Variation in Cervical Pedicle Morphology: Important Considerations for Posterior Cervical Procedures.

BACKGROUND: Safe posterior cervical spine surgery requires in-depth understanding of the surgical anatomy and common variations. The cervical pedicle attachment site to the vertebral body (VB) affects the location of exiting nerve roots and warrants preoperative evaluation. The relative site of attachment of the cervical pedicle has not been previously described. OBJECTIVE: To describe the site of the pedicle attachment to the VB in the subaxial cervical spine. METHODS: Cervical spine computed tomography scans without any structural, degenerative, or traumatic pathology as read by a board-certified neuroradiologist during 2021 were reviewed. Multiplanar reconstructions were created and cross-registered. The pedicle's attachment to the VB was measured relative to the VB height using a novel calculation system. RESULTS: Fifty computed tomography scans met inclusion criteria yielding 600 total pedicles between C3-T1 (100 per level). The average patient age was 26 ± 5.3 years, and 21/50 (42%) were female. 468/600 (78%) pedicles attached in the cranial third of the VB, 132/600 (22%) attached in the middle third, and 0 attached to the caudal third. The highest prevalence of variant anatomy occurred at C3 (36/100 C3 pedicles; 36%). CONCLUSION: In the subaxial cervical spine, pedicles frequently attach to the top third of the VB, but significant variation is observed. The rate of variation is highest at C3 and decreases linearly with caudal progression down the subaxial cervical spine to T1. This is the first report investigating this morphological phenomenon.

Intraoperative Simulation: Team Training for Resuscitation While Using Intraoperative Computed Tomography: 2-Dimensional Operative Video.

Spine surgeons increasingly use intraoperative computed tomography (iCT) to facilitate surgery. iCT has several advantages, including the ability to decrease radiation exposure, improve surgical accuracy, and decrease operative time.1-3 However, the large footprint of the equipment can impede fast patient access in the event of an emergency resuscitation. This challenge is compounded when the patient is prone with rigid head fixation. To achieve fast, high-quality resuscitation, a large team must overcome numerous challenges. Cohesive team functioning under these circumstances requires planning, practice, and refinement.4 As a result of our simulation sessions, we have made several changes to the setup of our iCT cases. The following equipment is now routinely used: extralong tubing between the anesthesia circuit and patient, portable vital monitor, additional intravenous access is obtained, and extension tubing is used with all lines. We have created educational diagrams to streamline 2 challenging processes: optimal bed placement (for supination) and removal of equipment from the operating room (OR) to accommodate an influx of emergency personnel and equipment. Since the implementation of this protocol, 1 prone posterior cervical patient had intraoperative cardiac arrest. The protocol was followed. Return of spontaneous circulation was achieved within 5 min. The patient was discharged from the hospital with no neurological sequelae. During debriefing, stakeholders uniformly credited the simulated practice with this positive outcome. Emergency planning is a multifaceted process that continually evolves. With a steady flux of personnel and equipment, ongoing practice is essential to ensure readiness. Here, we share the key elements of our twice-yearly simulation. This simulation was performed on a training mannequin. This study did not involve human subjects. Any depictions of care rendered to nonidentifiable patients were standard (nonexperimental).

Utility of invasive electroencephalography in children 3 years old and younger with refractory epilepsy.

OBJECTIVE: Early surgical intervention for pediatric refractory epilepsy is increasingly advocated as surgery has become safer and data have demonstrated improved outcomes with early seizure control. There is concern that the risks associated with staged invasive electroencephalography (EEG) in very young children outweigh the potential benefits. Here, the authors present a cohort of children with refractory epilepsy who were referred for invasive monitoring, and they evaluate the role and safety of staged invasive EEG in those 3 years old and younger. METHODS: The authors conducted a retrospective review of children 3 years and younger with epilepsy, who had been managed surgically at two institutions between 2001 and 2015. A cohort of pediatric patients older than 3 years of age was used for comparison. Demographics, seizure etiology, surgical management, surgical complications, and adverse events were recorded. Statistical analysis was completed using Stata version 13. A p < 0.05 was considered statistically significant. Fisher's exact test was used to compare proportions. RESULTS: Ninety-four patients (45 patients aged ≤ 3 [47.9%]) and 208 procedures were included for analysis. Eighty-six procedures (41.3%) were performed in children younger than 3 years versus 122 in the older cohort (58.7%). Forty-two patients underwent grid placement (14 patients aged ≤ 3 [33.3%]); 3 of them developed complications associated with the implant (3/42 [7.14%]), none of whom were among the younger cohort. Across all procedures, 11 complications occurred in the younger cohort versus 5 in the older patients (11/86 [12.8%] vs 5/122 [4.1%], p = 0.032). Two adverse events occurred in the younger group versus 1 in the older group (2/86 [2.32%] vs 1/122 [0.82%], p = 0.571). Following grid placement, 13/14 younger patients underwent guided resections compared to 20/28 older patients (92.9% vs 71.4%, p = 0.23). CONCLUSIONS: While overall complication rates were higher in the younger cohort, subdural grid placement was not associated with an increased risk of surgical complications in that population. Invasive electrocorticography informs management in very young children with refractory, localization-related epilepsy and should therefore be used when clinically indicated.

Single arm access venous sinus stenting (SAVeS) technique: Technical note.

Intracranial venous sinus stenting is gaining acceptance as an effective treatment for idiopathic intracranial hypertension (IIH). The typical approach is via femoral venous and arterial access for transvenous stenting with simultaneous angiography. These patients are at an above average risk for groin complications considering obesity is typically associated with IIH and the need for heparinization and dual antiplatelet therapy. Here, we describe cerebral venography, angiography, and venous sinus stenting via a single upper extremity. We utilize a transradial approach for angiography and a venous access via the brachial or basilic vein. Over a series of 28 consecutive procedures, we were able to successfully access the intracranial venous sinuses via the arm without access site complications. This method offers the advantages of immediate patient mobilization after the procedure and more easily monitored and compressible access sites for easier post-procedural care.

Hypertonic Saline is Superior to Mannitol for the Combined Effect on Intracranial Pressure and Cerebral Perfusion Pressure Burdens in Patients With Severe Traumatic Brain Injury.

BACKGROUND: Hypertonic saline (HTS) and mannitol are effective in reducing intracranial pressure (ICP) after severe traumatic brain injury (TBI). However, their simultaneous effect on the cerebral perfusion pressure (CPP) and ICP has not been studied rigorously. OBJECTIVE: To determine the difference in effects of HTS and mannitol on the combined burden of high ICP and low CPP in patients with severe TBI. METHODS: We performed a case-control study using prospectively collected data from the New York State TBI-trac® database (Brain Trauma Foundation, New York, New York). Patients who received only 1 hyperosmotic agent, either mannitol or HTS for raised ICP, were included. Patients in the 2 groups were matched (1:1 and 1:2) for factors associated with 2-wk mortality: age, Glasgow Coma Scale score, pupillary reactivity, hypotension, abnormal computed tomography scans, and craniotomy. Primary endpoint was the combined burden of ICPhigh (> 25 mm Hg) and CPPlow (< 60 mm Hg). RESULTS: There were 25 matched pairs for 1:1 comparison and 24 HTS patients matched to 48 mannitol patients in 1:2 comparisons. Cumulative median osmolar doses in the 2 groups were similar. In patients treated with HTS compared to mannitol, total number of days (0.6 ± 0.8 vs 2.4 ± 2.3 d, P < .01), percentage of days with (8.8 ± 10.6 vs 28.1 ± 26.9%, P < .01), and the total duration of ICPhigh + CPPlow (11.12 ± 14.11 vs 30.56 ± 31.89 h, P = .01) were significantly lower. These results were replicated in the 1:2 match comparisons. CONCLUSION: HTS bolus therapy appears to be superior to mannitol in reduction of the combined burden of intracranial hypertension and associated hypoperfusion in severe TBI patients.

Middle Meningeal Artery Embolization for Recurrent Chronic Subdural Hematoma: A Case Series.

BACKGROUND: Embolization of the middle meningeal artery (MMA) has recently been proposed as an alternative to surgery for treatment of chronic subdural hematoma (SDH). There is increasing evidence that fragile neovasculature arising from distal branches of the MMA found within the membrane that forms around a chronic SDH is responsible for high recurrence rates due to chronic, repeated rebleeding. Embolization of the MMA could thus potentially eliminate the blood supply to this membrane and prevent further rebleeding. METHODS: The cases of 6 patients with 7 recurrent SDHs treated with MMA embolization with polyvinyl alcohol particles were retrospectively reviewed. RESULTS: MMA embolization was performed successfully in all 6 patients with no complications. Of the 7 SDHs treated, 1 required surgical reevacuation due to recurrence. The other 6 were able to avoid surgery, with reduction in size from 12 mm to 11 mm over 3 weeks, 14 mm to 9 mm over 9 weeks, 21 mm to 5 mm over 31 weeks, 17 mm to 9 mm over 12 weeks, 18 mm to 3 mm over 8 weeks, and 25 mm to 6 mm over 24 weeks. All patients had resolution of symptoms at longest follow-up. CONCLUSIONS: In this case series of 6 patients harboring 7 recurrent, chronic SDHs, 6 of the 7 were successfully treated with MMA embolization and able to avoid surgery for reevacuation, suggesting that this minimally invasive technique may represent an effective alternative to surgery.

Treatment of Unruptured Brain Arteriovenous Malformations: A Single-Center Experience of 86 Patients and a Critique of the A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) Trial.

OBJECTIVE: The A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) trial has received fierce criticism, including considerable selection bias, poor generalizability, questionable clinical practices (only 15.8% underwent surgical resection, the gold standard for arteriovenous malformation [AVM] treatment), and short follow-up (33 months) for a disease process that carries a life-long risk. In this study, we sought to present our own experience treating unruptured brain AVMs to provide supporting evidence of the ARUBA trial criticism. METHODS: All cases of treated brain AVMs from 2004 to 2017 at our institution were retrospectively reviewed and included in the analysis if they met ARUBA trial inclusion criteria. The primary outcome was symptomatic stroke or death. Secondary outcomes included AVM obliteration, long-term clinical impairment (modified Rankin Scale score >1), and new major or minor postoperative deficit. RESULTS: Of the 245 reviewed cases, 86 met the ARUBA trial criteria. Treatment included microsurgical resection alone (2.3%), preoperative embolization followed by microsurgical resection (62.8%), stereotactic radiosurgery alone (10.5%), embolization followed by stereotactic radiosurgery (15.1%), and embolization alone (9.3%). The primary outcome was met in 8.3%, new perioperative major and minor complications occurred in 5.8% and 12.8%, and long-term clinical impairment in 4.5%. AVM obliteration was observed in 92.4% overall and in 100% of patients who underwent surgical resection. CONCLUSIONS: The criticism of the ARUBA trial is warranted, as our study found that treatment of unruptured brain AVMs has an acceptable safety profile when approached in a multidisciplinary manner at an experienced institution, using surgical resection as the primary treatment modality when applicable.

Cell-type specific expression of p11 controls cocaine reward.

BACKGROUND: The high rate of comorbidity between depression and cocaine addiction suggests shared molecular mechanisms and anatomical pathways. Limbic structures, such as the nucleus accumbens (NAc), play a crucial role in both disorders, yet how different cell types within these structures contribute to the pathogenesis remains elusive. Downregulation of p11 (S100A10), specifically in the NAc, elicits depressive-like behaviors in mice, but its role in drug addiction is unknown. METHODS: We combined mouse genetics and viral strategies to determine how the titration of p11 levels within the entire NAc affects the rewarding actions of cocaine on behavior (six to eight mice per group) and molecular correlates (three experiments, five to eight mice per group). Finally, the manipulation of p11 expression in distinct NAc dopaminoceptive neuronal subsets distinguished cell-type specific effects of p11 on cocaine reward (five to eight mice per group). RESULTS: We demonstrated that p11 knockout mice have enhanced cocaine conditioned place preference, which is reproduced by the focal downregulation of p11 in the NAc of wild-type mice. In wild-type mice, cocaine reduced p11 expression in the NAc, while p11 overexpression exclusively in the NAc reduced cocaine conditioned place preference. Finally, we identified dopamine receptor-1 expressing medium spiny neurons as key mediators of the effects of p11 on cocaine reward. CONCLUSIONS: Our data provide evidence that disruption of p11 homeostasis in the NAc, particularly in dopamine receptor-1 expressing medium spiny neurons, may underlie pathophysiological mechanisms of cocaine rewarding action. Treatments to counter maladaptation of p11 levels may provide novel therapeutic opportunities for cocaine addiction.

Results and risk factors for recurrence following endoscopic endonasal transsphenoidal surgery for pituitary adenoma.

BACKGROUND: Endoscopic endonasal (EE) transsphenoidal surgery is an important surgical approach to the treatment of sellar pathology, particularly for pituitary adenomas. Risk factors for the radiographic recurrence of pituitary adenomas resected using a purely endoscopic approach have not been established. This study investigates outcomes and identifies risk factors for recurrence following EE transsphenoidal surgery for pituitary adenoma. METHODS: We performed a retrospective review of 64 patients with pituitary adenomas undergoing EE surgery by a single, right-handed surgeon preferentially operating through the right nares. Post-operative MRI studies were utilized to monitor for residual disease or disease recurrence. RESULTS: Residual tumor was found in 31.2% of patients. Over a median follow-up period of 23.1 months (range 4-62.5), 4 (20%) of these patients showed recurrence. Two patients with inconclusive post-operative imaging had subsequent imaging consistent with recurrence, making the total recurrence in our series 9.4%. While no statistically significant effects of gender, age or history of previous treatment were seen, amenorrhea on presentation and maximum tumor diameter >10 mm were significant risk factors for radiographic recurrence (p = 0.044 and 0.005, respectively). No predominant side of residual tissue was identified in these tumors operated through the right nares. CONCLUSIONS: Only 20% of patients with residual tumor developed recurrent disease over a median follow up of 23.1 months. This recurrence rate may be an important consideration in cases where gross total resection is not feasible. Preferentially operating from the right does not seem to influence the location of residual tumor.