A hypertense, smoker, and alcoholic 30-year-old men presented with vertigo and multidirectional nystagmus lasting 30 days. Magnetic Resonance Imaging (MRI) showed subacute vermian infarction (Figures 1A and 1B). He underwent digital subtraction angiography (Figures 1C and 1D), which revealed duplication of the vertebrobasilar circulation through a branch of the right vertebral artery, connected to the main circulation by a hypoplastic branch, compatible with partial persistence of the primitive lateral basilovertebral anastomosis of Padget (PLBA) originating the left posterior inferior cerebellar artery (Figures 2A and 2B), an embryonic remnant. PLBA persistence increases stroke chances because of the abnormal pattern of arterial supply territories and subsequent deficient collaterality11. Gregg L, Gailloud P. The role of the primitive lateral basilovertebral anastomosis of Padget in variations of the vertebrobasilar arterial system. Anat Rec (Hoboken). 2017 Nov;300(11):2025-38. https://doi.org/10.1002/ar.23633
https://doi.org/https://doi.org/10.1002/...
,22. Morris P. Practical Neuroangiography. 3. ed. Philadelphia: Wolters Kluwer; 2013..
Axial diffusion weighted [DWI] (A) and Fluid attenuated inversion recovery [FLAIR] (B) images depict a subacute infarction area in the cerebellar vermis. Transfacial (C) and lateral (D) digital subtraction angiography with right vertebral injection images depict stenosis of the distal segment of the vertebral artery (V4) with primitive lateral basilovertebral anastomosis (black arrow) supplying the posterior inferior cerebellar artery (PICA) (hollow arrow); the anastomosis also includes a branch to the basilar artery (curved arrow), which is also connected to the anterior spinal artery (arrowhead).
Illustrative drawings depict the standard posterior circulation anatomical disposition (A), in right posterior oblique view, and the patient’s variant (B), in posterior view. While in most individuals both vertebral arteries connect to form the basilar artery, originating the PICA on their V4 segments, in this case such segment is hypoplastic; the anastomosis (black arrow) originates from the vertebral artery and develops the PICA (hollow arrow), with another smaller branch connecting this system to the basilar artery (curved arrow), after the emergence of the anterior spinal artery (arrowhead).
ACKNOWLEDGEMENTS
The authors thank Erasmo B. Silva Jr., from Instituto de Neurologia de Curitiba, for the illustrations.
References
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1Gregg L, Gailloud P. The role of the primitive lateral basilovertebral anastomosis of Padget in variations of the vertebrobasilar arterial system. Anat Rec (Hoboken). 2017 Nov;300(11):2025-38. https://doi.org/10.1002/ar.23633
» https://doi.org/https://doi.org/10.1002/ar.23633 -
2Morris P. Practical Neuroangiography. 3. ed. Philadelphia: Wolters Kluwer; 2013.
Publication Dates
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Publication in this collection
19 Apr 2021 -
Date of issue
Mar 2021
History
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Received
27 Mar 2020 -
Reviewed
18 May 2020 -
Accepted
28 July 2020