J Neurosurg 121:919–923, 2014 ©AANS, 2014
Microvascular decompression of a C-2 segmental-type vertebral artery producing trigeminal hypesthesia Case report Jonathan N. Sellin, M.D., Baraa Al-Hafez, M.D., and Edward A. M. Duckworth, M.D., M.S. Department of Neurosurgery, Baylor College of Medicine, Houston, Texas The authors report a case of trigeminal hypesthesia caused by compression of the spinal cord by a C-2 segmentaltype vertebral artery (VA) that was successfully treated with microvascular decompression. Aberrant intradural VA loops have been reported as causes of cervical myelopathy, some of which improved with microvascular decompression. A 52-year-old man presented with progressive complaints of headache, dizziness, left facial numbness, and left upperextremity paresthesia that worsened when turning his head to the right. Magnetic resonance imaging of the cervical spine showed the left VA passing intradurally between the axis and atlas, foregoing the C-1 foramen transversarium, and impinging on the spinal cord. The patient underwent left C-1 and C-2 hemilaminectomies followed by microvascular decompression of an aberrant VA loop compressing the spinal cord. The patient subsequently reported complete resolution of symptoms. (http://thejns.org/doi/abs/10.3171/2014.5.JNS131825)
Key Words • vertebral artery • microvascular decompression • trigeminal hypesthesia • vascular disorders
T
extradural vertebral artery (VA) loops have been reported as causes of cervical radiculopathy, some of which have benefited from anterior or posterior cervical decompression.1,6,7,9,13,18,23,25 Similarly, tortuous intradural VA loops have been reported as causes of brainstem compression, some of which improved with microvascular decompression.10–12,17,19,20,29,30 Vertebral arteries with an aberrant, not tortuous, segment are more rare. Cervical myelopathy with or without radiculopathy resulting from anomalous VA anatomy has been described.3,8,21,22,24,26,27,31–34 We present a case of the successful surgical treatment of symptomatic high cervical cord compression caused by an aberrant VA segment. Interestingly, the predominant symptom of this high cervical cord compression was facial hypesthesia. ortuous
Case Report History and Examination. A 52-year-old male police officer, formerly a Navy SEAL, with a medical history of hypertension and hyperlipidemia, presented with progressive complaints of headache, dizziness, left facial Abbreviation used in this paper: VA = vertebral artery.
J Neurosurg / Volume 121 / October 2014
numbness, and left upper-extremity paresthesia that worsened when he turned his head to the right. Findings from previous evaluations for stroke, neoplasm, and benign positional vertigo had been negative. According to the report, MRI of the cervical spine showed cervical stenosis. On examination, the patient was alert and fully oriented. Cranial nerves were intact, except for decreased sensation to touch in the left V1, V2, and V3 distributions. Motor strength was full throughout. Sensation was diminished diffusely to light touch and pin prick in the left upper extremity without discrete dermatomal distribution. Reflexes were normoactive without evidence of Hoffman, clonus, or Babinski signs. Magnetic resonance imaging of the cervical spine showed the left VA passing intradurally between the axis and atlas, foregoing the C-1 foramen transversarium, and impinging on the spinal cord (Fig. 1). Findings of a 4-vessel cerebral angiogram were negative for arteriovenous dural fistula or other vascular abnormalities but confirmed an aberrant course of the left VA, with premature entry intradurally between C-1 and C-2 (Fig. 2). Provocative movements and positioning of the head failed to demonstrate significant movement or kinking of the artery. This article contains some figures that are displayed in color online but in black-and-white in the print edition.
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J. N. Sellin, B. Al-Hafez, and E. A. M. Duckworth
Fig. 1. Left: Axial T2-weighted MR image of the cervical spine at the level of the C-2 vertebral body showing an aberrant left VA entering the spinal canal via the C1–2 foramen, passing intradurally, and abutting the spinal cord. Right: Sagittal T2weighted MR image of the cervical spine showing the aberrant left VA segment, which has passed intradurally prematurely, wrapping around the spinal cord.
Operation. A conservative course emphasizing blood pressure control and analgesia was undertaken unsuccessfully. After discussing the risks and benefits, the patient was taken to surgery for a vascular decompression of the cervical spinal cord. The patient was placed prone, and left C-1 and C-2 hemilaminectomies were performed. Under the operative microscope, the dura was opened and the aberrant, pulsatile VA was found compressing the cervical cord (Fig. 3). A microvascular decompression was accomplished by displacing the VA and cushioning it using Teflon. This decompression was then complemented with an expansion duraplasty using a dural substitute. A watertight seal was confirmed with
Valsalva maneuvers during inspection of the suture line under the microscope. Fat and dural sealant were used to supplement the repair (Video 1).
Video 1. Intraoperative video showing durotomy, microvascular decompression, and expansion duraplasty. Copyright Edward A. M. Duckworth. Published with permission. Click here to view with Media Player. Click here to view with Quick time.
Postoperative Course. On postoperative Day 1, the patient was neurologically intact and reported improved symptoms. On postoperative Day 3, with continued symptom improvement, he was discharged home without evidence of new neurological deficit or CSF leak. At the 2-week follow-up, the patient reported complete resolution of symptoms. Six months later, he was back at work as a police officer and otherwise doing well.
Discussion
Fig. 2. Lateral left vertebral injection cerebral arteriogram showing premature entry of the left VA via the left C1–2 foramen (arrow).
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Structural anomalies of the vertebrobasilar system can produce a variety of neurological symptoms. In cases of direct compression of neural structures by the vertebrobasilar system, local mass effect exacerbated by the pulsatile nature of arterial blood flow can produce cranial nerve or pontomedullary dysfunction, cervical myelopathy, or cervical radiculopathy. Tortuosity of the VA, in particular, has been shown to produce extradural cervical radiculopathy as well as intradural brainstem dysfunction by direct compression.1,6,7,9–13,17–20,23,25,29,30 Such tortuosity has been observed postmortem in anatomical studies, as well as in vivo on radiography, MRI, or via traditional angiography.2,5,28,35 Classically, Jannetta linked vascular compression of the trigeminal nerve to trigeminal neuralgia, and showed that microvascular decompression of the affected nerve could produce symptomatic relief.14–16 In these cases, trigeminal nerve dysfunction is secondary to compression by dolichoectatic or tortuous vessels of the posterior circulation. These tortuous vessels stray from natural anaJ Neurosurg / Volume 121 / October 2014
C-2 segmental-type VA producing trigeminal hypesthesia
Fig. 3. A: Dorsal intraoperative view of the operative field showing durotomy with accompanying tack-up sutures in the foreground and the aberrant left VA displacing dorsal nerve roots and compressing the spinal cord. B: Dorsal intraoperative view showing Teflon microvascular decompression of the lateral spinal cord. C: Dorsal intraoperative view showing expansion duraplasty.
tomical corridors and cause direct compression of the trigeminal nerve. Other dolichoectatic vessels can similarly affect cranial nerves, not exclusively those of the vertebrobasilar system.4 J Neurosurg / Volume 121 / October 2014
In our case, the patient likely had trigeminal distribution hypesthesia secondary to compression of the caudal reaches of the spinal trigeminal nucleus. The spinal trigeminal nucleus spans the medulla and upper cervical cord, receiving deep/crude touch, pain, and temperature sensations from the ipsilateral face via general somatic afferent fibers. Afferent fibers to the spinal trigeminal nucleus travel principally via branches of the trigeminal nerve, but the facial, glossopharyngeal, and vagal nerves also contribute sensory modalities from parts of the mouth, ear, and meninges. Peripheral nerve fibers, most prominently those with neurons in the trigeminal ganglion, send central projections to the brainstem, entering via the pons or medulla. These projections descend to the medulla and upper cervical cord, forming the spinal trigeminal tract, synapsing with neurons in the adjacent spinal trigeminal nucleus. Second-order neuronal projections cross the midline and ascend in the contralateral brainstem as the trigeminothalamic tract to the contralateral ventral posterior medial thalamus. Third-order neurons in the thalamus then project to neurons in the sensory cortex of the postcentral gyrus. As opposed to the classic microvascular compression of first-order neurons seen in trigeminal neuralgia, our patient likely had symptoms due to vascular compression of the central projections of these first-order neurons, as well as of the second-order neurons themselves (Fig. 4). Cervical myelopathy may be caused by VA tortuosity, which has been observed with an incidence of 2.7% in a cadaveric study, but can also result from arteries that follow an aberrant course.5 A review of 300 VA angiograms by Tokuda et al. found 7 cases of anomalous atlantoaxial portions of the VA.28 Of these anomalous angiograms, 2 were found to have VAs coursing into the spinal canal between C-1 and C-2, as was observed in our case; the term “C2 segmental type of the vertebral artery” was used to describe this anomaly. A review of the literature reveals 11 related cases, predominantly from Japan, of similar anomalies causing clinical symptoms. In these cases, the predominant symptoms were those of cervical myelopathy, caused by unilateral or bilateral premature intradural passage of the VA, or a fenestration of the VA, resulting in compression of the spinal cord.3,8,21,22,24,26,27,31–34 Interestingly, none of the patients in the aforementioned cases reported trigeminal distribution symptoms. Such VA anomalies may be more often symptomatic due to the limited diameter of the upper cervical canal, which, though generous, is not as wide as the spinal canal at the foramen magnum and cannot accommodate an intruding vascular structure without cervical cord compression. In some of the reported cases, surgical intervention was undertaken. Most commonly, posterior cervical approaches with some combination of suboccipital craniectomy, cervical laminectomy, and expansion duraplasty were used. Vascular decompression was frequently used; however, an additional technique often described is VA transposition followed by tacking using suture or prostheses.26,27 While cervical myelopathy secondary to aberrant VA compression has been described, our case seems to be the first reported instance of trigeminal hypesthesia from vascular compression of the spinal trigeminal tract and nucleus. 921
J. N. Sellin, B. Al-Hafez, and E. A. M. Duckworth
Fig. 4. Illustration demonstrating postulated compression of the spinal trigeminal tract (blue column) by a pulsatile, aberrant VA abutting the lateral spinal cord. Copyright Jovany Cruz Navarro. Published with permission.
Vertebral artery compression of the cervical spinal cord can produce symptoms of cervical myelopathy or cervicomedullary compression. Though the literature is sparse on the topic, several case reports have linked such compression to premature or aberrant intradural entry of the VA into the spinal canal. None of the previously reported cases, however, mention trigeminal distribution dysfunction as a predominant symptom. Surgical interventions have been undertaken with good effect. Our case supports the notion that surgical decompression of VA compression of the high cervical cord provides good outcomes, particularly in the relief of trigeminal hypesthesia. It remains unclear, however, which aspect of the surgical intervention—microvascular decompression with Teflon or cervical laminectomy with expansion duraplasty—resulted in symptomatic relief, if not both. Acknowledgment Illustration by Jovany C. Navarro. Disclosure The authors report no conflict of interest concerning the mate-
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rials or methods used in this study or the findings specified in this paper. Author contributions to the study and manuscript preparation include the following. Conception and design: Sellin. Acquisition of data: Duckworth, Al-Hafez. Analysis and interpretation of data: Sellin. Drafting the article: Sellin. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Duckworth. Study supervision: Duckworth, Sellin. References
1. Anderson RE, Shealy CN: Cervical pedicle erosion and rootlet compression caused by a tortuous vertebral artery. Radiology 96:537–538, 1970 2. Babin E, Haller M: Correlation between bony radiological signs and dolichoarterial loops of the cervical vertebral artery. Neuroradiology 7:15–17, 1974 3. Ball BG, Krueger BR, Piepgras DG: Anomalous vertebral artery compression of the spinal cord at the cervicomedullary junction. Surg Neurol Int 2:103, 2011 4. Colapinto EV, Cabeen MA, Johnson LN: Optic nerve compression by a dolichoectatic internal carotid artery: case report. Neurosurgery 39:604–606, 1996 5. Curylo LJ, Mason HC, Bohlman HH, Yoo JU: Tortuous course of the vertebral artery and anterior cervical decompression: a cadaveric and clinical case study. Spine (Phila Pa 1976) 25: 2860–2864, 2000
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C-2 segmental-type VA producing trigeminal hypesthesia 6. Detwiler PW, Porter RW, Harrington TR, Sonntag VKH, Spetzler RF: Vascular decompression of a vertebral artery loop producing cervical radiculopathy. Case report. J Neurosurg 89:485–488, 1998 7. Duthel R, Tudor C, Motuo-Fotso MJ, Brunon J: Cervical root compression by a loop of the vertebral artery: case report. Neurosurgery 35:140–142, 1994 8. Furumoto T, Nagase J, Takahashi K, Itabashi T, Iai H, Ishige N: Cervical myelopathy caused by the anomalous vertebral artery. A case report. Spine (Phila Pa 1976) 21:2280–2283, 1996 9. Hage ZA, Amin-Hanjani S, Wen D, Charbel FT: Surgical management of cervical radiculopathy caused by redundant vertebral artery loop. Case report. J Neurosurg Spine 17:337–341, 2012 10. Himi T, Kataura A, Tokuda S, Sumi Y, Kamiyama K, Shitamichi M: Downbeat nystagmus with compression of the medulla oblongata by the dolichoectatic vertebral arteries. Am J Otol 16:377–381, 1995 11. Hongo K, Kobayashi S, Hokama M, Sugita K: Vertebral artery section for treating arterial compression of the medulla oblongata. Case report. J Neurosurg 79:116–118, 1993 12. Hongo K, Nakagawa H, Morota N, Isobe M: Vascular compression of the medulla oblongata by the vertebral artery: report of two cases. Neurosurgery 45:907–910, 1999 13. Horgan MA, Hsu FP, Frank EH: Cervical radiculopathy secondary to a tortuous vertebral artery. Case illustration. J Neurosurg 89:489, 1998 14. Jannetta PJ: Arterial compression of the trigeminal nerve at the pons in patients with trigeminal neuralgia. J Neurosurg 26 (1 Part 2):159–162, 1967 15. Jannetta PJ: Neurovascular compression in cranial nerve and systemic disease. Ann Surg 192:518–525, 1980 16. Jannetta PJ: Trigeminal neuralgia: treatment by microvascular decompression, in Wilkins RH, Rengachary SS (eds): Neurosurgery. New York: McGraw-Hill, 1996, Vol 3, pp 3961–3968 17. Kim P, Ishijima B, Takahashi H, Shimizu H, Yokochi M: Hemiparesis caused by vertebral artery compression of the medulla oblongata. Case report. J Neurosurg 62:425–429, 1985 18. Korinth MC, Mull M: Vertebral artery loop causing cervical radiculopathy. Surg Neurol 67:172–173, 2007 19. Koyama S: Lower medulla and upper cervical cord compression caused by bilateral vertebral artery. Case illustration. J Neurosurg 94 (2 Suppl):337, 2001 20. Koyama S, Maeda T, Komine A: [Medulla and upper cervical cord compression by bilateral vertebral artery presented with myelopathy and drop attack: case report.] No To Shinkei 54:435–439, 2002 (Jpn) 21. Morikawa K, Ohkawa N, Yamashita S: [Surgical decompression for the C-1 and C-2 sensory roots and upper cervical cord in a case with cervical myelopathy and occipital neuralgia due to bilateral fenestration of vertebral artery: a case report.] No Shinkei Geka 21:1035–1038, 1993 (Jpn) 22. Nishiura T, Fujiwara K, Handa A, Gotoh M, Tsuno K, Ishimitsu H: [Cervical myelopathy caused by bilateral vertebral artery compression.] No Shinkei Geka 26:45–50, 1998 (Jpn) 23. Sakaida H, Okada M, Yamamoto A: Vascular reconstruction of a vertebral artery loop causing cervical radiculopathy and vertebrobasilar insufficiency. Case report. J Neurosurg 94 (1 Suppl):145–149, 2001
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24. Satoh S, Yamamoto N, Kitagawa Y, Umemori T, Sasaki T, Iida T: Cervical cord compression by the anomalous vertebral artery presenting with neuralgic pain. Case report. J Neurosurg 79:283–285, 1993 25. Sharma RR, Parekh HC, Prabhu S, Gurusinghe NT, Bertolis G: Compression of the C-2 root by a rare anomalous ectatic vertebral artery. Case report. J Neurosurg 78:669–672, 1993 26. Takahashi Y, Sugita S, Uchikado H, Miyagi T, Tokutomi T, Shigemori M: Cervical myelopathy due to compression by bilateral vertebral arteries—case report. Neurol Med Chir (Tokyo) 41:322–324, 2001 27. Takei H, Sagae M, Chiba K, Ogino T: The long-term follow-up of surgical treatment for cervical myelopathy with severe nape and upper arm pain caused by the anomalous vertebral artery: case report. Spine (Phila Pa 1976) 33:E611–E613, 2008 28. Tokuda K, Miyasaka K, Abe H, Abe S, Takei H, Sugimoto S, et al: Anomalous atlantoaxial portions of vertebral and posterior inferior cerebellar arteries. Neuroradiology 27:410–413, 1985 29. Tomasello F, Alafaci C, Salpietro FM, Longo M: Bulbar compression by an ectatic vertebral artery: a novel neurovascular construct relieved by microsurgical decompression. Neurosurgery 56 (1 Suppl):117–124, 2005 30. Ubogu EE, Chase CM, Verrees MA, Metzger AK, Zaidat OO: Cervicomedullary junction compression caused by vertebral artery dolichoectasia and requiring surgical treatment. Case report. J Neurosurg 96:140–143, 2002 31. Vincentelli F, Caruso G, Rabehanta PB, Rey M: Surgical treatment of a rare congenital anomaly of the vertebral artery: case report and review of the literature. Neurosurgery 28:416–420, 1991 32. Watanabe K, Hasegawa K, Takano K: Anomalous vertebral artery-induced cervical cord compression causing severe nape pain. Case report. J Neurosurg 95 (1 Suppl):146–149, 2001 33. Yano K, Murase S, Kuroda T, Noguchi K, Tanabe Y, Yamada H: Cervical cord compression by the vertebral artery causing a severe cervical pain: case report. Surg Neurol 40:43–46, 1993 34. Yousry TA, Seelos K, Widenka DC, Steiger HJ: Vertebral artery loop causing cervical compression. AJNR Am J Neuroradiol 17:1800–1801, 1996 35. Zimmerman HB, Farrell WJ: Cervical vertebral erosion caused by vertebral artery tortuosity. Am J Roentgenol Radium Ther Nucl Med 108:767–770, 1970 Manuscript submitted September 2, 2013. Accepted May 22, 2014. Please include this information when citing this paper: published online June 27, 2014; DOI: 10.3171/2014.5.JNS131825. Video 1: http://mfile.akamai.com/21490/wmv/digitalwbc.down load.akamai.com/21492/wm.digitalsource-na-regional/jns131825_video_1.asx (Media Player). http://mfile.akamai.com/21488/mov/digitalwbc.download.akamai. com/21492/qt.digitalsource-global/jns13-1825_video_1.mov (Quicktime). Address correspondence to: Edward A. M. Duckworth, M.D., M.S., Department of Neurosurgery, 1709 Dryden Rd., Ste. 750, Houston, TX 77030. email: [email protected].
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Microvascular decompression of a C-2 segmental-type vertebral artery producing trigeminal hypesthesia Case report Jonathan N. Sellin, M.D., Baraa Al-Hafez, M.D., and Edward A. M. Duckworth, M.D., M.S. Department of Neurosurgery, Baylor College of Medicine, Houston, Texas The authors report a case of trigeminal hypesthesia caused by compression of the spinal cord by a C-2 segmentaltype vertebral artery (VA) that was successfully treated with microvascular decompression. Aberrant intradural VA loops have been reported as causes of cervical myelopathy, some of which improved with microvascular decompression. A 52-year-old man presented with progressive complaints of headache, dizziness, left facial numbness, and left upperextremity paresthesia that worsened when turning his head to the right. Magnetic resonance imaging of the cervical spine showed the left VA passing intradurally between the axis and atlas, foregoing the C-1 foramen transversarium, and impinging on the spinal cord. The patient underwent left C-1 and C-2 hemilaminectomies followed by microvascular decompression of an aberrant VA loop compressing the spinal cord. The patient subsequently reported complete resolution of symptoms. (http://thejns.org/doi/abs/10.3171/2014.5.JNS131825)
Key Words • vertebral artery • microvascular decompression • trigeminal hypesthesia • vascular disorders
T
extradural vertebral artery (VA) loops have been reported as causes of cervical radiculopathy, some of which have benefited from anterior or posterior cervical decompression.1,6,7,9,13,18,23,25 Similarly, tortuous intradural VA loops have been reported as causes of brainstem compression, some of which improved with microvascular decompression.10–12,17,19,20,29,30 Vertebral arteries with an aberrant, not tortuous, segment are more rare. Cervical myelopathy with or without radiculopathy resulting from anomalous VA anatomy has been described.3,8,21,22,24,26,27,31–34 We present a case of the successful surgical treatment of symptomatic high cervical cord compression caused by an aberrant VA segment. Interestingly, the predominant symptom of this high cervical cord compression was facial hypesthesia. ortuous
Case Report History and Examination. A 52-year-old male police officer, formerly a Navy SEAL, with a medical history of hypertension and hyperlipidemia, presented with progressive complaints of headache, dizziness, left facial Abbreviation used in this paper: VA = vertebral artery.
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numbness, and left upper-extremity paresthesia that worsened when he turned his head to the right. Findings from previous evaluations for stroke, neoplasm, and benign positional vertigo had been negative. According to the report, MRI of the cervical spine showed cervical stenosis. On examination, the patient was alert and fully oriented. Cranial nerves were intact, except for decreased sensation to touch in the left V1, V2, and V3 distributions. Motor strength was full throughout. Sensation was diminished diffusely to light touch and pin prick in the left upper extremity without discrete dermatomal distribution. Reflexes were normoactive without evidence of Hoffman, clonus, or Babinski signs. Magnetic resonance imaging of the cervical spine showed the left VA passing intradurally between the axis and atlas, foregoing the C-1 foramen transversarium, and impinging on the spinal cord (Fig. 1). Findings of a 4-vessel cerebral angiogram were negative for arteriovenous dural fistula or other vascular abnormalities but confirmed an aberrant course of the left VA, with premature entry intradurally between C-1 and C-2 (Fig. 2). Provocative movements and positioning of the head failed to demonstrate significant movement or kinking of the artery. This article contains some figures that are displayed in color online but in black-and-white in the print edition.
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J. N. Sellin, B. Al-Hafez, and E. A. M. Duckworth
Fig. 1. Left: Axial T2-weighted MR image of the cervical spine at the level of the C-2 vertebral body showing an aberrant left VA entering the spinal canal via the C1–2 foramen, passing intradurally, and abutting the spinal cord. Right: Sagittal T2weighted MR image of the cervical spine showing the aberrant left VA segment, which has passed intradurally prematurely, wrapping around the spinal cord.
Operation. A conservative course emphasizing blood pressure control and analgesia was undertaken unsuccessfully. After discussing the risks and benefits, the patient was taken to surgery for a vascular decompression of the cervical spinal cord. The patient was placed prone, and left C-1 and C-2 hemilaminectomies were performed. Under the operative microscope, the dura was opened and the aberrant, pulsatile VA was found compressing the cervical cord (Fig. 3). A microvascular decompression was accomplished by displacing the VA and cushioning it using Teflon. This decompression was then complemented with an expansion duraplasty using a dural substitute. A watertight seal was confirmed with
Valsalva maneuvers during inspection of the suture line under the microscope. Fat and dural sealant were used to supplement the repair (Video 1).
Video 1. Intraoperative video showing durotomy, microvascular decompression, and expansion duraplasty. Copyright Edward A. M. Duckworth. Published with permission. Click here to view with Media Player. Click here to view with Quick time.
Postoperative Course. On postoperative Day 1, the patient was neurologically intact and reported improved symptoms. On postoperative Day 3, with continued symptom improvement, he was discharged home without evidence of new neurological deficit or CSF leak. At the 2-week follow-up, the patient reported complete resolution of symptoms. Six months later, he was back at work as a police officer and otherwise doing well.
Discussion
Fig. 2. Lateral left vertebral injection cerebral arteriogram showing premature entry of the left VA via the left C1–2 foramen (arrow).
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Structural anomalies of the vertebrobasilar system can produce a variety of neurological symptoms. In cases of direct compression of neural structures by the vertebrobasilar system, local mass effect exacerbated by the pulsatile nature of arterial blood flow can produce cranial nerve or pontomedullary dysfunction, cervical myelopathy, or cervical radiculopathy. Tortuosity of the VA, in particular, has been shown to produce extradural cervical radiculopathy as well as intradural brainstem dysfunction by direct compression.1,6,7,9–13,17–20,23,25,29,30 Such tortuosity has been observed postmortem in anatomical studies, as well as in vivo on radiography, MRI, or via traditional angiography.2,5,28,35 Classically, Jannetta linked vascular compression of the trigeminal nerve to trigeminal neuralgia, and showed that microvascular decompression of the affected nerve could produce symptomatic relief.14–16 In these cases, trigeminal nerve dysfunction is secondary to compression by dolichoectatic or tortuous vessels of the posterior circulation. These tortuous vessels stray from natural anaJ Neurosurg / Volume 121 / October 2014
C-2 segmental-type VA producing trigeminal hypesthesia
Fig. 3. A: Dorsal intraoperative view of the operative field showing durotomy with accompanying tack-up sutures in the foreground and the aberrant left VA displacing dorsal nerve roots and compressing the spinal cord. B: Dorsal intraoperative view showing Teflon microvascular decompression of the lateral spinal cord. C: Dorsal intraoperative view showing expansion duraplasty.
tomical corridors and cause direct compression of the trigeminal nerve. Other dolichoectatic vessels can similarly affect cranial nerves, not exclusively those of the vertebrobasilar system.4 J Neurosurg / Volume 121 / October 2014
In our case, the patient likely had trigeminal distribution hypesthesia secondary to compression of the caudal reaches of the spinal trigeminal nucleus. The spinal trigeminal nucleus spans the medulla and upper cervical cord, receiving deep/crude touch, pain, and temperature sensations from the ipsilateral face via general somatic afferent fibers. Afferent fibers to the spinal trigeminal nucleus travel principally via branches of the trigeminal nerve, but the facial, glossopharyngeal, and vagal nerves also contribute sensory modalities from parts of the mouth, ear, and meninges. Peripheral nerve fibers, most prominently those with neurons in the trigeminal ganglion, send central projections to the brainstem, entering via the pons or medulla. These projections descend to the medulla and upper cervical cord, forming the spinal trigeminal tract, synapsing with neurons in the adjacent spinal trigeminal nucleus. Second-order neuronal projections cross the midline and ascend in the contralateral brainstem as the trigeminothalamic tract to the contralateral ventral posterior medial thalamus. Third-order neurons in the thalamus then project to neurons in the sensory cortex of the postcentral gyrus. As opposed to the classic microvascular compression of first-order neurons seen in trigeminal neuralgia, our patient likely had symptoms due to vascular compression of the central projections of these first-order neurons, as well as of the second-order neurons themselves (Fig. 4). Cervical myelopathy may be caused by VA tortuosity, which has been observed with an incidence of 2.7% in a cadaveric study, but can also result from arteries that follow an aberrant course.5 A review of 300 VA angiograms by Tokuda et al. found 7 cases of anomalous atlantoaxial portions of the VA.28 Of these anomalous angiograms, 2 were found to have VAs coursing into the spinal canal between C-1 and C-2, as was observed in our case; the term “C2 segmental type of the vertebral artery” was used to describe this anomaly. A review of the literature reveals 11 related cases, predominantly from Japan, of similar anomalies causing clinical symptoms. In these cases, the predominant symptoms were those of cervical myelopathy, caused by unilateral or bilateral premature intradural passage of the VA, or a fenestration of the VA, resulting in compression of the spinal cord.3,8,21,22,24,26,27,31–34 Interestingly, none of the patients in the aforementioned cases reported trigeminal distribution symptoms. Such VA anomalies may be more often symptomatic due to the limited diameter of the upper cervical canal, which, though generous, is not as wide as the spinal canal at the foramen magnum and cannot accommodate an intruding vascular structure without cervical cord compression. In some of the reported cases, surgical intervention was undertaken. Most commonly, posterior cervical approaches with some combination of suboccipital craniectomy, cervical laminectomy, and expansion duraplasty were used. Vascular decompression was frequently used; however, an additional technique often described is VA transposition followed by tacking using suture or prostheses.26,27 While cervical myelopathy secondary to aberrant VA compression has been described, our case seems to be the first reported instance of trigeminal hypesthesia from vascular compression of the spinal trigeminal tract and nucleus. 921
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Fig. 4. Illustration demonstrating postulated compression of the spinal trigeminal tract (blue column) by a pulsatile, aberrant VA abutting the lateral spinal cord. Copyright Jovany Cruz Navarro. Published with permission.
Vertebral artery compression of the cervical spinal cord can produce symptoms of cervical myelopathy or cervicomedullary compression. Though the literature is sparse on the topic, several case reports have linked such compression to premature or aberrant intradural entry of the VA into the spinal canal. None of the previously reported cases, however, mention trigeminal distribution dysfunction as a predominant symptom. Surgical interventions have been undertaken with good effect. Our case supports the notion that surgical decompression of VA compression of the high cervical cord provides good outcomes, particularly in the relief of trigeminal hypesthesia. It remains unclear, however, which aspect of the surgical intervention—microvascular decompression with Teflon or cervical laminectomy with expansion duraplasty—resulted in symptomatic relief, if not both. Acknowledgment Illustration by Jovany C. Navarro. Disclosure The authors report no conflict of interest concerning the mate-
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rials or methods used in this study or the findings specified in this paper. Author contributions to the study and manuscript preparation include the following. Conception and design: Sellin. Acquisition of data: Duckworth, Al-Hafez. Analysis and interpretation of data: Sellin. Drafting the article: Sellin. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Duckworth. Study supervision: Duckworth, Sellin. References
1. Anderson RE, Shealy CN: Cervical pedicle erosion and rootlet compression caused by a tortuous vertebral artery. Radiology 96:537–538, 1970 2. Babin E, Haller M: Correlation between bony radiological signs and dolichoarterial loops of the cervical vertebral artery. Neuroradiology 7:15–17, 1974 3. Ball BG, Krueger BR, Piepgras DG: Anomalous vertebral artery compression of the spinal cord at the cervicomedullary junction. Surg Neurol Int 2:103, 2011 4. Colapinto EV, Cabeen MA, Johnson LN: Optic nerve compression by a dolichoectatic internal carotid artery: case report. Neurosurgery 39:604–606, 1996 5. Curylo LJ, Mason HC, Bohlman HH, Yoo JU: Tortuous course of the vertebral artery and anterior cervical decompression: a cadaveric and clinical case study. Spine (Phila Pa 1976) 25: 2860–2864, 2000
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C-2 segmental-type VA producing trigeminal hypesthesia 6. Detwiler PW, Porter RW, Harrington TR, Sonntag VKH, Spetzler RF: Vascular decompression of a vertebral artery loop producing cervical radiculopathy. Case report. J Neurosurg 89:485–488, 1998 7. Duthel R, Tudor C, Motuo-Fotso MJ, Brunon J: Cervical root compression by a loop of the vertebral artery: case report. Neurosurgery 35:140–142, 1994 8. Furumoto T, Nagase J, Takahashi K, Itabashi T, Iai H, Ishige N: Cervical myelopathy caused by the anomalous vertebral artery. A case report. Spine (Phila Pa 1976) 21:2280–2283, 1996 9. Hage ZA, Amin-Hanjani S, Wen D, Charbel FT: Surgical management of cervical radiculopathy caused by redundant vertebral artery loop. Case report. J Neurosurg Spine 17:337–341, 2012 10. Himi T, Kataura A, Tokuda S, Sumi Y, Kamiyama K, Shitamichi M: Downbeat nystagmus with compression of the medulla oblongata by the dolichoectatic vertebral arteries. Am J Otol 16:377–381, 1995 11. Hongo K, Kobayashi S, Hokama M, Sugita K: Vertebral artery section for treating arterial compression of the medulla oblongata. Case report. J Neurosurg 79:116–118, 1993 12. Hongo K, Nakagawa H, Morota N, Isobe M: Vascular compression of the medulla oblongata by the vertebral artery: report of two cases. Neurosurgery 45:907–910, 1999 13. Horgan MA, Hsu FP, Frank EH: Cervical radiculopathy secondary to a tortuous vertebral artery. Case illustration. J Neurosurg 89:489, 1998 14. Jannetta PJ: Arterial compression of the trigeminal nerve at the pons in patients with trigeminal neuralgia. J Neurosurg 26 (1 Part 2):159–162, 1967 15. Jannetta PJ: Neurovascular compression in cranial nerve and systemic disease. Ann Surg 192:518–525, 1980 16. Jannetta PJ: Trigeminal neuralgia: treatment by microvascular decompression, in Wilkins RH, Rengachary SS (eds): Neurosurgery. New York: McGraw-Hill, 1996, Vol 3, pp 3961–3968 17. Kim P, Ishijima B, Takahashi H, Shimizu H, Yokochi M: Hemiparesis caused by vertebral artery compression of the medulla oblongata. Case report. J Neurosurg 62:425–429, 1985 18. Korinth MC, Mull M: Vertebral artery loop causing cervical radiculopathy. Surg Neurol 67:172–173, 2007 19. Koyama S: Lower medulla and upper cervical cord compression caused by bilateral vertebral artery. Case illustration. J Neurosurg 94 (2 Suppl):337, 2001 20. Koyama S, Maeda T, Komine A: [Medulla and upper cervical cord compression by bilateral vertebral artery presented with myelopathy and drop attack: case report.] No To Shinkei 54:435–439, 2002 (Jpn) 21. Morikawa K, Ohkawa N, Yamashita S: [Surgical decompression for the C-1 and C-2 sensory roots and upper cervical cord in a case with cervical myelopathy and occipital neuralgia due to bilateral fenestration of vertebral artery: a case report.] No Shinkei Geka 21:1035–1038, 1993 (Jpn) 22. Nishiura T, Fujiwara K, Handa A, Gotoh M, Tsuno K, Ishimitsu H: [Cervical myelopathy caused by bilateral vertebral artery compression.] No Shinkei Geka 26:45–50, 1998 (Jpn) 23. Sakaida H, Okada M, Yamamoto A: Vascular reconstruction of a vertebral artery loop causing cervical radiculopathy and vertebrobasilar insufficiency. Case report. J Neurosurg 94 (1 Suppl):145–149, 2001
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24. Satoh S, Yamamoto N, Kitagawa Y, Umemori T, Sasaki T, Iida T: Cervical cord compression by the anomalous vertebral artery presenting with neuralgic pain. Case report. J Neurosurg 79:283–285, 1993 25. Sharma RR, Parekh HC, Prabhu S, Gurusinghe NT, Bertolis G: Compression of the C-2 root by a rare anomalous ectatic vertebral artery. Case report. J Neurosurg 78:669–672, 1993 26. Takahashi Y, Sugita S, Uchikado H, Miyagi T, Tokutomi T, Shigemori M: Cervical myelopathy due to compression by bilateral vertebral arteries—case report. Neurol Med Chir (Tokyo) 41:322–324, 2001 27. Takei H, Sagae M, Chiba K, Ogino T: The long-term follow-up of surgical treatment for cervical myelopathy with severe nape and upper arm pain caused by the anomalous vertebral artery: case report. Spine (Phila Pa 1976) 33:E611–E613, 2008 28. Tokuda K, Miyasaka K, Abe H, Abe S, Takei H, Sugimoto S, et al: Anomalous atlantoaxial portions of vertebral and posterior inferior cerebellar arteries. Neuroradiology 27:410–413, 1985 29. Tomasello F, Alafaci C, Salpietro FM, Longo M: Bulbar compression by an ectatic vertebral artery: a novel neurovascular construct relieved by microsurgical decompression. Neurosurgery 56 (1 Suppl):117–124, 2005 30. Ubogu EE, Chase CM, Verrees MA, Metzger AK, Zaidat OO: Cervicomedullary junction compression caused by vertebral artery dolichoectasia and requiring surgical treatment. Case report. J Neurosurg 96:140–143, 2002 31. Vincentelli F, Caruso G, Rabehanta PB, Rey M: Surgical treatment of a rare congenital anomaly of the vertebral artery: case report and review of the literature. Neurosurgery 28:416–420, 1991 32. Watanabe K, Hasegawa K, Takano K: Anomalous vertebral artery-induced cervical cord compression causing severe nape pain. Case report. J Neurosurg 95 (1 Suppl):146–149, 2001 33. Yano K, Murase S, Kuroda T, Noguchi K, Tanabe Y, Yamada H: Cervical cord compression by the vertebral artery causing a severe cervical pain: case report. Surg Neurol 40:43–46, 1993 34. Yousry TA, Seelos K, Widenka DC, Steiger HJ: Vertebral artery loop causing cervical compression. AJNR Am J Neuroradiol 17:1800–1801, 1996 35. Zimmerman HB, Farrell WJ: Cervical vertebral erosion caused by vertebral artery tortuosity. Am J Roentgenol Radium Ther Nucl Med 108:767–770, 1970 Manuscript submitted September 2, 2013. Accepted May 22, 2014. Please include this information when citing this paper: published online June 27, 2014; DOI: 10.3171/2014.5.JNS131825. Video 1: http://mfile.akamai.com/21490/wmv/digitalwbc.down load.akamai.com/21492/wm.digitalsource-na-regional/jns131825_video_1.asx (Media Player). http://mfile.akamai.com/21488/mov/digitalwbc.download.akamai. com/21492/qt.digitalsource-global/jns13-1825_video_1.mov (Quicktime). Address correspondence to: Edward A. M. Duckworth, M.D., M.S., Department of Neurosurgery, 1709 Dryden Rd., Ste. 750, Houston, TX 77030. email: [email protected].
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