Seizure Outcomes in Patients With Surgically Treated Cerebral Arteriovenous Malformations

Neurosurgery ◽  
2015 ◽  
Vol 77 (5) ◽  
pp. 762-768 ◽  
Author(s):  
Christian von der Brelie ◽  
Matthias Simon ◽  
Jonas Esche ◽  
Johannes Schramm ◽  
Azize Boström
Keyword(s):  
Life Quality ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Common Symptom ◽  
Extensive Resection ◽  
Chronic Epilepsy ◽  
Epilepsy Classification ◽  
Drug Resistant Epilepsy ◽  
Postoperative Seizure

Abstract BACKGROUND: Epilepsy is the second most common symptom in cerebral arteriovenous malformation (AVM) patients. The consecutive reduction of life quality is a clinically underrated problem because treatment usually focuses on the prevention of intracerebral hemorrhage. OBJECTIVE: To evaluate postoperative seizure outcome with the aim of more accurate counseling for postoperative seizure outcome. METHODS: From 1985 to 2012, 293 patients with an AVM were surgically treated by J.S. One hundred twenty-six patients with preoperative seizures or epilepsy could be identified; 103 of 126 had a follow-up of at least 12 months and were included in the analysis. The different epilepsy subtypes were categorized (sporadic seizures, chronic epilepsy, drug-resistant epilepsy [DRE]). Preoperative workup and surgical technique were evaluated. Seizure outcome was analyzed by using International League Against Epilepsy classification. RESULTS: Sporadic seizures were identified in 41% of patients (chronic epilepsy and DRE were identified in 36% and 23%, respectively). Detailed preoperative epileptological workup was done in 13%. Seizure freedom was achieved in 77% (79% at 5 years, 84% at 10 years). Outcome was significantly poorer in DRE cases. More extensive resection was performed in 11 cases with longstanding symptoms (>24 months) and resulted in better seizure outcome as well as the short duration of preoperative seizure history. CONCLUSION: Patients presenting with AVM-associated epilepsy have a favorable seizure outcome after surgical treatment. Long-standing epilepsy and the progress into DRE markedly deteriorate the chances to obtain seizure freedom and should be considered an early factor in establishing the indication for AVM removal.

Tailored multilobar disconnective epilepsy surgery in the posterior quadrant

2020 ◽  
Vol 132 (5) ◽  
pp. 1345-1357 ◽  
Author(s):  
Michele Rizzi ◽  
Martina Revay ◽  
Piergiorgio d’Orio ◽  
Pina Scarpa ◽  
Valeria Mariani ◽  
...  
Keyword(s):  
Safety Profile ◽  
Class I ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Type I ◽  
Drug Resistant ◽  
Presurgical Evaluation ◽  
Posterior Quadrant ◽  
Drug Resistant Epilepsy

OBJECTIVESurgical treatment of drug-resistant epilepsy originating from the posterior quadrant (PQ) of the brain often requires large multilobar resections, and disconnective techniques have been advocated to limit the risks associated with extensive tissue removal. Few previous studies have described a tailored temporoparietooccipital (TPO) disconnective approach; only small series with short postoperative follow-ups have been reported. The aim of the present study was to present a tailored approach to multilobar PQ disconnections (MPQDs) for epilepsy and to provide details about selection of patients, presurgical investigations, surgical technique, treatment safety profile, and seizure and cognitive outcome in a large, single-center series of patients with a long-term follow-up.METHODSIn this retrospective longitudinal study, the authors searched their prospectively collected database for patients who underwent MPQD for drug-resistant epilepsy in the period of 2005–2017. Tailored MPQDs were a posteriori grouped as follows: type I (classic full TPO disconnection), type II (partial TPO disconnection), type III (full temporooccipital [TO] disconnection), and type IV (partial TO disconnection), according to the disconnection plane in the occipitoparietal area. A bivariate statistical analysis was carried out to identify possible predictors of seizure outcome (Engel class I vs classes II–IV) among several presurgical, surgical, and postsurgical variables. Preoperative and postoperative cognitive profiles were also collected and evaluated.RESULTSForty-two consecutive patients (29 males, 24 children) met the inclusion criteria. According to the presurgical evaluation (including stereo-electroencephalography in 13 cases), 12 (28.6%), 24 (57.1%), 2 (4.8%), and 4 (9.5%) patients received a type I, II, III, or IV MPQD, respectively. After a mean follow-up of 80.6 months, 76.2% patients were in Engel class I at last contact; at 6 months and 2 and 5 years postoperatively, Engel class I was recorded in 80.9%, 74.5%, and 73.5% of cases, respectively. Factors significantly associated with seizure freedom were the occipital pattern of seizure semiology and the absence of bilateral interictal epileptiform abnormalities at the EEG (p = 0.02). Severe complications occurred in 4.8% of the patients. The available neuropsychological data revealed postsurgical improvement in verbal domains, whereas nonunivocal outcomes were recorded in the other functions.CONCLUSIONSThe presented data indicate that the use of careful anatomo-electro-clinical criteria in the presurgical evaluation allows for customizing the extent of surgical disconnections in PQ epilepsies, with excellent results on seizures and an acceptable safety profile.

Outcomes after hemispherectomy in adult patients with intractable epilepsy: institutional experience and systematic review of the literature

2018 ◽  
Vol 128 (3) ◽  
pp. 853-861 ◽  
Author(s):  
Courtney M. Schusse ◽  
Kris Smith ◽  
Cornelia Drees
Keyword(s):  
Neuropsychological Testing ◽  
Case Series ◽  
Intractable Epilepsy ◽  
Adult Patients ◽  
Morbidity Rate ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Surgical Tool ◽  
Drug Resistant Epilepsy

OBJECTIVEHemispherectomy is a surgical technique that is established as a standard treatment in appropriately selected patients with drug-resistant epilepsy. It has proven to be successful in pediatric patients with unilateral hemispheric lesions but is underutilized in adults. This study retrospectively evaluated the clinical outcomes after hemispherectomy in adult patients with refractory epilepsy.METHODSThis study examined 6 cases of hemispherectomy in adult patients at Barrow Neurological Institute. In addition, all case series of hemispherectomy in adult patients were identified through a literature review using MEDLINE and PubMed. Case series of patients older than 18 years were included; reports of patients without clear follow-up duration or method of validated seizure outcome quantification were excluded. Seizure outcome was based on the Engel classification.RESULTSA total of 90 cases of adult hemispherectomy were identified, including 6 newly added by Barrow Neurological Institute. Sixty-five patients underwent functional hemispherectomy; 25 patients had anatomical hemispherectomy. Length of follow-up ranged from 9 to 456 months. Seizure freedom was achieved in 80% of patients. The overall morbidity rate was low, with 9 patients (10%) having new or additional postoperative speech or language dysfunction, and 19 patients (21%) reporting some worsening of hemiparesis. No patients lost ambulatory or significant functional ability, and 2 patients had objective ambulatory improvement. Among the 41 patients who underwent additional formal neuropsychological testing postoperatively, overall stability or improvement was seen.CONCLUSIONSHemispherectomy is a valuable surgical tool for properly selected adult patients with pre-existing hemiparesis and intractable epilepsy. In published cases, as well as in this series, the procedure has overall been well tolerated without significant morbidity, and the majority of patients have been rendered free of seizures.

scholarly journals Predictors of seizure outcome following resective surgery for drug-resistant epilepsy associated with focal gliosis

2019 ◽  
Vol 130 (6) ◽  
pp. 2071-2079
Author(s):  
Gopal K. Dash ◽  
Chaturbhuj Rathore ◽  
Malcolm K. Jeyaraj ◽  
Pandurang Wattamwar ◽  
Sankara P. Sarma ◽  
...  
Keyword(s):  
Postoperative Outcome ◽  
Posterior Region ◽  
Seizure Outcome ◽  
Drug Resistant ◽  
Resective Surgery ◽  
Common Etiology ◽  
Neurological Infections ◽  
Drug Resistant Epilepsy ◽  
Postoperative Seizure

OBJECTIVEThe authors studied the clinical characteristics and postoperative outcomes of drug-resistant epilepsy associated with focal gliosis.METHODSFrom their epilepsy surgery database, the authors selected the patients with drug-resistant epilepsy and MRI-defined focal gliosis who underwent focal resective surgery. All patients underwent standard presurgical evaluation. Intracranial electroencephalography (EEG) was performed in patients with discordant presurgical data, ill-defined lesions, and lesions close to eloquent regions. Completeness of resection was defined on the basis of extraoperative and intraoperative electrocorticography studies. Favorable postoperative outcome was defined as Engel class I outcome during the last 2 years of follow-up.RESULTSSixty-six patients fulfilled inclusion criteria. An initial precipitating injury was present in 38 (57.6%) patients, mainly in the form of perinatal injury (n = 10), trauma (n = 10), and meningoencephalitis (n = 8). Gliosis involved a single lobe in 38 (57.6%) patients and 2 adjacent lobes in 14 (21.2%) patients; the remaining 14 (21.2%) patients had multilobar gliosis. In patients with unilobar or bilobar gliosis, the posterior region of the head was involved in 34 (65%) patients and the frontal lobes in 12 (23%) patients. During a median follow-up of 4 years (range 2–9 years), 41 (62.1%) patients had favorable outcome. On multivariate analysis, the presence of a well-defined aura (p = 0.019), electrocorticographically defined completeness of resection (p = 0.024), and normal postoperative EEG findings at 1 year (p = 0.003) were predictive of favorable postoperative seizure outcome.CONCLUSIONSFocal gliosis is a common etiology for drug-resistant extratemporal epilepsy in developing countries and is most often located in the posterior region of the head. The majority of these patients have perinatal injuries or neurological infections as initial precipitating injuries. Patients with focal gliosis have good postoperative seizure outcomes after well-planned resective surgery.

scholarly journals Corpus callosotomy for treatment of drug-resistant epilepsy: a review of 16 pediatric cases in northern Vietnam

2020 ◽  
Vol 25 (6) ◽  
pp. 582-587
Author(s):  
Nguyen Duc Lien ◽  
Dang Anh Tuan ◽  
Cao Vu Hung ◽  
Jacob R. Lepard ◽  
Brandon G. Rocque
Keyword(s):  
Neurological Deficits ◽  
Seizure Outcome ◽  
Drug Resistant ◽  
Imaging Findings ◽  
Corpus Callosotomy ◽  
Resource Limited Settings ◽  
Resource Limited ◽  
Drug Resistant Epilepsy ◽  
Postoperative Seizure

OBJECTIVEThe aim of this study was to evaluate postoperative seizure outcome in children with drug-resistant epilepsy not eligible for focal resection who underwent corpus callosotomy.METHODSThe study included 16 patients undergoing corpus callosotomy between September 2015 and May 2018. Seizure semiology and frequency, psychomotor status, and video electroencephalography and imaging findings were evaluated for all patients.RESULTSOf the 16 patients who underwent callosotomy during the study period, 11 underwent complete callosotomy and 5 underwent anterior only. Seizure improvement greater than 75% was achieved in 37.5% of patients, and another 50% of patients had seizure improvement of 50%–75%. No sustained neurological deficits were observed in these patients. There were no significant complications. Duration of postoperative follow-up ranged from 12 to 44 months.CONCLUSIONSCorpus callosotomy is an effective treatment for selected patients with drug-resistant epilepsy not eligible for focal resection in resource-limited settings. Fostering and developing international epilepsy surgery centers should remain a high priority for the neurosurgical community at large.

scholarly journals Seizure outcome in temporal glioblastoma surgery: lobectomy as a supratotal resection regime outclasses conventional gross-total resection

2021 ◽  
Author(s):  
Valeri Borger ◽  
Motaz Hamed ◽  
Inja Ilic ◽  
Anna-Laura Potthoff ◽  
Attila Racz ◽  
...  
Keyword(s):  
Tumor Resection ◽  
Temporal Lobectomy ◽  
Secondary Outcome ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Secondary Outcome Measure ◽  
Total Resection ◽  
Class 1 ◽  
Postoperative Seizure ◽  
The Impact

Abstract Introduction The postoperative seizure freedom represents an important secondary outcome measure in glioblastoma surgery. Recently, supra-total glioblastoma resection in terms of anterior temporal lobectomy (ATL) has gained growing attention with regard to superior long-term disease control for temporal-located glioblastoma compared to conventional gross-total resections (GTR). However, the impact of ATL on seizure outcome in these patients is unknown. We therefore analyzed ATL and GTR as differing extents of resection in regard of postoperative seizure control in patients with temporal glioblastoma and preoperative symptomatic seizures. Methods Between 2012 and 2018, 33 patients with preoperative seizures underwent GTR or ATL for temporal glioblastoma at the authors’ institution. Seizure outcome was assessed postoperatively and 6 months after tumor resection according to the International League Against Epilepsy (ILAE) classification and stratified into favorable (ILAE class 1) versus unfavorable (ILAE class 2–6). Results Overall, 23 out of 33 patients (70%) with preoperative seizures achieved favorable seizure outcome following resection of temporal located glioblastoma. For the ATL group, postoperative seizure freedom was present in 13 out of 13 patients (100%). In comparison, respective rates for the GTR group were 10 out of 20 patients (50%) (p = 0.002; OR 27; 95% CI 1.4–515.9). Conclusions ATL in terms of a supra-total resection strategy was associated with superior favorable seizure outcome following temporal glioblastoma resection compared to GTR. Regarding above mentioned survival benefit following ATL compared to GTR, ATL as an aggressive supra-total resection regime might constitute the surgical modality of choice for temporal-located glioblastoma.

Association Between Anatomical Location of Surgically Induced Lesions and Postoperative Seizure Outcome in Temporal Lobe Epilepsy

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000013033
Author(s):  
Ezequiel Gleichgerrcht ◽  
Daniel L. Drane ◽  
Simon Sean Keller ◽  
Kathryn A. Davis ◽  
Robert Gross ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Anterior Commissure ◽  
Piriform Cortex ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Anatomical Location ◽  
Surgical Interventions ◽  
Postoperative Seizure ◽  
Promising Source

Objective:To determine the association between surgical lesions of distinct grey and white structures and connections with favorable post-operative seizure outcomes.Methods:Patients with drug-resistant temporal lobe epilepsy (TLE) from three epilepsy centers were included. We employed a voxel-based and connectome-based mapping approach to determine the association between favorable outcomes and surgery-induced temporal lesions. Analyses were conducted controlling for multiple confounders, including total surgical resection/ablation volume, hippocampal volumes, side of surgery, and site where the patient was treated.Results:The cohort included 113 patients with TLE [54 women; 86 right-handed; 16.5 (SD = 11.9) age at seizure onset, 54.9% left] who were 61.1% free of disabling seizures (Engel class 1) at follow-up. Postoperative seizure freedom in TLE was associated with 1) surgical lesions that targeted the hippocampus as well as the amygdala-piriform cortex complex and entorhinal cortices; 2) disconnection of temporal, frontal, and limbic regions through loss of white matter tracts within the uncinate fasciculus, anterior commissure, and fornix; and 3) functional disconnection of the frontal (superior and middle frontal gyri, orbitofrontal region) and temporal (superior and middle pole) lobes.Conclusions:Better postoperative seizure freedom are associated with surgical lesions of specific structures and connections throughout the temporal lobes. These findings shed light on the key components of epileptogenic networks in TLE and constitute a promising source of new evidence for future improvements in surgical interventions.Classification of Evidence:This study provides Class II evidence that for patients with temporal lobe epilepsy, postoperative seizure freedom is associated with surgical lesions of specific temporal lobe structures and connections.

scholarly journals Tumor-Associated Epilepsy in Patients With Brain Metastases: Necrosis-to-Tumor Ratio Forecasts Postoperative Seizure Freedom

2021 ◽  
Author(s):  
Majd Bahna ◽  
Muriel Heimann ◽  
Christian Bode ◽  
Valeri Borger ◽  
Lars Eichhorn ◽  
...  
Keyword(s):  
Risk Factors ◽  
Brain Metastases ◽  
Volume Ratio ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Treatment Regimes ◽  
Related Quality ◽  
Health Related ◽  
Neurosurgical Treatment ◽  
Postoperative Seizure

Abstract Surgical resection is highly effective in the treatment of tumor-related epilepsy (TRE) in patients with brain metastases (BM). Nevertheless, some patients suffer from postoperative persistent epilepsy which negatively impacts health-related quality of life. Therefore, early identification of patients with potentially unfavorable seizure outcome after BM resection is important. Patients with TRE that had undergone surgery for BM at the authors’ institution between 2013 and 2018 and were analyzed with regard to preoperatively identifiable risk factors for unfavorable seizure outcome. Tumor tissue and tumor necrosis ratios were assessed volumetrically. According to the classification of the International League Against Epilepsy (ILAE), seizure outcome was categorized as favorable (ILAE 1) and unfavorable (ILAE 2 - 6) after 3 months in order to avoid potential interference with adjuvant cancer treatment.Among all 38 patients undergoing neurosurgical treatment for BM with concomitant TRE, 34 patients achieved a favorable seizure outcome (90%). Unfavorable seizure outcome was significantly associated with larger tumor volumes (p=0.012), a midline shift > 7 mm (p=0.025), and a necrosis/tumor volume ratio > 0.2 (p=0.047).The present study identifies preoperatively collectable risk factors for unfavorable seizure outcome in patients with BM and TRE. This might enable to preselect for highly vulnerable patients with postoperative persistent epilepsy who might benefit from accompanying neuro-oncological expertise during further systemical treatment regimes.

Surgical outcomes in children with bottom-of-sulcus dysplasia and drug-resistant epilepsy: a retrospective cohort study

2021 ◽  
pp. 1-11
Author(s):  
Puneet Jain ◽  
Ayako Ochi ◽  
Carter McInnis ◽  
Hiroshi Otsubo ◽  
O. Carter Snead ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Medical Records ◽  
Focal Cortical Dysplasia ◽  
Seizure Freedom ◽  
Language Mapping ◽  
Resective Surgery ◽  
Histological Data ◽  
Drug Resistant Epilepsy ◽  
Video Eeg

OBJECTIVE Bottom-of-sulcus dysplasia (BOSD) is challenging to identify radiologically. The aim of this study was to explore seizure outcomes after resective surgery or MR-guided laser interstitial thermal therapy (MRgLITT) in children with BOSD. METHODS Children with radiologically defined BOSD who underwent resective surgery or MRgLITT, with at least 1 year of follow-up were included. Clinical, radiological, neurophysiological, and histological data were extracted from medical records. Invasive video EEG (IVEEG) was used to evaluate the ictal onset zone or motor/language mapping, wherever appropriate. Histology of MRI-visible BOSD, including the overlying and adjacent cortex, was also evaluated. RESULTS Forty-one children with BOSD underwent surgical treatment. The lesion was initially overlooked on MRI in 20 patients (48.8%). Of 34 patients who underwent IVEEG and who had available ictal data, the ictal onset zone extended beyond the MRI-visible BOSD in 23 patients (67.6%). Surgical treatment included lesionectomy (24 patients), extended lesionectomy (12 patients), lobectomy (1 patient), and ablation of BOSD (4 patients). The pathology in 37 patients who underwent resection showed focal cortical dysplasia type IIB and type IIA in 21 (53.8%) and 16 patients (41%), respectively. Seizure freedom was achieved in 32 patients (78.1%) after a mean follow-up of 4.3 years. CONCLUSIONS Seizure outcomes after resective surgery or MRgLITT in children with BOSD were generally favorable. The authors found that the neurophysiological abnormality and pathology often extended beyond the MRI-visible BOSD.

Stereoelectroencephalography in Children and Adolescents With Difficult-to-Localize Refractory Focal Epilepsy

Neurosurgery ◽  
2014 ◽  
Vol 75 (3) ◽  
pp. 258-268 ◽  
Author(s):  
Jorge Gonzalez-Martinez ◽  
Jeffrey Mullin ◽  
Juan Bulacio ◽  
Ajay Gupta ◽  
Rei Enatsu ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Pediatric Patients ◽  
Focal Epilepsy ◽  
Early Experience ◽  
Morbidity Rate ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Epileptogenic Zone ◽  
Eloquent Cortex

Abstract BACKGROUND: Although stereoelectroencephalography (SEEG) has been shown to be a valuable tool for preoperative decision making in focal epilepsy, there are few reports addressing the utility and safety of SEEG methodology applied to children and adolescents. OBJECTIVE: To present the results of our early experience using SEEG in pediatric patients with difficult-to-localize epilepsy who were not considered candidates for subdural grid evaluation. METHODS: Thirty children and adolescents with the diagnosis of medically refractory focal epilepsy (not considered ideal candidates for subdural grids and strip placement) underwent SEEG implantation. Demographics, electrophysiological localization of the hypothetical epileptogenic zone, complications, and seizure outcome after resections were analyzed. RESULTS: Eighteen patients (60%) underwent resections after SEEG implantations. In patients who did not undergo resections (12 patients), reasons included failure to localize the epileptogenic zone (4 patients); multifocal epileptogenic zone (4 patients); epileptogenic zone located in eloquent cortex, preventing resection (3 patients); and improvement in seizures after the implantation (1 patient). In patients who subsequently underwent resections, 10 patients (55.5%) were seizure free (Engel class I) and 5 patients (27.7%) experienced seizure improvement (Engel class II or III) at the end of the follow-up period (mean, 25.9 months; range, 12 to 47 months). The complication rate in SEEG implantations was 3%. CONCLUSION: The SEEG methodology is safe and should be considered in children/adolescents with difficult-to-localize epilepsy. When applied to highly complex and difficult-to-localize pediatric patients, SEEG may provide an additional opportunity for seizure freedom in association with a low morbidity rate.

scholarly journals Blinded study: prospectively defined high frequency oscillations predict seizure outcome in individual patients

2020 ◽  
Author(s):  
V Dimakopoulos ◽  
P Mégevand ◽  
E Boran ◽  
S Momjian ◽  
M Seeck ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
High Frequency ◽  
Dwell Time ◽  
Nrem Sleep ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
University Hospitals ◽  
High Frequency Oscillations ◽  
Depth Electrodes

AbstractBackgroundInterictal high frequency oscillations (HFO) are discussed as biomarkers for epileptogenic brain tissue that should be resected in epilepsy surgery to achieve seizure freedom. The prospective classification of tissue sampled by individual electrode contacts remains a challenge. We have developed an automated, prospective definition of clinically relevant HFO in intracranial EEG (iEEG) from MNI Montreal and tested it in iEEG from Zurich. We here validate the algorithm on iEEG recorded in an independent epilepsy center so that HFO analysis was blinded to seizure outcome.MethodsWe selected consecutive patients from Geneva University Hospitals who underwent resective epilepsy surgery with postsurgical follow-up > 12 months. We analyzed long-term iEEG recordings during non-rapid eye movement (NREM) sleep that we segmented into intervals of 5 min. HFOs were defined in the ripple (80-250 Hz) and the fast ripple (FR, 250-500 Hz) frequency band. Contacts with the highest rate of ripples co-occurring with FR (FRandR) designated the HFO area. If the HFO area was not fully resected and the patient suffered from recurrent seizures (ILAE 2-6), this was classified as a true positive (TP) prediction.ResultsWe included iEEG recordings from 16 patients (median age 32 y, range [18-53]) with stereotactic depth electrodes and/or with subdural electrode grids (median follow-up 27 mo, range [12-55]). The HFO area had high test-retest reliability across intervals (median dwell time 95%). We excluded two patients with dwell time < 50% from further analysis.The HFO area was fully included in the resected volume in 2/4 patients who achieved postoperative seizure freedom (ILAE 1, specificity 50%) and was not fully included in 9/10 patients with recurrent seizures (ILAE > 1, sensitivity 90%), leading to an accuracy of 79%.ConclusionsWe validated the automated procedure to delineate the clinical relevant HFO area in individual patients of an independently recorded dataset and achieved the same good accuracy as in our previous studies.SignificanceThe reproducibility of our results across datasets is promising for a multicienter study testing the clinical application of HFO detection to guide epilepsy surgery.

Sign in / Sign up

Export Citation Format

Share Document