{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T03:16:52Z","timestamp":1785554212854,"version":"3.56.0"},"reference-count":24,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1993,4]]},"abstract":"<jats:p content-type=\"fine-print\">\u2713 Although the development of tonsillar herniation (acquired Chiari malformation) in association with lumboperitoneal (LP) shunting is well recognized, it has previously been considered rare. In order to ascertain the incidence of this complication after LP shunting, the authors undertook a retrospective study of all patients in whom this form of shunt had been inserted between 1974 and 1991 at The Hospital for Sick Children, Toronto. In the 143 patients, the mean age at insertion was 3.3 years and the indications for shunt placement were hydrocephalus (81%), pseudotumor cerebri (7%), cerebrospinal fluid fistula (6%), and posterior fossa pseudomeningocele (6%). The mean follow-up period was 5.7 years, during which time there was one shunt-related death due to unsuspected tonsillar herniation. Five other patients developed symptomatic tonsillar herniation treated by suboccipital decompression.<\/jats:p>\n<jats:p content-type=\"fine-print\">Review of all computerized tomography (CT) scans not degraded by artifact showed evidence of excess soft tissue at the level of the foramen magnum in 38 (70%) of 54 patients so studied. In order to confirm that this CT finding represented hindbrain herniation, sagittal and axial magnetic resonance (MR) images were obtained for 17 asymptomatic patients and revealed tonsillar herniation (range 2 to 21 mm) in 12 (70.6%). In addition, some of these asymptomatic patients had evidence of uncal herniation and mesencephalic distortion. Similarities and distinctions are drawn between the morphological changes occurring after LP shunting and those seen in association with the Chiari I and II malformations. Although less than 5% of this study population required treatment for tonsillar herniation, the incidence of this complication was high in asymptomatic patients; MR imaging surveillance for patients with LP shunts is therefore recommended.<\/jats:p>","DOI":"10.3171\/jns.1993.78.4.0568","type":"journal-article","created":{"date-parts":[[2009,5,27]],"date-time":"2009-05-27T15:15:10Z","timestamp":1243437310000},"page":"568-573","source":"Crossref","is-referenced-by-count":185,"title":["Tonsillar herniation: the rule rather than the exception after lumboperitoneal shunting in the pediatric population"],"prefix":"10.3171","volume":"78","author":[{"given":"Paul D.","family":"Chumas","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Derek C.","family":"Armstrong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James M.","family":"Drake","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abhaya V.","family":"Kulkarni","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Harold J.","family":"Hoffman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robin P.","family":"Humphreys","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James T.","family":"Rutka","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E. 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A complication of the treatment of hydrocephalus in children.","volume":"2","author":"Hoffman","year":"1976"},{"key":"b15","series-title":"Headache","first-page":"151","article-title":"Headache spectrum in Arnold-Chiari malformation.","volume":"31","author":"Khurana","year":"1991"},{"key":"b16","series-title":"J Neurosurg","first-page":"783","article-title":"Kyphoscoliosis following lumbar subarachnoid shunts.","volume":"34","author":"Kushner","year":"1971"},{"key":"b17","series-title":"J Pediatr Orthop","first-page":"687","article-title":"Orthopaedic complications of lumboperitoneal shunts.","volume":"8","author":"McIvor","year":"1988"},{"key":"b18","series-title":"Pediatr Neurosci","first-page":"1","article-title":"The cause of Chiari II malformation: a unified theory.","volume":"15","author":"McLone","year":"1989"},{"key":"b19","series-title":"J Neurosurg","first-page":"721","article-title":"Lumboperitoneal shunt combined with myelotomy for treament of syringomyelia.","volume":"70","author":"Park","year":"1989"},{"key":"b20","series-title":"J Neurosurg","first-page":"183","article-title":"Arnold-Chiari malformation. 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Report of three cases.","volume":"74","author":"Vengsarkar","year":"1991"},{"key":"b23","series-title":"J Neurosurg","first-page":"604","article-title":"Chiari I \u201cmalformation\u201d \u2014 an acquired disorder?","volume":"55","author":"Welch","year":"1981"},{"key":"b24","series-title":"Clinical Neurology.","first-page":"1558","article-title":"Malformations","volume":"II","author":"Williams","year":"1991"}],"container-title":["Journal of Neurosurgery"],"original-title":[],"link":[{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg\/78\/4\/article-p568.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg\/78\/4\/article-p568.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg\/78\/4\/article-p568.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,3,19]],"date-time":"2023-03-19T21:05:12Z","timestamp":1679259912000},"score":1,"resource":{"primary":{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg\/78\/4\/article-p568.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1993,4]]},"references-count":24,"journal-issue":{"issue":"4"},"URL":"https:\/\/doi.org\/10.3171\/jns.1993.78.4.0568","relation":{},"ISSN":["0022-3085"],"issn-type":[{"value":"0022-3085","type":"print"}],"subject":[],"published":{"date-parts":[[1993,4]]}}}