intervention.

METHODS

Patients who underwent PFD for CM-I by the senior author from November 2005 to January 2013 with complete radiological records were included in the analysis. The following data were obtained: objective measure of VBSC (pB–C2 distance); relationship of odontoid to Chamberlain’s, McGregor’s, McRae’s, and Wackenheim’s lines; clival length; foramen magnum diameter; and basal angle. Statistical analyses were performed using paired t-tests and a mixed-effects ANOVA model.

RESULTS

Thirty-one patients were included in the analysis. The mean age of the cohort was 10.0 years. There was a small but statistically significant increase in pB–C2 postoperatively (0.5 mm, p < 0.0001, mixed-effects ANOVA). Eleven patients had postoperative pB–C2 values greater than 9 mm. The mean distance from the odontoid tip to Wackenheim’s line did not change after PFD, signifying postoperative occipitocervical stability. No patients underwent transoral odontoidectomy or occipitocervical fusion. No patients experienced clinical deterioration after PFD.

CONCLUSIONS

The increase in pB–C2 in patients undergoing PFD may occur as a result of releasing the posterior vector on the ventral dura, allowing it to relax posteriorly. This increase appears to be well-tolerated, and a postoperative pB–C2 measurement of more than 9 mm in light of stable craniocervical metrics and a nonworsened clinical examination does not warrant further intervention.

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Joshua D. Burks, Andrew K. Conner, Phillip A. Bonney, Chad A. Glenn, Cordell M. Baker, Lillian B. Boettcher, Robert G. Briggs, Daniel L. O’Donoghue, Dee H. Wu and Michael E. Sughrue

OBJECTIVE

The orbitofrontal cortex (OFC) is understood to have a role in outcome evaluation and risk assessment and is commonly involved with infiltrative tumors. A detailed understanding of the exact location and nature of associated white matter tracts could significantly improve postoperative morbidity related to declining capacity. Through diffusion tensor imaging–based fiber tracking validated by gross anatomical dissection as ground truth, the authors have characterized these connections based on relationships to other well-known structures.

METHODS

Diffusion imaging from the Human Connectome Project for 10 healthy adult controls was used for tractography analysis. The OFC was evaluated as a whole based on connectivity with other regions. All OFC tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes. Ten postmortem dissections were then performed using a modified Klingler technique to demonstrate the location of major tracts.

RESULTS

The authors identified 3 major connections of the OFC: a bundle to the thalamus and anterior cingulate gyrus, passing inferior to the caudate and medial to the vertical fibers of the thalamic projections; a bundle to the brainstem, traveling lateral to the caudate and medial to the internal capsule; and radiations to the parietal and occipital lobes traveling with the inferior fronto-occipital fasciculus.

CONCLUSIONS

The OFC is an important center for processing visual, spatial, and emotional information. Subtle differences in executive functioning following surgery for frontal lobe tumors may be better understood in the context of the fiber-bundle anatomy highlighted by this study.

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Joshua D. Burks, Andrew K. Conner, Robert G. Briggs, Chad A. Glenn, Phillip A. Bonney, Ahmed A. Cheema, Sixia Chen, Naina L. Gross and Timothy B. Mapstone

OBJECTIVE

Experience has led us to suspect an association between shunt malfunction and recent abdominal surgery, yet information about this potential relationship has not been explored in the literature. The authors compared shunt survival in patients who underwent abdominal surgery to shunt survival in our general pediatric shunt population to determine whether such a relationship exists.

METHODS

The authors performed a retrospective review of all cases in which pediatric patients underwent ventriculoperitoneal shunt operations at their institution during a 7-year period. Survival time in shunt operations that followed abdominal surgery was compared with survival time of shunt operations in patients with no history of abdominal surgery. Univariate and multivariate analyses were used to identify factors associated with failure.

RESULTS

A total of 141 patients who underwent 468 shunt operations during the period of study were included; 107 of these 141 patients had no history of abdominal surgery and 34 had undergone a shunt operation after abdominal surgery. Shunt surgery performed more than 2 weeks after abdominal surgery was not associated with time to shunt failure (p = 0.86). Shunt surgery performed within 2 weeks after abdominal surgery was associated with time to failure (adjusted HR 3.6, 95% CI 1.3–9.6).

CONCLUSIONS

Undergoing shunt surgery shortly after abdominal surgery appears to be associated with shorter shunt survival. When possible, some patients may benefit from shunt placement utilizing alternative termini.

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Joshua D. Burks, Andrew K. Conner, Robert G. Briggs, Phillip A. Bonney, Adam D. Smitherman, Cordell M. Baker, Chad A. Glenn, Cameron A. Ghafil, Dillon P. Pryor, Kyle P. O’Connor and Bradley N. Bohnstedt

OBJECTIVE

A shifting emphasis on efficient utilization of hospital resources has been seen in recent years. However, reduced screening for blunt vertebral artery injury (BVAI) may result in missed diagnoses if risk factors are not fully understood. The authors examined the records of blunt trauma patients with fractures near the craniocervical junction who underwent CTA at a single institution to better understand the risk of BVAI imposed by occipital condyle fractures (OCFs).

METHODS

The authors began with a query of their prospectively collected trauma registry to identify patients who had been screened for BVAI using ICD-9-CM diagnostic codes. Grade and segment were recorded in instances of BVAI. Locations of fractures were classified into 3 groups: 1) OCFs, 2) C1 (atlas) fractures, and 3) fractures of the C2–6 vertebrae. Univariate and multivariate analyses were performed to identify any fracture types associated with BVAI.

RESULTS

During a 6-year period, 719 patients underwent head and neck CTA following blunt trauma. Of these patients, 147 (20%) had OCF. BVAI occurred in 2 of 43 patients with type I OCF, 1 of 42 with type II OCF, and in 9 of 62 with type III OCF (p = 0.12). Type III OCF was an independent risk factor for BVAI in multivariate modeling (OR 2.29 [95% CI 1.04–5.04]), as were fractures of C1–6 (OR 5.51 [95% CI 2.57–11.83]). Injury to the V4 segment was associated with type III OCF (p < 0.01).

CONCLUSIONS

In this study, the authors found an association between type III OCF and BVAI. While further study may be necessary to elucidate the mechanism of injury in these cases, this association suggests that thorough cerebrovascular evaluation is warranted in patients with type III OCF.

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Joshua D. Burks, Phillip A. Bonney, Andrew K. Conner, Chad A. Glenn, Robert G. Briggs, James D. Battiste, Tressie McCoy, Daniel L. O'Donoghue, Dee H. Wu and Michael E. Sughrue

OBJECTIVE

Gliomas invading the anterior corpus callosum are commonly deemed unresectable due to an unacceptable risk/benefit ratio, including the risk of abulia. In this study, the authors investigated the anatomy of the cingulum and its connectivity within the default mode network (DMN). A technique is described involving awake subcortical mapping with higher attention tasks to preserve the cingulum and reduce the incidence of postoperative abulia for patients with so-called butterfly gliomas.

METHODS

The authors reviewed clinical data on all patients undergoing glioma surgery performed by the senior author during a 4-year period at the University of Oklahoma Health Sciences Center. Forty patients were identified who underwent surgery for butterfly gliomas. Each patient was designated as having undergone surgery either with or without the use of awake subcortical mapping and preservation of the cingulum. Data recorded on these patients included the incidence of abulia/akinetic mutism. In the context of the study findings, the authors conducted a detailed anatomical study of the cingulum and its role within the DMN using postmortem fiber tract dissections of 10 cerebral hemispheres and in vivo diffusion tractography of 10 healthy subjects.

RESULTS

Forty patients with butterfly gliomas were treated, 25 (62%) with standard surgical methods and 15 (38%) with awake subcortical mapping and preservation of the cingulum. One patient (1/15, 7%) experienced postoperative abulia following surgery with the cingulum-sparing technique. Greater than 90% resection was achieved in 13/15 (87%) of these patients.

CONCLUSIONS

This study presents evidence that anterior butterfly gliomas can be safely removed using a novel, attention-task based, awake brain surgery technique that focuses on preserving the anatomical connectivity of the cingulum and relevant aspects of the cingulate gyrus.

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Andrew K. Conner, Joshua D. Burks, Cordell M. Baker, Adam D. Smitherman, Dillon P. Pryor, Chad A. Glenn, Robert G. Briggs, Phillip A. Bonney and Michael E. Sughrue

OBJECTIVE

The purpose of this study was to describe a method of resecting temporal gliomas through a keyhole lobectomy and to share the results of using this technique.

METHODS

The authors performed a retrospective review of data obtained in all patients in whom the senior author performed resection of temporal gliomas between 2012 and 2015. The authors describe their technique for resecting dominant and nondominant gliomas, using both awake and asleep keyhole craniotomy techniques.

RESULTS

Fifty-two patients were included in the study. Twenty-six patients (50%) had not received prior surgery. Seventeen patients (33%) were diagnosed with WHO Grade II/III tumors, and 35 patients (67%) were diagnosed with a glioblastoma. Thirty tumors were left sided (58%). Thirty procedures (58%) were performed while the patient was awake. The median extent of resection was 95%, and at least 90% of the tumor was resected in 35 cases (67%). Five of 49 patients (10%) with clinical follow-up experienced permanent deficits, including 3 patients (6%) with hydrocephalus requiring placement of a ventriculoperitoneal shunt and 2 patients (4%) with weakness. Three patients experienced early postoperative anomia, but no patients had a new speech deficit at clinical follow-up.

CONCLUSIONS

The authors provide their experience using a keyhole lobectomy for resecting temporal gliomas. Their data demonstrate the feasibility of using less invasive techniques to safely and aggressively treat these tumors.