LETTER TO THE EDITOR - NEUROSURGICAL ANATOMY

Complete bilateral arcuate foraminaand atlantoaxial subluxation

Luigi Rigante & Alexander I. Evins & Justin Burrell &André Beer-Furlan & Antonio Bernardo

Received: 2 August 2013 /Accepted: 23 September 2013 /Published online: 8 October 2013# Springer-Verlag Wien 2013

Letter to the EditorA cadaveric specimen undergoing a posterior cervical dissec-tion was noted to have complete bilateral ossification of theposterior atlanto-occipital membrane over the vertebral arterygroove and a type-1 atlantoaxial subluxation—atlas rotationon the odontoid process with no anterior displacement(Fig. 1). This ossification anomaly, known as Kimmerle’svariant, ponticulus posticus, arcuale foramen, and/or arcuateforamen, is found with partial and complete ossification in 6–18 % and 4–8 % (3.3–6.7 % unilateral, 0.7–1.3 % bilateral) ofthe population, respectively, with a debated higher reportedprevalence in females [2, 4, 7, 9]. This anomaly often remainsasymptomatic; however, compression of the neurovascularstructures within the foramina can induce pressure phenomenaof the periarterial sympathetic plexus, especially when rotat-ing the head, and induce vertebro-basilar insufficiency and/orclinical symptoms resembling Barre–Lieou syndrome, pre-senting with shoulder-arm and neck pain, cervical migraine,hearing loss, vertigo, and/or loss of consciousness [2, 5, 7].

The average age at clinical presentation has been debated inthe literature, and has been reported to be greatest between 11

and 20 years and 21–30 years, while another study indicatedthat presentation is most common during the third and fourthdecades of life [5, 8]. Though it is possible that ossificationprogresses over time, arcuate foramina have been reported inchildren as young as 2 years of age with one study reportingfour cases of partial and three cases of complete arcuateforamina in children younger than 10 years of age [1, 6].

Awareness of this dysmorphic feature is bothmedically andsurgically relevant, as intraoperative injury to the vertebralartery can result in disastrous neurological complications anddeficits. Knowledge of any variations in the course of thevertebral artery or in the morphology of the posterior vertebralarch is of critical importance when performing instrumenta-tion involving C1 or surgery of craniocervical junction [7].Preoperative CTangiography has been recommended in orderto preclude to the possibility of misidentifying an arcuateforamen as a broad lamina or widened posterior arch, andrisking injury to the vertebral artery [3, 12]. Several studies,with positive findings, have examined surgical excision of thearcuate foramen with decompression of the vertebral artery forthe treatment of bowhunter’s syndrome or vertigo [10, 11].

Electronic supplementary material The online version of this article(doi:10.1007/s00701-013-1899-2) contains supplementary material,which is available to authorized users.

L. Rigante :A. I. Evins : J. Burrell :A. Beer-Furlan :A. Bernardo (*)Department of Neurological Surgery, Weill Cornell Medical College,Cornell University, 1300 York Avenue, Baker F2212, New York,NY 10065, USAe-mail: anb2029@med.cornell.edu

Acta Neurochir (2013) 155:2357–2358DOI 10.1007/s00701-013-1899-2

Conflicts of interest None.

References

1. BunaM, CoghlanW, deGruchyM,Williams D, Zmiywsky O (1984)Ponticles of the atlas: a review and clinical perspective. J ManipPhysiol Ther 7:261–266

2. Cakmak O, Gurdal E, Ekinci G, Yildiz E, Cavdar S (2005) Arcuateforamen and its clinical significance. Saudi Med J 26:1409–1413

3. Huang MJ, Glaser JA (2003) Complete arcuate foramen precludingC1 lateral mass screw fixation in a patient with rheumatoid arthritis:case report. Iowa Orthop J 23:96–99

4. Kimmerle A (1930) Ponticulus posticus. Rontgenprax 2:479–4835. Koutsouraki E, Avdelidi E, Michmizos D, Kapsali S-E, Costa V,

Baloyannis S (2010) Kimmerle’s anomaly as a possible causativefactor of chronic tension-type headaches and neurosensory hearingloss: case report and literature review. Int J Neurosci 120:236–239

6. Schilling J, Alejandro S, Ivan S (2010) Ponticulus posticus on theposterior arch of atlas, prevalence analysis in asymptomatic patients.Int J Morphol 28:317–322

7. Simsek S, Yigitkanli K, Comert A, Acar HI, Seckin H, Er U, Belen D,Tekdemir I, Elhan A (2008) Posterior osseous bridging of C1. J ClinNeurosci 15:686–688

8. Split W, Sawrasewicz-Rybak M (2002) Clinical symptoms and signsin Kimmerle anomaly. Wiad Lek 55:416–422

9. Stubbs DM (1992) The arcuate foramen. Variability in distributionrelated to race and sex. Spine 17:1502–1504

10. Taylor WB 3rd, Vandergriff CL, Opatowsky MJ, Layton KF(2012) Bowhunter’s syndrome diagnosed with provocativedigital subtraction cerebral angiography. Proc (Baylor UnivMed Cent) 25:26–27

11. Tubbs RS, Johnson PC, Shoja MM, Loukas M, Oakes WJ (2007)Foramen arcuale: anatomical study and review of the literature. JNeurosurg Spine 6:31–34

12. Young J, Young P, Ackermann M, Anderson P, Riew K (2005) Theponticulus posticus: implications for screw insertion into the firstcervical lateral mass. J Bone Joint Surg Am 87:2495–2498

Fig. 1 Posteriomedial view ofthe arcuate foramina andatlantoaxial subluxation. 2D (a ,b) and 3D (b , c) photos of the left(a , c) and right (b , c) ossificationof the posterior atlanto-occipitalmembrane over the vertebralgroove. The vertebral artery,vertebral plexus, C2 ganglion,and dorsal and ventral roots arevisible

2358 Acta Neurochir (2013) 155:2357–2358