Arteriovenous malformation (AVM) presenting with epilepsy significantly impacts patient quality of life, and it should be considered very much a seizure disorder. Although hemorrhage prevention is the primary treatment aim of AVM surgery, seizure control should also be at the forefront of therapeutic management. Several hemodynamic and morphological characteristics of AVM have been identified to be associated with seizure presentation. This includes increased AVM flow, presence of long pial draining vein, venous outflow obstruction, and frontotemporal location, among other aspects. With the advent of high-throughput image processing and quantification methods, new radiographic attributes of AVM-related epilepsy have been identified. With respect to therapy, several treatment approaches are available, including conservative management or interventional modalities; this includes microsurgery, radiosurgery, and embolization or a combination thereof. Many studies, especially in the domain of microsurgery and radiosurgery, evaluate both techniques with respect to seizure outcomes. The advantage of microsurgery lies in superior AVM obliteration rates and swift seizure response. In addition, by incorporating electrophysiological monitoring during AVM resection, adjacent or even remote epileptogenic foci can be identified, leading to extended lesionectomy and improved seizure control. Radiosurgery, despite resulting in reduced AVM obliteration and prolonged time to seizure freedom, avoids the risks of surgery altogether and may provide seizure control through various antiepileptic mechanisms. Embolization continues to be used as an adjuvant for both microsurgery and radiosurgery. In this study, the authors review the latest imaging techniques in characterizing AVM-related epilepsy, in addition to reviewing each treatment modality.
Sauson Soldozy, Pedro Norat, Kaan Yağmurlu, Jennifer D. Sokolowski, Khadijeh A. Sharifi, Petr Tvrdik, Min S. Park and M. Yashar S. Kalani
Sauson Soldozy, Michelle Yeghyayan, Kaan Yağmurlu, Pedro Norat, Davis G. Taylor, M. Yashar S. Kalani, John A. Jane Jr. and Hasan R. Syed
The goal of this study was to systematically review the outcomes of endoscopic endonasal surgery (EES) for pediatric craniopharyngiomas so as to assess its safety and efficacy.
A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986 and 2019. All studies assessing outcomes following EES for pediatric craniopharyngiomas were included.
Of the total 48 articles identified in the original literature search, 13 studies were ultimately selected. This includes comparative studies with other surgical approaches, retrospective cohort studies, and case series.
EES for pediatric craniopharyngiomas is a safe and efficacious alternative to other surgical approaches. Achieving gross-total resection with minimal complications is feasible with EES and is comparable, if not superior in some cases, to traditional means of resection. Ideally, a randomized controlled trial might be implemented in the future to further elucidate the effectiveness of EES for resection of craniopharyngiomas.
Sauson Soldozy, Jacob Galindo, Harrison Snyder, Yusuf Ali, Pedro Norat, Kaan Yağmurlu, Jennifer D. Sokolowski, Khadijeh Sharifi, Petr Tvrdik, Min S. Park and M. Yashar S. Kalani
Neuroimaging is an indispensable tool in the workup and management of patients with neurological disorders. Arterial spin labeling (ASL) is an imaging modality that permits the examination of blood flow and perfusion without the need for contrast injection. Noninvasive in nature, ASL provides a feasible alternative to existing vascular imaging techniques, including angiography and perfusion imaging. While promising, ASL has yet to be fully incorporated into the diagnosis and management of neurological disorders. This article presents a review of the most recent literature on ASL, with a special focus on its use in moyamoya disease, brain neoplasms, seizures, and migraines and a commentary on recent advances in ASL that make the imaging technique more attractive as a clinically useful tool.
Kathryn N. Kearns, Jennifer D. Sokolowski, Kimberly Chadwell, Maureen Chandler, Therese Kiernan, Francesco Prada, M. Yashar S. Kalani and Min S. Park
Contrast-enhanced ultrasound (CEUS) is a relatively new imaging modality in the realm of neurosurgical disease. CEUS permits the examination of blood flow through arteries, veins, and capillaries via intravascular contrast agents and allows vascular architectural mapping with extreme sensitivity and specificity. While it has established utility in other organ systems such as the liver and kidneys, CEUS has not been studied extensively in the brain. This report presents a review of the literature on the neurosurgical applications of CEUS and provides an outline of the imaging modality’s role in the diagnosis, evaluation, and treatment of neurosurgical disease.
M. Yashar S. Kalani, Robert F. Spetzler, Rudolf Fahlbusch and James K. Liu
M. Yashar S. Kalani, Kaan Yağmurlu, Nikolay L. Martirosyan and Robert F. Spetzler
The lateral supracerebellar infratentorial (SCIT) approach provides advantageous access to lesions located in the lateral mesencephalon and mesencephalopontine junction. For lesions that abut the pial surface, a direct approach is ideal and well tolerated. For deep-seated lesions, the lateral mesencephalic sulcus (LMS) can be used to access lesions with minimal morbidity to the patient. This video demonstrates the use of the SCIT approach via the LMS to remove a cavernous malformation at the level of the mesencephalopontine junction. The use of somatosensory and motor evoked potential monitoring and intraoperative neuronavigation is essential for optimizing patient outcomes. Meticulous, multilayered closure is critical for optimal results in the posterior fossa. For optimal patient outcomes, approach selection for deep-seated lesions should combine the two-point method with safe entry zones. At follow-up, the patient had persistent sensory changes but was otherwise neurologically intact.
The video can be found here: https://youtu.be/bHFEZhG8dHw.
Sauson Soldozy, Pedro Norat, Mazin Elsarrag, Ajay Chatrath, John S. Costello, Jennifer D. Sokolowski, Petr Tvrdik, M. Yashar S. Kalani and Min S. Park
The pathogenesis of intracranial aneurysms remains complex and multifactorial. While vascular, genetic, and epidemiological factors play a role, nascent aneurysm formation is believed to be induced by hemodynamic forces. Hemodynamic stresses and vascular insults lead to additional aneurysm and vessel remodeling. Advanced imaging techniques allow us to better define the roles of aneurysm and vessel morphology and hemodynamic parameters, such as wall shear stress, oscillatory shear index, and patterns of flow on aneurysm formation, growth, and rupture. While a complete understanding of the interplay between these hemodynamic variables remains elusive, the authors review the efforts that have been made over the past several decades in an attempt to elucidate the physical and biological interactions that govern aneurysm pathophysiology. Furthermore, the current clinical utility of hemodynamics in predicting aneurysm rupture is discussed.
M. Yashar S. Kalani, Kaan Yağmurlu, Nikolay L. Martirosyan and Robert F. Spetzler
Dorsal pons lesions at the facial colliculus level can be accessed with a suboccipital telovelar (SOTV) approach using the superior fovea safe entry zone. Opening the telovelar junction allows visualization of the dorsal pons and lateral entry at the level of the fourth ventricle floor. Typically, a lateral entry into the floor of the fourth ventricle is better tolerated than a midline opening. This video demonstrates the use of the SOTV approach to remove a cavernous malformation at the level of the facial colliculus. This case is particularly interesting because of a large venous anomaly and several telangiectasias in the pons. Dissections in the video are reproduced with permission from the Rhoton Collection (http://rhoton.ineurodb.org).
The video can be found here: https://youtu.be/LqzCfN2J3lY.
Mazin Elsarrag, Sauson Soldozy, Parantap Patel, Pedro Norat, Jennifer D. Sokolowski, Min S. Park, Petr Tvrdik and M. Yashar S. Kalani
Enhanced recovery after surgery (ERAS) is a multidimensional approach to improving the care of surgical patients using subspecialty- and procedure-specific evidence-based protocols. The literature provides evidence of the benefits of ERAS implementation, which include expedited functional recovery, decreased postoperative morbidity, reduced costs, and improved subjective patient experience. Although extensively examined in other surgical areas, ERAS principles have been applied to spine surgery only in recent years. The authors examine studies investigating the application of ERAS programs to patients undergoing spine surgery.
The authors conducted a systematic review of the PubMed and MEDLINE databases up to November 20, 2018.
Twenty full-text articles were included in the qualitative analysis. The majority of studies were retrospective reviews of nonrandomized data sets or qualitative investigations lacking formal control groups; there was 1 protocol for a future randomized controlled trial. Most studies demonstrated reduced lengths of stay and no increase in rates of readmissions or complications after introduction of an ERAS pathway.
These introductory studies demonstrate the potential of ERAS protocols, when applied to spine procedures, to reduce lengths of stay, accelerate return of function, minimize postoperative pain, and save costs.
Daniel M. S. Raper, Nasser Mohammed, M. Yashar S. Kalani and Min S. Park
The preferred method for treating complex dural arteriovenous fistulae of the transverse and sigmoid sinuses is via endovascular, transarterial embolization using liquid embolysate. However, this treatment approach mandates access to distal dural feeding arteries that can be technically challenging by standard endovascular approaches. This video describes a left temporal craniotomy for direct stick microcatheterization of an endovascularly inaccessible distal posterior division of the middle meningeal artery for embolization of a complex left temporal dural arteriovenous fistula. The case was performed in the hybrid operative suite with biplane intraoperative angiography. Technical considerations, operative nuances, and outcomes are reviewed.
The video can be found here: https://youtu.be/Dnd4yHgaKcQ.