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Open access

Livio Pereira and Eduardo Vieira

In this surgical video, the authors present a case of a 24-year-old male patient who presented with sudden-onset headache and imbalance. On examination, he had a right-sided dysmetria and was otherwise neurologically intact. MRI showed a right cerebellar hematoma associated with multiple flow voids in the cerebellomesencephalic fissure and an enlarged lateral mesencephalic vein. Preoperative angiogram confirmed an arteriovenous malformation supplied by branches of the superior cerebellar artery. The patient underwent a lateral supracerebellar infratentorial approach for resection of the arteriovenous malformation (AVM). He recovered well from surgery and was discharged home on postoperative day 6. Postoperative angiogram confirmed complete AVM resection.

The video can be found here: https://youtu.be/tY4Go2n7V80

Free access

Victor E. Staartjes, Peter R. Seevinck, W. Peter Vandertop, Marijn van Stralen, and Marc L. Schröder

OBJECTIVE

Computed tomography scanning of the lumbar spine incurs a radiation dose ranging from 3.5 mSv to 19.5 mSv as well as relevant costs and is commonly necessary for spinal neuronavigation. Mitigation of the need for treatment-planning CT scans in the presence of MRI facilitated by MRI-based synthetic CT (sCT) would revolutionize navigated lumbar spine surgery. The authors aim to demonstrate, as a proof of concept, the capability of deep learning–based generation of sCT scans from MRI of the lumbar spine in 3 cases and to evaluate the potential of sCT for surgical planning.

METHODS

Synthetic CT reconstructions were made using a prototype version of the “BoneMRI” software. This deep learning–based image synthesis method relies on a convolutional neural network trained on paired MRI-CT data. A specific but generally available 4-minute 3D radiofrequency-spoiled T1-weighted multiple gradient echo MRI sequence was supplemented to a 1.5T lumbar spine MRI acquisition protocol.

RESULTS

In the 3 presented cases, the prototype sCT method allowed voxel-wise radiodensity estimation from MRI, resulting in qualitatively adequate CT images of the lumbar spine based on visual inspection. Normal as well as pathological structures were reliably visualized. In the first case, in which a spiral CT scan was available as a control, a volume CT dose index (CTDIvol) of 12.9 mGy could thus have been avoided. Pedicle screw trajectories and screw thickness were estimable based on sCT findings.

CONCLUSIONS

The evaluated prototype BoneMRI method enables generation of sCT scans from MRI images with only minor changes in the acquisition protocol, with a potential to reduce workflow complexity, radiation exposure, and costs. The quality of the generated CT scans was adequate based on visual inspection and could potentially be used for surgical planning, intraoperative neuronavigation, or for diagnostic purposes in an adjunctive manner.

Restricted access

Ailish Coblentz, Gavin J. B. Elias, Alexandre Boutet, Jurgen Germann, Musleh Algarni, Lais M. Oliveira, Clemens Neudorfer, Elysa Widjaja, George M. Ibrahim, Suneil K. Kalia, Mehr Jain, Andres M. Lozano, and Alfonso Fasano

OBJECTIVE

The objective of this study was to report the authors’ experience with deep brain stimulation (DBS) of the internal globus pallidus (GPi) as a treatment for pediatric dystonia, and to elucidate substrates underlying clinical outcome using state-of-the-art neuroimaging techniques.

METHODS

A retrospective analysis was conducted in 11 pediatric patients (6 girls and 5 boys, mean age 12 ± 4 years) with medically refractory dystonia who underwent GPi-DBS implantation between June 2009 and September 2017. Using pre- and postoperative MRI, volumes of tissue activated were modeled and weighted by clinical outcome to identify brain regions associated with clinical outcome. Functional and structural networks associated with clinical benefits were also determined using large-scale normative data sets.

RESULTS

A total of 21 implanted leads were analyzed in 11 patients. The average follow-up duration was 19 ± 20 months (median 5 months). Using a 7-point clinical rating scale, 10 patients showed response to treatment, as defined by scores < 3. The mean improvement in the Burke-Fahn-Marsden Dystonia Rating Scale motor score was 40% ± 23%. The probabilistic map of efficacy showed that the voxel cluster most associated with clinical improvement was located at the posterior aspect of the GPi, comparatively posterior and superior to the coordinates of the classic GPi target. Strong functional and structural connectivity was evident between the probabilistic map and areas such as the precentral and postcentral gyri, parietooccipital cortex, and brainstem.

CONCLUSIONS

This study reported on a series of pediatric patients with dystonia in whom GPi-DBS resulted in variable clinical benefit and described a clinically favorable stimulation site for this cohort, as well as its structural and functional connectivity. This information could be valuable for improving surgical planning, simplifying programming, and further informing disease pathophysiology.

Open access

Joshua S. Catapano, Rohin Singh, Visish M. Srinivasan, and Michael T. Lawton

Arteriovenous malformations (AVMs) in the brainstem, specifically medullary AVMs, are exceedingly rare and difficult to treat. These lesions are commonly more aggressive than supratentorial AVMs and pose their own unique treatment challenges. Current treatment options for these AVMs consist of endovascular embolization or open surgery. Radiosurgery is not favored because it is associated with potential risk to the brainstem and lower obliteration rates. Here the authors report the case of a 27-year-old man with a ruptured anterior medullary AVM. The patient underwent a successful far-lateral craniotomy for resection of the AVM.

The video can be found here: https://youtu.be/lyOfOQ3sBdU

Open access

Ehsan Dowlati, Kelsi Chesney, and Vikram V. Nayar

This is the case of a ruptured Spetzler-Martin grade II arteriovenous malformation (AVM) located in the cerebellopontine angle and draining into the transverse sinus. The AVM was initially treated with staged embolization using Onyx (ev3 Neurovascular). However, recurrence was noted and treatment with microsurgical resection was undertaken. The authors present technical nuances of the approach and strategies for microsurgical resection of a previously embolized recurrent AVM with the aid of intraoperative indocyanine green angiography. Follow-up after endovascular treatment is critical, and curative treatment with microsurgical resection can be achieved with low morbidity in such AVMs as demonstrated by this case.

The video can be found here: https://youtu.be/LMpz_YTFC0g

Open access

Walter Marani, Nicola Montemurro, Shoichiro Tsuji, Paolo Perrini, Kosumo Noda, Nakao Ota, Yu Kinoshita, Hiroyasu Kamiyama, and Rokuya Tanikawa

Cerebellar arteriovenous malformations (AVMs) represent 10%–15% of all intracranial AVMs and are associated with a greater risk for hemorrhagic presentation compared with supratentorial AVMs. When they reach the cerebellopontine angle cistern, neurovascular compression syndromes, including trigeminal neuralgia and hemifacial spasm, can occur. Due to the aggressive natural history of cerebellar AVM, an effective treatment strategy is required. In this video, the authors demonstrate the technical nuances of microsurgical resection of an unruptured cerebellar AVM in a 24-year-old female presenting with trigeminal neuralgia. The patient underwent right retrosigmoid craniotomy and complete resection of the AVM with resolution of trigeminal neuralgia.

The video can be found here: https://youtu.be/6GmNjgFQwx8

Open access

Brian M. Howard and Daniel L. Barrow

Many brain arteriovenous malformations (AVMs) derive dural blood supply, while 10%–15% of dural arteriovenous fistulas (dAVFs) have pial arterial input. To differentiate between the two is critical, as treatment of these entities is diametrically opposed. To treat dAVFs, the draining vein(s) is disconnected from feeding arteries, which portends hemorrhagic complications for AVMs. The authors present an operative video of a subtle cerebellar AVM initially treated as a dAVF by attempted embolization through dural vessels. The lesion was subsequently microsurgically extirpated. The authors show a comparison case of an AVM mistaken for a dAVF and transvenous embolization that resulted in a fatal hemorrhage.

The video can be found here: https://youtu.be/eDeiMrGoE0Q

Open access

Zeferino Demartini Jr., Guilherme H. W. Ceccato, Érico S. G. G. da Trindade, and Luis A. B. Borba

Intracranial hemorrhage is the most common presentation of posterior fossa arteriovenous malformations (AVMs) and may have serious consequences. The authors present a case of a 7-year-old girl with headache, vomiting, dysmetria, and ataxia due to a ruptured cerebellar grade III AVM. After two sessions of embolization, the patient underwent total microsurgical resection through a suboccipital craniotomy. There were no additional postoperative deficits, and the patient improved progressively during 6 months of rehabilitation. These challenging lesions should be removed after rupture, especially in children with long-term cumulative risk of rebleeding. Multimodal treatment reduces the perioperative bleeding, allowing better outcomes for pediatric AVM.

The video can be found here: https://youtu.be/HQWnjD8ENZQ

Free access

Prakash Shetty, Ujwal Yeole, Vikas Singh, and Aliasgar Moiyadi

OBJECTIVE

Intraoperative imaging is increasingly being used for resection control in diffuse gliomas, in which the extent of resection (EOR) is important. Intraoperative ultrasound (iUS) has emerged as a highly effective tool in this context. Navigated ultrasound (NUS) combines the benefits of real-time imaging with the benefits of navigation guidance. In this study, the authors investigated the use of NUS as an intraoperative adjunct for resection control in gliomas.

METHODS

The authors retrospectively analyzed 210 glioma patients who underwent surgery using NUS at their center. The analysis included intraoperative decision-making, diagnostic accuracy, and operative outcomes, particularly EOR and related factors influencing this.

RESULTS

US-defined gross-total resection (GTR) was achieved in 57.6% of patients. Intermediate resection control scans were evaluable in 115 instances. These prompted a change in the operative decision in 42.5% of cases (the majority being further resection of unanticipated residual tumor). Eventual MRI-defined GTR rates were similar (58.6%), although the concordance between US and MRI was 81% (170/210 cases). There were 21 false positives and 19 false negatives with NUS, resulting in a sensitivity of 78%, specificity of 83%, positive predictive value of 77%, and negative predictive value of 84%. A large proportion of patients (13/19 patients, 68%) with false-negative results eventually had near-total resections. Tumor resectability, delineation, enhancement pattern, eloquent location, and US image resolution significantly influenced the GTR rate, though only resectability and eloquent location were significant on multivariate analysis.

CONCLUSIONS

NUS is a useful intraoperative adjunct for resection control in gliomas, detecting unanticipated tumor residues and positively influencing the course of the resection, eventually leading to higher resection rates. Nevertheless, resection is determined by the innate resectability of the tumor and its relationship to eloquent location, reinforcing the need to combine iUS with functional mapping techniques to optimize resections.