1
|
Thomas JM, Sasankan D, Surendran S, Abraham M, Rajavelu A, Kartha CC. Aberrant regulation of retinoic acid signaling genes in cerebral arterio venous malformation nidus and neighboring astrocytes. J Neuroinflammation 2021; 18:61. [PMID: 33648532 PMCID: PMC7923665 DOI: 10.1186/s12974-021-02094-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/29/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebral arterio venous malformations (AVM) are a major causal factor for intracranial hemorrhage, which result in permanent disability or death. The molecular mechanisms of AVM are complex, and their pathogenesis remains an enigma. Current research on cerebral AVM is focused on characterizing the molecular features of AVM nidus to elucidate the aberrant signaling pathways. The initial stimuli that lead to the development of AVM nidus structures between a dilated artery and a vein are however not known. METHODS In order to understand the molecular basis of development of cerebral AVM, we used in-depth RNA sequencing with the total RNA isolated from cerebral AVM nidus. Immunoblot and qRT-PCR assays were used to study the differential gene expression in AVM nidus, and immunofluorescence staining was used to study the expression pattern of aberrant proteins in AVM nidus and control tissues. Immunohistochemistry was used to study the expression pattern of aberrant proteins in AVM nidus and control tissues. RESULTS The transcriptome study has identified 38 differentially expressed genes in cerebral AVM nidus, of which 35 genes were upregulated and 3 genes were downregulated. A final modular analysis identified an upregulation of ALDH1A2, a key rate-limiting enzyme of retinoic acid signaling pathway. Further analysis revealed that CYR61, a regulator of angiogenesis, and the target gene for retinoic acid signaling is upregulated in AVM nidus. We observed that astrocytes associated with AVM nidus are abnormal with increased expression of GFAP and Vimentin. Triple immunofluorescence staining of the AVM nidus revealed that CYR61 was also overexpressed in the abnormal astrocytes associated with AVM tissue. CONCLUSION Using high-throughput RNA sequencing analysis and immunostaining, we report deregulated expression of retinoic acid signaling genes in AVM nidus and its associated astrocytes and speculate that this might trigger the abnormal angiogenesis and the development of cerebral AVM in humans.
Collapse
Affiliation(s)
- Jaya Mary Thomas
- Cardio Vascular Diseases and Diabetes Biology, Rajiv Gandhi Centre for Biotechnology, Poojapura, Thycaud, Thiruvananthapuram, Kerala, 695014, India
- Manipal Academy of Higher Education, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - Dhakshmi Sasankan
- Cardio Vascular Diseases and Diabetes Biology, Rajiv Gandhi Centre for Biotechnology, Poojapura, Thycaud, Thiruvananthapuram, Kerala, 695014, India
| | - Sumi Surendran
- Cardio Vascular Diseases and Diabetes Biology, Rajiv Gandhi Centre for Biotechnology, Poojapura, Thycaud, Thiruvananthapuram, Kerala, 695014, India
| | - Mathew Abraham
- Department of Neurosurgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India
| | - Arumugam Rajavelu
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, Poojapura, Thycaud, Thiruvananthapuram, Kerala, 695014, India.
| | - Chandrasekharan C Kartha
- Cardio Vascular Diseases and Diabetes Biology, Rajiv Gandhi Centre for Biotechnology, Poojapura, Thycaud, Thiruvananthapuram, Kerala, 695014, India.
- Society for Continuing Medical Education and Research, Kerala Institute of Medical Sciences, Thiruvananthapuram, Kerala, 695029, India.
| |
Collapse
|
2
|
Florian IA, Beni L, Moisoiu V, Timis TL, Florian IS, Balașa A, Berindan-Neagoe I. 'De Novo' Brain AVMs-Hypotheses for Development and a Systematic Review of Reported Cases. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:201. [PMID: 33652628 PMCID: PMC7996785 DOI: 10.3390/medicina57030201] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/15/2021] [Accepted: 02/22/2021] [Indexed: 12/11/2022]
Abstract
Background and Objectives: Brain arteriovenous malformations AVMs have been consistently regarded as congenital malformations of the cerebral vasculature. However, recent case reports describing "de novo AVMs" have sparked a growing debate on the nature of these lesions. Materials and Methods: We have performed a systematic review of the literature concerning de novo AVMs utilizing the PubMed and Google Academic databases. Termes used in the search were "AVM," "arteriovenous," "de novo," and "acquired," in all possible combinations. Results: 53 articles including a total of 58 patients harboring allegedly acquired AVMs were identified by researching the literature. Of these, 32 were male (55.17%), and 25 were female (43.10%). Mean age at de novo AVM diagnosis was 27.833 years (standard deviation (SD) of 21.215 years and a 95% confidence interval (CI) of 22.3 to 33.3). Most de novo AVMs were managed via microsurgical resection (20 out of 58, 34.48%), followed by radiosurgery and conservative treatment for 11 patients (18.97%) each, endovascular embolization combined with resection for five patients (8.62%), and embolization alone for three (5.17%), the remaining eight cases (13.79%) having an unspecified therapy. Conclusions: Increasing evidence suggests that some of the AVMs discovered develop some time after birth. We are still a long way from finally elucidating their true nature, though there is reason to believe that they can also appear after birth. Thus, we reason that the de novo AVMs are the result of a 'second hit' of a variable type, such as a previous intracranial hemorrhage or vascular pathology. The congenital or acquired characteristic of AVMs may have a tremendous impact on prognosis, risk of hemorrhage, and short and long-term management.
Collapse
Affiliation(s)
- Ioan Alexandru Florian
- Clinic of Neurosurgery, Cluj County Emergency Clinical Hospital, 400012 Cluj-Napoca, Romania; (L.B.); (V.M.); (I.S.F.)
- Department of Neurosurgery, Iuliu Hatieganu University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Lehel Beni
- Clinic of Neurosurgery, Cluj County Emergency Clinical Hospital, 400012 Cluj-Napoca, Romania; (L.B.); (V.M.); (I.S.F.)
| | - Vlad Moisoiu
- Clinic of Neurosurgery, Cluj County Emergency Clinical Hospital, 400012 Cluj-Napoca, Romania; (L.B.); (V.M.); (I.S.F.)
| | - Teodora Larisa Timis
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania;
| | - Ioan Stefan Florian
- Clinic of Neurosurgery, Cluj County Emergency Clinical Hospital, 400012 Cluj-Napoca, Romania; (L.B.); (V.M.); (I.S.F.)
- Department of Neurosurgery, Iuliu Hatieganu University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Adrian Balașa
- Clinic of Neurosurgery, Tîrgu Mureș County Clinical Emergency Hospital, 540136 Tîrgu Mureș, Romania;
- Department of Neurosurgery, Tîrgu Mureș University of Medicine, Pharmacy, Science and Technology, 540139 Tîrgu Mureș, Romania
| | - Ioana Berindan-Neagoe
- Research Center for Functional Genomics, Biomedicine, and Translational Medicine, Institute of Doctoral Studies, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania;
| |
Collapse
|
3
|
Nagai Y, Anan M, Fujiki M. Cerebral Arteriovenous Malformations as Acquired Lesions: Case Reports and Review of the Literature. J Stroke Cerebrovasc Dis 2020; 29:105157. [PMID: 32912502 DOI: 10.1016/j.jstrokecerebrovasdis.2020.105157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 07/12/2020] [Indexed: 12/18/2022] Open
Abstract
Cerebral arteriovenous malformations (AVMs) are generally attributed to congenital lesions that arise from aberrant vasculogenesis between the fourth and eighth weeks of embryonic life. However, this dogma has been challenged by several recent observations, one of which is de novo formation of AVMs. Forty cases of de novo AVMs were published between 2000 and 2019, all of which involved a history of intracranial insult, such as vascular abnormalities or nonvascular conditions, prior to AVM diagnosis. We hereby present two unique operative cases of ruptured de novo AVMs in older adult patients. Case 1 is novel in the sense that the patient did not experience any kind of environmental trigger ("second hit") such as a previous intracranial insult, while Case 2 serves as the second report of a de novo AVM patient with a medical history of Bell's palsy. Although the exact mechanisms of AVM formation remain to be elucidated, it is likely to be a multifactorial process related to environmental and hemodynamic factors.
Collapse
Affiliation(s)
- Yasuyuki Nagai
- Department of Neurosurgery, National Hospital Organization Beppu Medical Center, 1473 Uchikamado, Beppu, Oita 8740011, Japan.
| | - Mitsuhiro Anan
- Department of Neurosurgery, National Hospital Organization Beppu Medical Center, 1473 Uchikamado, Beppu, Oita 8740011, Japan
| | - Minoru Fujiki
- Department of Neurosurgery, Oita University Faculty of Medicine, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 8795593, Japan
| |
Collapse
|
4
|
Lopez-Rivera V, Sheriff FG, Sandberg DI, Blackburn S, Dannenbaum M, Sheth SA, Day AL, Chen PR. De novo thalamic arteriovenous malformation in a boy with a brainstem cavernous malformation. J Clin Neurosci 2020; 76:226-228. [PMID: 32331948 DOI: 10.1016/j.jocn.2020.04.073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 04/14/2020] [Indexed: 11/16/2022]
Abstract
Brain arteriovenous malformations (bAVMs) have long been considered to be congenital, developing between the third and eighth weeks of embryogenesis. However, cases reporting their de novo formation suggest that these lesions can develop after birth and have challenged this concept. We present a case of a 6-year-old boy with a history of a brainstem cavernous malformation diagnosed after birth who later developed a de novo bAVM. The de novo occurrence of this bAVM distant to the site of the cavernous malformation and a prior negative catheter angiography contributes to the uncertainty of the dynamics and pathophysiology of bAVMs.
Collapse
Affiliation(s)
- Victor Lopez-Rivera
- Departments of Neurology, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Faheem G Sheriff
- Departments of Neurosurgery, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - David I Sandberg
- Departments of Neurosurgery, University of Texas Health Science Center at Houston, Houston, TX, United States; Departments of Division of Pediatric Neurosurgery, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Spiros Blackburn
- Departments of Neurosurgery, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Mark Dannenbaum
- Departments of Neurosurgery, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Sunil A Sheth
- Departments of Neurology, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Arthur L Day
- Departments of Neurosurgery, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Peng Roc Chen
- Departments of Neurosurgery, University of Texas Health Science Center at Houston, Houston, TX, United States.
| |
Collapse
|
5
|
Tasiou A, Tzerefos C, Alleyne CH, Boccardi E, Karlsson B, Kitchen N, Spetzler RF, Tolias CM, Fountas KN. Arteriovenous Malformations: Congenital or Acquired Lesions? World Neurosurg 2019; 134:e799-e807. [PMID: 31715403 DOI: 10.1016/j.wneu.2019.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Arteriovenous malformations (AVMs) were believed to be congenital. However, an increasing number of de novo AVM cases have questioned this doctrine. METHODS A consensus meeting of international experts attempted to establish a consensus on the nature of these relatively rare but challenging vascular lesions. In addition, an extensive search of the subject was performed using the PubMed medical database. RESULTS All participants agreed that genetic factors may play a role in the pathogenesis of AVMs. All but 1 participant believed that an underlying genetic predisposition may be detected later on in a patient's life, whereas genetic variations may contribute to sporadic AVM formation. The presence of genetic variations alone may not be enough for an AVM formation. A second hit is probably required. This consensus opinion is also supported by our literature search. CONCLUSIONS We discuss the literature on the genetics of AVMs and compare it with the consensus meeting outcomes. The congenital or noncongenital character of intracranial AVMs has an impact on the understanding their biological behavior, as well as their efficient short-term and long-term management.
Collapse
Affiliation(s)
- Anastasia Tasiou
- Department of Neurosurgery, University Hospital of Larissa, School of Medicine, University of Thessaly, Larissa, Greece.
| | - Christos Tzerefos
- Department of Neurosurgery, University Hospital of Larissa, School of Medicine, University of Thessaly, Larissa, Greece
| | | | - Edoardo Boccardi
- Department of Diagnostic and Interventional Neuroradiology, Niguarda Hospital, Milan, Italy
| | - Bengt Karlsson
- Department of Surgery, Division of Neurosurgery, National University Hospital, Singapore
| | - Neil Kitchen
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom
| | - Robert F Spetzler
- Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona, USA
| | - Christos M Tolias
- Department of Neurovascular Surgery, Kings College Hospital, London, United Kingdom
| | - Kostas N Fountas
- Department of Neurosurgery, University Hospital of Larissa, School of Medicine, University of Thessaly, Larissa, Greece
| |
Collapse
|
6
|
Gondar R, El Rahal A, Kulcsár Z, Schaller K, Momjian S. Spontaneous appearance of de novo intracranial arteriovenous malformation in hepatic cirrhosis. Neurochirurgie 2019; 65:393-396. [PMID: 31605684 DOI: 10.1016/j.neuchi.2019.09.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 08/23/2019] [Accepted: 09/22/2019] [Indexed: 11/18/2022]
Abstract
BACKGROUND Intracranial arteriovenous malformations (AVMs) are rare lesions that can be congenital or acquired in early childhood, with fatal outcome in approximately 30% of cases. De novo formation during adulthood without established predisposing vascular pathology or previous brain insult is even less frequent. CASE DESCRIPTION We present a case of de novo brain AVM in an alcoholic Child-B cirrhosis setting. Thirty previously reported cases presented de novo AVM in patients of all ages that had another previous brain pathology or insult, such as AVM resection. Seventeen of those cases occurred in adult patients, with only 2 showing no significant predisposing factor. The present pathophysiological review covers and completes Mullan's hemodynamic "two-hit" model, associating probable thrombotic predisposition to AVM with brain insult triggering a later stage based on angiogenic stimuli. CONCLUSIONS This case report and literature review renews previously discussed hemodynamic theories and contributes to a fuller understanding of the pathogenesis and progression of AVM. We postulate a causal link between hepatopathy and de novo AVM, which should be strengthened and interpreted based on recent genetic data and future prospective studies.
Collapse
Affiliation(s)
- R Gondar
- Neurosurgery Division, Department of Clinical Neurosciences, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland; Department of Spine Surgery and Neurosurgery, University of Fribourg, Hôpital Fribourgeois, Chemin des Pensionnats 2-6, 1700 Fribourg, Switzerland.
| | - A El Rahal
- Neurosurgery Division, Department of Clinical Neurosciences, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland
| | - Z Kulcsár
- Interventional Neuroradiology Division, Department of Radiology and Medical Informatics, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland; Department of Neuroradiology, University Hospital of Zurich, Frauenklinikstraße 10, 8091 Zürich, Switzerland
| | - K Schaller
- Neurosurgery Division, Department of Clinical Neurosciences, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland
| | - S Momjian
- Neurosurgery Division, Department of Clinical Neurosciences, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland
| |
Collapse
|
7
|
De novo brain arteriovenous malformation after tumor resection: case report and literature review. Acta Neurochir (Wien) 2018; 160:2191-2197. [PMID: 30206686 DOI: 10.1007/s00701-018-3668-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/31/2018] [Indexed: 02/03/2023]
Abstract
The congenital origin of brain arteriovenous malformations (bAVMs) has been increasingly challenged by reports of de novo bAVMs in patients previously confirmed to have no vascular malformation. We describe the oldest patient reported in the English language literature harboring a de novo bAVM. An uneventful frontal convexity meningioma resection was performed for a 60-year-old woman, and at 67 years of age, a bAVM was detected by MRI and confirmed by digital subtraction angiography at the site of the previous meningioma resection. This case adds to the growing literature that the etiology of bAVMs is most likely multifactorial.
Collapse
|
8
|
Dalton A, Dobson G, Prasad M, Mukerji N. De novo intracerebral arteriovenous malformations and a review of the theories of their formation. Br J Neurosurg 2018; 32:305-311. [DOI: 10.1080/02688697.2018.1478060] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- A. Dalton
- James Cook University Hospital, Middlesbrough, UK
| | - G. Dobson
- James Cook University Hospital, Middlesbrough, UK
| | - M. Prasad
- James Cook University Hospital, Middlesbrough, UK
| | - N. Mukerji
- James Cook University Hospital, Middlesbrough, UK
| |
Collapse
|
9
|
Lv X, Wang G. Review of de novo cerebral arteriovenous malformation: haemorrhage risk, treatment approaches and outcomes. Neuroradiol J 2018; 31:224-229. [PMID: 29469668 PMCID: PMC5958505 DOI: 10.1177/1971400918759811] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Objective A small number of patients has been reported to develop a completely new or de novo arteriovenous malformation (AVM) after brain surgery, haemorrhage, head trauma or ischaemic stroke. The natural history of these lesions is unknown. In this review, both ruptured and unruptured de novo AVMs and their treatments were reviewed. Methods Published literature in the PubMed database citing 'de novo cerebral arteriovenous malformation' was reviewed. Additional studies were identified through reference searches in each reviewed article. A review was performed using all published cases, the treatment approaches and outcomes. Results A total of 38 patients, including 37 de novo AVMs reported from 1988 to 17 November 2017 and our one patient, was collected. The age at AVM diagnosis was 5-73 years (mean ± SD, 27.6 ± 20.5 years). The duration time, from negative examination to AVM diagnosis, was 2 months to 25 years (mean ± SD, 6.6 ± 4.9 years). The presentation of de novo AVM was headaches in three (7.9%) patients, bleedings in 12 (31.6%), incidental in 14 (36.8%) and seizure in nine (23.7%). The estimated risk of haemorrhage was 4.8% per year. Seventeen (44.7%) patients were treated with surgical resection, 10 (26.3%) were conservatively observed, nine (23.7%) were treated with radiosurgery and two (5.3%) were endovascularly embolised. The morbidity and mortality were reported as 5.3% and 7.9%, respectively. Conclusion Post-natal de novo AVMs have been reported. Their annual haemorrhage risk is 4.8%. Most of them are treated by surgical resection and are associated with morbidity and mortality.
Collapse
Affiliation(s)
- Xianli Lv
- Neurosurgery Department, Beijing Tsinghua Changgung Hospital, Tsinghua University, China
| | - Guihuai Wang
- Neurosurgery Department, Beijing Tsinghua Changgung Hospital, Tsinghua University, China
| |
Collapse
|
10
|
Santos R, Aguilar-Salinas P, Entwistle JJ, Aldana PR, Beier AD, Hanel RA. De Novo Arteriovenous Malformation in a Pediatric Patient: Case Report and Review of the Literature. World Neurosurg 2018; 111:341-345. [DOI: 10.1016/j.wneu.2017.12.145] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/20/2017] [Accepted: 12/21/2017] [Indexed: 12/17/2022]
|
11
|
Abstract
Cerebral arteriovenous malformations (AVM) are tangles of blood vessels that permit shunting of blood from the arterial to venous phase without intervening capillaries. The malformation's arterialization of a low-pressure system creates a risk of rupture that is substantially higher when associated with an aneurysm. The annual hemorrhage rate is 2.2% per year as reported in the randomized trial of unruptured brain AVMs (ARUBA; rupture risk is increased after the first event. Ruptured AVMs have a 10% mortality rate and 20%-30% morbidity rate. The treatment of choice for AVMs is microvascular resection with or without preoperative embolization. Surgical risk can be stratified based on the Spetzler-Martin grading system. Liquid embolic material and coils may be used for the treatment of AVM associated aneurysms, especially in the setting of acute rupture as a bridge to delayed surgical resection. There is some limited reported success in total endovascular treatment of AVMs, but this is not considered standard therapy at this time. Stereotactic radiosurgery (SRS) has been recently described but mainly limited to AMVs deemed too risky to approach in an open fashion and limited to 2.5cm-3cm in size. The delayed protection from hemorrhage (approximately 2-3 years) and high marginal failure/recurrence rate are the greatest concerns.
Collapse
Affiliation(s)
- Orlando Diaz
- Neurovascular Center, Methodist Hospital, Houston, TX, USA.
| | - Robert Scranton
- Department of Neurosurgery, Methodist Hospital, Houston, TX, USA
| |
Collapse
|
12
|
Miller BA, Bass DI, Chern JJ. De novo AVM formation. Childs Nerv Syst 2015; 31:1023. [PMID: 25686897 DOI: 10.1007/s00381-015-2645-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/04/2015] [Indexed: 12/30/2022]
Affiliation(s)
- Brandon A Miller
- Department of Neurosurgery, School of Medicine, Emory University, 1365-B Clifton Road, Suite 6200, Atlanta, GA, 30322, USA,
| | | | | |
Collapse
|