{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T16:06:21Z","timestamp":1776096381043,"version":"3.50.1"},"reference-count":42,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"2","license":[{"start":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T00:00:00Z","timestamp":1768176000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Neurosurg Case Lessons"],"published-print":{"date-parts":[[2026,1,12]]},"abstract":"\n BACKGROUND<\/jats:title>\n Intradural spinal lipomas are a form of closed dysraphism and a frequent cause of tethered cord. Although usually adipocyte predominant, rare lesions may contain additional histological elements that can yield unexpected intraoperative behavior.<\/jats:p>\n <\/jats:sec>\n \n OBSERVATIONS<\/jats:title>\n A 13-year-old boy presented with progressive right foot deformity, distal weakness, gait limitation, and a low conus at S1\u20132 with a large terminal lipoma on spine MRI. He underwent detethering with debulking and L5 osteoplastic laminoplasty under intraoperative neuromonitoring (IONM). During microsurgical dissection, a pink band along the right aspect of the lipoma appeared unlike a nerve root. Targeted stimulation produced contraction within the thecal sac. The segment was isolated and divided under IONM guidance. Histopathological analysis confirmed skeletal muscle fibers intertwined with lobulated adipose tissue and fibrovascular elements of the filum terminale, consistent with a myolipoma. The patient had no postoperative sensory changes and progressed satisfactorily.<\/jats:p>\n <\/jats:sec>\n \n LESSONS<\/jats:title>\n Electrically evoked lipoma contraction is a physiological signature suggestive of myolipoma and can refine the extent of safe untethering. Although IONM adds value beyond evoked potential mapping by eliciting myogenic contraction and helping discriminate resectable elements from neural structures, the resulting EMG tracing becomes difficult to interpret in the presence of muscle and detethering proceeds based on visual assessment.<\/jats:p>\n \n https:\/\/thejns.org\/doi\/10.3171\/CASE25811<\/jats:ext-link>\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3171\/case25811","type":"journal-article","created":{"date-parts":[[2026,1,22]],"date-time":"2026-01-22T12:00:02Z","timestamp":1769083202000},"source":"Crossref","is-referenced-by-count":0,"title":["Intradural contractions: spinal lipoma surgery with equivocal electromyography activity. Illustrative case"],"prefix":"10.3171","volume":"11","author":[{"given":"Ignacio Mesina-","family":"Estarron","sequence":"first","affiliation":[{"name":"Division of Pediatric Neurosurgery, Children\u2019s Hospital of Orange County, Orange"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-5894-6963","authenticated-orcid":true,"given":"Rachel","family":"Zhang","sequence":"additional","affiliation":[{"name":"University of California at Irvine Medical School, Irvine"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fernando Cotrim","family":"Gomes","sequence":"additional","affiliation":[{"name":"Division of Pediatric Neurosurgery, Children\u2019s Hospital of Orange County, Orange"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anuraag","family":"Tandon","sequence":"additional","affiliation":[{"name":"Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aaron","family":"Sassoon","sequence":"additional","affiliation":[{"name":"Department of Pathology, Children\u2019s Hospital of Orange County, Orange"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maxwell","family":"Tran","sequence":"additional","affiliation":[{"name":"Medical Intelligence and Innovation Institute Summer Internship Program, Children\u2019s Hospital of Orange County, Orange, California"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aaron M.","family":"Yengo-Kahn","sequence":"additional","affiliation":[{"name":"Division of Pediatric Neurosurgery, Children\u2019s Hospital of Orange County, Orange"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1754","reference":[{"key":"bib1","series-title":"Congenital Spine Malformations","first-page":"151","article-title":"Intradural lipoma","author":"Elnahhas","year":"2024","unstructured":"Elnahhas ATalaia A.Intradural lipoma. In: AlAli KF, Hashim HT, eds. Congenital Spine Malformations. Springer Nature; 2024:151-164."},{"issue":"3","key":"bib2","series-title":"Neurosurgery","first-page":"511","article-title":"Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode: part I\u2014surgical technique","volume":"65","author":"Pang","year":"2009","unstructured":"Pang DZovickian JOviedo A.Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode: part I\u2014surgical technique. Neurosurgery. 2009;65(3):511-529."},{"issue":"3","key":"bib3","series-title":"Acta Neurochir (Wien)","first-page":"189","article-title":"Congenital spinal lipomatous malformations: part II\u2014clinical presentation, operative findings, and outcome","volume":"151","author":"Muthukumar","year":"2009","unstructured":"Muthukumar N.Congenital spinal lipomatous malformations: part II\u2014clinical presentation, operative findings, and outcome. Acta Neurochir (Wien). 2009;151(3):189-197."},{"issue":"6","key":"bib4","series-title":"Neurosurg Focus","first-page":"E18","article-title":"Tethered cord syndrome from pediatric and adult perspectives: a comprehensive systematic review of 6135 cases","volume":"56","author":"He","year":"2024","unstructured":"He KWang KLiu ZTethered cord syndrome from pediatric and adult perspectives: a comprehensive systematic review of 6135 cases. Neurosurg Focus. 2024;56(6):E18."},{"issue":"6","key":"bib5","series-title":"AJNR Am J Neuroradiol","first-page":"673","article-title":"International consensus statement on the radiologic evaluation of dysraphic malformations of the spine and spinal cord","volume":"45","author":"Balani","year":"2024","unstructured":"Balani ASidpra JSudhakar SInternational consensus statement on the radiologic evaluation of dysraphic malformations of the spine and spinal cord. AJNR Am J Neuroradiol. 2024;45(6):673-680."},{"issue":"3","key":"bib6","series-title":"J Pediatr Neurosci","first-page":"97","article-title":"Pediatric spinal lipomas: insights from a single institution\u2019s experience in surgical management of 55 cases","volume":"19","author":"Nazar","year":"2024","unstructured":"Nazar SAGerald MPavel VLPediatric spinal lipomas: insights from a single institution\u2019s experience in surgical management of 55 cases. J Pediatr Neurosci. 2024;19(3):97-102."},{"issue":"2","key":"bib7","series-title":"Neurosurgery","first-page":"253","article-title":"Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode, part II: outcome analysis and preoperative profiling","volume":"66","author":"Pang","year":"2010","unstructured":"Pang DZovickian JOviedo A.Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode, part II: outcome analysis and preoperative profiling. Neurosurgery. 2010;66(2):253-272."},{"key":"bib8","series-title":"J Clin Neurosci","first-page":"205","article-title":"Clinical observations on the release of tethered spinal cord in children with intra-operative neurophysiological monitoring: a retrospective study","volume":"71","author":"Jiang","year":"2020","unstructured":"Jiang JZhang SDai CClinical observations on the release of tethered spinal cord in children with intra-operative neurophysiological monitoring: a retrospective study. J Clin Neurosci. 2020;71:205-212."},{"issue":"2","key":"bib9","series-title":"J Neurosurg","first-page":"280","article-title":"Spinal angiolipomas: report of three cases","volume":"78","author":"Preul","year":"1993","unstructured":"Preul MCLeblanc RTampieri DRobitaille YPokrupa R.Spinal angiolipomas: report of three cases. J Neurosurg. 1993;78(2):280-286."},{"issue":"1","key":"bib10","series-title":"Arq Neuropsiquiatr","first-page":"112","article-title":"A rare case of intramedullary lipoma associated with cyst","volume":"59","author":"Falavigna","year":"2001","unstructured":"Falavigna ASegatto ACSalgado K.A rare case of intramedullary lipoma associated with cyst. Arq Neuropsiquiatr. 2001;59(1):112-115."},{"key":"bib11","series-title":"Trans Pathol Soc Lond","first-page":"19","article-title":"Myolipoma of spinal cord","volume":"27","author":"Gowers","year":"1876","unstructured":"Gowers WR.Myolipoma of spinal cord. Trans Pathol Soc Lond. 1876;27:19-22."},{"key":"bib12","series-title":"Riv Patol Nerv Ment","first-page":"640","article-title":"Lipomi intradurali. Discussione di un caso","volume":"83","author":"Schergna","year":"1962","unstructured":"Schergna ETurinese A.Lipomi intradurali. Discussione di un caso. Riv Patol Nerv Ment. 1962;83:640-660."},{"issue":"4","key":"bib13","series-title":"J Neurosurg","first-page":"564","article-title":"Histological features of congenital lipomas of the lower spinal canal","volume":"52","author":"Walsh","year":"1980","unstructured":"Walsh JWMarkesbery WR.Histological features of congenital lipomas of the lower spinal canal. J Neurosurg. 1980;52(4):564-569."},{"issue":"3","key":"bib14","series-title":"J Neurosurg","first-page":"457","article-title":"Lumbosacral intramedullary myolipoma: case report","volume":"66","author":"Knierim","year":"1987","unstructured":"Knierim DSWacker MPeckham NBedros AA.Lumbosacral intramedullary myolipoma: case report. J Neurosurg. 1987;66(3):457-459."},{"issue":"2","key":"bib15","series-title":"J Neuroimaging","first-page":"130","article-title":"Lumbosacral spinal intradural extramedullary paciniomyolipoma: magnetic resonance imaging. 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J Neurosurg Spine. 2000;92(2)(suppl):214-216."},{"issue":"suppl 2","key":"bib17","series-title":"Eur Spine J","first-page":"197","article-title":"Sacral myolipoma with symptomatic contraction of the conus at standing on tiptoe","volume":"23","author":"Shimizu","year":"2014","unstructured":"Shimizu SMiyazaki TMochizuki TOka H.Sacral myolipoma with symptomatic contraction of the conus at standing on tiptoe. Eur Spine J. 2014;23(suppl 2):197-200."},{"issue":"6","key":"bib18","series-title":"Int J Clin Med","first-page":"291","article-title":"Midline spinal cord hamartomas\u2014a report of six cases","volume":"4","author":"Rao","year":"2013","unstructured":"Rao DNCChakravarthy VKAruna ERatnam GVRao DR.Midline spinal cord hamartomas\u2014a report of six cases. Int J Clin Med. 2013;4(6):291-295."},{"issue":"8","key":"bib19","series-title":"Acta Neurochir (Wien)","first-page":"1433","article-title":"Myolipoma and tethered cord in a complex sacral malformation in a 26-year-old patient","volume":"157","author":"Iliescu","year":"2015","unstructured":"Iliescu BFChirita BCDumitrescu GFPoeata I.Myolipoma and tethered cord in a complex sacral malformation in a 26-year-old patient. Acta Neurochir (Wien). 2015;157(8):1433-1435."},{"issue":"23","key":"bib20","series-title":"J Neurosurg Case Lessons","first-page":"CASE2298","article-title":"Sacral myolipoma with involuntary contraction causing tethered cord syndrome: illustrative case","volume":"3","author":"Fujimoto","year":"2022","unstructured":"Fujimoto SAgari TKomori TTakai K.Sacral myolipoma with involuntary contraction causing tethered cord syndrome: illustrative case. J Neurosurg Case Lessons. 2022;3(23):CASE2298."},{"issue":"4","key":"bib21","series-title":"J Neurosurg Pediatr","first-page":"428","article-title":"New classification of spinal lipomas based on embryonic stage","volume":"19","author":"Morota","year":"2017","unstructured":"Morota NIhara SOgiwara H.New classification of spinal lipomas based on embryonic stage. J Neurosurg Pediatr. 2017;19(4):428-439."},{"key":"bib1","series-title":"Congenital Spine Malformations","first-page":"151","article-title":"Intradural lipoma","author":"Elnahhas","year":"2024","unstructured":"Elnahhas ATalaia A.Intradural lipoma. In: AlAli KF, Hashim HT, eds. Congenital Spine Malformations. Springer Nature; 2024:151-164."},{"issue":"3","key":"bib2","series-title":"Neurosurgery","first-page":"511","article-title":"Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode: part I\u2014surgical technique","volume":"65","author":"Pang","year":"2009","unstructured":"Pang DZovickian JOviedo A.Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode: part I\u2014surgical technique. Neurosurgery. 2009;65(3):511-529."},{"issue":"3","key":"bib3","series-title":"Acta Neurochir (Wien)","first-page":"189","article-title":"Congenital spinal lipomatous malformations: part II\u2014clinical presentation, operative findings, and outcome","volume":"151","author":"Muthukumar","year":"2009","unstructured":"Muthukumar N.Congenital spinal lipomatous malformations: part II\u2014clinical presentation, operative findings, and outcome. Acta Neurochir (Wien). 2009;151(3):189-197."},{"issue":"6","key":"bib4","series-title":"Neurosurg Focus","first-page":"E18","article-title":"Tethered cord syndrome from pediatric and adult perspectives: a comprehensive systematic review of 6135 cases","volume":"56","author":"He","year":"2024","unstructured":"He KWang KLiu ZTethered cord syndrome from pediatric and adult perspectives: a comprehensive systematic review of 6135 cases. Neurosurg Focus. 2024;56(6):E18."},{"issue":"6","key":"bib5","series-title":"AJNR Am J Neuroradiol","first-page":"673","article-title":"International consensus statement on the radiologic evaluation of dysraphic malformations of the spine and spinal cord","volume":"45","author":"Balani","year":"2024","unstructured":"Balani ASidpra JSudhakar SInternational consensus statement on the radiologic evaluation of dysraphic malformations of the spine and spinal cord. AJNR Am J Neuroradiol. 2024;45(6):673-680."},{"issue":"3","key":"bib6","series-title":"J Pediatr Neurosci","first-page":"97","article-title":"Pediatric spinal lipomas: insights from a single institution\u2019s experience in surgical management of 55 cases","volume":"19","author":"Nazar","year":"2024","unstructured":"Nazar SAGerald MPavel VLPediatric spinal lipomas: insights from a single institution\u2019s experience in surgical management of 55 cases. J Pediatr Neurosci. 2024;19(3):97-102."},{"issue":"2","key":"bib7","series-title":"Neurosurgery","first-page":"253","article-title":"Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode, part II: outcome analysis and preoperative profiling","volume":"66","author":"Pang","year":"2010","unstructured":"Pang DZovickian JOviedo A.Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode, part II: outcome analysis and preoperative profiling. Neurosurgery. 2010;66(2):253-272."},{"key":"bib8","series-title":"J Clin Neurosci","first-page":"205","article-title":"Clinical observations on the release of tethered spinal cord in children with intra-operative neurophysiological monitoring: a retrospective study","volume":"71","author":"Jiang","year":"2020","unstructured":"Jiang JZhang SDai CClinical observations on the release of tethered spinal cord in children with intra-operative neurophysiological monitoring: a retrospective study. J Clin Neurosci. 2020;71:205-212."},{"issue":"2","key":"bib9","series-title":"J Neurosurg","first-page":"280","article-title":"Spinal angiolipomas: report of three cases","volume":"78","author":"Preul","year":"1993","unstructured":"Preul MCLeblanc RTampieri DRobitaille YPokrupa R.Spinal angiolipomas: report of three cases. J Neurosurg. 1993;78(2):280-286."},{"issue":"1","key":"bib10","series-title":"Arq Neuropsiquiatr","first-page":"112","article-title":"A rare case of intramedullary lipoma associated with cyst","volume":"59","author":"Falavigna","year":"2001","unstructured":"Falavigna ASegatto ACSalgado K.A rare case of intramedullary lipoma associated with cyst. Arq Neuropsiquiatr. 2001;59(1):112-115."},{"key":"bib11","series-title":"Trans Pathol Soc Lond","first-page":"19","article-title":"Myolipoma of spinal cord","volume":"27","author":"Gowers","year":"1876","unstructured":"Gowers WR.Myolipoma of spinal cord. Trans Pathol Soc Lond. 1876;27:19-22."},{"key":"bib12","series-title":"Riv Patol Nerv Ment","first-page":"640","article-title":"Lipomi intradurali. Discussione di un caso","volume":"83","author":"Schergna","year":"1962","unstructured":"Schergna ETurinese A.Lipomi intradurali. Discussione di un caso. Riv Patol Nerv Ment. 1962;83:640-660."},{"issue":"4","key":"bib13","series-title":"J Neurosurg","first-page":"564","article-title":"Histological features of congenital lipomas of the lower spinal canal","volume":"52","author":"Walsh","year":"1980","unstructured":"Walsh JWMarkesbery WR.Histological features of congenital lipomas of the lower spinal canal. J Neurosurg. 1980;52(4):564-569."},{"issue":"3","key":"bib14","series-title":"J Neurosurg","first-page":"457","article-title":"Lumbosacral intramedullary myolipoma: case report","volume":"66","author":"Knierim","year":"1987","unstructured":"Knierim DSWacker MPeckham NBedros AA.Lumbosacral intramedullary myolipoma: case report. J Neurosurg. 1987;66(3):457-459."},{"issue":"2","key":"bib15","series-title":"J Neuroimaging","first-page":"130","article-title":"Lumbosacral spinal intradural extramedullary paciniomyolipoma: magnetic resonance imaging. Computed tomography","volume":"5","author":"Phillips","year":"1995","unstructured":"Phillips WEFigueroa REViloria JRansohoff J.Lumbosacral spinal intradural extramedullary paciniomyolipoma: magnetic resonance imaging. Computed tomography. J Neuroimaging. 1995;5(2):130-132."},{"issue":"2","key":"bib16","series-title":"J Neurosurg Spine","first-page":"214","article-title":"Myolipoma in a tethered cord: case report and review of the literature","volume":"92","author":"Brown","year":"2000","unstructured":"Brown PGShaver EG.Myolipoma in a tethered cord: case report and review of the literature. J Neurosurg Spine. 2000;92(2)(suppl):214-216."},{"issue":"suppl 2","key":"bib17","series-title":"Eur Spine J","first-page":"197","article-title":"Sacral myolipoma with symptomatic contraction of the conus at standing on tiptoe","volume":"23","author":"Shimizu","year":"2014","unstructured":"Shimizu SMiyazaki TMochizuki TOka H.Sacral myolipoma with symptomatic contraction of the conus at standing on tiptoe. Eur Spine J. 2014;23(suppl 2):197-200."},{"issue":"6","key":"bib18","series-title":"Int J Clin Med","first-page":"291","article-title":"Midline spinal cord hamartomas\u2014a report of six cases","volume":"4","author":"Rao","year":"2013","unstructured":"Rao DNCChakravarthy VKAruna ERatnam GVRao DR.Midline spinal cord hamartomas\u2014a report of six cases. Int J Clin Med. 2013;4(6):291-295."},{"issue":"8","key":"bib19","series-title":"Acta Neurochir (Wien)","first-page":"1433","article-title":"Myolipoma and tethered cord in a complex sacral malformation in a 26-year-old patient","volume":"157","author":"Iliescu","year":"2015","unstructured":"Iliescu BFChirita BCDumitrescu GFPoeata I.Myolipoma and tethered cord in a complex sacral malformation in a 26-year-old patient. Acta Neurochir (Wien). 2015;157(8):1433-1435."},{"issue":"23","key":"bib20","series-title":"J Neurosurg Case Lessons","first-page":"CASE2298","article-title":"Sacral myolipoma with involuntary contraction causing tethered cord syndrome: illustrative case","volume":"3","author":"Fujimoto","year":"2022","unstructured":"Fujimoto SAgari TKomori TTakai K.Sacral myolipoma with involuntary contraction causing tethered cord syndrome: illustrative case. J Neurosurg Case Lessons. 2022;3(23):CASE2298."},{"issue":"4","key":"bib21","series-title":"J Neurosurg Pediatr","first-page":"428","article-title":"New classification of spinal lipomas based on embryonic stage","volume":"19","author":"Morota","year":"2017","unstructured":"Morota NIhara SOgiwara H.New classification of spinal lipomas based on embryonic stage. 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