Evaluation of conus medullaris level in newborn infants

Year 2023, Volume: 48 Issue: 2, 629 - 636, 02.07.2023

Bülent Yıldız , Gaffari Tunç , Burçak Söylemez

https://doi.org/10.17826/cumj.1241867

Abstract

Purpose: Previous studies have reported that the conus medullaris (CM) is located between T12 and L2 in most adults, but no significant ascent has been observed during childhood. There is evidence that the normal position of the CM in an adult is acquired at birth in the majority of cases. Studies have shown that there are differences in CM levels in neonates. This situation causes problems for interventional procedures in the neonatal period. The aim of this study is to determine CM levels in preterm/term neonates using ultrasound (US).
Materials and Methods: Newborn infants (gestational age: 24–43 weeks) admitted to the neonatal intensive care unit between March 2020 and June 2021 were evaluated for CM levels by the postnatal US. Infants with central nervous system abnormalities, dysmorphic features, somatic or various genetic diseases, or their parent’s refusal to participate were excluded from the study.
Results: Of the 189 neonates infants included in our study, 85 (44.6%) were female, 104 (55.4%) were male, 139 (73.54%) were preterm (24–36 weeks), and 50 (26.46%) were term (37–42 weeks) neonates. As a result of the US performed on the first day of 189 neonates, CM levels, 31 (16.4%) were L1, 31 (16.4%) were L1-2, and 71 (37.6%) were L2. There is a strong correlation between birth weight and birth week (r 0.84). There is a negative relationship between birth weight and CM level (r -0,20), gestational age, and CM level (r -0,23).
Conclusion: Conus medullaris level was negatively correlated with gestational age and increased with advancing gestational age. In addition, the CM level shows a slower rise at 28-40 weeks of postmenstrual age and reaches the normal level (L1-L2) in the neonatal period, as in adults. Knowing the level of the CM in the newborn period will ensure that spinal procedures such as lumbar puncture to be applied to the spinal region can be performed safely.

Keywords

Newborn infant, ultrasound, Conus medullaris level

Supporting Institution

YOK

Project Number

YOK

Thanks

We would like to thank Ziynet Çınar, Faculty Member of the Biostatistics Department of Sivas Cumhuriyet University, for her contributions to the study and her assistance in this project. The authors would like to thank all the infant and their families who participated in this study.

Yenidoğan bebeklerde konus medullaris düzeyinin değerlendirilmesi

Abstract

Amaç: Yapılan araştırmalar, çoğu yetişkinde konus medullaris (KM) seviyesinin T12 ve L2 arasında olduğunu, ancak çocuklukta önemli bir KM yükselişinin olmadığını göstermektedir. Normal yetişkin pozisyonunun aslında vakaların çoğunda doğumla elde edildiğine dair kanıtlar mevcuttur. Yapılan çalışmalarda yenidoğanlarda KM seviyesinde farklılıklar olduğunu göstermiştir. Bu durum yenidoğan döneminde yapılacak girişimsel işlemlerde soruna neden olmaktadır. Bu çalışmada amacımız preterm/term yenidoğanlarda ultrason (US) kulanılarak KM seviyesini tespit etmektir.
Gereç ve Yöntem: Yenidoğan Yoğun Bakım Ünitesi’nde (YYBU) Mart 2020- Haziran 2021 tarihleri arasında kabul edilen preterm/term yenidoğanlarda (gestasyonel haftası 24-43) postnatal US ile KM seviyeleri değerlendirildi. Çalışmada santral sinir sistemi anomalileri, dismorfik vücut bulguları olan, somatik veya çeşitli genetik hastalığı olan olgular ve çalışmayı kabul etmeyen ailelerin bebekleri çalışma dışı bırakıldı.
Bulgular: Çalışmamıza dahil edilen 189 yenidoğanın 85'i (%44,6) kız, 104'ü (%55,4) erkek, 139'u (%73,54) preterme (24-36 hafta) ve 50'si (%26,46) term (37-42 hafta) bebekti. İlk gün yapılan US sonucunda KM seviyesinin 31’i (%16,4) L1, 31’i (%16,4) L1-2 ve 71’i (%37,6) L2 olduğu gözlemlendi. Doğum ağırlığı ile doğum haftası arasında güçlü bir ilişki bulundu (r 0.84). KM seviyesi ile doğum haftası (r -0,23) ve doğum ağırlığı (r -0,20) ile arasında negatif yönlü bir ilişki saptandı.
Sonuç: Konus medullaris seviyesi gebelik haftası ile negatif ilişkiliydi ve ilerleyen gebelik yaşı ile yükseliyordu. Ayrıca konus medullaris postmenstural 28-40 haftalarda daha yavaş bir yükselme göstermektedir ve yenidoğan döneminde erişkindeki gibi normal düzeye (L1-L2) ulaşmıştır. Yenidoğan döneminde konus medullarisin seviyesinin bilinmesi spinal bölgeye uygulanacak lomber ponksiyon gibi işlemlerin güvenle yapılabilmesini sağlayacaktır.

Keywords

Yenidoğan bebek, ultrasound, Konus medullaris düzeyi

Project Number

YOK

References

• Barson AJ. The vertebral level of termination of the spinal cord during normal and abnormal development. J Anat. 1970;106:489-97.
• James CCM, Lassman LP. Spinal dysraphism. Spina bifida occulta. 1st Edition. Newyork, Appleton-Century-Crofts. 1972
• Zalel Y, Lehavi O, Aizenstein O, Achiron R. Development of the fetal spinal cord: time of ascendance of the normal conus medullaris as detected by sonography. J Ultrasound Med. 2006;25:1397-401.
• Malas MA, Salbacak A, Köylüoğlu B, Erkul İ, Açıkgözoğlu S, Büyükmumcu M. Ultrasonographic determination of conus medullaris vertebral termination level during childhood between 0-7 years of age. Journal of SDU Faculty of Medicine. 1995;2:61-8.
• Sun M, Tao B, Gao G, Wang H, Shang A. Determination of the normal conus medullaris level in term infants: the role of MRI in early infancy. J Neurosurg Pediatr. 2021;29 100-5.
• Ursu TR, Porter RW, Navaratnam V. Development of the lumbar and sacral vertebral canal in utero. Spine. 1996;21:2705-8.
• Arthurs OJ, Thayyil S, Wade A, Chong WK, Sebire NJ, Taylor AM. Magnetic resonance imaging autopsy study collaborative group. Normal ascent of the conus medullaris: a post-mortem foetal MRI study. J Matern Fetal Neonatal Med. 2013;26:697-702.
• Sun M, Chen M, Gao G, Tao B, Shang A. Gestational age-specific reference standards of low-lying conus medullaris level in fetuses: a prospective cohort study. Childs Nerv Syst. 2023;39:997-1003.
• Sun M, Tao B, Gao G, Wang H, Shang A. Conus medullaris migration during the third trimester: A retrospective study. Prenat Diagn. 202;41:643-8.
• Gupta NK, Vaisnani H, Gupta P, Gandotra A. Morphometric analysis of spinal cord and its termination within the vertebral canal: an observational study in the fetuses of third trimester gestational age. Cureus. 2022;14:e30438.
• Arıncı K, Elhan A. Merkezi Sinir Sistemi. 1. Edition., Ankara, Murat Basımevi, 1993
• Williams PL, Warwich R, Dyson M, Bannewborn infants ter LH. Gray's Anatomy. 23rd Edition. London, Churchill Livingstone, 1992.
• Behrman RE, Kliegman RM, Nelson EW. Nelson textbook of pediatrics. 14th Edition. Philadelphia, Wb Saunders, 1992.
• Wolf S, Schneble F, Tröger J. The conus medullaris: time of ascendence to normal level. Pediatr Radiol. 1992;22:590-92.
• Di Pietro MA. The conus medullaris: normal US findings throughout childhood. Radiology. 1993;188:149-53.
• Fitz CR, Harwood Nash DC. The tethered conus. Am J Roentgenol. 1975;125:515-23.
• Raghavan N, Barkovich AJ, Edwards M, Norman D. MR imaging in the tethered spinal cord syndrome. Am J Roentgenol. 1989;152:843-52.
• Vettivel S. Vertebral level of the termination of the spinal cord in human fetuses. J Anatomy. 1991;179:149-61.
• Jit I, Charnalia VM. The vertebral level of the termination of the spinal cord. J Anat Soc India. 1959;8:93-101.
• Needles JH. The caudal level of termination of the spinal cord in American whites and American negroes. Anat Rec. 1935;63:417-24.
• Içten N, Memedova E, Süllü Y. Vertebral level of the ending of the spinal cord and its relationship to the length of the vertebral column in northern Turkish neonates. Surg Radiol Anat. 1995;17: 315-8.
• Barry A. A quantitative study of the prenatal changes in angulation of the spinal nerves. Anat Rec. 1956;126:97-110.
• Govender S, Charles RW, Haffejee MR. Level of termination of the spinal cord during normal and abnormal fetal development. S Afr Med J. 1989;75:484-7.
• Rao VS. The lower limit of the spinal cord in south Indian foetuses. J Anat. 1949; 83:175.
• Raghavendra BN, Epstein FJ. Sonography of the spine and spinal cord. Radiol Clin North Am. 1985;23:91-105.
• Wilson DA, Prince JR. John Caffey award. MR imaging determination of the location of the normal conus medullaris throughout childhood. Am J Roentgenol. 1989;152:1029-32.
• Robbin ML, Filly RA, Goldstein RB. The normal location of the fetal conus medullaris. J Ultrasound Med. 1994;13:541-6.
• Hill CA, Gibson PJ. Ultrasound determination of the normal location of the conus medullaris in neonates. Am J Neuroradiol. 1995;16:469-72.
• Beek FJ, de Vries LS, Gerards LJ, Mali WP. Sonographic determination of the position of the conus medullaris in preterm and term infants. Neuroradiology. 1996; 38: 174-7.
• Hawass ND, El-Badawi MG, Fatani JA, Meshari AA, Abbas FS, Edrees YB et al. Myelographic study of the spinal cord ascent during fetal development. Am J Neuroradiol. 1987;8:691-5.
• Saifuddin A, Burnett SJ, White J. The variation of position of the conus medullaris in an adult population. A magnetic resonance imaging study. Spine. 1998;23:1452-6.
• Soleiman J, Demaerel P, Rocher S, Maes F, Marchal G. Magnetic resonance imaging study of the level of termination of the conus medullaris and the thecal sac: influence of age and gender. Spine. 2005;30:1875-80.
• Kesler H, Dias MS, Kalapos P. Termination of the normal conus medullaris in children: a whole-spine magnetic resonance imaging study. Neurosurg Focus. 2007;23:7.
• Widjaja E, Whitby EH, Paley MN, Griffiths PD. Normal fetal lumbar spine on postmortem MR imaging. AJNR Am J Neuroradiol. 2006;27:553-9.
• Kim JT, Bahk JH, Sung J. Influence of age and sex on the position of the conus medullaris and Tuffier's line in adults. Anesthesiology. 2003; 99: 1359-63.
• Demiryürek D, Aydingöz U, Akşit MD, Yener N, Geyik PO. MR imaging determination of the normal level of conus medullaris. Clin Imaging. 2002;26: 375-77.
• Sahin F, Selçuki M, Ecin N, Zenciroğlu A, Unlü A, Yilmaz F et al. Level of conus medullaris in term and preterm neonates. Arch Dis Child Fetal Neonatal Ed. 1997;77:67-9.