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Lin H, Su H, Li C, Zhang P, Xiu B, Bai Y, Xu R. Classification of and individual treatment strategies for complex tethered cord syndrome. Front Surg 2024; 11:1277322. [PMID: 38322409 PMCID: PMC10844385 DOI: 10.3389/fsurg.2024.1277322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/09/2024] [Indexed: 02/08/2024] Open
Abstract
Objective To study the classification, diagnosis, and treatment strategies of complex tethered cord syndrome (C-TCS) on the basis of the patients' clinical symptoms, imaging findings, and therapeutic schedule. Methods The clinical data of 126 patients with C-TCS admitted to our department from January 2015 to December 2020 were retrospectively analyzed. Classification criteria for C-TCS were established by analyzing the causes of C-TCS. Different surgical strategies were adopted for different types of C-TCS. The Kirollos grading, visual analogue scale (VAS), critical muscle strength, and Japanese Orthopaedic Association (JOA) scores were used to evaluate the surgical outcomes and explore individualized diagnosis and treatment strategies for C-TCS. Results C-TCS was usually attributable to three or more types of tether-causing factors. The disease mechanisms could be categorized as pathological thickening and lipomatosis of the filum terminal (filum terminal type), arachnoid adhesion (arachnoid type), spina bifida with lipomyelomeningocele/meningocele (cele type), spinal lipoma (lipoma type), spinal deformity (bone type), and diastomyelia malformation (diastomyelia type). Patients with different subtypes showed complex and varied symptoms and required individualized treatment strategies. Conclusion Since C-TCS is attributable to different tether-related factors, C-TCS classification can guide individualized surgical treatment strategies to ensure complete release of the tethered cord and reduce surgical complications.
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Affiliation(s)
- Hepu Lin
- Department of Neurosurgery, The First Medical Center of the PLA General Hospital, Beijing, China
| | - Hui Su
- Department of Neurosurgery, The First Medical Center of the PLA General Hospital, Beijing, China
| | - Cuicui Li
- Department of Neurosurgery, The First Medical Center of the PLA General Hospital, Beijing, China
| | - Pengfei Zhang
- Department of Neurosurgery, The First Medical Center of the PLA General Hospital, Beijing, China
| | - Bo Xiu
- Department of Neurosurgery, The First Medical Center of the PLA General Hospital, Beijing, China
| | - Yunjing Bai
- Department of Neurosurgery, The Seventh Medical Center of the PLA General Hospital, Beijing, China
| | - Ruxiang Xu
- Department of Neurosurgery, Sichuan Provincial People’s Hospital, Chengdu, China
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2
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Abdulrazeq H, Leary OP, Tang OY, Karimi H, McElroy A, Gokaslan Z, Punsoni M, Donahue JE, Klinge PM. The Surgical Histopathology of the Filum Terminale: Findings from a Large Series of Patients with Tethered Cord Syndrome. J Clin Med 2023; 13:6. [PMID: 38202013 PMCID: PMC10779556 DOI: 10.3390/jcm13010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/16/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
This study investigated the prevalence of embryonic and connective tissue elements in the filum terminale (FT) of patients with tethered cord syndrome (TCS), examining both typical and pathological histology. The FT specimens from 288 patients who underwent spinal cord detethering from 2013 to 2021 were analyzed. The histopathological examination involved routine hematoxylin and eosin staining and specific immunohistochemistry when needed. The patient details were extracted from electronic medical records. The study found that 97.6% of the FT specimens had peripheral nerves, and 70.8% had regular ependymal cell linings. Other findings included ependymal cysts and canals, ganglion cells, neuropil, and prominent vascular features. Notably, 41% showed fatty infiltration, and 7.6% had dystrophic calcification. Inflammatory infiltrates, an underreported finding, were observed in 3.8% of the specimens. The research highlights peripheral nerves and ganglion cells as natural components of the FT, with ependymal cell overgrowth and other tissues potentially linked to TCS. Enlarged vessels may suggest venous congestion due to altered FT mechanics. The presence of lymphocytic infiltrations and calcifications provides new insights into structural changes and mechanical stress in the FT, contributing to our understanding of TCS pathology.
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Affiliation(s)
- Hael Abdulrazeq
- Department of Neurosurgery, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA; (O.P.L.); (J.E.D.)
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI 02903, USA
| | - Owen P. Leary
- Department of Neurosurgery, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA; (O.P.L.); (J.E.D.)
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI 02903, USA
| | - Oliver Y. Tang
- Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA; (O.Y.T.)
| | - Helen Karimi
- Department of Neurosurgery, Tufts Medical School, Boston, MA 02111, USA;
| | - Abigail McElroy
- Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA; (O.Y.T.)
| | - Ziya Gokaslan
- Department of Neurosurgery, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA; (O.P.L.); (J.E.D.)
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI 02903, USA
| | - Michael Punsoni
- Department of Neurosurgery, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA; (O.P.L.); (J.E.D.)
- Laboratory Medicine, Department of Pathology, Rhode Island Hospital, Providence, RI 02903, USA
| | - John E. Donahue
- Department of Neurosurgery, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA; (O.P.L.); (J.E.D.)
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI 02903, USA
- Laboratory Medicine, Department of Pathology, Rhode Island Hospital, Providence, RI 02903, USA
| | - Petra M. Klinge
- Department of Neurosurgery, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA; (O.P.L.); (J.E.D.)
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI 02903, USA
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Sala F. Intraoperative neurophysiology in pediatric neurosurgery: a historical perspective. Childs Nerv Syst 2023; 39:2929-2941. [PMID: 37776333 PMCID: PMC10613152 DOI: 10.1007/s00381-023-06155-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 10/02/2023]
Abstract
INTRODUCTION Intraoperative neurophysiology (ION) has been established over the past three decades as a valuable discipline to improve the safety of neurosurgical procedures with the main goal of reducing neurological morbidity. Neurosurgeons have substantially contributed to the development of this field not only by implementing the use and refinement of ION in the operating room but also by introducing novel techniques for both mapping and monitoring of neural pathways. METHODS This review provides a personal perspective on the evolution of ION in a variety of pediatric neurosurgical procedures: from brain tumor to brainstem surgery, from spinal cord tumor to tethered cord surgery. RESULTS AND DISCUSSION The contribution of pediatric neurosurgeons is highlighted showing how our discipline has played a crucial role in promoting ION at the turn of the century. Finally, a view on novel ION techniques and their potential implications for pediatric neurosurgery will provide insights into the future of ION, further supporting the view of a functional, rather than merely anatomical, approach to pediatric neurosurgery.
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Affiliation(s)
- Francesco Sala
- Section of Neurosurgery, Department of Neurosciences, Biomedicine and Movement Sciences, University Hospital, Verona, Italy.
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Kurogi A, Murakami N, Suzuki SO, Shimogawa T, Mukae N, Yoshimoto K, Morioka T. Retained medullary cord and caudal lipoma with histopathological presence of terminal myelocystocele in the epidural stalk. Surg Neurol Int 2023; 14:279. [PMID: 37680925 PMCID: PMC10481812 DOI: 10.25259/sni_479_2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/14/2023] [Indexed: 09/09/2023] Open
Abstract
Background The retained medullary cord (RMC), caudal lipoma, and terminal myelocystocele (TMCC) are thought to originate from the failed regression spectrum during the secondary neurulation, and the central histopathological feature is the predominant presence of a central canal-like ependyma-lined lumen (CC-LELL) with surrounding neuroglial tissues (NGT), as a remnant of the medullary cord. However, reports on cases in which RMC, caudal lipoma, and TMCC coexist are very rare. Case Description We present two patients with cystic RMC with caudal lipoma and caudal lipoma with an RMC component, respectively, based on their clinical, neuroradiological, intraoperative, and histopathological findings. Although no typical morphological features of TMCC were noted on neuroimaging, histopathological examination revealed that a CC-LELL with NGT was present in the extraspinal stalk, extending from the skin lesion to the intraspinal tethering tract. Conclusion This histopathological finding indicates the presence of TMCC that could not be completely regressed and further supports the idea that these pathologies can be considered consequences of a continuum of regression failure during secondary neurulation.
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Affiliation(s)
- Ai Kurogi
- Department of Neurosurgery, Fukuoka Children’s Hospital, Fukuoka, Japan
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children’s Hospital, Fukuoka, Japan
| | | | | | - Nobutaka Mukae
- Department of Neurosurgery, Iizuka Hospital, Iizuka, Japan
| | - Koji Yoshimoto
- Department of Neurosurgery, Kyushu University, Fukuoka, Japan
| | - Takato Morioka
- Department of Neurosurgery, Hachisuga Hospital, Munakata, Japan
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5
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Murakami N, Kurogi A, Suzuki SO, Shimogawa T, Mukae N, Yoshimoto K, Morioka T. Histopathological presence of dermal elements in resected margins of neural structures obtained from initial repair surgery for myelomeningocele. Surg Neurol Int 2023; 14:7. [PMID: 36751452 PMCID: PMC9899468 DOI: 10.25259/sni_989_2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/23/2022] [Indexed: 01/09/2023] Open
Abstract
Background Development of dermoid or epidermoid cysts in myelomeningocele (MMC) sites is generally thought to occur in a delayed fashion due to implantation of dermal elements during initial repair surgery. Another theory is that dermal and dermoid elements may already be present within dysplastic neural structures at birth. Methods We experienced histopathological presence of dermal elements in resected tissues at initial repair surgery in four out of 18 cases with MMC who required resection of parts or margins of the neural structures to perform cord untethering. Since one of these cases has already been reported, we describe the clinicopathological findings for the remaining three cases. Results In Case1, cryptic dermoid elements were discovered in the terminal filum-like structure (FT-LS) caudal to the open neural placode (NP). The FT-LS had histopathological characteristics similar to the retained medullary cord. In Case 2, dermoid elements were discovered in the caudal margin of the dysplastic conus medullaris. In Case 3, a thin squamous epithelial layer overlapped the rostral margin of the NP where the NP was located near the skin. Case 1 developed an epidermoid cyst at 1 year and 2 months of age, which was totally resected. Conclusion Prenatally existing cryptic dermoid elements in the caudal portion of neural structures and remnants of dermal elements overlapping the rostral margin of the NP are associated with delayed occurrence of dermoid/ epidermoid cysts. Postoperative histopathological investigation of the resected specimens is recommended. Once dermal elements are revealed, repeated imaging examination and additional surgery should be considered.
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Affiliation(s)
- Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children’s Hospital, Fukuoka, Japan,Corresponding author: Nobuya Murakami, Department of Neurosurgery, Fukuoka Children’s Hospital, Fukuoka, Japan.
| | - Ai Kurogi
- Department of Neurosurgery, Fukuoka Children’s Hospital, Fukuoka, Japan
| | | | - Takafumi Shimogawa
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Iizuka, Japan
| | - Nobutaka Mukae
- Department of Neurosurgery, Iizuka Hospital, Iizuka, Japan
| | - Koji Yoshimoto
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Iizuka, Japan
| | - Takato Morioka
- Department of Neurosurgery, Hachisuga Hospital, Fukuoka, Japan
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6
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Pang D, Thompson DNP. The Current Status of the Surgical Management of Complex Spinal Cord Lipomas: Still Navigating the Labyrinth? Adv Tech Stand Neurosurg 2023; 47:145-214. [PMID: 37640875 DOI: 10.1007/978-3-031-34981-2_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
This review summarises the classification, anatomy and embryogenesis of complex spinal cord lipomas and describes in some detail the technique of total lipoma resection and radical reconstruction of the affected neural placode. Its specific mission is to tackle two main issues surrounding the management of complex dysraphic lipomas: whether total resection confers better long-term benefits than partial resection and whether total resection does better than conservative treatment, i.e. no surgery, for asymptomatic lipomas. Accordingly, the 24-year progression-free survival data of the senior author and colleagues' series of over 300 cases of total resection are compared with historical data from multiple series (including our own) of partial resection, and total resection data specifically for asymptomatic lesions are compared with the two known series of non-surgical treatment of equivalent patients. These comparisons so far amply support the author's recommendation of total resection for most complex lipomas, with or without symptoms. The notable exception is the asymptomatic chaotic lipoma, whose peculiar anatomical relationship with the neural tissue defies even our aggressive surgical approach, and consequently projects worse results (admittedly of small number of cases) than for the other two lipoma subtypes of dorsal and transitional lesions. Prophylactic resection of asymptomatic chaotic lipomas is therefore not currently endorsed. We have also recently found that some dorsal lipomas with clear outline of the conus on preoperative imaging had a significantly better long-term prognosis of preserving neurourological functions without surgery. Whether this subset of lipomas should be managed conservatively until symptoms arise is now an open question awaiting a longer follow-up of a larger cohort of such patients.
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Affiliation(s)
- Dachling Pang
- Department of Paediatric Neurosurgery, University of California, Davis, USA
- Great Ormond Street Hospital for Children, NHS Trust, London, UK
| | - Dominic N P Thompson
- Great Ormond Street Hospital for Children, NHS Trust, London, UK
- Department of Developmental Neuroscience, University College London-Institute of Child Health, London, UK
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7
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Eibach S, Pang D. Junctional Neural Tube Defect (JNTD): A Rare and Relatively New Spinal Dysraphic Malformation. Adv Tech Stand Neurosurg 2023; 47:129-143. [PMID: 37640874 DOI: 10.1007/978-3-031-34981-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Junctional neurulation completes the sequential embryological processes of primary and secondary neurulation as the intermediary step linking the end of primary neurulation and the beginning of secondary neurulation. Its exact molecular process is a matter of ongoing scientific debate. Abnormality of junctional neurulation-junctional neural tube defect (JNTD)-was first described in 2017 based on a series of three patients who displayed a well-formed secondary neural tube, the conus, that is physically separated by a fair distance from its companion primary neural tube and functionally disconnected from rostral corticospinal control. Several other cases conforming to this bizarre neural tube arrangement have since appeared in the literature, reinforcing the validity of this entity. The clinical, neuroimaging, and electrophysiological features of JNTD, as well as the hypothesis of its embryogenetic mechanism, will be described in this chapter.
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Affiliation(s)
- Sebastian Eibach
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
- Paediatric Neurosurgery, Sydney Children's Hospital Randwick, Sydney, Australia
| | - Dachling Pang
- Great Ormond Street Hospital for Children, NHS Trust, London, UK
- Department of Paediatric Neurosurgery, University of California, Davis, USA
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8
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Kim KH, Lee JY, Wang KC. Secondary Neurulation Defects: Retained Medullary Cord. Adv Tech Stand Neurosurg 2023; 47:215-223. [PMID: 37640876 DOI: 10.1007/978-3-031-34981-2_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Retained medullary cord (RMC) is a defect resulting from impaired secondary neurulation. Intraoperatively, RMC is recognizable as an elongated cord-like structure caudal to the conus, that contains histologically confirmed neuroglial components and a lumen with an ependymal lining. It characteristically does not possess neurological function. This chapter aims to summarize (1) the mechanisms that lead to the occurrence of RMC; (2) the various forms of RMC, such as cystic RMC and 'possible RMC', and (3) the treatment strategies, especially untethering through limited exposure.
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Affiliation(s)
- Kyung Hyun Kim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Republic of Korea
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ji Yeoun Lee
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Republic of Korea
- Department of Anatomy and Cell Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyu-Chang Wang
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Neuro-oncology Clinic, National Cancer Center, Goyang, Republic of Korea.
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9
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Oketani H, Harimaya K, Ono T, Terado K, Inoha S, Suzuki SO, Morioka T. A Presenile Patient with Filar Lipoma Who Developed Tethered Spinal Cord Syndrome Triggered by Lumbar Canal Stenosis. NMC Case Rep J 2023; 10:109-113. [PMID: 37197285 PMCID: PMC10185357 DOI: 10.2176/jns-nmc.2022-0347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 02/09/2023] [Indexed: 05/19/2023] Open
Abstract
Lumbar canal stenosis (LCS) has been reported as a precipitating factor by which a tethered spinal cord, which is asymptomatic during childhood, develops into tethered cord syndrome (TCS) in adulthood. However, only a few reports on surgical strategies for such cases are available. A 64-year-old woman presented with unbearable pain in the left buttock and dorsal aspect of the thigh approximately 1 year ago. Magnetic resonance imaging showed cord tethering with a filar-type spinal lipoma and LCS due to the thickening of the ligamentum flavum at the L4-5 vertebral level. Five months after the decompressive laminectomy for the treatment of LCS, an untethering surgery was performed at the dural cul-de-sac at the S4 level. The severed end of the filum was elevated rostrally by 7 mm, and the pain subsided postoperatively. This case study shows that surgeries for both lesions should be indicated for adult-onset TCS triggered by LCS.
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Affiliation(s)
- Hiroshi Oketani
- Department of Neurosurgery, Hachisuga Hospital, Munakata, Fukuoka, Japan
| | - Katsumi Harimaya
- Department of Orthopedic Surgery, Kyushu University Beppu Hospital, Beppu, Oita, Japan
| | - Teruaki Ono
- Department of Orthopedic Surgery, Kyushu University Beppu Hospital, Beppu, Oita, Japan
| | - Kazushige Terado
- Department of Orthopedic Surgery, Hachisuga Hospital, Munakata, Fukuoka, Japan
| | - Satoshi Inoha
- Department of Neurosurgery, Hachisuga Hospital, Munakata, Fukuoka, Japan
| | - Satoshi O Suzuki
- Department of Psychiatry, Shourai Hospital, Karatsu, Saga, Japan
| | - Takato Morioka
- Department of Neurosurgery, Hachisuga Hospital, Munakata, Fukuoka, Japan
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10
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Pasquali C, Basaldella F, Sala F. Updates on Intraoperative Neurophysiology During Surgery for Spinal Dysraphism. Adv Tech Stand Neurosurg 2023; 47:235-272. [PMID: 37640878 DOI: 10.1007/978-3-031-34981-2_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Spinal dysraphism is a group of disorders resulting from an embryologic failure of spinal cord development which can lead to a radicular-medullary mechanical stretch that generates vascular compromise and hypoxic-ischemic damage to the nervous structures of the conus-cauda region.Thus, the clinical relevance of the different types of spinal dysraphism is related to the possible neurologic deficits resulting from spinal cord tethering. The clinical presentation is heterogenous: from asymptomatic to very compromised patients. The indications and the time of a detethering surgery are still subject of debate, although there is an agreement on the high standards of treatment that have to be offered by the surgery. Intraoperative neurophysiology (ION) contributes to the safety of tethered cord surgery in reducing the risks of iatrogenic neurological damages.
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Affiliation(s)
- Claudia Pasquali
- Section of Neurosurgery, Department of Neurosciences, Biomedicine and Movement Sciences, University Hospital, Verona, Italy
| | - Federica Basaldella
- Section of Neurosurgery, Department of Neurosciences, Biomedicine and Movement Sciences, University Hospital, Verona, Italy
| | - Francesco Sala
- Section of Neurosurgery, Department of Neurosciences, Biomedicine and Movement Sciences, University Hospital, Verona, Italy.
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Embryopathological relationship between retained medullary cord and caudal spinal lipoma. INTERDISCIPLINARY NEUROSURGERY 2022. [DOI: 10.1016/j.inat.2022.101534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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12
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Spina Bifida: A Review of the Genetics, Pathophysiology and Emerging Cellular Therapies. J Dev Biol 2022; 10:jdb10020022. [PMID: 35735913 PMCID: PMC9224552 DOI: 10.3390/jdb10020022] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/13/2022] [Accepted: 05/23/2022] [Indexed: 12/11/2022] Open
Abstract
Spina bifida is the most common congenital defect of the central nervous system which can portend lifelong disability to those afflicted. While the complete underpinnings of this disease are yet to be fully understood, there have been great advances in the genetic and molecular underpinnings of this disease. Moreover, the treatment for spina bifida has made great advancements, from surgical closure of the defect after birth to the now state-of-the-art intrauterine repair. This review will touch upon the genetics, embryology, and pathophysiology and conclude with a discussion on current therapy, as well as the first FDA-approved clinical trial utilizing stem cells as treatment for spina bifida.
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13
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Shim Y, Park HJ, Kim KH, Park SH, Wang KC, Lee JY. Retained medullary cord and terminal myelocystocele as a spectrum: case report. Childs Nerv Syst 2022; 38:1223-1228. [PMID: 34535806 DOI: 10.1007/s00381-021-05351-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/30/2021] [Indexed: 10/20/2022]
Abstract
The caudal portion of the spinal cord, the medullary cord, is formed by secondary neurulation. One of the distinctive features of secondary neurulation compared to primary neurulation is that the medullary cord normally degenerates into a filum in humans. Various anomalies have been known to originate from degenerating process errors. One anomaly is terminal myelocystocele (TMCC), which is a closed spinal dysraphism with an elongated caudal spinal cord. The terminal part is filled with cerebrospinal fluid (CSF) and protrudes into the dorsal extradural space. Another anomaly is the retained medullary cord (RMC), which is a nonfunctioning cord-like structure extending to the cul-de-sac. In a 1-month-old boy, we identified an RMC with cystic dilatation of the caudal end extending to the epidural space at the very bottom of the cul-de-sac, resembling a degenerating terminal balloon, which is an essential feature of TMCC. Hence, this case may be considered an intermediate form between TMCC and RMC. This case provides clinical evidence that TMCC and RMC share the same pathoembryogenic origin, namely, failure of the regression phase of secondary neurulation.
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Affiliation(s)
- Youngbo Shim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, 101 Daehak-ro, Jongno-gu, 03080, Seoul, Republic of Korea
| | - Hyun Joo Park
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea
| | - Kyung Hyun Kim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, 101 Daehak-ro, Jongno-gu, 03080, Seoul, Republic of Korea
| | - Sung-Hye Park
- Department of Pathology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Kyu-Chang Wang
- Center for Rare Cancers, Neuro-Oncology Clinic, National Cancer Center, Goyang, Gyeonggi-do, Republic of Korea
| | - Ji Yeoun Lee
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, 101 Daehak-ro, Jongno-gu, 03080, Seoul, Republic of Korea. .,Department of Anatomy and Cell Biology, Seoul National University College of Medicine, Seoul, Republic of Korea.
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14
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Kurogi A, Murakami N, Mukae N, Shimogawa T, Goto K, Shono T, Suzuki SO, Yoshimoto K, Morioka T. Congenital dermal sinus and filar lipoma located in close proximity at the dural cul-de-sac mimicking limited dorsal myeloschisis. INTERDISCIPLINARY NEUROSURGERY 2022. [DOI: 10.1016/j.inat.2021.101455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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15
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Matsubara Y, Murakami N, Kurogi A, Lee S, Mukae N, Shimogawa T, Shono T, Suzuki SO, Yoshimoto K, Morioka T. Intramedullary abscess at thoracolumbar region transmitted from infected dermal sinus and dermoid through retained medullary cord. Surg Neurol Int 2022; 13:54. [PMID: 35242420 PMCID: PMC8888283 DOI: 10.25259/sni_1197_2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/28/2022] [Indexed: 11/23/2022] Open
Abstract
Background: A retained medullary cord (RMC) is a relatively newly defined entity of closed spinal dysraphism that is thought to originate from regression failure of the medullary cord during secondary neurulation. A congenital dermal sinus (CDS) may provide a pathway for intraspinal infections such as repeated meningitis. Intramedullary abscesses are the rarest but most serious complication of a CDS. Case Description: We treated a female infant with an intramedullary abscess in the thoracolumbar region, which was caused by infection of the CDS. Surgery revealed that the cord-like structure (C-LS) started from the cord with the intramedullary abscess, extended to the dural cul-de-sac, and further continued to the CDS tract and skin dimple. The boundary between the functional cord and the non-functional CL-S was electrophysiologically identified, and the entire length of the C-LS (the RMC) with an infected dermoid cyst was resected. As a result, the abscess cavity was opened and thorough irrigation and drainage of the pus could be performed. Histopathological examination of the C-LS revealed an infected dermoid cyst and abscess cavity with keratin debris in the fibrocollagenous tissue. The abscess cavity had a central canal-like ependymal lined lumen (CCLELL), with surrounding glial fibrillary acidic protein (GFAP)-immunopositive neuroglial tissues. Conclusion: We demonstrated that the transmission of an infection through the RMC was involved in the development of the intramedullary abscess. A good postoperative outcome was obtained because a terminal ventriculostomy for pus drainage could be achieved by excising the nonfunctional RMC.
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Affiliation(s)
- Yoshie Matsubara
- Department of Pediatric Neurology, Fukuoka Children’s Hospital, Fukuoka,
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children’s Hospital, Fukuoka,
| | - Ai Kurogi
- Department of Neurosurgery, Fukuoka Children’s Hospital, Fukuoka,
| | - Sooyoung Lee
- Department of Pediatrics, National Hospital Organization, Fukuoka-Higashi Medical Center, Koga, Fukuoka,
| | - Nobutaka Mukae
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka,
| | - Takafumi Shimogawa
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka,
| | - Tadahisa Shono
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka,
| | | | - Koji Yoshimoto
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka,
| | - Takato Morioka
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka,
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16
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Chellathurai A, Kathirvelu G, Mukkada PJ, Rajendran K, Ramani R. Spinal Dysraphisms: A New Anatomical–Clinicoradiological Classification. Indian J Radiol Imaging 2022; 31:809-829. [PMID: 35136492 PMCID: PMC8817824 DOI: 10.1055/s-0041-1741100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
Abstract
Background Spinal dysraphisms refer to the congenital abnormalities of the spine and spinal cord due to aberrations in the processes of gastrulation, primary neurulation, and secondary neurulation. Embryology of many complex spinal dysraphisms are yet poorly understood and there is no agreeable anatomical–clinicoradiological classification with inclusion of recently documented and complex spinal dysraphisms.
Aims and Objectives The main objective of this study was to review the imaging features of spinal dysraphisms with a better understanding of embryological abnormalities and propose a new classification inclusive of all complex and unusual dysraphisms based on anatomical and clinicoradiological correlation.
Materials and Methods This was a retrospective single institutional observational study of 391 cases of spinal dysraphism for 10 years in our institution. Of 391 cases included in the study, 204 were males and 187 were females. Also, 123 cases belonged to the 0–6 months age group, 38 cases belonged to the 7–12 months age group, 156 belonged to the 1–5 years age group, 39 cases belonged to the 6–10 years age group, and 35 cases belonged to 10–20 years age group.
Results An anatomical–clinicoradiological analysis of cases yielded a high proportion of cases of spinal lipomas, including lipomyeloceles and lipomyelomeningoceles (31.3%) and posterior myelomeningocele (14.2%). Anterior myelocoele (0.2%), sacral chordoma(0.2%), and intrasacral meningocele (0.2%) formed the least proportion of cases. A new classification was proposed based on the analysis of acquired data.
Conclusion A structured approach in imaging spinal dysraphism is necessary for imaging evaluation in recent years. The proposed new classification based on clinicoradiological correlation and anatomic location is inclusive of unusual and complex dysraphisms.
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Affiliation(s)
- Amarnath Chellathurai
- Department of Radiodiagnosis, Government Stanley Medical College, Chennai, Tamil Nadu, India
| | | | | | - Kiruthika Rajendran
- Department of Radiodiagnosis, Government Stanley Medical College, Chennai, Tamil Nadu, India
| | - Rajashree Ramani
- Department of Radiodiagnosis, Government Stanley Medical College, Chennai, Tamil Nadu, India
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17
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Howells M, Hamby T, Honeycutt J, Donahue DJ. Detethering of MRI-Demonstrated Tethered Cord Syndrome. Pediatr Neurosurg 2022; 57:85-92. [PMID: 35066504 DOI: 10.1159/000522135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/21/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Recognition of tethered cord syndrome (TCS) in children is important because as the child grows, the spinal cord is stretched, leading to ischemia and subsequent neurological deficits, including bowel or bladder dysfunction, back and leg pain, or lower extremity weakness. Imaging findings raising concerns for tethering include presence of a fatty and/or thickened filum or a conus medullaris located caudal to L2. OBJECTIVES The objective of this study was to describe the symptomatic presentation of TCS in our institution, detect demographic and diagnostic predictors of signs and symptoms, assess changes in symptoms over time, and examine whether demographic and diagnostic variables affect changes in symptoms over time. METHODS Using a retrospective chart review from patients who underwent detethering at our institution between April 1, 2015 and March 31, 2019, we report on the signs and symptoms of patients undergoing detethering surgery at presentation and examine possible demographic and diagnostic predictors of those symptoms and changes in symptoms over time. Logistic regression analyses were used to determine whether symptoms at presentation were related to demographic and diagnostic predictors and to assess a change in symptoms over time. RESULTS A total of 273 patients underwent detethering and were analyzed. Of these, 144 (53%) were <5 years of age, 151 (55%) were male, 233 (85%) had a fatty filum, 179 (66%) had a thickened filum, and 106 (39%) had a low-lying conus. Patients <5 years of age were less likely to have urological, gastrointestinal, and neurological or orthopedic symptoms; patients with thickened fila (i.e., greater than 2 mm in diameter regardless of fat-infiltration) were less likely to have urological symptoms; and patients with low-lying coni were less likely to have gastrointestinal symptoms. Patients exhibiting symptoms at presentation had reduced rates of symptoms at the follow-up, but a reduction in rates of symptoms over time was unrelated to demographic or diagnostic variables. Surprisingly, 123 (45%) patients presented with intractable constipation. CONCLUSION In the population studied, several presenting symptoms, particularly constipation, were commonly reported. Children <5 years old were less likely to manifest clinically evident neurological/orthopedic, urological, and gastrointestinal symptoms than the older cohorts. Patients were less likely to report symptoms at both their first and second postoperative visit compared to presentation.
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Affiliation(s)
- Madeleine Howells
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Tyler Hamby
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, Texas, USA.,Department of Research Operations, Cook Children's Health Care System, Fort Worth, Texas, USA
| | - John Honeycutt
- Department of Neurosciences, Cook Children's Health Care System, Fort Worth, Texas, USA
| | - David J Donahue
- Department of Neurosciences, Cook Children's Health Care System, Fort Worth, Texas, USA
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18
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Kurogi A, Murakami N, Mukae N, Shimogawa T, Shono T, Suzuki SO, Morioka T. Retained Medullary Cord Associated with Terminal Myelocystocele and Intramedullary Arachnoid Cyst. Pediatr Neurosurg 2022; 57:184-190. [PMID: 35259748 DOI: 10.1159/000523976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 03/04/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The retained medullary cord (RMC) is a newly defined entity of closed spinal dysraphism that is thought to originate from regression failure of the medullary cord during the last phase of secondary neurulation. The terminal myelocystocele (TMC) is an unusual type of closed spinal dysraphism, characterized by localized cystic dilatation of the terminal part of the central canal that then herniates through a posterior spinal bifida. The co-occurrence of RMC and TMC is extremely rare. CASE PRESENTATION We treated a baby girl with a huge sacrococcygeal meningocele-like sac with two components. Untethering surgery and repair surgery for the sac revealed that RMC, associated with intramedullary arachnoid cyst (IMAC), was terminated at the bottom of the rostral cyst, forming the septum of the two cystic components, and the caudal cyst was TMC derived from the central canal-like ependymal lining lumen (CC-LELL) of the RMC at the septum. IMAC within the RMC communicated with TMC, and both contained xanthochromic fluid with the same properties. CONCLUSION We speculated that the mass effect of the coexistent IMAC impeded the flow of cerebrospinal fluid in the CC-LELL within the RMC and eventually formed a huge TMC. In surgical strategies for such complex pathologies, it is important to identify the electrophysiological border between the functional cord and nonfunctional RMC and the severe RMC to untether the cord, as with a typical or simple RMC.
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Affiliation(s)
- Ai Kurogi
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Nobutaka Mukae
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | | | - Tadahisa Shono
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka, Japan
| | | | - Takato Morioka
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka, Japan
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19
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Yang J, Lee JY, Kim KH, Yang HJ, Wang KC. Disorders of Secondary Neurulation: Suggestion of a New Classification According to Pathoembryogenesis. Adv Tech Stand Neurosurg 2022; 45:285-315. [PMID: 35976454 DOI: 10.1007/978-3-030-99166-1_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Recently, advanced knowledge on secondary neurulation and its application to the clinical experience have led to the deeper insight into the pathoembryogenesis of secondary neurulation with new classifications of the caudal spinal dysraphic entities. Here, we summarize the dynamic changes in the concepts of disordered secondary neurulation over the last two decades. In addition, we suggest our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase may cause various corresponding lesions, such as (1) failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), (2) dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), (3) abnormal continuity of medullary cord to the surrounding layers, namely, failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neurocutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), and neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and (4) regression failure spectrum of the medullary cord (thickened filum and filar cyst, retained medullary cord and low-lying conus, terminal myelocele, and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association of the caudal cell mass with the activity of caudal mesenchymal tissue involves a wider range of surrounding structures in secondary neurulation than in primary neurulation. Although the majority of the data are from animals and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.
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Affiliation(s)
- Jeyul Yang
- Neuro-Oncology Clinic, Center for Rare Cancers, National Cancer Center, Goyang, Kyounggi-do, South Korea
| | - Ji Yeoun Lee
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, South Korea
- Department of Anatomy and Cell Biology, Seoul National University College of Medicine, Seoul, South Korea
| | - Kyung Hyun Kim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, South Korea
| | - Hee Jin Yang
- Department of Neurosurgery, SMG-SNU Boramae Medical Center, Seoul, South Korea
| | - Kyu-Chang Wang
- Neuro-Oncology Clinic, Center for Rare Cancers, National Cancer Center, Goyang, Kyounggi-do, South Korea.
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20
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Galloway G, Sala F. Mapping and monitoring of tethered cord and cauda equina surgeries. HANDBOOK OF CLINICAL NEUROLOGY 2022; 186:257-270. [PMID: 35772890 DOI: 10.1016/b978-0-12-819826-1.00018-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Surgery involving the cauda equina and tethered cord can be associated with significant functional disability including pain, motor and sensory deficits, as well as bladder, bowel, and sexual dysfunction. Neurophysiologic intraoperative monitoring and mapping during these surgeries using a variety of techniques and applications contributes to lessen the risk of permanent injury. This chapter reviews the anatomy of the pelvic floor, describes the techniques involved in monitoring and mapping this area, and describes the limitations of neurophysiology applications. Additionally, this chapter details mapping and monitoring techniques as they apply to tethered cord surgical release in both children and adults with review of outcome studies, and describes complications which can arise from tethered cord repair and injury to the cauda equina despite appropriate neurophysiologic intraoperative involvement.
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Affiliation(s)
- Gloria Galloway
- Department of Neurology, Wexner Medical Center, Ohio State University Medical Center, Columbus, OH, United States.
| | - Francesco Sala
- Section of Neurosurgery, Department of Neurosciences, Biomedicine and Movement Sciences, University Hospital, Verona, Italy
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21
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Morioka T, Murakami N, Suzuki SO, Mukae N, Shimogawa T, Kurogi A, Shono T, Mizoguchi M. Surgical histopathology of a filar anomaly as an additional tethering element associated with closed spinal dysraphism of primary neurulation failure. Surg Neurol Int 2021; 12:373. [PMID: 34513140 PMCID: PMC8422463 DOI: 10.25259/sni_340_2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/09/2021] [Indexed: 11/12/2022] Open
Abstract
Background: Closed spinal dysraphism of primary neurulation failure could be associated with filar anomalies, such as filar lipoma or thickened and tight filum terminale (TFT), resulting from impaired secondary neurulation. Retained medullary cord (RMC) is a remnant of the cavitary medullary cord originating from the secondary neurulation failure. Some filar lipomas are known to contain a central canal-like ependyma-lined lumen with surrounding neuroglial tissues (E-LC w/NGT), that is, a characteristic histopathology of RMC. To clarify the embryological background of these filar anomalies, we evaluated the histopathological findings. Methods: Among 41 patients with lesions of primary neurulation failure who underwent initial untethering surgery, the filum including cord-like structure (C-LS) was additionally resected in 10 patients (five dorsal and transitional lipomas; five limited dorsal myeloschisis). We retrospectively analyzed the clinical, neuroradiological, intraoperative, and histopathological findings. Results: Among 10 patients, two patients were diagnosed with RMC based on morphological features and intraoperative neurophysiological monitoring. The diagnosis of filar lipoma was made in six patients, since various amounts of fibroadipose tissue were histopathologically noted in the filum. Two patients were diagnosed with TFT, since the filum was composed solely of fibrocollagenous tissue. E-LC w/NGT was noted not only in both C-LSs of RMCs but also in two out of six fila both with filar lipomas and fila with TFTs. Conclusion: These findings provide further evidence for the idea that entities, such as filar lipoma, TFT, and RMC, can be considered consequences of a continuum of regression failure occurring during late secondary neurulation.
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Affiliation(s)
- Takato Morioka
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan.,Department of Neurosurgery, Harasanshin Hospital, Karatsu, Saga
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | | | - Nobutaka Mukae
- Department of Neurosurgery, Graduate School of Medical Sciences, Fukuoka, Japan
| | | | - Ai Kurogi
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Tadahisa Shono
- Department of Neurosurgery, Harasanshin Hospital, Karatsu, Saga
| | - Masahiro Mizoguchi
- Department of Neurosurgery, Graduate School of Medical Sciences, Fukuoka, Japan
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22
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Kim KH, Lee JY, Yang J, Park SH, Kim SK, Wang KC. Cystic retained medullary cord in an intraspinal J-shaped cul-de-sac: a lesion in the spectrum of regression failure during secondary neurulation. Childs Nerv Syst 2021; 37:2051-2056. [PMID: 33112990 DOI: 10.1007/s00381-020-04943-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 10/22/2020] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Retained medullary cord (RMC) is thought to be a product of arrested secondary neurulation during the regression phase. A cord-like structure with a caudal non-functional part ends at the cul-de-sac. If the arrest occurs at the cavitation phase of secondary neurulation, the medullary cord has a cystic portion making "RMC of cystic type." CLINICAL PRESENTATION We report a case of a 4-month-old girl who had a low-lying conus with an extradural-looking dorsal cyst. Preoperative diagnosis was RMC with a lumbosacral extradural cyst such as an arachnoid cyst. At surgery, we found that the extradural cyst was an extension of dural sac with the caudal portion of the cystic RMC inside. The RMC was untethered and the dural sac was reconstructed. The histopathologic examination revealed findings compatible with cystic RMC attached to the cul-de-sac. CONCLUSIONS We regard this case as an intermediate form between the typical RMC in which is regarded as regression arrest occurred after the terminal balloon collapsed and the medullary cord detached from the skin to the normal cul-de-sac, and the terminal myelocystocele which is considered the result of arrest at the phase of the persisted terminal balloon attached to the skin.
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Affiliation(s)
- Kyung Hyun Kim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Republic of Korea.,Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ji Yeoun Lee
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Republic of Korea.,Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jeyul Yang
- Center for Rare Cancers, National Cancer Center, Goyang, Kyounggi-do, Republic of Korea
| | - Sung-Hye Park
- Department of Pathology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Seung-Ki Kim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Republic of Korea.,Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyu-Chang Wang
- Center for Rare Cancers, National Cancer Center, Goyang, Kyounggi-do, Republic of Korea.
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23
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Yang J, Lee JY, Kim KH, Wang KC. Disorders of Secondary Neurulation : Mainly Focused on Pathoembryogenesis. J Korean Neurosurg Soc 2021; 64:386-405. [PMID: 33906343 PMCID: PMC8128515 DOI: 10.3340/jkns.2021.0023] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/16/2021] [Indexed: 12/22/2022] Open
Abstract
Recent advancements in basic research on the process of secondary neurulation and increased clinical experience with caudal spinal anomalies with associated abnormalities in the surrounding and distal structures shed light on further understanding of the pathoembryogenesis of the lesions and led to the new classification of these dysraphic entities. We summarized the changing concepts of lesions developed from the disordered secondary neurulation shown during the last decade. In addition, we suggested our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase of development may cause corresponding lesions, such as failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neuro-cutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and regression failure spectrum of the medullary cord (thickened filum and filar cyst, low-lying conus, retained medullary cord, terminal myelocele and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association with the activity of caudal mesenchymal tissue in secondary neurulation involves a wider range of surrounding structures than in primary neurulation. Although the majority of the data are from animals, not from humans and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.
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Affiliation(s)
- Jeyul Yang
- Neuro-oncology Clinic, Center for Rare Cancers, National Cancer Center, Goyang, Korea
| | - Ji Yeoun Lee
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea.,Department of Anatomy, Seoul National University College of Medicine, Seoul, Korea
| | - Kyung Hyun Kim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea
| | - Kyu-Chang Wang
- Neuro-oncology Clinic, Center for Rare Cancers, National Cancer Center, Goyang, Korea
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24
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Morioka T, Murakami N, Suzuki SO, Nakamura R, Mizoguchi M. Subpial Lumbar Lipoma Associated with Retained Medullary Cord. NMC Case Rep J 2021; 8:51-55. [PMID: 34012749 PMCID: PMC8116927 DOI: 10.2176/nmccrj.cr.2020-0073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 05/08/2020] [Indexed: 11/20/2022] Open
Abstract
Subpial lipomas, which are also known as nondysraphic intramedullary spinal cord lipomas, are not associated with spinal dysraphism resulting from the failed primary neurulation. Retained medullary cord (RMC) is a newly defined entity of closed spinal dysraphism that originates from the late arrest of secondary neurulation. We treated a 6-year-old boy presented with myoclonus of the lower limbs, who had subpial lipoma at the lumbar cord, just rostral to the low-lying conus, which was tethered by a cord-like structure (C-LS) continuous from the conus and extending to the dural cul-de-sac. Following cord untethering from C-LS and minimal debulking of the lipoma, the myoclonus was improved. Histological examination of C-LS revealed a large central canal-like structure in the neuroglial core and the diagnosis of RMC was made. Subpial lipomas can be incidentally coexistent with spinal dysraphism resulting from the failed secondary neurulation, such as RMC.
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Affiliation(s)
- Takato Morioka
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Fukuoka, Japan
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Fukuoka, Japan
| | - Satoshi O Suzuki
- Department of Neuropathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan
| | - Ryoko Nakamura
- Department of Pediatrics, Japan Community Health Care Organization (JCHO), Kyushu Hospital, Kitakyushu, Fukuoka, Japan
| | - Masahiro Mizoguchi
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan
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25
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Kurogi A, Murakami N, Morioka T, Mukae N, Shimogawa T, Kudo K, Suzuki SO, Mizoguchi M. Two cases of retained medullary cord running parallel to a terminal lipoma. Surg Neurol Int 2021; 12:112. [PMID: 33880217 PMCID: PMC8053431 DOI: 10.25259/sni_626_2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 02/08/2021] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Retained medullary cord (RMC) is a newly defined entity believed to originate from the late arrest of secondary neurulation. Some RMCs contain varying amounts of lipomatous tissues, which need to be differentiated from spinal lipomas, such as filar and caudal lipomas (terminal lipomas). CASE DESCRIPTION We surgically treated two patients with a nonfunctional cord-like structure (C-LS) that was continuous from the cord and extended to the dural cul-de-sac, and ran parallel to the terminal lipoma. In both cases, untethering surgery was performed by resecting the C-LS with lipoma as a column, under intraoperative neurophysiological monitoring. Histopathological examination confirmed that the central canal-like ependyma-lined lumen with surrounding neuroglial and fibrocollagenous tissues, which is the central histopathological feature of an RMC, was located on the unilateral side of the resected column, while the fibroadipose tissues of the lipoma were located on the contralateral side. CONCLUSION Our findings support the idea proposed by Pang et al. that entities such as RMC and terminal lipomas are members of a continuum of regression failure occurring during late secondary neurulation, and the coexistence of RMC and terminal lipoma is not a surprising finding. Therefore, it may be difficult in clinical practice to make a distinct diagnosis between these two entities.
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Affiliation(s)
- Ai Kurogi
- Department of Neurosurgery, Fukuoka Children’s Hospital, Saga, Japan
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children’s Hospital, Saga, Japan
| | - Takato Morioka
- Department of Neurosurgery, Harasanshin Hospital, Saga, Japan
| | - Nobutaka Mukae
- Department of Neurosurgery, Kyushu University, Saga, Japan
| | | | - Kyoko Kudo
- Department of Dermatology, Fukuoka Children’s Hospital, Saga, Japan
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26
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Rhodes RH. Congenital Spinal Lipomatous Malformations. Part 2. Differentiation from Selected Closed Spinal Malformations. Fetal Pediatr Pathol 2021; 40:32-68. [PMID: 31535937 DOI: 10.1080/15513815.2019.1651799] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Congenital spinal lipomatous malformations (spinal lipomas, lipomyeloceles, and lipomyelomeningoceles) are closed neural tube defects over the lower back. Differentiation from some other closed neural tube defects in this region can be problematic for pathologists. MATERIALS AND METHODS This review is based on PubMed searches of the embryology, gross and histopathologic findings, and laboratory reporting requisites for retained medullary spinal cords, coccygeal medullary vestiges and cysts, myelocystoceles, true human vestigial tails, and pseudotails for comparison with congenital spinal lipomatous malformations. RESULTS Embryology, imaging, gross and histopathology of these closed neural tube lesions have different but overlapping features compared to congenital spinal lipomatous malformations, requiring context for diagnosis. CONCLUSION The lipomyelocele spectrum and to some degree all of the malformations discussed, even though they may not share gross appearance, anatomic site, surgical approach, or prognosis, require clinical and histopathologic correlation for final diagnosis.
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Affiliation(s)
- Roy H Rhodes
- Department of Pathology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
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27
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Mukae N, Morioka T, Suzuki SO, Murakami N, Shimogawa T, Kanata A, Tsukamoto H, Mizoguchi M. Two Cases of Large Filar Cyst Associated with Terminal Lipoma: Relationship with Retained Medullary Cord. World Neurosurg 2020; 142:294-298. [PMID: 32668332 DOI: 10.1016/j.wneu.2020.07.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 07/04/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND A small, incidental filar cyst associated with terminal lipoma is thought to be caused by failure of secondary neurulation; however, the precise embryologic background is not fully understood. Retained medullary cord (RMC) also originates from late arrest of secondary neurulation. The central feature of RMC histopathology is a central canal-like ependyma-lined lumen with surrounding neuroglial core. CASE DESCRIPTION We surgically treated 2 patients with a large cyst in the rostral part of the filum and lipoma in the caudal filum. At cord untethering surgery, the filum was severed at the caudal part of the cyst. Histopathologically, the filar cyst was the cystic dilatation of the central canal-like structure at the marginal part of the lipoma. The central canal-like structure was continuous caudally in the lipoma, and its size decreased toward the caudal side. CONCLUSIONS The present findings support the idea raised by Pang et al that entities such as filar cyst, terminal lipomas, and RMC can all be considered consequences of a continuum of regression failure occurring during late secondary neurulation.
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Affiliation(s)
- Nobutaka Mukae
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Takato Morioka
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka, Japan
| | | | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Takafumi Shimogawa
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Akiko Kanata
- Department of Neurosurgery, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
| | - Haruhisa Tsukamoto
- Department of Neurosurgery, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
| | - Masahiro Mizoguchi
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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28
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Rhodes RH. Congenital Spinal Lipomatous Malformations. Part 1. Spinal Lipomas, Lipomyeloceles, and Lipomyelomeningoceles. Fetal Pediatr Pathol 2020; 39:194-245. [PMID: 31342816 DOI: 10.1080/15513815.2019.1641859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background: Lumbosacral spinal lipomas and lipomyeloceles are usually identified in early childhood. Terminology, histopathology, and diagnosis for these malformations can be confusing. Materials and Methods: This is a PubMed review with comparison of embryology, gross, and histopathology, and reporting requisites for these and related closed spinal malformations. Results: The spinal lipoma group (congenital spinal lipomatous malformations) includes subcutaneous, transdural, intradural, and noncontiguous malformations stretching through the entire lower spinal region. This lipomyelocele trajectory overlaps the embryonic tail's caudal eminence. Histopathologically, the lipomyelocele spectrum is a heterogeneous, stereotypical set of findings encountered from dermis to spinal cord. Diagnosis requires detailed correlation of images, intraoperative inspection, and histopathology. Conclusions: Appropriate terminology and clinicopathologic correlation to arrive at a diagnosis is a critical activity shared by pathologist and clinician. Prognostic and management differences depend on specific diagnoses. Familial and genetic influences play little if any role in patient management in closed spinal malformations.
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Affiliation(s)
- Roy H Rhodes
- LSUHSC, Pathology, New Orleans, Louisiana, USA.,Rutgers Robert Wood Johnson Medical School, Pathology, New Brunswick, New Jersey, USA
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29
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Pang D. Surgical Management of Complex Spinal Cord Lipomas : A New Perspective. J Korean Neurosurg Soc 2020; 63:279-313. [PMID: 32392666 PMCID: PMC7218203 DOI: 10.3340/jkns.2020.0024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/28/2020] [Indexed: 11/27/2022] Open
Abstract
This review summarises the classification, anatomy and embryogenesis of complex spinal cord lipomas, and describes in some detail the new technique of total lipoma resection and radical reconstruction of the affected neural placode. Its specific mission is to tackle two main issues surrounding the management of complex dysraphic lipomas : whether total resection confers better long term benefits than partial resection, and whether total resection does better than conservative treatment, i.e., no surgery, for asymptomatic lipomas. Accordingly, the 24 years progression-free survival data of the author and colleagues’ series of over 350 cases of total resection are compared with historical data from multiple series (including our own) of partial resection, and total resection data specifically for asymptomatic lesions are compared with the two known series of non-surgical treatment of equivalent patients. These comparisons amply support the author’s recommendation of total resection for most complex lipomas, with or without symptoms. The notable exception is the asymptomatic chaotic lipoma, whose peculiar anatomical relationship with the neural tissue defies even our aggressive surgical approach, and consequently projects worse results (admittedly of small number of cases) than for the other two lipoma subtypes of dorsal and transitional lesions. Prophylactic resection of asymptomatic chaotic lipomas is therefore not currently endorsed.
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Affiliation(s)
- Dachling Pang
- Department of Paediatric Neurosurgery, Great Ormond Street Hospital for Children, NHS Trust, London, UK.,Department of Paediatric Neurosurgery, University of California, Davis, CA, USA
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30
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Pang D. Perspectives on Spinal Dysraphism : Past, Present, and Future. J Korean Neurosurg Soc 2020; 63:366-372. [PMID: 32392668 PMCID: PMC7218193 DOI: 10.3340/jkns.2020.0023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 04/28/2020] [Indexed: 11/27/2022] Open
Abstract
This article recounts the author's personal views and recollections of the history, conception of embryogenetic theories, application of intraoperative electrophysiology, and development of prospective treatment recommendations of several important spinal dysraphic malformations, including limited dorsal myeloschisis, dermal sinus tract, retained medullary cord, terminal myelocystocoele, and complex spinal cord lipomas.
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Affiliation(s)
- Dachling Pang
- Department of Paediatric Neurosurgery, Great Ormond Street Hospital for Children, NHS Trust, London, UK.,Department of Paediatric Neurosurgery, University of California, Davis, CA, USA
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31
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Wang KC. Spinal Dysraphism in the Last Two Decades : What I Have Seen during the Era of Dynamic Advancement. J Korean Neurosurg Soc 2020; 63:272-278. [PMID: 32336058 PMCID: PMC7218192 DOI: 10.3340/jkns.2020.0068] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/02/2020] [Indexed: 12/26/2022] Open
Abstract
Compared to any other decade, the last two decades have been the most dynamic period in terms of advances in the knowledge on spinal dysraphism. Among the several factors of rapid advancement, such as embryology during secondary neurulation and intraoperative neurophysiological monitoring, there is no doubt that Professor Dachling Pang stood high amidst the period. I review here the last two decades from my personal point of view on what has been achieved in the field of spinal dysraphism, focusing on occult tethered cord syndrome, lumbosacral lipomatous malformation, terminal myelocystocele, retained medullary cord, limited dorsal myeloschisis and junctional neural tube defect. There are still many issues to revise, add and extend. Profound knowledge of basic science is critical, as well as refined clinical analysis. I expect that young scholars who follow the footsteps of precedent giants will shed bright light on this topic in the future.
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Affiliation(s)
- Kyu-Chang Wang
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea
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32
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Eibach S, Pang D. Junctional Neural Tube Defect. J Korean Neurosurg Soc 2020; 63:327-337. [PMID: 32336064 PMCID: PMC7218194 DOI: 10.3340/jkns.2020.0018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/09/2020] [Indexed: 02/07/2023] Open
Abstract
Junctional neurulation represents the most recent adjunct to the well-known sequential embryological processes of primary and secondary neurulation. While its exact molecular processes, occurring at the end of primary and the beginning of secondary neurulation, are still being actively investigated, its pathological counterpart -junctional neural tube defect (JNTD)- had been described in 2017 based on three patients whose well-formed secondary neural tube, the conus, is widely separated from its corresponding primary neural tube and functionally disconnected from corticospinal control from above. Several other cases conforming to this bizarre neural tube arrangement have since appeared in the literature, reinforcing the validity of this entity. The cardinal clinical, neuroimaging, and electrophysiological features of JNTD, and the hypothesis of its embryogenetic mechanism, form part of this review.
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Affiliation(s)
- Sebastian Eibach
- Department of Clinical Medicine, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia.,Department of Neurosurgery, Macquarie University Hospital, Sydney, Australia.,Department of Paediatric Neurosurgery, Sydney Children's Hospital Randwick, Sydney, Australia
| | - Dachling Pang
- Department of Paediatric Neurosurgery, Great Ormond Street Hospital for Children, NHS Trust, London, UK.,Department of Paediatric Neurosurgery, University of California, Davis, CA, USA
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33
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Kim KH, Lee JY, Wang KC. Secondary Neurulation Defects-1 : Retained Medullary Cord. J Korean Neurosurg Soc 2020; 63:314-320. [PMID: 32336057 PMCID: PMC7218196 DOI: 10.3340/jkns.2020.0052] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 03/13/2020] [Indexed: 11/27/2022] Open
Abstract
Retained medullary cord (RMC) is a relatively recent term. Pang et al. newly defined the RMC as a late arrest of secondary neurulation leaving a non-functional vestigial portion at the tip of the conus medullaris. RMC, which belongs to the category of closed spinal dysraphism, is a cord-like structure that is elongated from the conus toward the cul-de-sac. Because intraoperative electrophysiological confirmation of a non-functional conus is essential for the diagnosis of RMC, only a tentative or an assumptive diagnosis is possible before surgery or in cases of limited surgical exposure. We suggest the term ‘possible RMC’ for these cases. An RMC may cause tethered cord syndrome and thus requires surgery. This article reviews the literature to elucidate the pathoembryogenesis, clinical significance and treatment of RMCs.
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Affiliation(s)
- Kyung Hyun Kim
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea
| | - Ji Yeoun Lee
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea.,Department of Anatomy, Seoul National University College of Medicine, Seoul, Korea
| | - Kyu-Chang Wang
- Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea
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34
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Morioka T, Murakami N, Kanata A, Tsukamoto H, Suzuki SO. Retained medullary cord with sacral subcutaneous meningocele and congenital dermal sinus. Childs Nerv Syst 2020; 36:423-427. [PMID: 31297584 DOI: 10.1007/s00381-019-04301-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/07/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND A retained medullary cord (RMC) is a rare closed spinal dysraphism with a robust elongated cord-like structure extending continuously from the conus medullaris to the dural cul-de-sac that is caused by late arrest of secondary neurulation. Five patients with RMC extending to an associated sacral subcutaneous meningocele have been reported. CASE PRESENTATION We report an additional patient with RMC, in whom a congenital dermal sinus (CDS) was found in the caudal portion of the RMC. At the age of 3 days, the patient underwent surgery consisting of meningocele excision and cord untethering, and CDS was noted histologically in the proximal cut end of the RMC. During a second surgery at the age of 5 months, after determining the exact border of the nonfunctional RMC and the true conus by neurophysiological mapping, we removed the entire length of the remnant RMC, including newly developed epidermoid cysts in the CDS. CONCLUSION Although the exact pathoembryogenesis of concurrent RMC and CDS is unknown, an associated subcutaneous meningocele, caused by failure of primary neurulation, could be involved. Surgeons should be aware of the possibility of the coexistence of CDS when dealing with RMCs that extend out to the extradural space.
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Affiliation(s)
- Takato Morioka
- Department of Neurosurgery, Fukuoka Children's Hospital, 5-1-1 Kashii-teriha, Higashi-ku, Fukuoka, 813-0017, Japan.
| | - Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children's Hospital, 5-1-1 Kashii-teriha, Higashi-ku, Fukuoka, 813-0017, Japan
| | - Akiko Kanata
- Department of Neurosurgery, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
| | - Haruhisa Tsukamoto
- Department of Neurosurgery, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
| | - Satoshi O Suzuki
- Department of Neuropathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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35
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Morioka T, Murakami N, Ichiyama M, Kusuda T, Suzuki SO. Congenital Dermal Sinus Elements in Each Tethering Stalk of Coexisting Thoracic Limited Dorsal Myeloschisis and Retained Medullary Cord. Pediatr Neurosurg 2020; 55:380-387. [PMID: 33271568 DOI: 10.1159/000511876] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 09/19/2020] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The embryogenesis of limited dorsal myeloschisis (LDM) likely involves impaired disjunction between the cutaneous and neural ectoderms during primary neurulation. Because LDM and congenital dermal sinus (CDS) have a shared origin in this regard, CDS elements can be found in the LDM stalk. Retained medullary cord (RMC) is a closed spinal dysraphism involving a robust, elongated, cord-like structure extending from the conus medullaris to the dural cul-de-sac. Because the RMC is assumed to be caused by impaired secondary neurulation, concurrent RMC and CDS cannot be explained embryologically. In the present article, we report a case in which CDS elements were noted in each tethering stalk of a coexisting LDM and RMC. CASE PRESENTATION A 2.5-month-old boy with left clubfoot and frequent urinary and fecal leakage had 2 tethering tracts. The upper tract, which ran from the thoracic tail-like cutaneous appendage, had CDS elements in the extradural stalk and a tiny dermoid cyst in the intradural stalk immediately after the dural entry. In the lower tract, which ran from the lumbosacral dimple, the CDS as an extradural stalk continued to the RMC at the dural cul-de-sac. Both stalks were entirely resected through skip laminotomy/laminectomy at 1 stage to untether the cord and resect the CDS elements. CONCLUSION Surgeons should be aware that CDS elements, in addition to LDM, may coexist with RMC that extends out to the extradural space.
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Affiliation(s)
- Takato Morioka
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan, .,Department of Neurosurgery, Harasanshin Hospital, Fukuoka, Japan,
| | - Nobuya Murakami
- Department of Neonatology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Masako Ichiyama
- Department of Neonatology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Takeshi Kusuda
- Department of Neonatology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Satoshi O Suzuki
- Department of Neuropathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Department of Psychiatry, Shourai Hospital, Saga, Japan
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36
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Concepts in the neurosurgical care of patients with spinal neural tube defects: An embryologic approach. Birth Defects Res 2019; 111:1564-1576. [DOI: 10.1002/bdr2.1588] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 02/04/2023]
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37
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Naidich TP, Schefflein J, Cedillo MA, Deutsch JP, Murthy S, Fowkes M. The Distal Spine. Neuroimaging Clin N Am 2019; 29:385-409. [DOI: 10.1016/j.nic.2019.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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38
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Guédon A, Condette-Auliac S, Consoli A, Di Maria F, Coskun O, Rodesch G. Primary conus medullaris arteriovenous shunt and secondary lumbo-sacral epidural arteriovenous fistula: One malformation can hide another. J Neuroradiol 2019; 48:16-20. [PMID: 31323304 DOI: 10.1016/j.neurad.2019.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/06/2019] [Accepted: 07/08/2019] [Indexed: 11/24/2022]
Abstract
We report an anatomical-based association between conus medullaris pial arteriovenous shunt that drain caudally towards the lumbosacral area with very delayed onset of an acquired lumbar epidural shunt, draining secondarily towards intradural veins and responsible for a venous congestive myelopathy with identical clinical symptoms. These patients require close clinical and imaging follow-ups in order to propose adequate treatments before onset of irreversible neurological deficits. MRA should include the lumbo-sacral area in its field of view.
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Affiliation(s)
- Alexis Guédon
- Department of diagnostic and therapeutic neuroradiology, hopital Foch, Suresnes, Hauts-de-Seine, France.
| | - Stéphanie Condette-Auliac
- Department of diagnostic and therapeutic neuroradiology, hopital Foch, Suresnes, Hauts-de-Seine, France.
| | - Arturo Consoli
- Department of diagnostic and therapeutic neuroradiology, hopital Foch, Suresnes, Hauts-de-Seine, France.
| | - Federico Di Maria
- Department of diagnostic and therapeutic neuroradiology, hopital Foch, Suresnes, Hauts-de-Seine, France.
| | - Oguzhan Coskun
- Department of diagnostic and therapeutic neuroradiology, hopital Foch, Suresnes, Hauts-de-Seine, France.
| | - Georges Rodesch
- Department of diagnostic and therapeutic neuroradiology, hopital Foch, Suresnes, Hauts-de-Seine, France.
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39
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Pang D. Surgical management of complex spinal cord lipomas: how, why, and when to operate. A review. J Neurosurg Pediatr 2019; 23:537-556. [PMID: 31042665 DOI: 10.3171/2019.2.peds18390] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 02/04/2019] [Indexed: 11/06/2022]
Abstract
This review summarizes the classification, anatomy, and embryogenesis of complex spinal cord lipomas, and it describes in some detail the new technique of total lipoma resection and radical reconstruction of the affected neural placode. Its specific mission is to tackle two main issues surrounding the management of complex dysraphic lipomas: whether total resection confers better long-term benefits than partial resection and whether total resection fares better than conservative treatment-i.e., no surgery-for asymptomatic lipomas. Accordingly, the 24-year progression-free survival data of the author and colleagues' series of over 300 cases of total resection are compared with historical data from multiple series (including the author and colleagues' own) of partial resection, and total resection data specifically for asymptomatic lesions are compared with the two known series of nonsurgical treatment of equivalent numbers of patients. These comparisons amply support the author's recommendation of total resection for most complex lipomas, with or without symptoms. The notable exception is the asymptomatic chaotic lipoma, whose peculiar anatomical relationship with the neural tissue defies even this aggressive surgical approach and consequently projects worse results (admittedly of a small number of cases) than for the other two lipoma subtypes of dorsal and transitional lesions. Prophylactic resection of asymptomatic chaotic lipomas is therefore not currently endorsed.
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40
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Enlargement of sacral subcutaneous meningocele associated with retained medullary cord. Childs Nerv Syst 2018; 34:1785-1790. [PMID: 29704125 DOI: 10.1007/s00381-018-3812-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 04/17/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND A retained medullary cord (RMC) is a rare closed spinal dysraphism with a robust elongated neural structure continuous from the conus and extending to the dural cul-de-sac. Four cases of RMC extending down to the base of an associated subcutaneous meningocele at the sacral level have been reported. CLINICAL PRESENTATION We report an additional case of RMC, in whom serial MRI examination revealed an enlargement of the meningocele associated with RMC over a 3-month period between 8 and 11 months of age, when he began to stand. At the age of 12 months, untethering of the cord was performed. Histologically, the presence of ependyma-lined central canals in the dense neuroglial cores was noted in all cord-like structures in the intradural and intrameningocele sacs and at the attachment to the meningocele. CONCLUSION It is conceivable that the hydrodynamic pressure with standing position and the check valve phenomenon were involved in meningocele enlargement. We should be mindful of these potential morphological changes.
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41
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Florea SM, Faure A, Brunel H, Girard N, Scavarda D. A case of junctional neural tube defect associated with a lipoma of the filum terminale: a new subtype of junctional neural tube defect? J Neurosurg Pediatr 2018; 21:601-605. [PMID: 29600904 DOI: 10.3171/2018.1.peds17492] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The embryological development of the central nervous system takes place during the neurulation process, which includes primary and secondary neurulation. A new form of dysraphism, named junctional neural tube defect (JNTD), was recently reported, with only 4 cases described in the literature. The authors report a fifth case of JNTD. This 5-year-old boy, who had been operated on during his 1st month of life for a uretero-rectal fistula, was referred for evaluation of possible spinal dysraphism. He had urinary incontinence, clubfeet, and a history of delayed walking ability. MRI showed a spinal cord divided in two, with an upper segment ending at the T-11 level and a lower segment at the L5-S1 level, with a thickened filum terminale. The JNTDs represent a recently classified dysraphism caused by an error during junctional neurulation. The authors suggest that their patient should be included in this category as the fifth case reported in the literature and note that this would be the first reported case of JNTD in association with a lipomatous filum terminale.
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Affiliation(s)
| | | | - Hervé Brunel
- 3Neuroradiology, Hôpital Timone Enfants, Marseille, France
| | - Nadine Girard
- 3Neuroradiology, Hôpital Timone Enfants, Marseille, France
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42
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Retained medullary cord extending to a sacral subcutaneous meningocele. Childs Nerv Syst 2018; 34:527-533. [PMID: 29101613 DOI: 10.1007/s00381-017-3644-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 10/18/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND A retained medullary cord (RMC) is a rare closed spinal dysraphism with a robust elongated neural structure continuous from the conus and extending to the dural cul-de-sac. One case extending down to the base of a subcutaneous meningocele at the sacral level has been reported. CLINICAL PRESENTATION We report on three cases of closed spinal dysraphism, in which a spinal cord-like tethering structure extended out from the dural cul-de-sac and terminated at a skin-covered meningocele sac in the sacrococcygeal region, which was well delineated in curvilinear coronal reconstructed images of 3D-heavily T2-weighted images (3D-hT2WI). Intraoperative neurophysiology revealed the spinal cord-like tethering structure was nonfunctional, and histopathology showed that it consisted of central nervous system tissue, consistent with RMC. The tethering structure histologically contained a glioneuronal core with an ependymal-like lumen and smooth muscle, which may indicate developmental failure during secondary neurulation. CONCLUSIONS When the RMC extending to a meningocele is demonstrated with the detailed magnet resonance imaging including 3D-hT2WI, decision to cut the cord-like structure for untethering of the nervous tissue should be made under careful intraoperative neurophysiological monitoring.
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43
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Murakami N, Morioka T, Shimogawa T, Mukae N, Inoha S, Sasaguri T, Suzuki SO, Iihara K. Ependyma-Lined Canal with Surrounding Neuroglial Tissues in Lumbosacral Lipomatous Malformations: Relationship with Retained Medullary Cord. Pediatr Neurosurg 2018; 53:387-394. [PMID: 30391938 DOI: 10.1159/000494029] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/23/2018] [Indexed: 11/19/2022]
Abstract
BACKGROUND An ependyma-lined canal with surrounding neuroglial tissues can be present in lumbosacral lipomatous malformations; however, the precise embryological significance is still unclear. METHOD Six out of 50 patients with lipomatous malformations had ependymal structures. We retrospectively analyzed the clinical, neuroradiological, and histological findings of these patients to demonstrate the relationship with the embryological background of the retained medullary cord (RMC), which normally regresses, but was retained here because of late arrest of secondary neurulation. RESULTS Five (13.9%) of 36 patients with filar and caudal types and 1 of 3 lipomyelomeningoceles had ependymal structures, while none with dorsal and transitional types had these tissues. Histologically, the ependymal structures surrounded by neuroglial tissue and containing various amounts of adipose tissue bear a striking resemblance to the ependymal structures in RMC. CONCLUSION The 13.9% incidence of association between the ependymal structures and filar and caudal types is thought to be because of second ary neurulation failure with the same embryological background as that of RMC. Dorsal and transitional types, resulting from primary neurulation failure, therefore, did not have ependymal structures.
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Affiliation(s)
- Nobuya Murakami
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan,
| | - Takato Morioka
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Takafumi Shimogawa
- Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan.,Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Nobutaka Mukae
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Satoshi Inoha
- Department of Neurosurgery, Japan Community Health Care Organization (JCHO), Kyushu Hospital, Kitakyushu, Japan
| | - Takakazu Sasaguri
- Department of Pathology, Japan Community Health Care Organization (JCHO), Kyushu Hospital, Kitakyushu, Japan
| | - Satoshi O Suzuki
- Department of Neuropathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Koji Iihara
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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44
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Eibach S, Moes G, Hou YJ, Zovickian J, Pang D. Unjoined primary and secondary neural tubes: junctional neural tube defect, a new form of spinal dysraphism caused by disturbance of junctional neurulation. Childs Nerv Syst 2017; 33:1633-1647. [PMID: 27796548 DOI: 10.1007/s00381-016-3288-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 10/20/2016] [Indexed: 01/29/2023]
Abstract
INTRODUCTION Primary and secondary neurulation are the two known processes that form the central neuraxis of vertebrates. Human phenotypes of neural tube defects (NTDs) mostly fall into two corresponding categories consistent with the two types of developmental sequence: primary NTD features an open skin defect, an exposed, unclosed neural plate (hence an open neural tube defect, or ONTD), and an unformed or poorly formed secondary neural tube, and secondary NTD with no skin abnormality (hence a closed NTD) and a malformed conus caudal to a well-developed primary neural tube. METHODS AND RESULTS We encountered three cases of a previously unrecorded form of spinal dysraphism in which the primary and secondary neural tubes are individually formed but are physically separated far apart and functionally disconnected from each other. One patient was operated on, in whom both the lumbosacral spinal cord from primary neurulation and the conus from secondary neurulation are each anatomically complete and endowed with functioning segmental motor roots tested by intraoperative triggered electromyography and direct spinal cord stimulation. The remarkable feature is that the two neural tubes are unjoined except by a functionally inert, probably non-neural band. CONCLUSION The developmental error of this peculiar malformation probably occurs during the critical transition between the end of primary and the beginning of secondary neurulation, in a stage aptly called junctional neurulation. We describe the current knowledge concerning junctional neurulation and speculate on the embryogenesis of this new class of spinal dysraphism, which we call junctional neural tube defect.
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Affiliation(s)
- Sebastian Eibach
- Paediatric Neurosurgery, Regional Centre of Paediatric Neurosurgery, Kaiser Foundation Hospitals of Northern California, Oakland, CA, USA
- Paediatric Neurosurgery, Altona Children's Hospital, Hamburg, Germany
| | - Greg Moes
- Neuropathology, Regional Centre of Paediatric Neurosurgery, Kaiser Foundation Hospitals of Northern California, Oakland, CA, USA
- Adjunct Faculty of Neuropathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Yong Jin Hou
- Intraoperative Neurophysiology, Regional Centre of Paediatric Neurosurgery, Kaiser Foundation Hospitals of Northern California, Oakland, CA, USA
| | - John Zovickian
- Paediatric Neurosurgery, Regional Centre of Paediatric Neurosurgery, Kaiser Foundation Hospitals of Northern California, Oakland, CA, USA
| | - Dachling Pang
- Regional Centre of Paediatric Neurosurgery, Kaiser Foundation Hospitals of Northern California, Oakland, CA, USA.
- Paediatric Neurosurgery, University of California, Davis, CA, USA.
- Great Ormond Street Hospital for Children, NHS Trust, London, UK.
- Department of Paediatric Neurosurgery, Kaiser Permanente Medical Centre, Third Floor, Suite 39, 3600 Broadway, Oakland, CA, 94611, USA.
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Abstract
OBJECTIVE Spinal lipomas are generally thought to occur as a result of failed primary neurulation. However, some clinical features cannot be explained by this theory. The authors propose a novel classification of spinal lipomas based on embryonic changes seen during primary and secondary neurulation. METHODS A total of 677 patients with occult spinal dysraphism underwent 699 surgeries between August 2002 and May 2015 at the National Center for Child Health and Development and Tokyo Metropolitan Children's Medical Center. This group of patients had 378 spinal lipomas, including 119 conus spinal lipomas, 27 lipomyelomeningoceles, and 232 filum lipomas, which the authors classified into 4 types based on neural tube formation during embryonic development. Type 1 is defined as pure primary neurulation failure; Type 2 ranges from primary to secondary neurulation failure; Type 3 consists of secondary neurulation failure (early phase); and Type 4 is defined as secondary neurulation failure (late phase). The authors also review embryogenesis in secondary neurulation and analyze the clinical utility of the new classification. RESULTS There were 55 Type 1 spinal lipomas, 29 Type 2, 62 Type 3, and 232 Type 4. All filum lipomas fell into the Type 4 spinal lipoma category. Association with anorectal and/or sacral anomalies was seen in none of the Type 1 cases, 15 (52%) of Type 2, 35 (56%) of Type 3, and 31 (13%) of Type 4. Urogenital anomalies were observed in none of the Type 1 or Type 2 cases, 1 (2%) of Type 3, and 28 (12%) of Type 4. Anomaly syndromes were present in none of the Type 1 cases, 6 (21%) of Type 2, 3 (5%) of Type 3, and 16 (7%) of Type 4. Associated anomalies or anomaly syndromes were clearly observed only for Type 2-4 spinal lipomas encompassing failed secondary neurulation. Radical resection was feasible for Type 1 spinal lipomas. CONCLUSIONS Secondary neurulation of the spinal cord gives rise to the conus medullaris and filum terminale, which are often involved in spinal lipomas. Formation of spinal lipomas seems to be a continuous process overlapping primary and secondary neurulation in some cases. Association with other anomalies was higher in Type 2-4 spinal lipomas, which included failed secondary neurulation, than in Type 1 lipomas, with failed primary neurulation. On the other hand, radical resection was indicated for Type 1, but not for Type 2, spinal lipomas. The new classification of spinal lipomas based on embryonic stage has the potential for clinical use and agrees well with both clinical and surgical findings. The classification proposed here is still preliminary. Further studies and verification are necessary to establish its clinical utility.
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Affiliation(s)
- Nobuhito Morota
- Division of Neurosurgery, Tokyo Metropolitan Children's Medical Center
| | - Satoshi Ihara
- Division of Neurosurgery, Tokyo Metropolitan Children's Medical Center
| | - Hideki Ogiwara
- Division of Neurosurgery, National Center for Child Health and Development, Tokyo, Japan
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Retained medullary cord confirmed by intraoperative neurophysiological mapping. Childs Nerv Syst 2014; 30:1287-91. [PMID: 24562472 DOI: 10.1007/s00381-014-2372-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 01/23/2014] [Indexed: 10/25/2022]
Abstract
INTRODUCTION A retained medullary cord (RMC) is a rare dysraphic malformation, recently described as a late arrest of secondary neurulation. RMC is also a severely tethering lesion. The critical role of intraoperative neurophysiology to safely manage a RMC has been only anecdotally reported. CASE REPORT We describe the case of a RMC in a 1.5-year-old child with Currarino syndrome. At surgery, an apparently normal-looking spinal cord, stretched and tethered by a lipoma to the level of S2-S3, was observed. The border between the functional conus and the non functional RMC was defined through neurophysiological mapping. The cord was sharply interrupted at this level and untethered. A specimen was sent for pathology, which confirmed the presence of glial and neural elements. The post-operative neurological exam was normal. CONCLUSION Neurosurgical procedure for RMC should only be rendered with intraoperative neurophysiological mapping, as the anatomical judgment would not suffice to allow a safe cutting of these "normal-looking" neural structures.
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Intraoperative neurophysiology in tethered cord surgery: techniques and results. Childs Nerv Syst 2013; 29:1611-24. [PMID: 24013331 DOI: 10.1007/s00381-013-2188-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 05/24/2013] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Intraoperative neurophysiologic monitoring (IOM) is nowadays extensively used to minimize neurological morbidity in tethered cord surgery. Our goal is to describe and discuss the standard IOM techniques used during these surgical procedures and to summarize our clinical experience using a multimodal IOM approach. MATERIAL AND METHODS Neurophysiological mapping of the conus-cauda is performed through direct stimulation of these structures and bilateral recording from segmental target muscles. While mapping identifies ambiguous neural structures, their functional integrity during surgery can be assessed by monitoring techniques only, such as somatosensory evoked potentials (SEPs), transcranial motor-evoked potentials (MEPs) from the limb muscles and anal sphincters, and the bulbocavernosus reflex (BCR). RESULTS Between 2002 and 2012, we performed 48 surgical procedures in 47 patients with a tethered cord secondary to a variety of spinal dysraphisms. The monitorability rate was 84 % for SEPs, 97 % for limb muscle MEPs, 74 % for the anal sphincter MEPs, and 59 % for the BCR. In all patients but one, SEP, MEP, and BCR remained stable during surgery. Postoperatively, two out of 47 patients presented a significant-though transient-neurological worsening. In six patients, an unexpected muscle response was evoked by stimulating tissue macroscopically considered as not functional. CONCLUSIONS Mapping techniques allow identifying and sparing functional neural tissue and vice versa to cut nonfunctional structures that may contribute to cord tethering. Monitoring techniques, MEP and BCR in particular, improve the reliability of intraoperative neurophysiology, though these may require a higher degree of neuromonitoring expertise. IOM minimizes neurological morbidity in tethered cord surgery.
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Valentini LG, Selvaggio G, Erbetta A, Cordella R, Pecoraro MG, Bova S, Boni E, Beretta E, Furlanetto M. Occult spinal dysraphism: lessons learned by retrospective analysis of 149 surgical cases about natural history, surgical indications, urodynamic testing, and intraoperative neurophysiological monitoring. Childs Nerv Syst 2013; 29:1657-69. [PMID: 24013336 DOI: 10.1007/s00381-013-2186-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE Prophylactic surgery is indicated for lipoma of the filum, while it is still debated for the conus lipomas and more complex tethering malformations of the cord. METHODS We retrospectively reviewed the preoperative and postoperative clinical histories and long-term outcomes of 149 operated patients (33 adults, 116 children). Intraoperative neurophysiological monitoring (NPM) was utilized since 1998. Their malformative lesions were reclassified following recent Pang's embryological criteria for surgical complexity. In nine cases, the spinal tethering malformation was associated with an anorectal malformation (ARM) and in nine with a Chiari I malformation (CM1). RESULTS One hundred nineteen (80 %) patients were symptomatic at the time of surgery, 66 (44 %) having presented with progressive preoperative deterioration. Postoperative surgery-related deterioration was observed in 6 % of the cases operated on under the intraoperative NPM control. Surgery did not improve any deficit, especially of sphincter functions, independently from the type of associated malformation (ARM, CM1). Urodynamic testing was a reliable predictor both in the preoperative and in the follow-up period of subsequent neurological deterioration. In the long-term follow-up, an increasing percentage of retethering was observed, especially concerning complex cases submitted to partial excision. The surgical risk increased with repeated operations. CONCLUSIONS This study demonstrates that the rate of the natural deterioration associated with a conservative approach is higher than in patients operated on prophylactically, if the operation is performed by a team with a special expertise. However, the first surgical procedure should be aimed at detethering the conus completely, with the aid of intraoperative NPM; even in expert hands, it is associated with a high risk of clinical deterioration. Based on these results, we are increasing the percentage of children to whom surgery is offered when still asymptomatic as well as the degree of the lipoma excision to prevent retethering. However, in cases of rethetering and subjects presenting in adult age, we suggest to consider for surgery only those symptomatic. Urodynamic testing and magnetic resonance imaging in prone position were, in our experience, the best tools for screening those patients at risk of symptomatic retethering.
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Affiliation(s)
- Laura Grazia Valentini
- Department of Neurosurgery, Fondazione Istituto Neurologico "C. Besta", Via Celoria 11, 20133 Milan, Italy.
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Abstract
PURPOSE This paper shows the long-term benefits of total/near-total resection of complex spinal cord lipomas and meticulous reconstruction of the neural placode, and specifically, its advantage over partial resection, and over non-surgical treatment for the subset of children with asymptomatic virgin lipomas. METHODS The technique of total resection and placode reconstruction, together with technical nuances, are described in detail. We added 77 patients with complex lipomas to our original lipoma series published in 2009 and 2010, to a total of 315 patients who had had total or near-total resection and followed for a span of 20 years. Long-term outcome is measured by overall progression-free survival (PFS) with the Kaplan-Meier analysis, and by subgroup Cox proportional recurrence hazard analysis for the influence on outcome of 4 predictor variables of lipoma type, presence of symptoms, prior surgery, and post-operative cord-sac ratio. These results are compared to an age-matched, lesion-matched series of 116 patients who underwent partial lipoma resection over 11 years. The results for total resection is also compared to two large published series of asymptomatic lipomas followed without surgery over 9 to 10 years, to determine whether prophylactic total resection confers better long-term protection over conservative treatment for children with asymptomatic lipomas.. RESULTS The PFS after total resection for all lipoma types and clinical subgroups is 88.1 % over 20 years versus 34.6 % for partial resection at 10.5 years (p < 0.0001). Culling only the asymptomatic patients with virgin (previously unoperated) lipomas, the PFS for prophylactic total resection for this subgroup rose to 98.8 % over 20 years, versus 67 % at 9 years for one group of non-surgical treatment and 60 % at 10 years for another group of conservative treatment. Our own as well as other published results of partial resection also compare poorly to non-surgical treatment for the subset of asymptomatic virgin lipomas. Multivariate subgroup analyses show that cord-sac ratio is the only independent variable that predicts outcome, with a 96.9 % PFS for ratio < 30 % (loosest sac), 86.2 % for ratio between 30 and 50 %, and 78.3 % for ratio > 50 % (tightest sac), and a threefold increase in recurrence hazard for high ratios (p = 0.0009). Pre-operative patient profiling using multiple correspondence analysis shows the ideal patient for total resection is a child less than 2 years old with a virgin asymptomatic lipoma, who, with a PFS of 99.2 %, is virtually cured by total resection. CONCLUSION Total/near-total resection of complex lipomas and complete reconstruction of the neural placode achieves far better long-term protection against symptomatic recurrence than partial resection for all lesions; and for the subset of asymptomatic virgin lipomas, also better than non-surgical treatment. Partial resection in many cases produces worse outcome than conservative treatment for asymptomatic lesions.
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Affiliation(s)
- Dachling Pang
- Paediatric Neurosurgery, University of California, Davis, CA, USA.
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Gurzu S, Gozar H, Derzsi Z, Szabo B, Jung I. Second case of a fetal sacrococcygeal neuroectodermal cyst in a male newborn. Pathology 2013; 45:188-91. [PMID: 23250044 DOI: 10.1097/pat.0b013e32835c7804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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