Two simultaneous anatomical variations of the cervical spine – a case report discussing the concept of tandem anomalies
Abstract
forming a bony opening through which the vertebral artery (VA) enters the vertebral canal. Block vertebra is a synostosis of at least two vertebral bodies that did not separate during the embryological development. It is worth distinguishing it from the Klippel-Feil syndrome, as the latter oftentimes involves other abnormalities (namely skeletal) and is typically diagnosed in childhood. Both variants could potentially lead to an impairment of the blood flow through the VA. Case report: The following case report presents a finding of two anomalies of the cervical spine, found in a 38 y.o. female patient suffering from dizziness. A synostosis of the C4 and C5 vertebral bodies, arches and zygapophysial (facet) joint, was noted by the examining radiologist, with marked narrowing of the intervertebral foramen. Furthermore, second anatomical variation in the form of the complete bilateral arcuate foramen was identified superior to the groove for the VA on the upper surface of the posterior arch of the atlas. Conclusions: To the best knowledge of the authors, this case report is the first to present a co-existing block vertebra and bilateral complete arcuate foramen. Common presence of at least two anatomical variations that could have a synergistic clinical effect could possibly be termed ‘tandem anomaly.’ Notwithstanding, identification of a single anomaly explaining a patient's symptoms does not absolve the medical professionals from searching for any other potential variations that could also be present and could further influence the clinical picture.
Keywords: arcuate foramenvertebral synostosisvertebral arteryanatomyradiology
References
- Abd el-Bary TH, Dujovny M, Ausman JI. Microsurgical anatomy of the atlantal part of the vertebral artery. Surg Neurol. 1995; 44(4): 392–400; discussion 400.
- Alonso F, Iwanaga J, Fisahn C, et al. Adjacent segment level disease in Klippel-Feil syndrome patients with congenital cervical fusion in the setting of anterolisthesis: Should management be altered in the presence of anterolisthesis? Transl Res Anat. 2017; 6: 1–3.
- Brassier G, Morandi X, Riffaud L, et al. Basilar artery anatomy. J Neurosurg. 2000; 93(2): 368–369.
- Cushing KE, Ramesh V, Gardner-Medwin D, et al. Tethering of the vertebral artery in the congenital arcuate foramen of the atlas vertebra: a possible cause of vertebral artery dissection in children. Dev Med Child Neurol. 2001; 43(7): 491–496.
- Dahiphale VP, Bahetee BH. The retro-articular vertebral artery ring of the atlas and its significance. J Anat Soc India. 2009; 58(2): 149–151.
- Erdil H, Yildiz N, Cimen M. Congenital fusion of cervical vertebrae and its clinical significance. J Anat Soc India. 2003; 52(2): 125–127.
- Frikha R. Klippel-Feil syndrome: a review of the literature. Clin Dysmorphol. 2020; 29(1): 35–37.
- Gruber J, Saleh A, Bakhsh W, et al. The prevalence of Klippel-Feil syndrome: a computed tomography-based analysis of 2,917 patients. Spine Deform. 2018; 6(4): 448–453.
- Hamdy RC, Uhthoff HK. The development of the cervical spine. In: Hamdy RC. ed. The embryology of the human locomotor system. Springer-Verlag, Berlin/Heidelberg 1990: 43–50.
- Hamilton WJ, Boyd JD, Mossman HW. Branches of the dorsal aortae. In: Hamilton WJ, Boyd JD, Mossman HW. ed. Human embryology (Prenatal development of form and function). W. Heffer & Sons Ltd., Cambridge 1945: 137–139.
- Henry BM, Roy J, Ramakrishnan PK, et al. Association of migraine headaches with anatomical variations of the Circle of Willis: Evidence from a meta-analysis. Neurol Neurochir Pol. 2015; 49(4): 272–277.
- Henry BM, Vikse J, Pekala P, et al. Consensus guidelines for the uniform reporting of study ethics in anatomical research within the framework of the anatomical quality assurance (AQUA) checklist. Clin Anat. 2018; 31(4): 521–524.
- Hindenes LB, Håberg AK, Johnsen LH, et al. Variations in the Circle of Willis in a large population sample using 3D TOF angiography: The Tromsø Study. PLoS One. 2020; 15(11): e0241373.
- Illingworth RS. Attacks of unconsciousness in association with fused cervical vertebrae. Arch Dis Child. 1956; 31(155): 8–11.
- Kim MS. Anatomical variant of atlas: arcuate foramen, occpitalization of atlas, and defect of posterior arch of atlas. J Korean Neurosurg Soc. 2015; 58(6): 528–533.
- Klimek-Piotrowska W, Kopeć M, Kochana M, et al. Configurations of the circle of Willis: a computed tomography angiography based study on a Polish population. Folia Morphol. 2013; 72(4): 293–299.
- Klippel M, Feil A. Un cas d'absence des vertèbres cervicales avec cage thoracique remontant jusqu’ à la base du crâne (cage thoracique cervicale). Nouv Iconogr Salpêtr (Paris). 1912; 25: 223–250.
- Knoplich J. Isolated vertebral blocks in the cervical spine. Rev Paul Med. 1992; 110(1): 2–7.
- Krishnamurthy A, Nayak SR, Khan S, et al. Arcuate foramen of atlas: incidence, phylogenetic and clinical significance. Rom J Morphol Embryol. 2007; 48(3): 263–266.
- Limousin CA. Foramen arcuale and syndrome of Barre-Lieou. Its surgical treatment. Int Orthop. 1980; 4(1): 19–23.
- Magklara EP, Pantelia ET, Solia E, et al. Vertebral artery variations revised: origin, course, branches and embryonic development. Folia Morphol. 2021; 80(1): 1–12.
- Miki T, Oka M, UrushidaniI H, et al. Ponticulus posticus: its clinical significance. Acta Med Kinki Univ. 1979; 4(2): 427–430.
- O’Rahilly R, Benson DR. The development of the vertebral colum. In: Bradford DS, Hensinger RM. ed. The pediatric spine. Thieme, Stuttgart 1985: 3–18.
- Pękala PA, Henry BM, Pękala JR, et al. Prevalence of foramen arcuale and its clinical significance: a meta-analysis of 55,985 subjects. J Neurosurg Spine. 2017; 27(3): 276–290.
- Pizzutillo PD, Woods M, Nicholson L, et al. Risk factors in Klippel-Feil syndrome. Spine (Phila Pa 1976). 1994; 19(18): 2110–2116.
- Sabir H, Kumbhare S, Rout P. Evaluation of ponticulus posticus on digital lateral cephalograms and cone beam computed tomography in patients with migraine and healthy individuals: a comparative study. Oral Surg Oral Med Oral Pathol Oral Radiol. 2014; 118(3): 348–354.
- Samartzis DD, Herman J, Lubicky JP, et al. Classification of congenitally fused cervical patterns in Klippel-Feil patients: epidemiology and role in the development of cervical spine-related symptoms. Spine (Phila Pa 1976). 2006; 31(21): E798–E804.
- Sanchis-Gimeno J, Ercan I, Llido S, et al. Arcuate foramen prevalence in South African subjects: A cadaveric study based on 120 atlas vertebrae. Translational Research in Anatomy. 2023; 33: 100271.
- Schilling J, Schilling A, Galdames IS. Ponticulus posticus on the posterior arch of atlas, prevalence analysis in asymptomatic patients. Int J Morphol. 2010; 28(1): 317–322.
- Shanthi KC, Ravichandran D. The incidence and dimensions of the foramen arcuale in Tamil Nadu state. Natl J Basic Med Sci. 2011; 2: 96–98.
- Skrzat J, Mróz I, Jaworek JK, et al. A case of occipitalization in the human skull. Folia Morphol. 2010; 69(3): 134–137.
- Smoker WR. Craniovertebral junction: normal anatomy, craniometry, and congenital anomalies. Radiographics. 1994; 14(2): 255–277.
- Tracy MR, Dormans JP, Kusumi K. Klippel-Feil syndrome: clinical features and current understanding of etiology. Clin Orthop Relat Res. 2004(424): 183–190.
- Uhthoff HK. The early development of the spine. In: Uhthoff HK. ed. The embryology of the human locomotor system. Springer-Verlag, Berlin/Heidelberg : 33–42.
- Wang S, Wang C, Liu Yi, et al. Anomalous vertebral artery in craniovertebral junction with occipitalization of the atlas. Spine (Phila Pa 1976). 2009; 34(26): 2838–2842.
- Wight S, Osborne N, Breen AC. Incidence of ponticulus posterior of the atlas in migraine and cervicogenic headache. J Manipulative Physiol Ther. 1999; 22(1): 15–20.
- Yadav Y, Goswami P, Bharihoke V. Cervical vertebra synostosis (C2-C3) — a case report. Am J Case Rep. 2014; 2(6): 120–122.
- Young JP, Young PH, Ackermann MJ, et al. The ponticulus posticus: implications for screw insertion into the first cervical lateral mass. J Bone Joint Surg Am. 2005; 87(11): 2495–2498.