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Sean Martin, Mario Teo and Nigel Suttner

OBJECT

Trigeminal neuralgia (TN) is more common in multiple sclerosis (MS) patients than in the general population and among the former has an incidence of approximately 2%. The pathophysiology of TN in MS patients is believed to be caused by a demyelinating plaque at the root entry zone, and therefore procedures that cause direct nerve damage are thought to be the most effective surgical modality. The authors aimed to compare the efficacy of percutaneous balloon compression (PBC) in TN patients with and without MS.

METHODS

Retrospectively collected clinical data on 80 consecutive patients who underwent 144 procedures and who received PBC forTN treatment between January 2000 and January 2010 were analyzed. The cohort included 17 MS and 63 non-MS patients.

RESULTS

The mean age at first operation was significantly younger in the MS group compared with the non-MS group (59 years vs 72 years, respectively, p < 0.0001). After a mean follow-up of 43 months (MS group) and 25 months (non-MS group), the symptom recurrence rate following the first operation was higher in the MS group compared with that in the non-MS group (86% vs 47%, respectively, p < 0.01). During long-term follow-up, more than 70% of MS patients required multiple procedures compared with only 44% of non-MS patients. Excellent or satisfactory outcomes were not significantly different between the MS and non-MS cohorts, respectively, at 1 day postoperatively (82% vs 91%, p = 0.35), 3 months postoperatively (65% vs 81%, p = 0.16), and at last follow-up (65% vs 76%, p = 0.34). A similar incidence of postoperative complications was observed in the 2 groups.

CONCLUSIONS

PBC is effective in the treatment of trigeminal neuralgia in patients with MS, but, compared with that in non-MS patients, symptom recurrence is higher and requires multiple procedures.

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Mario Teo and Sam Eljamel

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Reid Hoshide, Harrison Faulkner, Mario Teo and Charles Teo

OBJECTIVE

There are numerous treatment strategies in the management for large vestibular schwannomas, including resection only, staged resections, resections followed by radiosurgery, and radiosurgery only. Recent evidence has pointed toward maximal resection as being the optimum strategy to prevent tumor recurrence; however, durable tumor control through aggressive resection has been shown to occur at the expense of facial nerve function and to risk other approach-related complications. Through a retrospective analysis of their single-institution series of keyhole neurosurgical approaches for large vestibular schwannomas, the authors aim to report and justify key techniques to maximize tumor resection and reduce surgical morbidity.

METHODS

A retrospective chart review was performed at the Centre for Minimally Invasive Neurosurgery. All patients who had undergone a keyhole retrosigmoid approach for the resection of large vestibular schwannomas, defined as having a tumor diameter of ≥ 3.0 cm, were included in this review. Patient demographics, preoperative cranial nerve status, perioperative data, and postoperative follow-up were obtained. A review of the literature for resections of large vestibular schwannomas was also performed. The authors’ institutional data were compared with the historical data from the literature.

RESULTS

Between 2004 and 2017, 45 patients met the inclusion criteria for this retrospective chart review. When compared with findings in a historical cohort in the literature, the authors’ minimally invasive, keyhole retrosigmoid technique for the resection of large vestibular schwannomas achieved higher rates of gross-total or near-total resection (100% vs 83%). Moreover, these results compare favorably with the literature in facial nerve preservation (House-Brackmann I–II) at follow-up after gross-total resections (81% vs 47%, p < 0.001) and near-total resections (88% vs 75%, p = 0.028). There were no approach-related complications in this series.

CONCLUSIONS

It is the experience of the senior author that complete or near-complete resection of large vestibular schwannomas can be successfully achieved via a keyhole approach. In this series of 45 large vestibular schwannomas, a greater extent of resection was achieved while demonstrating high rates of facial nerve preservation and low approach-related and postoperative complications compared with the literature.

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Venkatesh S. Madhugiri, Mario K. C. Teo, Joli Vavao, Teresa Bell-Stephens and Gary K. Steinberg

OBJECTIVE

Brainstem arteriovenous malformations (AVMs) are rare lesions that are difficult to diagnose and treat. They are often more aggressive in their behavior when compared with their supratentorial counterparts. The consequence of a brainstem hemorrhage is often devastating, and many patients are in poor neurological status at presentation. The authors examine the factors associated with angiographically confirmed cure and those affecting management outcomes for these complex lesions.

METHODS

This was a retrospective analysis of data gathered from the prospectively maintained Stanford AVM database. Lesions were grouped based on their location in the brainstem (medulla, pons, or midbrain) and the quadrant they occupied. Angiographic cure was dichotomized as completely obliterated or not, and functional outcome was dichotomized as either independent or not independent at last follow-up.

RESULTS

Over a 23-year period, 39 lesions were treated. Of these, 3 were located in the medulla, 14 in the pons, and 22 in the midbrain. At presentation, 92% of the patients had hemorrhage, and only 43.6% were functionally independent. Surgery resulted in the best radiographic cure rates, with a morbidity rate of 12.5%. In all, 53% of patients either improved or remained stable after surgery. Absence of residual nidus and female sex correlated with better outcomes.

CONCLUSIONS

Brainstem AVMs usually present with hemorrhage. Surgery offers the best chance of cure, either in isolation or in combination with other modalities as appropriate.

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Mario K. Teo, Venkatesh S. Madhugiri and Gary K. Steinberg

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Asem Salma, Ahmed Alkhani and Hazem Akil

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Xing-ju Liu, Dong Zhang, Shuo Wang, Yuan-li Zhao, Mario Teo, Rong Wang, Yong Cao, Xun Ye, Shuai Kang and Ji-Zong Zhao

OBJECT

The aim of this study was to describe the baseline clinical features and long-term outcomes of patients with moyamoya disease (MMD) based on a 25-year period at a single center in China.

METHODS

 Data obtained in 528 consecutive patients with MMD treated at the authors' hospital from 1984 to 2010 were reviewed retrospectively. Events of transient ischemic attack, new infarction, and hemorrhage were included. The Kaplan-Meier risk of stroke was calculated.

RESULTS

 The mean (± SD) patient age was 26 ± 13 years (range 2–67 years), and the female/male ratio was 0.9:1. There were 332 cases of ischemia and 196 hemorrhages. Adults had a higher rate of bleeding than children (50.7% vs 14.0%, respectively; p < 0.001). One hundred twenty-two patients were treated conservatively, and 406 patients underwent revascularization procedures. Of 528 patients, 331 (62.7%) had at least 1 year of follow-up (median 39.5 months) and data from these patients were analyzed. Rebleeding and mortality rates in patients with hemorrhagic MMD (n = 104) were higher than in those with ischemic MMD (n = 227) (26.9% vs 2.2% [p < 0.001] and 4.8% vs 0.4% [p < 0.05], respectively). Twenty-five of 60 (41.7%) conservatively treated patients and 8 of 271 (2.9%) surgically treated patients experienced rebleeding events, a difference that was significant in the Kaplan-Meier curve of rebleeding (p < 0.01). An improvement in perfusion was found in 164 of 224 (73.2%) surgically treated patients 1 month after discharge. However, there was no significant difference in the rate of ischemic events in the surgical and conservative groups (18.8% and 28.3%, respectively; p = 0.09). Among the 104 hemorrhagic cases, rebleeding attacks were observed in 25 patients in the nonsurgical group (n = 60) and 3 patients in the surgical group (n = 44) (41.7% and 6.8%, respectively; OR 9.7 [95% CI 2.7–35.0]; p < 0.01).

CONCLUSIONS

 There was no difference in the sex distribution of Chinese patients with MMD. Patients with hemorrhagic MMD had a much higher rate of rebleeding and poorer prognosis than those with the ischemic type. Surgical revascularization procedures can improve cerebral perfusion and have a positive impact in preventing rebleeding in patients with hemorrhagic MMD.

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Mario Teo, Jeremiah N. Johnson, Teresa E. Bell-Stephens, Michael P. Marks, Huy M. Do, Robert L. Dodd, Michael B. Bober and Gary K. Steinberg

OBJECTIVE

Majewski osteodysplastic primordial dwarfism Type II (MOPD II) is a rare genetic disorder. Features of it include extremely small stature, severe microcephaly, and normal or near-normal intelligence. Previous studies have found that more than 50% of patients with MOPD II have intracranial vascular anomalies, but few successful surgical revascularization or aneurysm-clipping cases have been reported because of the diminutive arteries and narrow surgical corridors in these patients. Here, the authors report on a large series of patients with MOPD II who underwent surgery for an intracranial vascular anomaly.

METHODS

In conjunction with an approved prospective registry of patients with MOPD II, a prospectively collected institutional surgical database of children with MOPD II and intracranial vascular anomalies who underwent surgery was analyzed retrospectively to establish long-term outcomes.

RESULTS

Ten patients with MOPD II underwent surgery between 2005 and 2012; 5 patients had moyamoya disease (MMD), 2 had intracranial aneurysms, and 3 had both MMD and aneurysms. Patients presented with transient ischemic attack (TIA) (n = 2), ischemic stroke (n = 2), intraparenchymal hemorrhage from MMD (n = 1), and aneurysmal subarachnoid hemorrhage (n = 1), and 4 were diagnosed on screening. The mean age of the 8 patients with MMD, all of whom underwent extracranial-intracranial revascularization (14 indirect, 1 direct) was 9 years (range 1–17 years). The mean age of the 5 patients with aneurysms was 15.5 years (range 9–18 years). Two patients experienced postoperative complications (1 transient weakness after clipping, 1 femoral thrombosis that required surgical repair). During a mean follow-up of 5.9 years (range 3–10 years), 3 patients died (1 of subarachnoid hemorrhage, 1 of myocardial infarct, and 1 of respiratory failure), and 1 patient had continued TIAs. All of the surviving patients recovered to their neurological baseline.

CONCLUSIONS

Patients with MMD presented at a younger age than those in whom aneurysms were more prevalent. Microneurosurgery with either intracranial bypass or aneurysm clipping is extremely challenging but feasible at expert centers in patients with MOPD II, and good long-term outcomes are possible.

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Patcharin Intarakhao, Peeraphong Thiarawat, Behnam Rezai Jahromi, Danil A. Kozyrev, Mario K. Teo, Joham Choque-Velasquez, Teemu Luostarinen and Juha Hernesniemi

OBJECTIVE

The purpose of this study was to analyze the impact of adenosine-induced cardiac arrest (AiCA) on temporary clipping (TC) and the postoperative cerebral infarction rate among patients undergoing intracranial aneurysm surgery.

METHODS

In this retrospective matched-cohort study, 65 patients who received adenosine for decompression of aneurysms during microsurgical clipping were identified (Group A) and randomly matched with 65 selected patients who underwent clipping but did not receive adenosine during surgery (Group B). The matching criteria included age, Fisher grade, aneurysm size, rupture status, and location of aneurysms. The primary outcomes were TC time and the postoperative infarction rate. The secondary outcome was the incidence of intraoperative aneurysm rupture (IAR).

RESULTS

In Group A, 40 patients underwent clipping with AiCA alone and 25 patients (38%) received AiCA combined with TC, and in Group B, 60 patients (92%) underwent aneurysm clipping under the protection of TC (OR 0.052; 95% CI 0.018–0.147; p < 0.001). Group A required less TC time (2.04 minutes vs 4.46 minutes; p < 0.001). The incidence of postoperative lacunar infarction was equal in both groups (6.2%). There was an insignificant between-group difference in the incidence of IAR (1.5% in Group A vs 6.1% in Group B; OR 0.238; 95% CI 0.026–2.192; p = 0.171).

CONCLUSIONS

AiCA is a useful technique for microneurosurgical treatment of cerebral aneurysms. AiCA can minimize the use of TC and does not increase the risk of IAR and postoperative infarction.

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Venkatesh S. Madhugiri, Mario K. C. Teo, Erick M. Westbroek, Steven D. Chang, Michael P. Marks, Huy M. Do, Richard P. Levy and Gary K. Steinberg

OBJECTIVE

Arteriovenous malformations (AVMs) of the basal ganglia and thalamus are particularly difficult lesions to treat, accounting for 3%–13% of all AVMs in surgical series and 23%–44% of malformations in radiosurgery series. The goal of this study was to report the results of multimodal management of basal ganglia and thalamic AVMs and investigate the factors that influence radiographic cure and good clinical outcomes.

METHODS

This study was a retrospective analysis of a prospectively maintained database of all patients treated at the authors’ institution. Clinical, radiological, follow-up, and outcome data were analyzed. Univariate and multivariate analyses were conducted to explore the influence of various factors on outcome.

RESULTS

The results and data analysis pertaining to 123 patients treated over 32 years are presented. In this cohort, radiographic cure was achieved in 50.9% of the patients. Seventy-five percent of patients had good clinical outcomes (stable or improved performance scores), whereas 25% worsened after treatment. Inclusion of surgery and radiosurgery independently predicted obliteration, whereas nidus diameter and volume predicted clinical outcomes. Nidus volume/diameter and inclusion of surgery predicted the optimal outcome, i.e., good clinical outcomes with lesion obliteration.

CONCLUSIONS

Good outcomes are possible with multimodal treatment in these complex patients. Increasing size and, by extension, higher Spetzler-Martin grade are associated with worse outcomes. Inclusion of multiple modalities of treatment as indicated could improve the chances of radiographic cure and good outcomes.