{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,8,2]],"date-time":"2023-08-02T06:51:12Z","timestamp":1690959072962},"reference-count":10,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2019,11,15]],"date-time":"2019-11-15T00:00:00Z","timestamp":1573776000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2020,3,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>Objectives<\/jats:title>\n                  <jats:p>The S1 dorsal foramen is the route for 30% of lumbar transforaminal epidural injections; it is therefore important to identify structures impeding S1 foraminal access. The study objective was to characterize the imaging findings, prevalence, and anatomic origin of synovial cysts presenting within the S1 neural foramen.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>A case series (N\u2009=\u200914) established imaging characteristics of S1 synovial cysts. Imaging studies of 400 patients undergoing epidural injections were reviewed for lesions compromising S1 foraminal access. Cadaveric dissections defined the relationship of the inferior recess of the L5-S1 facet to the S1 dorsal foramen.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Elderly patients (mean age = 76) exhibited S1 synovial cysts. Synovial cysts were typically 1\u20132\u2009cm in diameter, hyperintense on sagittal T2 weighted magnetic resonance images (MRIs), fluid-density on computed tomography, and dorsal to the S1 spinal nerve. Sixty percent of cysts exhibited complex MRI signal characteristics (thick wall, internal structure). Tarlov cysts, in contrast, were larger, lobular, and exhibited pure fluid intensity. Lesions impeded access to the S1 dorsal foramina in 5% of reviewed imaging studies (16 Tarlov cysts, three synovial cysts, one conjoint S1-S2 nerve root). The multifidus muscle was interposed between the L5-S1 facet inferior recess and the S1 dorsal foramen on dissection specimens; severe atrophy of the ipsilateral multifidus was noted on imaging in 17\/18 synovial cysts.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>The S1 neural foramina should be inspected on sagittal MRI, when available, for confounding lesions before performing S1 epidural injections. Tarlov cysts are more common than synovial cysts; the latter are seen in elderly patients with severe multifidus atrophy.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/pm\/pnz298","type":"journal-article","created":{"date-parts":[[2019,10,10]],"date-time":"2019-10-10T18:49:56Z","timestamp":1570733396000},"page":"570-575","source":"Crossref","is-referenced-by-count":4,"title":["Synovial Cysts Confounding Access to the Dorsal S1 Neural Foramen in Transforaminal Epidural Steroid Injections"],"prefix":"10.1093","volume":"21","author":[{"given":"Christine A","family":"El-Yahchouchi","sequence":"first","affiliation":[{"name":"Department of Anesthesiology, American University of Beirut Medical Center, Beirut, Lebanon"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Frank H","family":"Willard","sequence":"first","affiliation":[{"name":"Department of Anatomy, University of New England, College of Osteopathic Medicine, Biddeford, Maine"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Timothy J","family":"Kaufmann","sequence":"first","affiliation":[{"name":"Department of Radiology"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John T","family":"Wald","sequence":"first","affiliation":[{"name":"Department of Radiology"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Felix E","family":"Diehn","sequence":"first","affiliation":[{"name":"Department of Radiology"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jennifer R","family":"Geske","sequence":"first","affiliation":[{"name":"Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Timothy P","family":"Maus","sequence":"first","affiliation":[{"name":"Department of Radiology"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[2019,11,15]]},"reference":[{"issue":"8","key":"2020030702332846400_pnz298-B1","doi-asserted-by":"crossref","first-page":"1126","DOI":"10.1111\/pme.12122","article-title":"Clinical effectiveness of single lumbar transforaminal epidural steroid injections","volume":"14","author":"Kaufmann","year":"2013","journal-title":"Pain Med"},{"issue":"2","key":"2020030702332846400_pnz298-B2","doi-asserted-by":"crossref","first-page":"91","DOI":"10.2176\/nmc.53.91","article-title":"Prevalence of spinal meningeal cyst in the sacrum","volume":"53","author":"Tani","year":"2013","journal-title":"Neurol Med Chir (Tokyo)"},{"issue":"2","key":"2020030702332846400_pnz298-B3","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1053\/crad.1999.0340","article-title":"Correlation between the MRI changes in the lumbar multifidus muscles and leg pain","volume":"55","author":"Kader","year":"2000","journal-title":"Clin Radiol"},{"key":"2020030702332846400_pnz298-B4","article-title":"Are MRI-defined fat infiltrations in the multifidus muscles associated with low back pain?","author":"Kjaer","journal-title":"BMC Med"},{"issue":"1","key":"2020030702332846400_pnz298-B5","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1007\/s00586-010-1482-y","article-title":"Does minimally invasive lumbar disc surgery result in less muscle injury than conventional surgery? A randomized controlled trial","volume":"20","author":"Arts","year":"2011","journal-title":"Eur Spine J"},{"issue":"1","key":"2020030702332846400_pnz298-B6","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1097\/01.bsd.0000133495.78245.71","article-title":"The clinical relevance of Tarlov cysts","volume":"18","author":"Langdown","year":"2005","journal-title":"J Spinal Disord Tech"},{"issue":"2","key":"2020030702332846400_pnz298-B7","doi-asserted-by":"crossref","first-page":"373","DOI":"10.3174\/ajnr.A4517","article-title":"Treatment of 213 patients with symptomatic Tarlov cysts by CT-guided percutaneous injection of fibrin sealant","volume":"37","author":"Murphy","year":"2016","journal-title":"Am J Neuroradiol"},{"issue":"8","key":"2020030702332846400_pnz298-B8","doi-asserted-by":"crossref","first-page":"874","DOI":"10.1097\/00007632-200404150-00010","article-title":"Synovial cysts of the lumbar facet joints in a symptomatic population","volume":"29","author":"Doyle","year":"2004","journal-title":"Spine"},{"issue":"4","key":"2020030702332846400_pnz298-B9","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1007\/s003300050973","article-title":"MR imaging of lumbar facet joint synovial cysts","volume":"10","author":"Apostolaki","year":"2000","journal-title":"Eur Radiol"},{"issue":"8","key":"2020030702332846400_pnz298-B10","doi-asserted-by":"crossref","first-page":"1661","DOI":"10.3174\/ajnr.A3441","article-title":"Lumbar facet joint synovial cysts: Does T2 signal intensity predict outcomes after percutaneous rupture?","volume":"34","author":"Cambron","year":"2013","journal-title":"Am J Neuroradiol"}],"container-title":["Pain Medicine"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/academic.oup.com\/painmedicine\/article-pdf\/21\/3\/570\/32841614\/pnz298.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/academic.oup.com\/painmedicine\/article-pdf\/21\/3\/570\/32841614\/pnz298.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,3,7]],"date-time":"2020-03-07T07:34:08Z","timestamp":1583566448000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/painmedicine\/article\/21\/3\/570\/5626073"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,11,15]]},"references-count":10,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2019,11,15]]},"published-print":{"date-parts":[[2020,3,1]]}},"URL":"https:\/\/doi.org\/10.1093\/pm\/pnz298","relation":{},"ISSN":["1526-2375","1526-4637"],"issn-type":[{"value":"1526-2375","type":"print"},{"value":"1526-4637","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2020,3]]},"published":{"date-parts":[[2019,11,15]]}}}