Case Report
From Basilar Artery Dolichoectasia to Basilar Artery Aneurysm: Natural History in Images Panagiotis Zis, MD, PhD, Stylianos Fragkis, MD, Maria Lykouri, MD, Ioannis Bageris, MD, Georgios Kolovos, MD, Panagiotis Angelidakis, MD, and Antonios Tavernarakis, MD
Dolichoectasia is a medical term used to describe elongated and dilated vessels that follow a tortuous and windy course with frequent loops and curves. We are presenting the natural history in images of a normal basilar artery becoming dolichoectatic, followed by the formation of an aneurysm, over a period of many years, in 60-yearold Caucasian man with a long history of secondary progressive multiple sclerosis and uncontrolled arterial hypertension, who was diagnosed with dolichoectasia of basilar artery in 2008. Although relatively stable at this point, eventually his mobility deteriorated and signs from the cranial nerves, such as trigeminal neuralgia and bilateral palsy of the VI and the VII nerves were added in the clinical picture. In 2014, both computed tomography and magnetic resonance imaging of the brain revealed the formation of an unruptured aneurysm of the basilar artery. Key Words: Dolichoectasia—aneurysm—natural history—basilar artery. Ó 2015 Published by Elsevier Inc. on behalf of National Stroke Association
Dolichoectasia is a medical term used to describe elongated and dilated vessels that follow a tortuous and windy course with frequent loops and curves.1,2 The word dolichoectasia derives from the Greek words d olico2 (dolichos, meaning elongated) and εktasίa (ectasia, meaning dilatation). The intracranial vertebral and basilar arteries are most often affected.
From the Department of Neurology, Evangelismos General Hospital, Athens, Greece. Received October 29, 2014; revision received December 30, 2014; accepted January 9, 2015. There are no sources of funding. There are no conflicts of interest. Address correspondence to Panagiotis Zis, MD, PhD, Department of Neurology, Evangelismos General Hospital, 72-74 Vas. Sophias Ave, 11528 Athens, Greece. E-mail: [email protected]. 1052-3057/$ - see front matter Ó 2015 Published by Elsevier Inc. on behalf of National Stroke Association http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2015.01.019
Case A 60-year-old Caucasian man with a 31-year history of secondary progressive multiple sclerosis and uncontrolled arterial hypertension was diagnosed with dolichoectasia of basilar artery in 2008 in a follow-up magnetic resonance imaging (MRI) scan. At this point, the most prominent signs of his clinical picture were the right-sided hemiparesis and mild hemisensory loss. Eventually, his mobility deteriorated (Expanded Disability Status Scale, 7.0), and signs from the cranial nerves, such as left trigeminal neuralgia (in 2010) and bilateral palsy of the VI and the VII nerves (in 2013) were added in the clinical picture. In 2014, both computed tomography and MRI of the brain revealed the formation of an unruptured aneurysm of the basilar artery, for which he was referred to undergo endovascular embolization. Figure 1 shows the natural history of the formation of the basilar artery aneurysm.
Journal of Stroke and Cerebrovascular Diseases, Vol. 24, No. 5 (May), 2015: pp e117-e119
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Figure 1. (A) Brain magnetic resonance imaging (MRI) (T2*, axial) in 2002, showing normal basilar artery diameter. (B) Brain MRI (T2*, axial) in 2008, showing enlarged diameter of the basilar artery. (C) Brain MRI (T1, coronal) in 2013, showing basilar artery dolichoectasia. (D) Brain MRI (T2, axial) in 2014, showing the unruptured basilar artery aneurysm. (E) Brain computed tomography in 2014, showing the unruptured basilar artery aneurysm.
Discussion The pathogenesis of intracranial arterial dolichoectasia remains unclear. Multiple pathophysiologic processes might contribute to its development, such as systemic arterial hypertension.3 Histologic studies support the hypothesis that, along with the systemic hypertension, the degeneration of the internal elastic lamina and thinning of the media secondary to smooth muscle atrophy is at the basis of the pathophysiology.4,5 The role of atherosclerosis remains debatable with some supporting that it contributes to the pathogenesis,3 when others believe that it does not play a role because atherosclerosis mainly involves the intima and endothelia of larger and medium size vessels, whereas dilatative arteriopathy involved mainly the intima of intracranial arteries.6 Dolichoectatic arteries may be responsible for acute brain ischemia, a progressive course related to compression of cranial nerves, the brainstem, or the third ventricle, or even a catastrophic outcome caused by vascular rupture.7,8 Similarly, the exact pathogenesis of intracranial artery aneurysm is not clear. An attractive theory is the one proposed by Ferguson,9 who suggested that cerebral aneu-
rysms result from mechanically induced degeneration of arteries. Maximal hemodynamic stress occurs at the apices and bifurcations of arteries. The imbalance between the strength of an artery at a particular bifurcation and the hemodynamic stresses applied to it may cause degeneration of the internal elastic lamina and aneurysmal outpouching. Turbulent flow in and around the aneurysms further produces vibration in the vessel wall weakening; thus, the vessel’s structural integrity and allowing aneurysm growth.9,10 Factors affecting the formation and the growth of intracranial aneurysms include female gender, arterial stiffness, and cigarette smoking.11,12 On the other hand, more recent research projects support the molecular basis for intracranial aneurysm formation.13,14 With this case, we present the natural history in images of a normal basilar artery becoming dolichoectatic, followed by the formation of an aneurysm, over a period of many years. Definitely, which were the exact pathogenic processes that lead to the formation of the aneurysm cannot be determined. However, the link between the dolichoectasia and the aneurysm is worth noting. Definitely future studies are needed to reveal the pathophysiological links.
NATURAL HISTORY OF BASILAR DOLICHOECTASIA
The clinical entity of dolichoectasia of the cerebral arteries is often under-recognized as symptoms caused by the elongated and dilated vessels may be attributed to other comorbidities. Thus, the progressive course of the compression of brainstem in our case could have been attributed to the progressive course of the multiple sclerosis. Therefore, we would like to highlight that the imaging findings, especially in the MRI and the magnetic resonance angiography, can help the clinician to make the correct diagnosis. Acknowledgment: the patient.
The authors express their gratitude to
References 1. Passero SG, Rossi S. Natural history of vertebrobasilar dolichoectasia. Neurology 2008;70:66-72. 2. Passero S, Filosomi G. Posterior circulation infarcts in patients with vertebrobasilar dolichoectasia. Stroke 1998; 29:653-659. 3. Nijensohn DE, Saez RJ, Reagan TJ. Clinical significance of basilar artery aneurysms. Neurology 1974;24:301-305. 4. Gautier JC, Hauw JJ, Awada A, et al. Dolichoectatic intracranial arteries. Association with aneurysms of the abdominal aorta. Rev Neurol 1988;144:437-446.
e119 5. Hegedus K. Ectasia of the basilar artery with special reference to possible pathogenesis. Surg Neurol 1985; 24:463-469. 6. Lou M, Caplan LR. Vertebrobasilar dilatative arteriopathy (dolichoectasia). Ann N Y Acad Sci 2010;1184: 121-133. 7. Caplan LR. Dilatative arteriopathy (dolichoectasia): what is known and not known. Ann Neurol 2005;57:469-471. 8. Savitz SI, Ronthal M, Caplan LR. Vertebral artery compression of the medulla. Arch Neurol 2006;63: 234-241. 9. Ferguson GG. Physical factors in the initiation, growth, and rupture of human intracranial saccular aneurysms. J Neurosurg 1972;37:666-677. 10. Caplan LR. Caplan’s stroke: a clinical approach. Elsevier Health Sciences 2009. 11. Juvela S, Poussa K, Porras M. Factors affecting formation and growth of intracranial aneurysms: a long-term follow-up study. Stroke 2001;32:485-491. 12. Matsukawa H, Shinoda M, Fujii M, et al. Arterial stiffness as a risk factor for cerebral aneurysm. Acta Neurol Scand 2014;130:394-399. 13. Fukuda M, Aoki T. Molecular basis for intracranial aneurysm formation. Acta Neurochir Suppl 2015;120: 13-15. 14. Zhang HF, Zhao MG, Liang GB, et al. Downregulation of T cell immunoglobulin and mucin protein 3 in the pathogenesis of intracranial aneurysm. Inflammation 2015 Feb; 38(1):368-374 [Epub ahead of print].
From Basilar Artery Dolichoectasia to Basilar Artery Aneurysm: Natural History in Images Panagiotis Zis, MD, PhD, Stylianos Fragkis, MD, Maria Lykouri, MD, Ioannis Bageris, MD, Georgios Kolovos, MD, Panagiotis Angelidakis, MD, and Antonios Tavernarakis, MD
Dolichoectasia is a medical term used to describe elongated and dilated vessels that follow a tortuous and windy course with frequent loops and curves. We are presenting the natural history in images of a normal basilar artery becoming dolichoectatic, followed by the formation of an aneurysm, over a period of many years, in 60-yearold Caucasian man with a long history of secondary progressive multiple sclerosis and uncontrolled arterial hypertension, who was diagnosed with dolichoectasia of basilar artery in 2008. Although relatively stable at this point, eventually his mobility deteriorated and signs from the cranial nerves, such as trigeminal neuralgia and bilateral palsy of the VI and the VII nerves were added in the clinical picture. In 2014, both computed tomography and magnetic resonance imaging of the brain revealed the formation of an unruptured aneurysm of the basilar artery. Key Words: Dolichoectasia—aneurysm—natural history—basilar artery. Ó 2015 Published by Elsevier Inc. on behalf of National Stroke Association
Dolichoectasia is a medical term used to describe elongated and dilated vessels that follow a tortuous and windy course with frequent loops and curves.1,2 The word dolichoectasia derives from the Greek words d olico2 (dolichos, meaning elongated) and εktasίa (ectasia, meaning dilatation). The intracranial vertebral and basilar arteries are most often affected.
From the Department of Neurology, Evangelismos General Hospital, Athens, Greece. Received October 29, 2014; revision received December 30, 2014; accepted January 9, 2015. There are no sources of funding. There are no conflicts of interest. Address correspondence to Panagiotis Zis, MD, PhD, Department of Neurology, Evangelismos General Hospital, 72-74 Vas. Sophias Ave, 11528 Athens, Greece. E-mail: [email protected]. 1052-3057/$ - see front matter Ó 2015 Published by Elsevier Inc. on behalf of National Stroke Association http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2015.01.019
Case A 60-year-old Caucasian man with a 31-year history of secondary progressive multiple sclerosis and uncontrolled arterial hypertension was diagnosed with dolichoectasia of basilar artery in 2008 in a follow-up magnetic resonance imaging (MRI) scan. At this point, the most prominent signs of his clinical picture were the right-sided hemiparesis and mild hemisensory loss. Eventually, his mobility deteriorated (Expanded Disability Status Scale, 7.0), and signs from the cranial nerves, such as left trigeminal neuralgia (in 2010) and bilateral palsy of the VI and the VII nerves (in 2013) were added in the clinical picture. In 2014, both computed tomography and MRI of the brain revealed the formation of an unruptured aneurysm of the basilar artery, for which he was referred to undergo endovascular embolization. Figure 1 shows the natural history of the formation of the basilar artery aneurysm.
Journal of Stroke and Cerebrovascular Diseases, Vol. 24, No. 5 (May), 2015: pp e117-e119
e117
e118
P. ZIS ET AL.
Figure 1. (A) Brain magnetic resonance imaging (MRI) (T2*, axial) in 2002, showing normal basilar artery diameter. (B) Brain MRI (T2*, axial) in 2008, showing enlarged diameter of the basilar artery. (C) Brain MRI (T1, coronal) in 2013, showing basilar artery dolichoectasia. (D) Brain MRI (T2, axial) in 2014, showing the unruptured basilar artery aneurysm. (E) Brain computed tomography in 2014, showing the unruptured basilar artery aneurysm.
Discussion The pathogenesis of intracranial arterial dolichoectasia remains unclear. Multiple pathophysiologic processes might contribute to its development, such as systemic arterial hypertension.3 Histologic studies support the hypothesis that, along with the systemic hypertension, the degeneration of the internal elastic lamina and thinning of the media secondary to smooth muscle atrophy is at the basis of the pathophysiology.4,5 The role of atherosclerosis remains debatable with some supporting that it contributes to the pathogenesis,3 when others believe that it does not play a role because atherosclerosis mainly involves the intima and endothelia of larger and medium size vessels, whereas dilatative arteriopathy involved mainly the intima of intracranial arteries.6 Dolichoectatic arteries may be responsible for acute brain ischemia, a progressive course related to compression of cranial nerves, the brainstem, or the third ventricle, or even a catastrophic outcome caused by vascular rupture.7,8 Similarly, the exact pathogenesis of intracranial artery aneurysm is not clear. An attractive theory is the one proposed by Ferguson,9 who suggested that cerebral aneu-
rysms result from mechanically induced degeneration of arteries. Maximal hemodynamic stress occurs at the apices and bifurcations of arteries. The imbalance between the strength of an artery at a particular bifurcation and the hemodynamic stresses applied to it may cause degeneration of the internal elastic lamina and aneurysmal outpouching. Turbulent flow in and around the aneurysms further produces vibration in the vessel wall weakening; thus, the vessel’s structural integrity and allowing aneurysm growth.9,10 Factors affecting the formation and the growth of intracranial aneurysms include female gender, arterial stiffness, and cigarette smoking.11,12 On the other hand, more recent research projects support the molecular basis for intracranial aneurysm formation.13,14 With this case, we present the natural history in images of a normal basilar artery becoming dolichoectatic, followed by the formation of an aneurysm, over a period of many years. Definitely, which were the exact pathogenic processes that lead to the formation of the aneurysm cannot be determined. However, the link between the dolichoectasia and the aneurysm is worth noting. Definitely future studies are needed to reveal the pathophysiological links.
NATURAL HISTORY OF BASILAR DOLICHOECTASIA
The clinical entity of dolichoectasia of the cerebral arteries is often under-recognized as symptoms caused by the elongated and dilated vessels may be attributed to other comorbidities. Thus, the progressive course of the compression of brainstem in our case could have been attributed to the progressive course of the multiple sclerosis. Therefore, we would like to highlight that the imaging findings, especially in the MRI and the magnetic resonance angiography, can help the clinician to make the correct diagnosis. Acknowledgment: the patient.
The authors express their gratitude to
References 1. Passero SG, Rossi S. Natural history of vertebrobasilar dolichoectasia. Neurology 2008;70:66-72. 2. Passero S, Filosomi G. Posterior circulation infarcts in patients with vertebrobasilar dolichoectasia. Stroke 1998; 29:653-659. 3. Nijensohn DE, Saez RJ, Reagan TJ. Clinical significance of basilar artery aneurysms. Neurology 1974;24:301-305. 4. Gautier JC, Hauw JJ, Awada A, et al. Dolichoectatic intracranial arteries. Association with aneurysms of the abdominal aorta. Rev Neurol 1988;144:437-446.
e119 5. Hegedus K. Ectasia of the basilar artery with special reference to possible pathogenesis. Surg Neurol 1985; 24:463-469. 6. Lou M, Caplan LR. Vertebrobasilar dilatative arteriopathy (dolichoectasia). Ann N Y Acad Sci 2010;1184: 121-133. 7. Caplan LR. Dilatative arteriopathy (dolichoectasia): what is known and not known. Ann Neurol 2005;57:469-471. 8. Savitz SI, Ronthal M, Caplan LR. Vertebral artery compression of the medulla. Arch Neurol 2006;63: 234-241. 9. Ferguson GG. Physical factors in the initiation, growth, and rupture of human intracranial saccular aneurysms. J Neurosurg 1972;37:666-677. 10. Caplan LR. Caplan’s stroke: a clinical approach. Elsevier Health Sciences 2009. 11. Juvela S, Poussa K, Porras M. Factors affecting formation and growth of intracranial aneurysms: a long-term follow-up study. Stroke 2001;32:485-491. 12. Matsukawa H, Shinoda M, Fujii M, et al. Arterial stiffness as a risk factor for cerebral aneurysm. Acta Neurol Scand 2014;130:394-399. 13. Fukuda M, Aoki T. Molecular basis for intracranial aneurysm formation. Acta Neurochir Suppl 2015;120: 13-15. 14. Zhang HF, Zhao MG, Liang GB, et al. Downregulation of T cell immunoglobulin and mucin protein 3 in the pathogenesis of intracranial aneurysm. Inflammation 2015 Feb; 38(1):368-374 [Epub ahead of print].
