{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T02:59:48Z","timestamp":1790391588145,"version":"4.1.0"},"reference-count":13,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,7,24]]},"abstract":"\n OBJECTIVE<\/jats:title>\n Filum terminale lipoma and low-set conus medullaris may cause tethered cord syndrome; however, the natural course of these lesions has not yet been fully elucidated. In this study, the authors investigated the natural history of filum terminale lipoma and low-set conus medullaris.<\/jats:p>\n <\/jats:sec>\n \n METHODS<\/jats:title>\n The authors retrospectively analyzed the data of patients who were diagnosed with filum terminale lipoma or low-set conus medullaris and followed without untethering surgery. Cases with a follow-up period of < 12 months were excluded.<\/jats:p>\n <\/jats:sec>\n \n RESULTS<\/jats:title>\n From 2010 to 2021, 1070 cases were diagnosed with filum terminale lipoma and\/or low-set conus medullaris on initial lumbar MRI at our hospital. Of these, 960 cases underwent untethering surgery after initial diagnosis. One hundred ten cases were followed without untethering surgery. Of these cases, 92 were evaluated, excluding those with a follow-up period of < 12 months. Among those, 12 cases had abnormal findings on initial cystography or abdominal ultrasound and were considered symptomatic, while 80 cases were asymptomatic. Of the 12 symptomatic cases, 3 (25%) developed worsening or new symptoms. These 3 cases underwent untethering surgery, with 2 (67%) showing improvement in symptoms and 1 remaining unchanged. During follow-up, 21 of 80 asymptomatic cases (26%) developed symptoms. Among these, 14 cases had filum terminale lipoma and 8 cases had low-set conus medullaris (1 case had both). Of these, 19 cases underwent untethering surgery; 10 cases (53%) improved, 2 cases remain unchanged, and the results of 7 cases are unknown.<\/jats:p>\n <\/jats:sec>\n \n CONCLUSIONS<\/jats:title>\n In this study, 26% of asymptomatic patients with filum terminale lipoma or low-set conus medullaris eventually developed symptoms, and 25% of symptomatic patients had worsening or new symptoms. These incidence rates should be considered when discussing preventive surgery for these lesions.<\/jats:p>\n <\/jats:sec>","DOI":"10.3171\/2026.3.peds25539","type":"journal-article","created":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T00:01:29Z","timestamp":1784678489000},"page":"1-6","source":"Crossref","is-referenced-by-count":0,"title":["Natural history of filum terminale lipoma and low-set conus medullaris"],"prefix":"10.3171","author":[{"given":"Kenichiro","family":"Nagai","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, National Center for Child Health and Development, Tokyo, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hideki","family":"Ogiwara","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, National Center for Child Health and Development, Tokyo, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"issue":"2","key":"b1","series-title":"J Neurosurg Pediatr","first-page":"196","article-title":"Predictors of surgical treatment in children with tethered fibrofatty filum terminale","volume":"25","author":"Kashlan ON","year":"2020","unstructured":"Kashlan ON, Wilkinson DA, Morgenstern H, Khalsa SS, Maher CO. Predictors of surgical treatment in children with tethered fibrofatty filum terminale. J Neurosurg Pediatr. 2020;25(2):196\u2013203. doi:10.3171\/2019.8.PEDS19292"},{"issue":"7","key":"b2","series-title":"Childs Nerv Syst","first-page":"1265","article-title":"Spinal lipoma of the filum terminale: review of 174 consecutive patients","volume":"32","author":"Usami K","year":"2016","unstructured":"Usami K, Lallemant P, Roujeau T, Spinal lipoma of the filum terminale: review of 174 consecutive patients. Childs Nerv Syst. 2016;32(7):1265\u20131272. doi:10.1007\/s00381-016-3072-8"},{"issue":"6","key":"b3","series-title":"Childs Nerv Syst","first-page":"298","article-title":"Congenital lumbosacral lipomas","volume":"13","author":"Pierre-Kahn A","year":"1997","unstructured":"Pierre-Kahn A, Zerah M, Renier D, Congenital lumbosacral lipomas. Childs Nerv Syst. 1997;13(6):298\u2013335. doi:10.1007\/s003810050090"},{"issue":"6","key":"b4","series-title":"Pediatr Neurosurg","first-page":"295","article-title":"Spinal lipomas in children","volume":"32","author":"Xenos C","year":"2000","unstructured":"Xenos C, Sgouros S, Walsh R, Hockley A. Spinal lipomas in children. Pediatr Neurosurg. 2000;32(6):295\u2013307. doi:10.1159\/000028958"},{"issue":"1","key":"b5","series-title":"Neurosurg Focus","first-page":"e3","article-title":"Spinal lipomas","volume":"10","author":"Blount JP","year":"2001","unstructured":"Blount JP, Elton S. Spinal lipomas. Neurosurg Focus. 2001;10(1):e3. doi:10.3171\/foc.2001.10.1.4"},{"issue":"5","key":"b6","series-title":"J Neurosurg Pediatr","first-page":"559","article-title":"Filum terminale lipomas: imaging prevalence, natural history, and conus position","volume":"13","author":"Cools MJ","year":"2014","unstructured":"Cools MJ, Al-Holou WN, Stetler WR, Filum terminale lipomas: imaging prevalence, natural history, and conus position. J Neurosurg Pediatr. 2014;13(5):559\u2013567. doi:10.3171\/2014.2.PEDS13528"},{"issue":"3","key":"b7","series-title":"J Neurosurg Pediatr","first-page":"342","article-title":"Retethering risk in pediatric spinal lipoma of the conus medullaris","volume":"29","author":"Hayashi T","year":"2022","unstructured":"Hayashi T, Kimiwada T, Shirane R, Tominaga T. Retethering risk in pediatric spinal lipoma of the conus medullaris. J Neurosurg Pediatr. 2022;29(3):342\u2013349. doi:10.3171\/2021.9.PEDS21413"},{"issue":"4","key":"b8","series-title":"Neurosurgery","first-page":"868","article-title":"Conservative management of asymptomatic spinal lipomas of the conus","volume":"54","author":"Kulkarni AV","year":"2004","unstructured":"Kulkarni AV, Pierre-Kahn A, Zerah M. Conservative management of asymptomatic spinal lipomas of the conus. Neurosurgery. 2004;54(4):868\u2013875. doi:10.1227\/01.neu.0000114923.76542.81"},{"issue":"10","key":"b9","series-title":"Childs Nerv Syst","first-page":"1731","article-title":"Asymptomatic lumbosacral lipomas\u2013a natural history study","volume":"28","author":"Wykes V","year":"2012","unstructured":"Wykes V, Desai D, Thompson DN. Asymptomatic lumbosacral lipomas\u2013a natural history study. Childs Nerv Syst. 2012;28(10):1731\u20131739. doi:10.1007\/s00381-012-1775-z"},{"issue":"6","key":"b10","series-title":"Neurosurgery","first-page":"1594","article-title":"Symptomatic retethering of the spinal cord after section of a tight filum terminale","volume":"68","author":"Yong RL","year":"2011","unstructured":"Yong RL, Habrock-Bach T, Vaughan M, Kestle JR, Steinbok P. Symptomatic retethering of the spinal cord after section of a tight filum terminale. Neurosurgery. 2011;68(6):1594\u20131602. doi:10.1227\/NEU.0b013e31821246c6"},{"issue":"2","key":"b11","series-title":"J Neurosurg Pediatr","first-page":"158","article-title":"Prevention of retethering in untethering surgery of a tight filum terminale","volume":"32","author":"Ogawa S","year":"2023","unstructured":"Ogawa S, Ogiwara H. Prevention of retethering in untethering surgery of a tight filum terminale. J Neurosurg Pediatr. 2023;32(2):158\u2013162. doi:10.3171\/2023.3.PEDS22542"},{"issue":"1","key":"b12","series-title":"World Neurosurg","first-page":"187","article-title":"Outcome, reoperation, and complications in 99 consecutive children operated for tight or fatty filum","volume":"77","author":"Ostling LR","year":"2012","unstructured":"Ostling LR, Bierbrauer KS, Kuntz C. Outcome, reoperation, and complications in 99 consecutive children operated for tight or fatty filum. World Neurosurg. 2012;77(1):187\u2013191. doi:10.1016\/j.wneu.2011.05.017"},{"issue":"1","key":"b13","series-title":"J Neurosurg Pediatr","first-page":"42","article-title":"Retethering of transected fatty filum terminales","volume":"7","author":"Ogiwara H","year":"2011","unstructured":"Ogiwara H, Lyszczarz A, Alden TD, Bowman RM, McLone DG, Tomita T. Retethering of transected fatty filum terminales. J Neurosurg Pediatr. 2011;7(1):42\u201346. doi:10.3171\/2010.10.PEDS09550"}],"container-title":["Journal of Neurosurgery: Pediatrics"],"original-title":[],"link":[{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg-pediatr\/aop\/article-10.3171-2026.3.PEDS25539\/article-10.3171-2026.3.PEDS25539.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg-pediatr\/aop\/article-10.3171-2026.3.PEDS25539\/article-10.3171-2026.3.PEDS25539.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T02:19:08Z","timestamp":1790389148000},"score":1,"resource":{"primary":{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg-pediatr\/aop\/article-10.3171-2026.3.PEDS25539\/article-10.3171-2026.3.PEDS25539.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,24]]},"references-count":13,"URL":"https:\/\/doi.org\/10.3171\/2026.3.peds25539","relation":{},"ISSN":["1933-0707","1933-0715"],"issn-type":[{"value":"1933-0707","type":"print"},{"value":"1933-0715","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,24]]}}}