Direct Versus Indirect Revascularization for Moyamoya: a Large Multicenter Study.

BACKGROUND: Moyamoya is a chronic occlusive cerebrovascular disease of unknown etiology causing neovascularization of the lenticulostriate collaterals at the base of the brain. Although revascularization surgery is the most effective treatment for moyamoya, there is still no consensus on the best surgical treatment modality as different studies provide different outcomes. OBJECTIVE: In this large case series, we compare the outcomes of direct (DR) and indirect revascularisation (IR) and compare our results to the literature in order to reflect on the best revascularization modality for moyamoya. METHODS: We conducted a multicenter retrospective study in accordance with the Strengthening the Reporting of Observational studies in Epidemiology guidelines of moyamoya affected hemispheres treated with DR and IR surgeries across 13 academic institutions predominantly in North America. All patients who underwent surgical revascularization of their moyamoya-affected hemispheres were included in the study. The primary outcome of the study was the rate of symptomatic strokes. RESULTS: The rates of symptomatic strokes across 515 disease-affected hemispheres were comparable between the two cohorts (11.6% in the DR cohort vs 9.6% in the IR cohort, OR 1.238 (95% CI 0.651 to 2.354), p=0.514). The rate of total perioperative strokes was slightly higher in the DR cohort (6.1% for DR vs 2.0% for IR, OR 3.129 (95% CI 0.991 to 9.875), p=0.052). The rate of total follow-up strokes was slightly higher in the IR cohort (8.1% vs 6.6%, OR 0.799 (95% CI 0.374 to 1.709) p=0.563). CONCLUSION: Since both modalities showed comparable rates of overall total strokes, both modalities of revascularization can be performed depending on the patient's risk assessment.

Comparative outcomes of awake spine surgery under spinal versus general anesthesia: a comprehensive systematic review and meta-analysis.

BACKGROUND: Awake surgery, under spinal anesthesia (SA), is an alternative to surgery under general anesthesia (GA), in neurological and spine surgery. In the literature, there seem to be some evidence supporting benefits associated with the use of this anesthetic modality, as compared to GA. Currently, there is a notable lack of updated and comprehensive review addressing the complications associated with both awake SA and GA in spine surgery. We hence aimed to perform a systematic review of the literature and meta-analysis on the topic. METHODS: A systematic search was conducted to identify studies that assessed SA in spine surgery from database inception to April 14, 2023, in PubMed, Medline, Embase, and Cochrane databases. Outcomes of interest included estimated blood loss, length of hospital stay, operative time, and overall complications. Meta-analysis was conducted using random effects models. RESULTS: In total, 38 studies that assessed 7820 patients were included. The majority of the operations that were treated with SA were single-level lumbar cases. Awake patients had significantly shorter lengths of hospital stay (Mean difference (MD): - 0.40 days; 95% CI - 0.64 to - 0.17) and operative time (MD: - 19.17 min; 95% CI - 29.68 to - 8.65) compared to patients under GA. The overall complication rate was significantly higher in patients under GA than SA (RR, 0.59 [95% CI 0.47-0.74]). Patients under GA had significantly higher rates of postoperative nausea/vomiting RR, 0.60 [95% CI 0.39-0.90]) and urinary retention (RR, 0.61 [95% CI 0.37-0.99]). CONCLUSIONS: Patients undergoing awake spine surgery under SA had significantly shorter operations and hospital stays, and fewer rates of postoperative nausea and urinary retention as compared to GA. In summary, awake spine surgery offers a valid alternative to GA and added benefits in terms of postsurgical complications, while being associated with relatively low morbidity.

GABAergic modulation of olfactomotor transmission in lampreys.

Odor-guided behaviors, including homing, predator avoidance, or food and mate searching, are ubiquitous in animals. It is only recently that the neural substrate underlying olfactomotor behaviors in vertebrates was uncovered in lampreys. It consists of a neural pathway extending from the medial part of the olfactory bulb (medOB) to locomotor control centers in the brainstem via a single relay in the caudal diencephalon. This hardwired olfactomotor pathway is present throughout life and may be responsible for the olfactory-induced motor behaviors seen at all life stages. We investigated modulatory mechanisms acting on this pathway by conducting anatomical (tract tracing and immunohistochemistry) and physiological (intracellular recordings and calcium imaging) experiments on lamprey brain preparations. We show that the GABAergic circuitry of the olfactory bulb (OB) acts as a gatekeeper of this hardwired sensorimotor pathway. We also demonstrate the presence of a novel olfactomotor pathway that originates in the non-medOB and consists of a projection to the lateral pallium (LPal) that, in turn, projects to the caudal diencephalon and to the mesencephalic locomotor region (MLR). Our results indicate that olfactory inputs can induce behavioral responses by activating brain locomotor centers via two distinct pathways that are strongly modulated by GABA in the OB. The existence of segregated olfactory subsystems in lampreys suggests that the organization of the olfactory system in functional clusters may be a common ancestral trait of vertebrates.

Transcirculation Pipeline embolization device deployment: a rescue technique.

The Pipeline embolization device (PED) has become a very important tool in the treatment of nonruptured cerebral aneurysms. However, a patient's difficult anatomy or vascular stenosis may affect the device delivery. The purpose of this article was to describe an alternate technique for PED deployment when ipsilateral anatomy is not amenable for catheter navigation. A 44-year-old woman with a symptomatic 6-mm right superior hypophyseal artery aneurysm and a known history of right internal carotid artery dissection presented for PED treatment of her aneurysm. An angiogram showed persistence of the arterial dissection with luminal stenosis after 6 months of dual antiplatelet treatment. The contralateral internal carotid artery was catheterized and the PED was deployed via a transcirculation approach, using the anterior communicating artery. Transcirculation deployment of a PED is a viable option when ipsilateral anatomy is difficult or contraindicated for this treatment.

Off-label uses of the Pipeline embolization device: a review of the literature.

The Pipeline embolization device (PED) is the most widely used flow diverter in endovascular neurosurgery. In 2011, the device received FDA approval for the treatment of large and giant aneurysms in the internal carotid artery extending from the petrous to the superior hypophyseal segments. However, as popularity of the device grew and neurosurgeons gained more experience, its use has extended to several other indications. Some of these off-label uses include previously treated aneurysms, acutely ruptured aneurysms, small aneurysms, distal circulation aneurysms, posterior circulation aneurysms, fusiform aneurysms, dissecting aneurysms, pseudoaneurysms, and even carotid-cavernous fistulas. The authors present a literature review of the safety and efficacy of the PED in these off-label uses.

Transarterial Embolization of Intracranial Dural Arteriovenous Fistulas Cognard Type V With Direct Drainage Into the Perimedullary Veins: Case Report and Literature Review.

BACKGROUND AND IMPORTANCE: Cognard type V fistula (CVF) is a rare type of dural arteriovenous fistula characterized by spinal perimedullary venous drainage. Owing to the lack of pathognomonic findings, misdiagnosis is common. Patients often undergo multiple spinal angiograms negative for spinal vascular malformations. Digital subtraction angiography is the gold standard diagnostic tool. The preferred treatment option is endovascular management with embolization through a transarterial, transvenous, or combined approach. Other options include open surgery, stereotactic radiosurgery, or a combination of both. CLINICAL PRESENTATION: The patient from case # 1 presented with progressive weakness and hypoesthesia in the bilateral lower extremities, with urinary and bowel incontinence. The DSA identified a CVF fed by the meningohypophyseal trunk and a draining perimedullary vein. Embolization with 0.1 ccs of Onyx-18 was performed with complete fistula occlusion. The patient from case # 2 developed bilateral lower extremity weakness, diffuse numbness, and urinary incontinence. The DSA showed a CVF fed by tributaries from the ascending pharyngeal artery and posterior meningeal artery branches of the V3 segment, draining into a perimedullary vein. Embolization with 0.3 cc of Onyx-18 was performed with 100% occlusion of the fistula. A 1-year follow-up angiogram confirmed complete fistula occlusion. Both patients consented to the procedure. CONCLUSION: Even if a patient only presents symptoms of myelopathy, CVF should be considered. Herein, we present 2 cases of CVF with direct drainage into the perimedullary veins which presented exclusively with myelopathy syndrome and describe treatment with trasarterial embolization with Onyx.

First United States multicenter experience with the new-generation FRED X surface-modified flow diversion stent: feasibility, safety, and short-term efficacy.

OBJECTIVE: Flow diversion created a paradigm shift in the treatment of intracranial aneurysms. The new flow redirection endoluminal device with X technology (FRED X) is the latest update of the recent Food and Drug Administration-approved FRED. The FRED X is engineered to reduce material thrombogenicity and enhance vessel healing. In this study, the authors aimed to evaluate the feasibility and early safety and efficacy of the new FRED X. METHODS: The authors retrospectively collected and analyzed data from patients who had undergone flow diversion with the new FRED X at four tertiary cerebrovascular centers in the United States from February 2022 through July 2022. RESULTS: Forty-four patients with 45 aneurysms treated using 46 devices comprised the overall study cohort and were divided into two groups: 39 patients with unruptured aneurysms and 5 patients with ruptured aneurysms. The mean patient age was 57.7 ± 9.1 years, and most patients were female (84%). Ninety-one percent of the aneurysms were saccular, with the majority (93%) located in the anterior circulation, specifically the posterior communicating (27%) and carotid ophthalmic (27%) territories. The mean maximum aneurysm diameter was 5.6 ± 4.6 mm, and 20% of the lesions had been previously treated. The mean procedure time was 61.6 minutes, with a mean cumulative fluoroscopy time of 24.6 minutes. Additionally, 7% of the lesions received adjunct treatment. Stent placement was successful in 100% of cases, achieving good wall apposition and complete neck coverage. Further, immediate aneurysm contrast stasis > 90% was observed in 61% of cases. Symptomatic postoperative complications occurred in 3 patients in the unruptured cohort and 1 patient in the ruptured cohort. All patients in the study were discharged on dual antiplatelet regimens with a modified Rankin Scale score of 0. At 6 months after treatment, 89% of cases had adequate occlusion, with < 6% of cases having asymptomatic in-stent stenosis. All patients had excellent functional outcomes. CONCLUSIONS: FRED X for the treatment of an intracranial aneurysm is technically feasible alone or in conjunction with intrasaccular embolization. In addition, the study results showed very promising early safety and efficacy. Follow-up studies should establish the long-term safety and efficacy profiles of this new stent.

Correlation of CT Angiography (CTA) to Digital Subtraction Angiography in Carotid Stenosis (CS) with Real-world Assessment of Overestimation of CS on CTA.

PURPOSE: Computerized tomography angiography (CTA) is a well-established diagnostic modality for carotid stenosis (CS). However, false-positive CTA results may expose patients to unnecessary procedural complications in cases where surgical intervention is not warranted. We aim to assess the correlation of CTA to DSA in CS and characterize patients who were referred for intervention based on CTA and did not require it based on DSA. METHODS: We retrospectively reviewed 186 patients who underwent carotid angioplasty and stenting following pre-procedural CTA at our institution from April 2017 to December 2022. RESULTS: Twenty-one of 186 patients (11.2%) were found to have <50% carotid stenosis on DSA (discordant group). Severe plaque calcification on CTA was associated with a discordant degree of stenosis on DSA (LR+ = 7.4). Among 186 patients, agreement between the percentage of stenosis from CTA and DSA was weak-moderate (r2 = 0.27, p <0.01). Among concordant pairs, we found moderate-strong agreement between CTA and DSA (adj r2=0.37)(p<0.0001). Of 186 patients, 127 patients had CTA stenosis of ≥70%, and 59 had CTA of 50-69%. Correlation between CTA and DSA in severe CTA stenosis was weak (r2=0.11, p <0.01). CONCLUSION: In patients with stenosis found on CTA, over 88% also had stenosis on DSA, with this PPV in line with previous studies. The percent-stenosis value from CTA and DSA was weakly correlated but does not affect clinical judgement of stenosis overall. Severe calcification found on CTA may potentially indicate non-stenosis on DSA.

Impact of the pandemic and concomitant COVID-19 on the management and outcomes of middle cerebral artery strokes: a nationwide registry-based study.

OBJECTIVES: To investigate the impact of the COVID-19 pandemic as well as concomitant COVID-19 itself on stroke care, focusing on middle cerebral artery (MCA) territory infarctions. DESIGN: Registry-based study. SETTING: We used the National Inpatient Sample (NIS) database, which covers a wide range of hospitals within the USA. PARTICIPANTS: The NIS was queried for patients with MCA strokes between 2016 and 2020. In total, 35 231 patients were included. OUTCOME MEASURES: Outcome measures were postprocedural complications, length of stays (LOSs), in-hospital mortality and non-routine discharge. Propensity score matching using all available baseline variables was performed to reduce confounders when comparing patients with and without concomitant COVID-19. RESULTS: Mechanical thrombectomy (MT) was performed in 48.4%, intravenous thrombolysis (IVT) in 38.2%, and both MT and IVT (MT+IVT) in 13.4% of patients. A gradual increase in the use of MT and an opposite decrease in the use of IVT (p<0.001) was detected during the study period. Overall, 25.0% of all patients were admitted for MCA strokes during the pandemic period (2020), of these 209 (2.4%) were concomitantly diagnosed with COVID-19. Patients with MCA strokes and concomitant COVID-19 were significantly younger (64.9 vs 70.0; p<0.001), had significantly worse NIH Stroke Severity scores, and worse outcomes in terms of LOS (12.3 vs 8.2; p<0.001), in-hospital mortality (26.3% vs 9.8%; p<0.001) and non-routine discharge (84.2% vs 76.9%; p=0.013), as compared with those without COVID-19. After matching, only in-hospital mortality rates remained significantly higher in patients with COVID-19 (26.7% vs 8.5%; p<0.001). Additionally, patients with COVID-19 had higher rates of thromboembolic (12.3% vs 7.6%; p=0.035) and respiratory (11.3% vs 6.6%; p=0.029) complications. CONCLUSIONS: Among patients with MCA stroke, those with concomitant COVID-19 were significantly younger and had higher stroke severity scores. They were more likely to experience thromboembolic and respiratory complications and in-hospital mortality compared with matched controls.

General Versus Nongeneral Anesthesia for Carotid Endarterectomy: A Prospective Multicenter Registry-Based Study on 25 000 Patients.

BACKGROUND AND OBJECTIVES: Carotid endarterectomy (CEA) is a well-established treatment option for carotid stenosis. The choice between general anesthesia (GA) and nongeneral anesthesia (non-GA) during CEA remains a subject of debate, with concerns regarding perioperative complications, particularly myocardial infarctions. This study aimed to evaluate the outcomes associated with GA vs non-GA CEA using a large, nationwide database. METHODS: The National Surgical Quality Improvement Project database was queried for patients undergoing CEA between 2013 and 2020. Primary outcome measures including surgical outcomes and 30-day postoperative complications were compared between the 2 anesthesia methods, after 2:1 propensity score matching. RESULTS: After propensity score matching, a total of 25 356 patients (16 904 in the GA and 8452 in the non-GA group) were included. Non-GA compared with GA CEA was associated with significantly shorter operative times (101.9, 95% CI: 100.5-103.3 vs 115.8 95% CI: 114.4-117.2 minutes, P < .001), reduced length of hospital stays (2.3, 95% CI: 2.15-2.4 vs 2.5, 95% CI: 2.4-2.6 days, P < .001), and lower rates of 30-day postoperative complications, including myocardial infarctions (0.8% vs 1.2%, P = .003), unplanned intubations (0.8% vs 1.1%, P = .016), pneumonia (0.5% vs 1%, P < .001), and urinary tract infections (0.4% vs 0.7%, P = .003). These outcomes were notably more pronounced in the younger (≤70 years) and high morbidity (American Society of Anesthesiologists 3-5) cohorts. CONCLUSION: In this nationwide registry-based study, non-GA CEA was associated with better short-term outcomes in terms of perioperative complications, compared with GA CEA. The findings suggest that non-GA CEA may be a safer alternative, especially in younger patients and those with more comorbidities.

Predictors of occlusion, long-term outcomes, and safety in a cohort of 674 aneurysms treated with the Pipeline embolization device.

OBJECTIVE: By providing a more physiological approach to the treatment of intracranial aneurysms, the Pipeline embolization device (PED) has revolutionized the endovascular treatment of aneurysms. Although there are many flow diverters on the market, the authors report their experience with the PED, the first flow diverter to be approved by the Food and Drug Administration. They aimed to assess the efficacy and safety of PED flow diversion for the treatment of a wide range of aneurysms, as well as to look at factors affecting occlusion. METHODS: This is a retrospective study of a prospectively maintained database of patients treated with the PED between January 2011 and December 2019. Charts were reviewed for patient, aneurysm, and procedure characteristics. The primary outcomes of interest were complication rates, occlusion outcomes (O'Kelly-Marotta grading scale), and functional outcomes (modified Rankin Scale [mRS]). Secondary outcomes included predictors of incomplete occlusion at 6 and 24 months of follow-up. RESULTS: The study cohort included 581 patients with 674 aneurysms. Most aneurysms (90.5%) were in the anterior circulation and had a saccular morphology (85.6%). Additionally, 638 aneurysms (94.7%) were unruptured, whereas 36 (5.3%) were acutely ruptured. The largest mean aneurysm diameter was 8.3 ± 6.1 mm. Complications occurred at a rate of 5.5% (n = 32). The complete occlusion rate was 89.3% at 24 months' follow-up, and 94.8% of patients had a favorable neurological outcome (mRS score 0-2) at the last follow-up. On multivariate analysis, predictors of incomplete aneurysm occlusion at 6 months were hypertension (OR 1.7, p = 0.03), previous aneurysm treatment (OR 2.4, p = 0.001), and increasing aneurysm neck diameter (OR 1.2, p = 0.02), whereas a saccular morphology was protective (OR 0.5, p = 0.05). Predictors of incomplete occlusion at 24 months were increasing aneurysm neck diameter (OR 1.2, p = 0.01) and previous aneurysm treatment (OR 2.3, p = 0.01). CONCLUSIONS: The study findings are corroborated by those of previous studies and trials. The complete occlusion rate was 89.3% at 24 months' follow-up, with 94.8% of patients having favorable functional outcomes (mRS score 0-2). Aneurysm treatment before PED deployment and an increasing aneurysm neck diameter increase the risk of incomplete occlusion at 6 and 24 months.

A novel neural substrate for the transformation of olfactory inputs into motor output.

It is widely recognized that animals respond to odors by generating or modulating specific motor behaviors. These reactions are important for daily activities, reproduction, and survival. In the sea lamprey, mating occurs after ovulated females are attracted to spawning sites by male sex pheromones. The ubiquity and reliability of olfactory-motor behavioral responses in vertebrates suggest tight coupling between the olfactory system and brain areas controlling movements. However, the circuitry and the underlying cellular neural mechanisms remain largely unknown. Using lamprey brain preparations, and electrophysiology, calcium imaging, and tract tracing experiments, we describe the neural substrate responsible for transforming an olfactory input into a locomotor output. We found that olfactory stimulation with naturally occurring odors and pheromones induced large excitatory responses in reticulospinal cells, the command neurons for locomotion. We have also identified the anatomy and physiology of this circuit. The olfactory input was relayed in the medial part of the olfactory bulb, in the posterior tuberculum, in the mesencephalic locomotor region, to finally reach reticulospinal cells in the hindbrain. Activation of this olfactory-motor pathway generated rhythmic ventral root discharges and swimming movements. Our study bridges the gap between behavior and cellular neural mechanisms in vertebrates, identifying a specific subsystem within the CNS, dedicated to producing motor responses to olfactory inputs.

Mechanical Thrombectomy for Stroke Due to Acute Basilar Artery Occlusion, a Safety and Efficacy Analysis.

BACKGROUND: Acute basilar artery occlusion accounts for 1% of all ischemic strokes but often leads to devastating neurological injury and mortality. Many institutions still opt for best medical therapy for these patients; however, there is increasing evidence that mechanical thrombectomy (MT) for these patients leads to better outcomes. OBJECTIVE: To assess the safety and efficacy of MT for patients presenting with acute basilar artery occlusion (BAO). METHODS: This study was a retrospective chart review of a prospectively maintained database for patients with acute BAO treated with MT from January 2014 through March 2022. RESULTS: Our study included a total of 74 patients. The mean age was 62.7 years, and 55.4% were male. The most common comorbidity was hypertension (73%). The mean door to puncture time was 75 minutes, and the mean procedure time was 54 minutes. 86.5% of patients had a good modified treatment in cerebral ischemia score (≥2b). There were 4 patients who had procedural complications and 3 who had symptomatic intracerebral hemorrhage. At 90 days, 62.5% of patients had a modified Rankin Scale, 0 to 3. The mortality rate was 32.4% and 2% during hospital admission and 90 days, respectively. On univariate analysis, adjunctive angioplasty/stenting and higher presenting National Institutes of Health Stroke Scale score were associated with modified Rankin Scale 4 to 6 at 90 days ( P -value, .03 and <.001, respectively). Shorter procedure time was associated with modified treatment in cerebral ischemia score ≥ 2b ( P -value, .0015). CONCLUSION: Our findings showed that MT is safe and effective for patients presenting with acute BAO and is in conjunction with previous literature. The results from upcoming trials should hopefully establish MT as gold standard for these patients.

Transradial versus transfemoral access routes for diagnostic cerebral angiography: a large single-center comparative cost-analysis study.

OBJECTIVE: Recently, the transradial (TR) approach has become a common alternative because of its safety profile and increased patient satisfaction compared with the transfemoral (TF) route. Both routes are associated with their respective associated costs, and differences typically emerge on the basis of patient anatomy, operator expertise, and occurrence of complications. The authors' objective was to compare the overall costs of diagnostic cerebral angiography via both routes and to shed light on the individual equipment costs of each route. METHODS: This retrospective single-center study of 926 elective diagnostic angiograms was performed between December 2019 and March 2022. RESULTS: The study comprised of 314 and 612 angiograms performed through the TF and TR routes, respectively. A significantly greater proportion of female patients were included in the TF cohort (79.3% vs 67.8%, p < 0.001), and most other demographic characteristics and baseline modified Rankin Scale scores were comparable between cohorts. The overall cost of patients utilizing the TR route was comparable to that of the TF route (mean ± SD $12,591.80 ± $19,128.00 vs $12,789.50 ± 18,424.00, p = 0.88). However, the median cost of catheters was significantly higher in TR group ($55.20 vs $12.40, p = 0.03), while the median costs of closure devices ($87.00 vs $20.20 p < 0.001) and sheaths ($44.60 ± 11.3 vs $41.10 ± 3.10, p < 0.001) were significantly higher in the TF group. CONCLUSIONS: Overall, the authors' study showed that the TR approach can be a less expensive option for patients undergoing diagnostic cerebral angiography, especially if complications occur. Future studies may corroborate these findings and potentially lead to the adoption of TR as a low-cost, efficient, gold-standard technique for cerebral angiography.

The Rate and Predictors of 30-Day Readmission in Patients Treated for Unruptured Cerebral Aneurysms: A Large Single-Center Study.

BACKGROUND AND OBJECTIVES: Numerous studies of various populations and diseases have shown that unplanned 30-day readmission rates are positively correlated with increased morbidity and all-cause mortality. In this study, we aim to provide the rate and predictors of 30-day readmission in patients undergoing treatment for unruptured intracranial aneurysms. METHODS: This is a retrospective study of 525 patients presenting for aneurysm treatment between 2017 and 2022. All patients who were admitted and underwent a successful treatment of their unruptured intracerebral aneurysms were included in the study. The primary outcome was the rate and predictors of 30-day readmission. RESULTS: The rate of 30-day readmission was 6.3%, and the mean duration to readmission was 7.8 days ± 6.9. On univariate analysis, factors associated with 30-day readmission were antiplatelet use on admission (odds ratio [OR]: 0.4, P = .009), peri-procedural rupture (OR: 15.8, P = .007), surgical treatment of aneurysms (OR: 2.2, P = .035), disposition to rehabilitation (OR: 9.5, P < .001), and increasing length of stay (OR: 1.1, P = .0008). On multivariate analysis, antiplatelet use on admission was inversely correlated with readmission (OR: 0.4, P = .045), whereas peri-procedural rupture (OR: 9.5, P = .04) and discharge to rehabilitation (OR: 4.5, P = .029) were independent predictors of 30-day readmission. CONCLUSION: In our study, risk factors for 30-day readmission were aneurysm rupture during the hospital stay and disposition to rehabilitation, whereas the use of antiplatelet on admission was inversely correlated with 30-day readmission. Although aneurysm rupture is a nonmodifiable risk factor, more studies are encouraged to focus on the correlation of antiplatelet use and rehabilitation disposition with 30-day readmission rates.

Utility of intraoperative neuromonitoring for decompression of Chiari type I malformation in 93 adult patients.

OBJECTIVE: There is currently a lack of consensus on the utility of intraoperative neuromonitoring (IONM) for decompression of Chiari type I malformation (CM-I). Commonly used monitoring modalities include somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), and brainstem auditory evoked potentials (BAEPs). The purpose of this study was to evaluate the utility of IONM in preventing neurological injury for CM-I decompression. METHODS: The authors conducted a retrospective study of a population of adult patients (ages 17-76 years) diagnosed with CM-I between 2013 and 2021. IONM modalities included SSEPs, MEPs, and/or BAEPs. Prepositioning baseline signals and operative alerts of significant signal attenuation were recorded. RESULTS: Ninety-three patients (average age 38.4 ± 14.6 years) underwent a suboccipital craniectomy for CM-I decompression. Eighty-two (88.2%) of 93 patients underwent C1 laminectomy, 8 (8.6%) underwent C1 and C2 laminectomy, and 4 (4.3%) underwent suboccipital craniectomy with concomitant cervical decompression and fusion in the setting of degenerative cervical spondylosis. Radiographically, the average cerebellar tonsillar ectopia/descent was 1.1 ± 0.5 cm and 53 (57.0%) of 93 patients presented with a syrinx. The average number of vertebral levels traversed by the syrinx was 5.3 ± 3.5, and the average maximum width of the syrinx was 5.8 ± 3.3 mm. There was one instance (1/93, 1.1%) of an MEP alert, which resolved spontaneously after 10 minutes in a patient who had concomitant stenosis due to pannus formation at C1-2. No patient developed a permanent neurological complication. CONCLUSIONS: There were no permanent complications related to intraoperative neurological injury. Transient fluctuations in IONM signals can be detected without clinical significance. The authors suggest that CM-I suboccipital decompression surgery may be performed safely without IONM. The use of IONM in patients with additional occipitocervical pathology should be left as an option to the performing surgeon on a case-by-case basis.

Gastric perforation from a migrating ventriculoperitoneal shunt: A case report and review of literature.

Ventriculoperitoneal (VP) shunts represent a surgical option for patients affected by increased intracranial hypertension when medical management fails or is contraindicated. Complications following implantation include shunt obstruction, infection, over and under drainage, migration or disconnection of the tube, formation of a pseudocyst, and allergy to the silicone tube. We report the case of a 31-year-old woman who presented to the emergency room with nausea and generalized malaise, found to have the distal segment of the VP catheter perforating her gastric wall into the stomach lumen which required surgical intervention. In this report, we describe a rare complication associated with the implantation of ventriculoperitoneal shunt (VPS) catheters and the subsequent management plan.

Intraoperative chyle leak repair during right-sided anterior cervical discectomy and fusion.

Iatrogenic chyle leak (CL) following lymphatic vessel damage is an uncommon but serious complication of neck dissections. In the setting of anterior cervical discectomy and fusion (ACDF), left-sided CL are an exceedingly rare complication, with an incidence of only 0.02 %. Only three cases of right-sided CL during an ACDF have been reported. The case presented is the first right-sided CL to be successfully identified intraoperatively and treated. Intraoperative and postoperative management are discussed. This case will hopefully bring clinical and surgical awareness to providers caring for patients undergoing an ACDF.

Hypoglossal nerve injury with C1 lateral mass screw placement: A case report and review of the literature.

We report the case of a 62-year-old man who presented with a progressive myelopathy secondary to spinal cord compression from an odontoid process fracture and subaxial central canal stenosis. The patient underwent a C1-T2 posterior decompression and instrumented fusion (PCDF) and did well immediately postoperatively. However, on POD1, he developed a right hypoglossal nerve (HN) palsy attributed to direct mechanical compression or injury from the C1 lateral mass screw (LMS), which improved following a revision and screw replacement. While HN injury is a known complication of high anterior and anterolateral cervical spine approaches as well as transcondylar screw fixation, this case aims to expand on the limited reports available regarding hypoglossal nerve injury following placement of bicortical C1 LMS. Furthermore, the use of fluoroscopic guidance in addition to anatomic landmarks and triggered electromyography of the tongue are offered as potential solutions to prevent HN injury intraoperatively.

Does the Number of Levels of Decompression Have an Impact on the Clinical Outcomes of Patients With Lumbar Degenerative Spondylolisthesis: A Retrospective Study in Single-Level Fused Patients.

Introduction The American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) 2014 lumbar fusion guidelines for stenosis with degenerative spondylolisthesis (DS) support surgical decompression and fusion as an effective treatment option for symptomatic stenosis associated with DS. The association between the number of levels decompressed in patients with single-level fusion and clinical outcomes has never been published. Methods A retrospective analysis of a single-center, prospectively collected database was performed on 77 patients to compare the effect of the number of decompression levels in patients that received single-level fusion surgery. A total of 77 patients met the criteria. Group one had one level decompressed, group two had two levels decompressed, and group three had three or four levels decompressed. All patients received lumbar fusion surgery at a single spinal level. Outcomes at six months included: Substantial Clinical Benefit (SCB) (ΔODI ≥ 10 points); Minimal Clinically Important Difference (MCID) (ΔODI ≥ 5); no MCID (ΔODI <5 points). Student's t-tests, one-way analysis of variance (ANOVA), and post hoc comparison using unpaired two-tailed student's t-test with Holm-Bonferroni correction were performed. p -values were ranked from smallest to largest, and alpha level adjustments were made.  Results A sub-analysis of each group's clinical outcomes showed that patients with two levels decompressed reached greater clinical outcomes. SCB was obtained by approximately 60% (group one: 12.5% vs. group three: 40%) of the patients. A total of 77.6% (38/49) achieved MCID (group one: 62.5% vs. group three: 55%). Single-level fused patients with two levels of decompression showed an improvement of 48% from baseline ODI, as opposed to group one: 17.85% and group three: 21.1%. Patients belonging to group two showed the lowest rate of no improvement. Baseline ODI scores were similar upon presentation (p=0.46), and the difference was found among groups after six months of follow-up (p=0.009). Post hoc comparison showed statistical significance in the comparison between group two and group three (p=0.009, alpha value: 0.017). Conclusion The addition of more than two levels of decompression to single-level fused patients might be associated with poor clinical outcomes and spinal instability.