Use of Sundt Clip Graft for the Treatment of Intracranial Aneurysms: 2-Dimensional Operative Video

Dr Thoralf Sundt III joined the department of neurosurgery at Mayo Clinic in 1969 and served as chairman from 1980 until his death in 1992. Dr Sundt was a pioneer in the field of cerebrovascular neurosurgery and among his many contributions to neurosurgical technology was the introduction of the Sundt clip graft (Codman, Raynham, Massachusetts), which was developed in partnership with Dr George Kees. This device is a vessel-encircling Teflon or Dacron graft loaded on a circular metallic spring initially designed to repair injuries to vessel walls during intracranial aneurysm surgery,1 which was not an uncommon complication resulting from the use of contemporary aneurysm clips.2 When used for this purpose, the clip graft has demonstrated both safety and efficacy in a modern series of surgical treatment of intracranial aneurysm.3 An additional application of the clip graft is the direct clipping of aneurysms, particularly side-wall aneurysms, though Dr Sundt recognized that the potential to occlude perforating arteries adjacent to the aneurysm neck would limit the general use of the clip graft for aneurysm clipping.2 In the following video, we present archival footage of Dr Sundt utilizing the Sundt clip graft during intracranial aneurysm surgery. The 3 cases are of the treatment of posterior communicating, middle cerebral, and anterior communicating artery aneurysms and depict the potential applications of the clip graft during aneurysm surgery. We also present footage of animal experiments Dr Sundt performed to validate the use of the clip graft. This footage likely represents some of the first microscopic neurosurgical recordings ever made. The patients consented to the procedure and to presentation of video recordings at the time of initial surgery. Image of Sundt at 0:11, Reproduced with permission from the American Association of Neurological Surgeons, 5550 Meadowbrook Dr, Rolling Meadows, IL 60008. Figures at 2:26 and 2:28, from Park PJ, Meyer FB, The Sundt clip graft, Neurosurgery, 2010;66(6 suppl operative):300-305, by permission of the Congress of Neurological Surgeons. Figure at 2:35, ©2009 Mayo, Clingman. Used with permission.

Does pituitary compression/empty sella syndrome contribute to MRI-negative Cushing's disease? A single-institution experience

OBJECTIVE

Cushing's disease arises from functioning adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. These tumors can be very small and evade detection by MRI. Empty sella syndrome is a phenomenon by which an arachnoid outpouching of CSF into the sella leads to compression of the pituitary, likely due to intracranial hypertension (a common issue in Cushing's disease), further leading to difficulty in visualizing the pituitary gland that may contribute to difficulty in finding a tumor on MRI, so-called MRI-negative Cushing's disease. The authors sought to examine the association between empty sella syndrome and MRI-negative Cushing's disease.

METHODS

A single-institution database of Cushing's disease cases from 2000 to 2017 was reviewed, and 197 cases were included in the analysis. One hundred eighty patients had a tissue diagnosis of Cushing's disease and 17 had remission with surgery, but no definitive tissue diagnosis was obtained. Macroadenomas (tumors > 1 cm) were excluded. The degree of empty sella syndrome was graded on the degree of CSF visualized in the sella on midline sagittal T1-weighted MRI.

RESULTS

Of the 197 cases identified, 40 (20%) presented with MRI-negative disease, and empty sella syndrome was present in 49 cases (25%). MRI-negative disease was found in 18 (37%) of 49 empty sella cases versus 22 (15%) of 148 cases without empty sella syndrome present. Empty sella syndrome was significantly associated with MRI-negative disease (OR 3.32, 95% CI 1.61-6.74, p = 0.0018). Decreased thickness of the pituitary gland was also associated with MRI-negative disease (mean thickness 5.6 vs 6.8 mm, p = 0.0002).

CONCLUSIONS

Empty sella syndrome is associated with an increased rate of MRI-negative Cushing's disease. Pituitary compression causing a relative reduction in the volume of the pituitary for imaging is a plausible cause for not detecting the tumor mass with MRI.

Sinonasal adenocarcinoma: Population-based analysis of demographic and socioeconomic disparities

BACKGROUND

Sinonasal adenocarcinoma (SNAC) is a rare tumor. The impact of health disparities on survival, stage at presentation, and utilization of surgery is not well understood in patients with SNAC.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for cases of SNAC from 1973 to 2015. Cases were analyzed to assess for disparities in presentation, treatment, and survival.

RESULTS

SNAC was identified in 630 patients. In a multivariate model of overall survival, an age increase of 10 years (Hazard Ratio (HR) = 1.37, p < 0.001), male sex (HR = 1.26, p = 0.045), and more recent decade of diagnosis (HR = 0.74, p < 0.001) were significantly related to time-to-death. There is a higher rate of SNAC-related death in counties with more rural populations (p = 0.027).

CONCLUSION

Future interventions targeting rural and less well-educated populations may improve care with the goal of increasing the span of healthy life and reducing survival disparities related to SNAC.

Acute Sialadenitis After Skull Base Surgery: Systematic Review and Summative Practice Recommendations

BACKGROUND

Sialadenitis is a rare complication of skull base neurosurgery, in which the submandibular gland undergoes acute inflammation with edema after surgery. Although attributable to transient obstruction or manual compression, presentation may be rapidly life-threatening as a result of airway obstruction. Understanding risk factors is limited at present, and no practical management guidelines have been reported. Our objective was to survey the literature and to characterize the associated risk factors, treatment considerations, and overall trends in outcomes for patients experiencing post skull base neurosurgery sialadenitis.

METHODS

A search of the Ovid EMBASE, SCOPUS, and PubMed databases from inception through August 2020 was performed via Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Systematic review identified 13 publications describing 18 cases of acute sialadenitis after skull base surgery. We describe the 19th reported case. Commonalities include the need for aggressive respiratory support as intubation or emergent tracheostomy is almost universally required. Risk factors are poorly understood but may include extreme flexion and/or rotation of the head and neck. Outcomes are favorable overall, although secondary complications have been described.

CONCLUSIONS

Sialadenitis is a rare but potentially life-threatening complication of skull base neurosurgery, owing to acute loss of airway and the potential for a diverse array of secondary complications.

Preoperative embolization of jugular paraganglioma tumors using particles is safe and effective

BACKGROUND

Jugular paragangliomas represent a surgical challenge due to their vascularity and proximity to vital neurovascular structures. Preoperative embolization aids in reducing intraoperative blood loss, transfusion requirements, and improves surgical visualization. Several embolization agents have been used.

OBJECTIVE

The aim of this study is to evaluate the safety and efficacy of PVA in pre-operative embolization of jugular paragangliomas.

METHODS

A retrospective review of all patients who underwent jugular paraganglioma resection with pre-operative embolization between 2000 and 2020 was performed. Pre-operative data including baseline patient and tumor characteristics were documented. Outcomes of preoperative embolization including extent of devascularization and post-embolization complications were recorded. Early and long-term postoperative outcomes were reported.

RESULTS

Twenty-nine patients met study criteria with a median age of 38 years. Average tumor size was 3.4±1.8 cm. The most commonly encountered arterial feeder was the ascending pharyngeal artery followed by the posterior auricular artery. More than 50% reduction in tumor blush was achieved in 25 patients (86.2%). None of the patients experienced new or worsening cranial neuropathy following embolization. Gross total or Near total resection was achieved in 13 patients (44.8%). A STR or NTR was chosen in these patients to preserve cranial nerve function or large vessel integrity. Average intraoperative estimated blood loss was 888 ml, 9 patients (31%) required intra-operative transfusion of blood products. Extent of resection and post-operative complications did not correlate with extent of devascularization.

CONCLUSION

Pre-operative embolization of jugular paraganglioma tumors with PVA particles is an effective strategy with a high safety profile.

Long-term outcomes of grade I/II skull base chondrosarcoma: an insight into the role of surgery and upfront radiotherapy

PURPOSE

To clarify the need for post-operative radiation treatment in skull base chondrosarcomas (SBCs).

METHODS

A retrospective analysis of patients with grade I or II SBC. Patients were divided according to post-surgical treatment strategies: (A) planned upfront radiotherapy and (B) watchful waiting. Tumor control and survival were compared between the treatment groups. The median follow-up after resection was 105 months (range, 9-376).

RESULTS

Thirty-two patients (Grade 1, n = 16; Grade 2, n = 16) were included. The most frequent location was petroclival (21, 64%). A gross total resection (GTR) was achieved in 11 patients (34%). Fourteen (44%) underwent upfront radiotherapy (group A) whereas 18 (56%) were followed with serial MRI alone (group B). The tumor control rate for the entire group was 77% and 69% at 10- and 15-year, respectively. Upfront radiotherapy (P = 0.25), extent of resection (P = 0.11) or tumor grade (P = 0.83) did not affect tumor control. The majority of Group B patients with recurrent tumors (5/7) obtained tumor control with repeat resection (n = 2), salvage radiotherapy (n = 2), or a combination of both (n = 1). The 10-year disease-specific survival was 95% with no difference between the group A and B (P = 0.50).

CONCLUSION

For patients with grade I/II SBC, a reasonable strategy is deferral of radiotherapy after maximum safe resection until tumor progression or recurrence. At that time, most patients can be successfully managed with salvage radiotherapy or surgery. Late recurrences may occur, and life-long follow-up is advisable.

A new method for quantification and 3D visualization of brain tumor adhesion using slip interface imaging in patients with meningiomas

OBJECTIVES

To develop an objective quantitative method to characterize and visualize meningioma-brain adhesion using MR elastography (MRE)-based slip interface imaging (SII).

METHODS

This retrospective study included 47 meningiomas (training dataset: n = 35; testing dataset: n = 12) with MRE/SII examinations. Normalized octahedral shear strain (NOSS) values were calculated from the acquired MRE displacement data. The change in NOSS at the tumor boundary (ΔNOSS_bdy) was computed, from which a 3D ΔNOSS_bdy map of the tumor surface was created and the probability distribution of ΔNOSS_bdy over the entire tumor surface was calculated. Statistical features were calculated from the probability histogram. After eliminating highly correlated features, the capability of the remaining feature for tumor adhesion classification was assessed using a one-way ANOVA and ROC analysis.

RESULTS

The magnitude and location of the tumor adhesion can be visualized by the reconstructed 3D ΔNOSS_bdy surface map. The entropy of the ΔNOSS_bdy histogram was significantly different between adherent tumors and partially/completely non-adherent tumors in both the training (AUC: 0.971) and testing datasets (AUC: 0.900). Based on the cutoff values obtained from the training set, the ΔNOSS_bdy entropy in the testing dataset yielded an accuracy of 0.83 for distinguishing adherent versus partially/non-adherent tumors, and 0.67 for distinguishing non-adherent versus completely/partially adherent tumors.

CONCLUSIONS

SII-derived ΔNOSS_bdy values are useful for quantification and classification of meningioma-brain adhesion. The reconstructed 3D ΔNOSS_bdy surface map presents the state and location of tumor adhesion in a "clinician-friendly" manner, and can identify meningiomas with a high risk of adhesion to adjacent brain parenchyma.

KEY POINTS

• MR elastography (MRE)-based slip interface imaging shows promise as an objective tool to preoperatively discriminate meningiomas with a high risk of intraoperative adhesion. • Measurement of the change of shear strain at meningioma boundaries can provide quantitative metrics depicting the state of adhesion at the tumor-brain interface. • The surface map of tumor adhesion shows promise in assisting precise adhesion localization, using a comprehensible, "clinician-friendly" 3D visualization.

Clinical, biological, radiological, and pathological comparison of sparsely and densely granulated somatotroph adenomas: a single center experience from a cohort of 131 patients with acromegaly

PURPOSE

Growth hormone-producing pituitary adenomas are divided into two clinically relevant histologic subtypes, densely (DG-A) and sparsely (SG-A) granulated. Histologic subtype was evaluated in a large cohort of patients with acromegaly, separating DG-A and SG-A, and correlated with clinicopathological characteristics.

METHODS

Patients with acromegaly undergoing surgery as initial therapy between 1995 and 2015 were identified. Histologic subtype was determined by keratin expression pattern with CAM5.2 and correlated with clinical and imaging parameters, somatostatin receptor subtype 2 (SST2) expression, post-surgical remission rate, and application of a prognostic scoring system incorporating proliferation and invasiveness.

RESULTS

One hundred thirty-one patients were included. Tumors were classified as DG-A (75, 57.3%), SG-A (29, 22.1%), intermediate (I-A) (9, 6.9%), and unclassified (18, 13.7%) when CAM5.2 was negative. DG-A and I-A were combined for analysis (DG/I-A) and compared to SG-A. Age, gender, proliferation, and post-surgical remission did not differ. SG-A were larger [2 vs. 1.5 cm (median), p = 0.03], more frequently invasive [65.5% vs. 32.9%, p = 0.004], associated with higher MRI T2-weighted signal ratio [1.01 vs. 0.82 (median), p = 0.01], showed lower SST2 expression (p < 0.0001), and scored higher in the prognostic classification (p = 0.004). Surgical remission occurred in 41.7% DG/I-A and 41.4% SG-A (p = 1.0). On multivariate analysis, absence of invasion (p = 0.009) and lower pre-operative IGF-1 index (p = 0.0002) were associated with post-surgical remission.

CONCLUSION

CAM5.2 allowed distinction between DG/I-A and SG-A in most but not all cases. Histologic subtype did not predict surgical outcome. Absence of invasion and lower pre-operative IGF-1 index were the only significant predictors of post-surgical remission in this cohort.

Aneurysmal Bone Cysts of the Paranasal Sinuses: The Mayo Clinic Experience and Review of the Literature

OBJECTIVE/HYPOTHESIS

Aneurysmal bone cysts (ABCs) are benign, lytic bone lesions, which rarely present in the paranasal sinuses. There is no published consensus on the appropriate diagnostic or treatment approach. Our objective was to elucidate the clinical behavior, treatment, and outcomes for patients with ABCs of the paranasal sinuses (psABCs).

STUDY DESIGN

Retrospective case series and system review of the literature.

METHODS

A retrospective chart review was performed to identify patients evaluated at the authors' institution with psABC and consolidated with literature reports of psABC.

RESULTS

Eighty-nine patients met inclusion criteria. The most common presenting symptom was painless facial swelling (n = 35, 39%). The ethmoid sinuses were the most common site involved (n = 55, 62%). Surgical approach was reported in 74 cases including 20 endoscopic and 54 with an open or combined approach. Fifty-nine patients (71%) underwent gross total resection. Follow up data was reported for 67 patients. Fifteen patients (22%) were found to have recurrence or progression at follow up; 10/15 (66%) patients within the first 12 months, 14/15 (93%) within the first 24 months, and 1/15 (7%) greater than 24 months after treatment. Patients were more likely to have recurrence/progression if they presented with nasal discharge (P = .05), proptosis (P = .01), or orbital involvement (P = .03).

CONCLUSIONS

psABCs typically present with painless swelling or nasal obstruction. Orbital involvement is a negative prognostic indicator with these patients more likely to have recurrence after treatment. Recurrence or progression of disease is most likely to occur within 2 years after treatment. Therefore, patients should be monitored closely during this time.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E2525-E2533, 2021.

Collision of Craniopharyngioma and Pituitary Adenoma: Comprehensive Review of an Extremely Rare Sellar Condition

OBJECTIVE

The collision of pituitary adenoma and craniopharyngioma is extremely rare and thus there remains a paucity of data.

METHODS

We described a patient from our institution. We also performed a systematic review and subsequent quantitative synthesis of the literature (n = 21) and our institutional case to yield an integrated cohort, and a descriptive analysis was carried out.

RESULTS

Twenty-two patients (15 males and 7 females) were included in the integrated cohort. The median age was 47.0 years (range, 8-75 years). The tumor subtypes were 5 somatotropic, 5 lactotropic, 4 nonfunctioning, 3 gonadotropic, 2 corticotropic, 1 plurihormonal, and 1 silent subtype 3 for pituitary adenomas, and 19 adamantinomatous, 2 papillary, and 1 unknown subtype for craniopharyngiomas. Three different radiographic patterns were observed: solid mass with cystic component (n = 5), coexistence of two distinct solid components (n = 3), and a mixed-intensity solid mass (n = 5). The first 2 were consistent with histologically separate collision, whereas the third was consistent with histologically admixed collision. Among 19 patients in whom the postoperative course was recorded, a secondary intervention was required in 14 (73.7%) because of tumor progression or residual. The recurrence rate after gross total resection was 33.3%. Postoperative hormone replacement was required in 33.3%. The 10-year cumulative overall survival was 73.1%.

CONCLUSIONS

Most craniopharyngiomas were adamantinomatous. There are 2 types of collisions: separated and admixed. Tumor control, overall survival, and endocrinologic remission are more challenging to achieve than for solitary tumors, but gross total resection of both tumors is important for satisfactory tumor control.

Fluorescence guided surgery for pituitary adenomas

PURPOSE

Resection of pituitary adenomas presents a number of unique challenges in neuro-oncology. The proximity of these lesions to key vascular and endocrine structures as well as the need to interpret neuronavigation in the context of shifting tumor position increases the complexity of the operation. More recently, substantial advances in fluorescence-guided surgery have been demonstrated to facilitate the identification of numerous tumor types and result in increased rates of complete resection and overall survival.

METHODS

A review of the literature was performed, and data regarding the mechanism of the fluorescence agents, their administration, and intraoperative tumor visualization were extracted. Both in vitro and in vivo studies were assessed. The application of these agents to pituitary tumors, their advantages and limitations, as well as future directions are presented here.

RESULTS

Numerous laboratory and clinical studies have described the use of 5-ALA, fluorescein, indocyanine green, and OTL38 in pituitary lesions. All of these drugs have been demonstrated to accumulate in tumor cells. Several studies have reported the successful use of the majority of the agents in inducing intraoperative tumor fluorescence. However, their sensitivity and specificity varies across the literature and between functioning and non-functioning adenomas.

CONCLUSIONS

At present, numerous studies have shown the feasibility and safety of these agents for pituitary adenomas. However, further research is needed to assess the applicability of fluorescence-guided surgery across different tumor subtypes as well as explore the relationship between their use and postoperative clinical outcomes.

A Comprehensive Study of Spindle Cell Oncocytoma of the Pituitary Gland: Series of 6 Cases and Meta-Analysis of 85 Cases

OBJECTIVE

To discuss optimal treatment strategy for spindle cell oncocytoma (SCO) of the pituitary gland.

METHODS

Institutional cases were retrospectively reviewed. A systematic literature search and subsequent quantitative synthesis were performed for further analysis. The detailed features were summarized and the tumor control rate (TCR) was calculated.

RESULTS

Eighty-five patients (6 institutional and 79 literature) were included. The annual incidence was approximately 0.01-0.03/100,000. The mean age was 56 years. Vision loss was present in 60%. Seventy-three percent showed hormonal abnormalities. On magnetic resonance imaging, tumor was avidly enhancing, and the normal gland was commonly displaced anterosuperiorly. Evidence of hypervascularity was seen in 77%. Gross total resection (GTR) was achieved in only 24% because of its hypervascular, fibrous, and adhesive nature. The mean postoperative follow-up was 3.3 years for institutional cases and 2.3 years for the integrated cohort. The TCR was significantly better after GTR (5-year TCR, 75%; P = 0.012) and marginally better after non-GTR + upfront radiotherapy (5-year TCR, 76%; P = 0.103) than after non-GTR alone (5-year TCR, 24%). The TCRs for those with low Ki-67 index (≤5%) were marginally better than those with higher Ki-67 index (5-year rate, 57% vs. 23%; P = 0.110).

CONCLUSIONS

Frequent endocrine-related symptoms, hypervascular signs, and anterosuperior displacement of the gland support preoperative diagnosis of SCO. GTR seems to have better long-term tumor control, whereas the fibrous, hypervascular, and adhesive nature of SCO makes it difficult to achieve GTR. In patients with non-GTR, radiotherapy may help decrease tumor progression.

Prospective Study of Disease-Specific Quality-of-Life in Sporadic Vestibular Schwannoma Comparing Observation, Radiosurgery, and Microsurgery

BACKGROUND

Previous cross-sectional studies analyzing quality of life (QOL) outcomes in patients with sporadic vestibular schwannoma (VS) have shown surprisingly little difference among treatment modalities. To date, there is limited prospective QOL outcome data available comparing baseline to posttreatment scores.

STUDY DESIGN

Prospective longitudinal study using the disease-specific Penn Acoustic Neuroma Quality of Life (PANQOL) scale.

SETTING

Large academic skull base center.

PATIENTS

Patients diagnosed with unilateral VS who completed a baseline survey before treatment and at least one posttreatment survey.

MAIN OUTCOME MEASURES

Change in PANQOL scores from baseline to most recent survey.

RESULTS

A total of 244 patients were studied, including 78 (32%) who elected observation, 118 (48%) microsurgery, and 48 (20%) stereotactic radiosurgery. Patients who underwent microsurgery were younger (p < 0.001) and had larger tumors (p < 0.001) than those who underwent observation or radiosurgery; there was no significant difference in duration of follow-up among management groups (mean 2.1 yrs; p = 0.28). When comparing the total PANQOL score at baseline to the most recent survey, the net change was only -1.1, -0.1, and 0.3 points on a 100-point scale for observation, microsurgery, and radiosurgery, respectively (p = 0.89). After multivariable adjustment for baseline features, there were no statistically significant changes when comparing baseline to most recent scores within each management group for facial function, general health, balance, hearing loss, energy, and pain domains or total score. However, the microsurgical group experienced a 10.8-point improvement (p = 0.002) in anxiety following treatment, compared with 1.5 (p = 0.73) and 5.3 (p = 0.31) for observation and radiosurgery, respectively.

CONCLUSIONS

In this prospective longitudinal study investigating differences in QOL outcomes among VS treatment groups using the disease-specific PANQOL instrument, treatment did not modify QOL in most domains. Microsurgery may confer an advantage with regard to patient anxiety, presumably relating to the psychological benefit of "cure" from having the tumor removed.

Minimally Invasive, Endoscopic-Assisted Device for Subdural Electrode Implantation in Epilepsy

BACKGROUND

Subdural grids and strip electrodes provide wide coverage of the cerebral cortex, precise delineation of the extent of the seizure onset zone, and improved spatial sampling to perform functional mapping for eloquent cortex.

OBJECTIVE

To describe a novel device that allows for a minimally invasive approach to implantation of subdural grid and strip electrodes.

METHODS

A skull mounted device was created to allow for implantation of subdural electrodes through a keyhole craniotomy with direct visualization using the aid of a flexible neurovideoscope. The initial studies in preparation for grid development performed on cadaveric skulls were analyzed to determine the size of craniotomy required for deployment, maximal distance of strip electrode deployment from center of craniotomy, and visual inspection of the cortex was performed for any underlying damage.

RESULTS

The device allowed for the placement of subdural electrodes through a 40-mm craniotomy. Subdural electrodes were deployed in multiple directions to a distance of a 70-mm radius from the center of the craniotomy. There was no visual damage to the underlying cortex after the procedures were completed.

CONCLUSION

Large craniotomies are typically desired to provide direct visualization of the implantation of subdural electrodes, but can increase the risk of subdural hemorrhages and infections. This study describes a novel minimally invasive endoscopically assisted device for the implantation of subdural strip electrodes under direct visualization. With this device, we are able to limit the size of the craniotomy, avoid incision through the temporalis muscle, and implant subdural electrodes with visualization of the cortex.

Outcomes following surgical management of vagus nerve stimulator-related infection: a retrospective multi-institutional study

OBJECTIVE

Surgical site infection (SSI) is a rare but significant complication after vagus nerve stimulator (VNS) placement. Treatment options range from antibiotic therapy alone to hardware removal. The optimal therapeutic strategy remains open to debate. Therefore, the authors conducted this retrospective multicenter analysis to provide insight into the optimal management of VNS-related SSI (VNS-SSI).

METHODS

Under institutional review board approval and utilizing an institutional database with 641 patients who had undergone 808 VNS-related placement surgeries and 31 patients who had undergone VNS-related hardware removal surgeries, the authors retrospectively analyzed VNS-SSI.

RESULTS

Sixteen cases of VNS-SSI were identified; 12 of them had undergone the original VNS placement procedure at the authors' institutions. Thus, the incidence of VNS-SSI was calculated as 1.5%. The mean (± standard deviation) time from the most recent VNS-related surgeries to infection was 42 (± 27) days. Methicillin-sensitive staphylococcus was the usual causative bacteria (58%). Initial treatments included antibiotics with or without nonsurgical procedures (n = 6), nonremoval open surgeries for irrigation (n = 3), generator removal (n = 3), and total or near-total removal of hardware (n = 4). Although 2 patients were successfully treated with antibiotics alone or combined with generator removal, removal of both the generator and leads was eventually required in 14 patients. Mild swallowing difficulties and hoarseness occurred in 2 patients with eventual resolution.

CONCLUSIONS

Removal of the VNS including electrode leads combined with antibiotic administration is the definitive treatment but has a risk of causing dysphagia. If the surgeon finds dense scarring around the vagus nerve, the prudent approach is to snip the electrode close to the nerve as opposed to attempting to unwind the lead completely.

Teflon versus Ivalon in Microvascular Decompression for Trigeminal Neuralgia: A 2-Center 10-Year Comparison

BACKGROUND

Trigeminal neuralgia features jolts of pain along the distribution of the trigeminal nerve. If patients fail conservative management, microvascular decompression (MVD) is typically the next step in treatment. MVD consists of implanting a separating material, often Teflon, between the nerve and compressive lesions. A review found similar success and complication rates between Teflon and Ivalon, another commonly used material. The aim of this study was to analyze outcomes and complications associated with Teflon and Ivalon in MVD.

METHODS

We conducted a 2-center retrospective cohort study of trigeminal neuralgia treated with MVD between 2005 and 2019. Patients with no postoperative follow-up were excluded. Postoperative pain was graded using the Barrow Neurological Institute (BNI) pain intensity score. Relapse was defined as a BNI score of 4-5 during follow-up after initial pain improvement or an initial BNI score of 1-3.

RESULTS

The study included 221 MVD procedures in 219 patients. Ivalon was implanted in 121 procedures, and Teflon was implanted in 100 procedures. Multivariate analysis found that implant type had no effect on final BNI score (P = 0.305). Relapse rates were similar at 5- and 10-year follow-up (5-year: Ivalon 10.7%, Teflon 18.0%, P = 0.112; 10-year: Ivalon 11.6%, Teflon 19.0%, P = 0.123). There was no difference in postoperative immediate facial numbness (P = 0.125). Postoperative hearing difficulty was higher in the Ivalon cohort (8.4% vs. 1.0%; P = 0.016).

CONCLUSIONS

We found no significant difference in final BNI score or risk of relapse between Ivalon and Teflon. Complications were similar, although Ivalon was more associated with temporary postoperative hearing loss.

Deep brain stimulation for orthostatic tremor: A single-center case series

Background

Orthostatic tremor (OT) is a high-frequency weight-bearing tremor of the legs and trunk associated with progressive disability and is often refractory to medications. Case reports suggest that thalamic deep brain stimulation (DBS) is effective. We report 5 female patients with medication-refractory OT who underwent bilateral thalamic DBS at the Mayo Clinic and assess factors associated with a successful DBS outcome.

Methods

Demographic, clinical, electrophysiology, and DBS data were abstracted. Outcomes were change in tremor-onset latency, standing time, standing ADLs, and patient and clinician global impression of change (PGIC; CGIC).

Results

All 5 patients had improved standing time (72 vs 408 seconds, p ≤ 0.001) and improved standing ADLs after surgery, without change in tremor-onset latency (16 vs 75 seconds, p = 0.14). Maximal benefit was reached up to 3 years after surgery and sustained for up to 6 years. CGIC was "much improved" in all; PGIC was "much improved" in 4 and "minimally improved" in 1. There were no major complications. Postoperative electrophysiology (n = 1) showed lower tremor amplitude and slower tremor ramp-up on vs off stimulation.

Conclusions

Bilateral thalamic DBS improved OT symptoms with benefit lasting up to 6 years. A modest increase in standing time of several minutes was associated with meaningful improvement in standing ADLs. Microlesional effect and bilateral stimulation are likely favorable features, while baseline standing time of several minutes may be unfavorable. These findings may inform clinician and patient counseling and require confirmation in larger studies.

Population-based analysis on the effect of nodal and distant metastases in sinonasal adenocarcinoma

BACKGROUND

Minimal information has been reported on the effect of distant and nodal metastases at the time of diagnosis on survival in patients with sinonasal adenocarcinoma (SNAC).

METHODS

The Surveillance, Epidemiology, and End Results database was utilized to compare overall survival (OS) and disease-specific survival (DSS).

RESULTS

Of the 325 patients with SNAC identified, 5-year and 10-year OS for all included patients was 64% and 58%, respectively. On multivariate analysis, the presence of distant metastases (P < .0001), maxillary and frontal sinus primary tumors (P = .0042, P = .0006), and increasing age (P = .007) were risk factors for worsened DSS. The presence of regional spread to multiple cervical nodal basins (OS RR 3.26, P = .002; DSS RR 2.51, P = .013) and a single nodal basin (DSS RR 2.19, P = .046) was associated with worsened survival compared to no regional spread.

CONCLUSION

Survival in SNAC was significantly worsened with increasing age, tumor site of origin, and distant metastatic disease.

Ataxia and tolerance after thalamic deep brain stimulation for essential tremor

BACKGROUND

Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) thalamus is highly effective to treat medication-refractory essential tremor (ET). Complications of stimulation-induced ataxia and tolerance have been reported in limited series, ranging from 5 to 40%.

OBJECTIVE

We analyzed a large single-center cohort of ET patients treated with thalamic DBS to assess rates of ataxia and tolerance.

METHODS

Retrospective study of all ET patients that underwent VIM DBS at Mayo Clinic from 2010 to 2014. Demographic, clinical and DBS data were extracted. Risk factors, complications and time to onset of tolerance and ataxia were examined.

RESULTS

One hundred and thirteen ET patients (51% male) of mean age 68 ± 10 years and mean ET duration 27 ± 18 years underwent DBS during the study period. Of these, 98 (87%) had follow-up of ≥6 months (mean 4.0 ± 1.5 years) and were included for analysis. Complications of isolated ataxia (26%), isolated tolerance (4%), both tolerance and ataxia (9%), or neither (61%) were identified. Development of ataxia was about 3 times more common than tolerance (35% vs. 13%). The mean time to ataxia was 5.5 ± 0.3 years postoperatively. Risk factors for ataxia were baseline ataxic features, older age, and shorter ET disease duration. Small sample size limited calculation of risk factors and onset time for tolerance.

CONCLUSIONS

Stimulation-related ataxia occurred in one-third of ET patients, while tolerance was less common. Presence of baseline ataxia, age, and disease duration may aid counseling of stimulation-related ataxia risk. Larger studies are warranted to confirm these findings and further assess risk factors for tolerance.

Cortical and thalamic electrode implant followed by temporary continuous subthreshold stimulation yields long-term seizure freedom: A case report

Neuromodulation strategies that target the epileptogenic network are options for treating focal drug-resistant epilepsy. These brain stimulation approaches include responsive neurostimulation and more recently, chronic subthreshold stimulation. Long-term seizure freedom with neuromodulation is uncommon. Seizure control typically requires ongoing froms of electrical stimulation. Here, we present the case of a patient implanted with three cortical electrodes targeting the inferior frontal lobe, insula, and one subcortical electrode targeting the ipsilateral anterior thalamic nucleus. This patient received continuous subthreshold electrical stimulation to the frontal electrodes for 7 months, at which time stimulation was inadvertently stopped. He has now been free of seizures for 42 months. This case suggests the possibility that neuromodulation can alter epileptogenic networks and lead to seizure freedom without ongoing electrical stimulation.