Seizures after posterior fossa surgery: Exploring the unknown, a systematic review-

Seizures after posterior fossa surgery: Exploring the unknown, a systematic review- | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Seizures after posterior fossa surgery: Exploring the unknown, a systematic review- Ravish R keni, Surya Prakash Rao, Luis Rafael Moscote-Salazar, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-25132/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Seizures due to posterior fossa lesions is an uncommon phenomenon. In this study systemic literature review was done to i) study the incidence of seizures in posterior fossa lesions ii) determine factors associated with high risk for seizures and iii) ascertain role of prophylactic AEDs in such cases. Methods Systemic literature review was done, for the MeSH terms “posterior cranial fossa” AND “seizures” AND “anticonvulsants”. All original research articles, case reports and systematic reviews pertaining to seizures or use of anticonvulsants in posterior fossa lesions were considered for inclusion. Results A total of 79 cases of posterior fossa lesions, identified from 8 studies, were included for analysis. Incidence of seizures in posterior fossa lesions ranged from 1.8–5% in various studies. The highest incidence for seizures was reported with medulloblastoma, cerebellar haemorrhage and during microvascular decompression for cases of neurovascular conflict. The most significant risk factor for seizures in post-operative period was use to ventricular shunt or ventriculostomy. AEDs were administered symptomatically after the occurrence of seizures in 78 cases except for the use of prophylactic AEDs in a single case of posterior cranial fossa lipoma. Conclusion Seizures in association with posterior fossa lesions are rare and associated with a poor prognosis. Clinical detection can often be difficult and EEG helps in early diagnosis and treatment. Further studies are needed to confirm the role of prophylactic AEDs in high-risk cases. Neurosurgery posterior cranial fossa seizures anticonvulsants Background The occurrence of seizures in association with supra-tentorial lesions is well reported and prophylactic antiepileptic drugs (AEDs) are frequently used to reduce seizure recurrence [ 1 – 5 ]. There is no clear indication that these drugs reduce the incidence of seizures and long-term use is not recommended by most authors [ 1 – 5 ]. However, seizures due to posterior fossa lesions is an uncommon phenomenon and there is dearth of literature with regards to this [ 6 ]. The importance of addressing the issue of seizures in posterior fossa lesions, is due to the anatomical configuration where in the posterior fossa being a tight compartment resists even a mild increase in intracranial pressure and can lead to cerebral herniation and threaten life. In this paper, we did a literature review to i) study the incidence of seizures in posterior fossa lesions ii) determine factors associated with high risk for seizures and ii) ascertain role of prophylactic AEDs in such cases. Methods We searched various databases including PubMed, Cochrane and the grey literature, including relevant organisational websites, for the MeSH terms “posterior cranial fossa” AND “seizures” AND “anticonvulsants”. All original research articles, case reports and systematic reviews pertaining to seizures or use of anticonvulsants in posterior fossa lesions were considered for inclusion. Excluded were cases having i) multiple intracranial lesions ii) lesions situated in other areas of brain but were approached via posterior cranial fossa iii) posterior fossa lesions which neither had seizures nor AEDs were used prophylactically. Results A total of 79 cases of posterior fossa lesions, identified from 8 studies; who either presented with seizures or in whom AEDs were prophylactically used; were included for analysis. Seizures occurred pre-operatively in 15 cases and post-operatively in 63 cases. The various studies dealing with seizures in posterior fossa lesions are summarised in Table 1 . Table 1 Summary of literature data on seizures in posterior fossa lesions Study group Timing of seizure Number of cases and type of lesion Risk factors for post-operative seizures AED administered prophylactically or symptomatically Outcome Lee et al. [6] (1990) Post-operative Posterior fossa lesions (13) Medulloblastoma (4), Microvascular decompression (3) Haemorrhage (2) Acoustic neuroma (2), Astrocytoma (1), Meningioma (1), Metabolic acidosis (4), Hyponatremia (1), Meningitis (2) Ventriculostomy or shunt (9) Symptomatic - Patir and Banarjee [7] (1990) Post-operative Posterior fossa tumors (13) Medulloblastoma (6), Acoustic neuroma (3), Astrocytoma (2), Meningioma (2), Shunt (11) Symptomatic Poor Bazowski et al. [8] (1994) Nil Posterior fossa lipoma (1) - Prophylactic - Suri et al. [9] (1997) Post-operative Posterior fossa lesions (36), Operation in sitting position, intraoperative air embolism, postoperative pneumocephalus, hyponatraemia, metabolic acidosis, meningitis Symptomatic - Mclone [10] (1998) Pre-operative Cerebellar hamartoma (1) - Symptomatic Good Brown and Verheyden [11] (2009) Post-operative Posterior fossa infarction (1) - Symptomatic Poor Grill et al. [12] (2009) Pre-operative Number of patients (13), Aneurysms (4), Cavernous malformations (3), Cerebellar haemorrhage (3), Posterior fossa tumors (2), PRES (1) Sepsis (3), Use of drugs: cephalosporins (6), levofloxacin (3), bupropion (1) Symptomatic Poor Triana-Perez et al. [13] (2011) Pre-operative Rosai-Dorfman disease (1) - Symptomatic - Risk of seizures associated the various posterior fossa lesions A. Tumors The most common posterior fossa tumors associated with seizures were medulloblastoma (n = 10, 47%) followed by acoustic neuroma (n = 5, 23.8%). The other tumors less frequently associated with seizures were astrocytoma, meningioma, as well as a rare case of Rossai-Dorfman disease. B. Vascular lesions The most common vascular lesions in the posterior fossa associated with seizures were cerebellar haemorrhage (n = 6, 62.5%), followed by aneurysm (n = 4, 33%). Other lesions were one case each of cerebellar hamartoma and posterior fossa infarction respectively. C. Miscellaneous Other causes of seizures related to posterior fossa lesions were three cases of neurovascular conflict in whom microvascular decompression was attempted and one case of posterior reversible encephalopathy syndrome (PRES). Risk factors for post-operative seizures The most significant risk factor for seizures in post-operative period was use to ventricular shunt or ventriculostomy (n = 20,50%). The other risk factors were metabolic acidosis, hyponatremia, sepsis, meningitis, use of drugs which predispose to seizures such as cephalosporins, levofloxacin or bupropion and operation in sitting position which predisposed to air embolism and pneumocephalus. Role of prophylactic AEDs AEDs were administered symptomatically after the occurrence of seizures in 78 cases and prophylactic AEDs were only used in a single case of posterior cranial fossa lipoma. Outcomes of patients having seizures in posterior fossa lesions Amongst the four studies, which looked at patient outcomes in posterior fossa lesions presenting with seizures; poor outcomes were reported in three studies and a single case of cerebellar hamartoma had good outcome after seizures were controlled. Discussion Posterior cranial fossa contains several structures which are pertinent for maintaining normal level of consciousness. Structural lesion involving the posterior cranial fossa may cause impairment of consciousness commonly by virtue of mass effect leading to raised intracranial pressure and brainstem compression. An important differential diagnosis for sudden deterioration in sensorium of patients having posterior fossa lesions is seizure; which may be convulsive or non-convulsive. Seizures may cause altered consciousness or post-ictal weakness which may mimic clinical deterioration from other causes. Unlike supratentorial lesions which are commonly associated with seizures, the incidence of seizures in posterior fossa lesions is rare ranging from 1.8–5% in various series [ 6 , 7 , 12 ]. The mechanism of seizures in posterior fossa lesions, especially the role played by cerebellum in controlling epilepsy is a matter of dispute. Dysfunctional cerebellum has been found to be linked with disinhibition of epileptic activity in the cerebral cortex [ 14 – 16 ]. Pathologic cerebellar alterations lead to decrease in inhibitory purkinje cell output to the dentate nucleus and can result in seizures via the excitatory dentatothalamocortical tracts. The incidence of seizures either pre or post-operatively is largely dependant upon the type of lesion [ 6 – 13 ] and use of ventricular shunt or ventriculostomy [ 6 , 7 ]. The highest incidence for seizures was reported with medulloblastoma, cerebellar haemorrhage and during microvascular decompression for cases of neurovascular conflict. The high risk for seizures associated with this entities is plausibly due breach of the blood-brain barrier and intracranial deposition of hemosiderin, which is considered highly epileptogenic. Majority of patients with seizures in posterior fossa lesions tend to have poor outcome [ 7 , 11 , 12 ]. Early detection and prompt administration of AEDs is necessary as seizures can cause cerebral hypoxia, metabolic acidosis and a further increase in intracranial pressure. However, clinical detection of seizures in posterior fossa lesions is difficult, as convulsive seizures need to be differentiated from decerebrate or decorticate posturing secondary to raised intracranial pressure. Similarly altered sensorium due to non-convulsive status epilepticus (NCSE) needs to be differentiated from coma due to structural lesion. EEG is a vital tool to facilitate seizure diagnosis and initiate prompt treatment. It is mandatory to order continuous EEG monitoring in all patients with a posterior fossa lesions who develop altered mental status before or after surgery. There is no literature evidence regarding use prophylactic AEDs or choice of particular AEDs for seizure management [ 6 , 7 , 9 – 13 ]. However, in certain cases associated with high risk of seizures as discussed earlier, it is worth considering the possible use of prophylactic AEDs. Prevention of seizures could result in an improved prognosis for such patients. In addition, the use of prophylactic AEDs may also be cost-effective given the increased morbidity and mortality in those patients who do develop seizures and NCSE. Further studies and possibly large scale multi-centric trials are warranted to investigate whether the use of prophylactic AEDs can be recommended in high-risk posterior fossa lesions. Conclusion Seizures in association with sub-tentorial posterior fossa lesions are rare and are associated with a poor prognosis. Clinical detection can often be difficult and EEG helps in early diagnosis and treatment. Further studies are needed to confirm the role of prophylactic AEDs in high-risk cases. Abbreviations AED-anti-epileptic drugs, NCSE-non-convulsive status epilepticus, PRES-posterior reversible encephalopathy syndrome Declarations Availability of data and materials The data that support the findings of this study are available from the corresponding author, [Dr.Agarwal] upon reasonable request. References Forsyth PA, Weaver S, Fulton D, Brasher PM, Sutherland G, Stewart D, et al. Prophylactic anticonvulsants in patients with brain tumour. Can J Neurol Sci. 2003;30(2):106–12. Sirven JI, Wingerchuk DM, Drazkowski JF, Lyons MK, Zimmerman RS. Seizure prophylaxis in patients with brain tumors: a meta-analysis. Mayo Clin Proc. 2004; 79(12):1489-94. Mikkelsen T, Paleologos NA, Robinson PD, Ammirati M, Andrews DW, Asher AL, et al. The role of prophylactic anticonvulsants in the management of brain metastases: a systematic review and evidence-based clinical practice guideline. J Neurooncol. 2010;96(1):97–102. Chandra V, Rock AK, Opalak C, Stary JM, Sima AP, Carr M, et al. A systematic review of perioperative seizure prophylaxis during brain tumor resection: the case for a multicenter randomized clinical trial. Neurosurg Focus. 2017;43(5):E18. Dewan MC, Thompson RC, Kalkanis SN, Barker FG II, Hadjipanayis CG. Prophylactic antiepileptic drug administration following brain tumor resection: results of a recent AANS/CNS Section on Tumors survey. J Neurosurg. 2017;126(6):1772–8. Lee ST, Lui TN, Chang CN, Cheng WC. Early postoperative seizures after posterior fossa surgery. J Neurosurg. 1990;73(4):541–4. Patir R, Banerji AK. Complications related to pre-craniotomy shunts in posterior fossa tumours. Br J Neurosurg. 1990;4(5):387–90. Bazowski P, Mandera M, Rudnik A, Baron J. Two cases of intracranial lipomas. Neurol Neurochir Pol. 1994;28(1):115–21. Suri A, Mahapatra AK, Bithal P. Seizures following posterior fossa surgery. Br J Neurosurg. 1998;12(1):41–4. McLone DG, Stieg PE, Scott RM, Barnett F, Barnes PD, Folkerth R. Cerebellar epilepsy. Neurosurgery. 1998 May;42(5):1106–11. Brown M, Verheyden C. Posterior fossa infarction following cleft palate repair and the arcuate foramen. Plast Reconstr Surg. 2009;124(5):237e-9e. Grill MF, Treiman DM, Maganti RK. Status epilepticus associated with subtentorial posterior fossa lesions. Arch Neurol. 2009;66(12):1500–4. Triana-Pérez AB, Sánchez-Medina Y, Pérez-Del Rosario PA, Millán-Corada AM, Gómez-Perals LF, Domínguez-Báez JJ. Isolated intracranial Rosai-Dorfman disease: a case report and literature review. Neurocirugia. 2011;22(3):255–60. Wong JC, Escayg A. Illuminating the cerebellum as a potential target for treating epilepsy. Epilepsy Curr. 2015;15:277–8. Marcián V, Filip P, Bareš M, Brázdil M. Cerebellar Dysfunction and Ataxia in Patients with Epilepsy: Coincidence, Consequence, or Cause? Tremor Other Hyperkinet Mov (N Y). 2016; 6:376. Erratum in: Tremor Other Hyperkinet Mov (N Y). 2016; 6:416. Park KM, Han YH, Kim TH, Mun CW, Shin KJ, Ha SY, et al. Cerebellar white matter changes in patients with newly diagnosed partial epilepsy of unknown etiology. Clin Neurol Neurosurg. 2015;138:25–30. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-25132","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research","associatedPublications":[],"authors":[{"id":522582,"identity":"4cdc1863-4418-4af1-b55e-df3e014a0d53","order_by":1,"name":"Ravish R keni","email":"","orcid":"https://orcid.org/0000-0002-6278-9540","institution":"","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ravish","middleName":"R","lastName":"keni","suffix":""},{"id":522583,"identity":"c1acd5c1-4b47-4a10-9310-a7adaba0b5f7","order_by":2,"name":"Surya Prakash Rao","email":"","orcid":"","institution":"","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Surya","middleName":"Prakash","lastName":"Rao","suffix":""},{"id":522584,"identity":"22d898eb-0b05-42bf-93ad-224a586e996a","order_by":3,"name":"Luis Rafael Moscote-Salazar","email":"","orcid":"","institution":"","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Luis","middleName":"Rafael","lastName":"Moscote-Salazar","suffix":""},{"id":522585,"identity":"451426eb-a575-44d2-9eb1-209ae7777e93","order_by":4,"name":"Harsh Deora","email":"","orcid":"","institution":"","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Harsh","middleName":"","lastName":"Deora","suffix":""},{"id":522586,"identity":"93b823d6-070c-4a96-8456-93a8091bb243","order_by":5,"name":"Quiñones-Ossa GA","email":"","orcid":"","institution":"","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Quiñones-Ossa","middleName":"","lastName":"GA","suffix":""},{"id":522587,"identity":"87d7f6dc-e2da-4a83-a97b-c267f3534f55","order_by":6,"name":"Amit Agrawal","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+ElEQVRIiWNgGAWjYDCCA0CcAOM8qAASzMwNRGiB6Uk4A9LCSIQWuDWJbSCSgBa+24efbnj4w85ue/sZww+J82qj+duBWn5UbMOpRfJcmtmNhITk5DlncowlErcdz51xmLGBsefMbZxaDM4wgLQwJ0sw5G4AajmW2wDUwszYhk8L+zeglvpkCf63m38kzjmWO5+wFh6QLYftJCRyt0kkNtTkbiCkRfIMT9mNhLTjCRIS779ZJBw7kLsRqOUgPr/wnWHfdvOHTbW9BH9a8o0PNXW5884fPvjgRwVuLTCQ2AChD4PJAwTVA4E9lK4jRvEoGAWjYBSMMAAA6HpjVWsgYnAAAAAASUVORK5CYII=","orcid":"","institution":"","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Amit","middleName":"","lastName":"Agrawal","suffix":""}],"badges":[],"createdAt":"2020-04-24 11:06:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-25132/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-25132/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":13501589,"identity":"13400817-9801-45f9-a46c-2cf4b5311bad","added_by":"auto","created_at":"2021-09-16 23:11:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":321774,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-25132/v1/0e3834ec-2e2d-4699-b08c-0a37a99032a9.pdf"}],"financialInterests":"","formattedTitle":"Seizures after posterior fossa surgery: Exploring the unknown, a systematic review-","fulltext":[{"header":"Background","content":" \u003cp\u003eThe occurrence of seizures in association with supra-tentorial lesions is well reported and prophylactic antiepileptic drugs (AEDs) are frequently used to reduce seizure recurrence [\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. There is no clear indication that these drugs reduce the incidence of seizures and long-term use is not recommended by most authors [\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, seizures due to posterior fossa lesions is an uncommon phenomenon and there is dearth of literature with regards to this [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The importance of addressing the issue of seizures in posterior fossa lesions, is due to the anatomical configuration where in the posterior fossa being a tight compartment resists even a mild increase in intracranial pressure and can lead to cerebral herniation and threaten life.\u003c/p\u003e \u003cp\u003eIn this paper, we did a literature review to i) study the incidence of seizures in posterior fossa lesions ii) determine factors associated with high risk for seizures and ii) ascertain role of prophylactic AEDs in such cases.\u003c/p\u003e "},{"header":"Methods","content":" \u003cp\u003eWe searched various databases including PubMed, Cochrane and the grey literature, including relevant organisational websites, for the MeSH terms \u0026ldquo;posterior cranial fossa\u0026rdquo; AND \u0026ldquo;seizures\u0026rdquo; AND \u0026ldquo;anticonvulsants\u0026rdquo;. All original research articles, case reports and systematic reviews pertaining to seizures or use of anticonvulsants in posterior fossa lesions were considered for inclusion. Excluded were cases having i) multiple intracranial lesions ii) lesions situated in other areas of brain but were approached via posterior cranial fossa iii) posterior fossa lesions which neither had seizures nor AEDs were used prophylactically.\u003c/p\u003e "},{"header":"Results","content":" \u003cp\u003eA total of 79 cases of posterior fossa lesions, identified from 8 studies; who either presented with seizures or in whom AEDs were prophylactically used; were included for analysis. Seizures occurred pre-operatively in 15 cases and post-operatively in 63 cases. The various studies dealing with seizures in posterior fossa lesions are summarised in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSummary of literature data on seizures in posterior fossa lesions\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStudy group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTiming of seizure\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNumber of cases\u003c/p\u003e \u003cp\u003eand type of lesion\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRisk factors for post-operative seizures\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAED administered prophylactically or symptomatically\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLee et al.\u003csup\u003e[6]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(1990)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePost-operative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePosterior fossa lesions (13)\u003c/p\u003e \u003cp\u003eMedulloblastoma (4),\u003c/p\u003e \u003cp\u003eMicrovascular decompression (3)\u003c/p\u003e \u003cp\u003eHaemorrhage (2)\u003c/p\u003e \u003cp\u003eAcoustic neuroma (2),\u003c/p\u003e \u003cp\u003eAstrocytoma (1),\u003c/p\u003e \u003cp\u003eMeningioma (1),\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMetabolic acidosis (4),\u003c/p\u003e \u003cp\u003eHyponatremia (1),\u003c/p\u003e \u003cp\u003eMeningitis (2)\u003c/p\u003e \u003cp\u003eVentriculostomy or shunt (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptomatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatir and Banarjee \u003csup\u003e[7]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(1990)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePost-operative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePosterior fossa tumors (13)\u003c/p\u003e \u003cp\u003eMedulloblastoma (6),\u003c/p\u003e \u003cp\u003eAcoustic neuroma (3),\u003c/p\u003e \u003cp\u003eAstrocytoma (2),\u003c/p\u003e \u003cp\u003eMeningioma (2),\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eShunt (11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptomatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBazowski et al. \u003csup\u003e[8]\u003c/sup\u003e (1994)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNil\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePosterior fossa lipoma (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eProphylactic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuri et al. \u003csup\u003e[9]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(1997)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePost-operative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePosterior fossa lesions (36),\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOperation in sitting position,\u003c/p\u003e \u003cp\u003eintraoperative air embolism,\u003c/p\u003e \u003cp\u003epostoperative pneumocephalus, hyponatraemia,\u003c/p\u003e \u003cp\u003emetabolic acidosis,\u003c/p\u003e \u003cp\u003emeningitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptomatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMclone \u003csup\u003e[10]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(1998)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePre-operative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCerebellar hamartoma (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptomatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBrown and Verheyden \u003csup\u003e[11]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(2009)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePost-operative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePosterior fossa infarction (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptomatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrill et al. \u003csup\u003e[12]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(2009)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePre-operative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNumber of patients (13),\u003c/p\u003e \u003cp\u003eAneurysms (4),\u003c/p\u003e \u003cp\u003eCavernous malformations (3),\u003c/p\u003e \u003cp\u003eCerebellar haemorrhage (3), Posterior fossa tumors (2),\u003c/p\u003e \u003cp\u003ePRES (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSepsis (3),\u003c/p\u003e \u003cp\u003eUse of drugs:\u003c/p\u003e \u003cp\u003ecephalosporins (6),\u003c/p\u003e \u003cp\u003elevofloxacin (3),\u003c/p\u003e \u003cp\u003ebupropion (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptomatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTriana-Perez et al. \u003csup\u003e[13]\u003c/sup\u003e (2011)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePre-operative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRosai-Dorfman disease (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptomatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eRisk of seizures associated the various posterior fossa lesions\u003c/b\u003e \u003c/p\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eA. Tumors\u003c/h2\u003e \u003cp\u003eThe most common posterior fossa tumors associated with seizures were medulloblastoma (n\u0026thinsp;=\u0026thinsp;10, 47%) followed by acoustic neuroma (n\u0026thinsp;=\u0026thinsp;5, 23.8%). The other tumors less frequently associated with seizures were astrocytoma, meningioma, as well as a rare case of Rossai-Dorfman disease.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eB. Vascular lesions\u003c/h2\u003e \u003cp\u003eThe most common vascular lesions in the posterior fossa associated with seizures were cerebellar haemorrhage (n\u0026thinsp;=\u0026thinsp;6, 62.5%), followed by aneurysm (n\u0026thinsp;=\u0026thinsp;4, 33%). Other lesions were one case each of cerebellar hamartoma and posterior fossa infarction respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eC. Miscellaneous\u003c/h2\u003e \u003cp\u003eOther causes of seizures related to posterior fossa lesions were three cases of neurovascular conflict in whom microvascular decompression was attempted and one case of posterior reversible encephalopathy syndrome (PRES).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eRisk factors for post-operative seizures\u003c/h2\u003e \u003cp\u003eThe most significant risk factor for seizures in post-operative period was use to ventricular shunt or ventriculostomy (n\u0026thinsp;=\u0026thinsp;20,50%). The other risk factors were metabolic acidosis, hyponatremia, sepsis, meningitis, use of drugs which predispose to seizures such as cephalosporins, levofloxacin or bupropion and operation in sitting position which predisposed to air embolism and pneumocephalus.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eRole of prophylactic AEDs\u003c/h2\u003e \u003cp\u003eAEDs were administered symptomatically after the occurrence of seizures in 78 cases and prophylactic AEDs were only used in a single case of posterior cranial fossa lipoma.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eOutcomes of patients having seizures in posterior fossa lesions\u003c/h2\u003e \u003cp\u003eAmongst the four studies, which looked at patient outcomes in posterior fossa lesions presenting with seizures; poor outcomes were reported in three studies and a single case of cerebellar hamartoma had good outcome after seizures were controlled.\u003c/p\u003e \u003c/div\u003e "},{"header":"Discussion","content":" \u003cp\u003ePosterior cranial fossa contains several structures which are pertinent for maintaining normal level of consciousness. Structural lesion involving the posterior cranial fossa may cause impairment of consciousness commonly by virtue of mass effect leading to raised intracranial pressure and brainstem compression. An important differential diagnosis for sudden deterioration in sensorium of patients having posterior fossa lesions is seizure; which may be convulsive or non-convulsive. Seizures may cause altered consciousness or post-ictal weakness which may mimic clinical deterioration from other causes. Unlike supratentorial lesions which are commonly associated with seizures, the incidence of seizures in posterior fossa lesions is rare ranging from 1.8\u0026ndash;5% in various series [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe mechanism of seizures in posterior fossa lesions, especially the role played by cerebellum in controlling epilepsy is a matter of dispute. Dysfunctional cerebellum has been found to be linked with disinhibition of epileptic activity in the cerebral cortex [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Pathologic cerebellar alterations lead to decrease in inhibitory purkinje cell output to the dentate nucleus and can result in seizures via the excitatory dentatothalamocortical tracts.\u003c/p\u003e \u003cp\u003eThe incidence of seizures either pre or post-operatively is largely dependant upon the type of lesion [\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10 CR11 CR12\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] and use of ventricular shunt or ventriculostomy [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The highest incidence for seizures was reported with medulloblastoma, cerebellar haemorrhage and during microvascular decompression for cases of neurovascular conflict. The high risk for seizures associated with this entities is plausibly due breach of the blood-brain barrier and intracranial deposition of hemosiderin, which is considered highly epileptogenic.\u003c/p\u003e \u003cp\u003eMajority of patients with seizures in posterior fossa lesions tend to have poor outcome [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Early detection and prompt administration of AEDs is necessary as seizures can cause cerebral hypoxia, metabolic acidosis and a further increase in intracranial pressure. However, clinical detection of seizures in posterior fossa lesions is difficult, as convulsive seizures need to be differentiated from decerebrate or decorticate posturing secondary to raised intracranial pressure. Similarly altered sensorium due to non-convulsive status epilepticus (NCSE) needs to be differentiated from coma due to structural lesion. EEG is a vital tool to facilitate seizure diagnosis and initiate prompt treatment. It is mandatory to order continuous EEG monitoring in all patients with a posterior fossa lesions who develop altered mental status before or after surgery.\u003c/p\u003e \u003cp\u003eThere is no literature evidence regarding use prophylactic AEDs or choice of particular AEDs for seizure management [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan additionalcitationids=\"CR10 CR11 CR12\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. However, in certain cases associated with high risk of seizures as discussed earlier, it is worth considering the possible use of prophylactic AEDs. Prevention of seizures could result in an improved prognosis for such patients. In addition, the use of prophylactic AEDs may also be cost-effective given the increased morbidity and mortality in those patients who do develop seizures and NCSE. Further studies and possibly large scale multi-centric trials are warranted to investigate whether the use of prophylactic AEDs can be recommended in high-risk posterior fossa lesions.\u003c/p\u003e "},{"header":"Conclusion","content":" \u003cp\u003eSeizures in association with sub-tentorial posterior fossa lesions are rare and are associated with a poor prognosis. Clinical detection can often be difficult and EEG helps in early diagnosis and treatment. Further studies are needed to confirm the role of prophylactic AEDs in high-risk cases.\u003c/p\u003e "},{"header":"Abbreviations","content":"\u003cp\u003eAED-anti-epileptic drugs,\u003c/p\u003e \u003cp\u003eNCSE-non-convulsive status epilepticus,\u003c/p\u003e \u003cp\u003ePRES-posterior reversible encephalopathy syndrome\u003c/p\u003e "},{"header":"Declarations","content":"\u003ch2\u003eAvailability of data and materials\u003c/h2\u003e \n \u003cp\u003eThe data that support the findings of this study are available from the corresponding author, [Dr.Agarwal] upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e \u003cspan\u003eForsyth PA, Weaver S, Fulton D, Brasher PM, Sutherland G, Stewart D, et al. Prophylactic anticonvulsants in patients with brain tumour. Can J Neurol Sci. 2003;30(2):106\u0026ndash;12.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eSirven JI, Wingerchuk DM, Drazkowski JF, Lyons MK, Zimmerman RS. Seizure prophylaxis in patients with brain tumors: a meta-analysis. Mayo Clin Proc. 2004; 79(12):1489-94.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eMikkelsen T, Paleologos NA, Robinson PD, Ammirati M, Andrews DW, Asher AL, et al. The role of prophylactic anticonvulsants in the management of brain metastases: a systematic review and evidence-based clinical practice guideline. J Neurooncol. 2010;96(1):97\u0026ndash;102.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eChandra V, Rock AK, Opalak C, Stary JM, Sima AP, Carr M, et al. A systematic review of perioperative seizure prophylaxis during brain tumor resection: the case for a multicenter randomized clinical trial. Neurosurg Focus. 2017;43(5):E18.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eDewan MC, Thompson RC, Kalkanis SN, Barker FG II, Hadjipanayis CG. Prophylactic antiepileptic drug administration following brain tumor resection: results of a recent AANS/CNS Section on Tumors survey. J Neurosurg. 2017;126(6):1772\u0026ndash;8.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eLee ST, Lui TN, Chang CN, Cheng WC. Early postoperative seizures after posterior fossa surgery. J Neurosurg. 1990;73(4):541\u0026ndash;4.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003ePatir R, Banerji AK. Complications related to pre-craniotomy shunts in posterior fossa tumours. Br J Neurosurg. 1990;4(5):387\u0026ndash;90.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eBazowski P, Mandera M, Rudnik A, Baron J. Two cases of intracranial lipomas. Neurol Neurochir Pol. 1994;28(1):115\u0026ndash;21.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eSuri A, Mahapatra AK, Bithal P. Seizures following posterior fossa surgery. Br J Neurosurg. 1998;12(1):41\u0026ndash;4.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eMcLone DG, Stieg PE, Scott RM, Barnett F, Barnes PD, Folkerth R. Cerebellar epilepsy. Neurosurgery. 1998 May;42(5):1106\u0026ndash;11.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eBrown M, Verheyden C. Posterior fossa infarction following cleft palate repair and the arcuate foramen. Plast Reconstr Surg. 2009;124(5):237e-9e.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eGrill MF, Treiman DM, Maganti RK. Status epilepticus associated with subtentorial posterior fossa lesions. Arch Neurol. 2009;66(12):1500\u0026ndash;4.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eTriana-P\u0026eacute;rez AB, S\u0026aacute;nchez-Medina Y, P\u0026eacute;rez-Del Rosario PA, Mill\u0026aacute;n-Corada AM, G\u0026oacute;mez-Perals LF, Dom\u0026iacute;nguez-B\u0026aacute;ez JJ. Isolated intracranial Rosai-Dorfman disease: a case report and literature review. Neurocirugia. 2011;22(3):255\u0026ndash;60.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eWong JC, Escayg A. Illuminating the cerebellum as a potential target for treating epilepsy. Epilepsy Curr. 2015;15:277\u0026ndash;8.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003eMarci\u0026aacute;n V, Filip P, Bareš M, Br\u0026aacute;zdil M. Cerebellar Dysfunction and Ataxia in Patients with Epilepsy: Coincidence, Consequence, or Cause? Tremor Other Hyperkinet Mov (N Y). 2016; 6:376. Erratum in: Tremor Other Hyperkinet Mov (N Y). 2016; 6:416.\u003c/span\u003e \u003c/li\u003e \u003cli\u003e \u003cspan\u003ePark KM, Han YH, Kim TH, Mun CW, Shin KJ, Ha SY, et al. Cerebellar white matter changes in patients with newly diagnosed partial epilepsy of unknown etiology. Clin Neurol Neurosurg. 2015;138:25\u0026ndash;30.\u003c/span\u003e \u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"posterior cranial fossa, seizures, anticonvulsants","lastPublishedDoi":"10.21203/rs.3.rs-25132/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-25132/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eSeizures due to posterior fossa lesions is an uncommon phenomenon. In this study systemic literature review was done to i) study the incidence of seizures in posterior fossa lesions ii) determine factors associated with high risk for seizures and iii) ascertain role of prophylactic AEDs in such cases.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eSystemic literature review was done, for the MeSH terms \u0026ldquo;posterior cranial fossa\u0026rdquo; AND \u0026ldquo;seizures\u0026rdquo; AND \u0026ldquo;anticonvulsants\u0026rdquo;. All original research articles, case reports and systematic reviews pertaining to seizures or use of anticonvulsants in posterior fossa lesions were considered for inclusion.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 79 cases of posterior fossa lesions, identified from 8 studies, were included for analysis. Incidence of seizures in posterior fossa lesions ranged from 1.8\u0026ndash;5% in various studies. The highest incidence for seizures was reported with medulloblastoma, cerebellar haemorrhage and during microvascular decompression for cases of neurovascular conflict. The most significant risk factor for seizures in post-operative period was use to ventricular shunt or ventriculostomy. AEDs were administered symptomatically after the occurrence of seizures in 78 cases except for the use of prophylactic AEDs in a single case of posterior cranial fossa lipoma.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eSeizures in association with posterior fossa lesions are rare and associated with a poor prognosis. Clinical detection can often be difficult and EEG helps in early diagnosis and treatment. Further studies are needed to confirm the role of prophylactic AEDs in high-risk cases.\u003c/p\u003e","manuscriptTitle":"Seizures after posterior fossa surgery: Exploring the unknown, a systematic review-","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2020-04-30 23:53:35","doi":"10.21203/rs.3.rs-25132/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ca720410-d3c5-4718-b780-3d13f353c82a","owner":[],"postedDate":"April 30th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":92289,"name":"Neurosurgery"}],"tags":[],"updatedAt":"2020-06-05T16:51:24+00:00","versionOfRecord":[],"versionCreatedAt":"2020-04-30 23:53:35","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-25132","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-25132","identity":"rs-25132","version":["v1"]},"buildId":"cBFmMYwuxLRRLfASyISRj","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}