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Spontaneous thrombosis of cerebral aneurysms presenting with ischemic stroke
Journal of the Neurological Sciences 254 (2007) 95 – 98 www.elsevier.com/locate/jns
Short communication
Spontaneous thrombosis of cerebral aneurysms presenting with ischemic stroke José E. Cohen a,c , Eyal Yitshayek a , John Moshe Gomori c , Savvas Grigoriadis a,⁎, Guy Raphaeli b , Sergei Spektor a , Gustavo Rajz d a
Department of Neurosurgery, Hadassah Hebrew University Hospital, Jerusalem, Israel Department of Neurology, Hadassah Hebrew University Hospital, Jerusalem, Israel c Department of Radiology, Hadassah Hebrew University Hospital, Jerusalem, Israel d Department of Neurosurgery, Sheba Medical Center, Tel Hashomer, Israel
b
Received 28 September 2006; accepted 13 December 2006 Available online 26 January 2007
Abstract Complete spontaneous thrombosis of an unruptured cerebral aneurysm is a rare event that can be discovered incidentally on advanced neuroradiologic studies. Occasionally, this phenomenon may be symptomatic and can present as an ischemic stroke. The presumed mechanism is probably due to extension of the thrombi to the parent vessel, embolization of intra-aneurysmatic thrombi to distal arteries or arterial compression due to increased aneurysm mass effect. We present documented cases of this unusual entity and review the literature. © 2006 Elsevier B.V. All rights reserved. Keywords: Cerebral aneurysm; Spontaneous thrombosis; Ischemic stroke; Subarachnoid hemorrhage; Cerebral vessels; Aneurysmal thrombus
1. Introduction Cerebral aneurysms usually present with subarachnoid hemorrhage. Less frequently, they present with ischemic stroke secondary to different mechanisms [1–7]. Giant saccular and fusiform aneurysms have a variable component of endoluminal thrombus. These partially or more rarely completely thrombosed aneurysms are considered unstable and dynamic structures that may either grow, recanalize, bleed, compress or give rise to thromboembolic events [1,8– 11]. In non-giant unruptured cerebral aneurysms, the process of spontaneous endosaccular thrombosis (occurring not in relation with previous aneurysm rupture) has been described rarely and in general, is poorly understood [2,7,11]. Several factors (i.e., geometrical configuration of the aneurysm neck and fundus, hemodynamic, biological) have been implicated
⁎ Corresponding author. Hadassah Ein Kerem, Jerusalem, 91120, Israel. Tel.: +972 302310345365; fax: +972 306948362726, +972 302310314952. E-mail address: [email protected] (S. Grigoriadis). 0022-510X/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.jns.2006.12.008
in the delicate balance between thrombogenesis and thrombolysis within the aneurysm lumen [9–12]. This event can be either asymptomatic, mimic a cerebral tumor, provoke seizures or present with ischemic stroke [1–7]. We describe three cases of spontaneous thrombosis of saccular aneurysms presenting with ischemic stroke and review the pathogenic mechanisms and management implications. 2. Clinical cases 2.1. Patient 1 A 51-year-old woman was admitted to our neurosurgical department for a diagnostic cerebral angiography. Patient past medical history was unremarkable except for mild hypertension and smoking for more than ten years. One month prior to admission, she suffered an episode of sudden onset frontal headache, associated with dizziness and nausea that persisted for two weeks. Neurological examination revealed horizontal nystagmus, trunk ataxia, gait imbalance and left dysmetria. She underwent a head magnetic resonance imaging that
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Fig. 1. A: Axial T2-weighted scan through the inferior posterior fossa shows the thrombosed left PICA aneurysm and a small infarction of the associated tonsil. B: Anteroposterior digital subtraction angiography of the left vertebral artery confirms thrombosis of the aneurysm and left PICA.
Fig. 2. A: Axial FLAIR image shows a left thalamic infarction. B: Axial T1-weighted image shows subacute thrombosis of a left posterior communicating artery (PComA) aneurysm. C: Axial T2-weighted image shows subacute thrombosis of a left PComA aneurysm. D: Axial T2-weighted image shows contraction of the chronically thrombosed left PComA aneurysm.
J.E. Cohen et al. / Journal of the Neurological Sciences 254 (2007) 95–98
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3. Discussion
Fig. 3. Axial T2-weighted MRI shows a right anterior cerebral artery (ACA) infarction associated with a thrombosed ACA aneurysm.
showed a complete thrombosis of a left saccular posterior inferior cerebellar artery (PICA) aneurysm (Fig. 1A). Cerebral angiography revealed a small neck remnant of the PICA aneurysm (Fig. 1B). Follow-up angiogram after one year showed persistent occlusion of the aneurysm. 2.2. Patient 2 A 27-year-old man, cocaine and ecstasy abuser was admitted for a right hemispheric sensorimotor transient ischemic attack after use of ecstasy. One year ago he was admitted for an episode of tonicoclonic seizures that was managed with chronic oral carbamazepine. Two weeks after he presented sudden onset mild hemiparesis and complained of associated hemiparesthesia. Brain MRI revealed an acutely thrombosed posterior communicating artery saccular aneurysm with associated thalamic infarct (Fig. 2A–C). Cerebral angiography confirmed the complete exclusion of the aneurysm. One-year follow-up MRI and MRA confirmed stable occlusion of the aneurysm which had decreased in size (Fig. 2D). 2.3. Patient 3 A 76-year-old man, with multiple vascular risk factors presented to the emergency room with sudden onset frontal headache and isolated left leg weakness. Computed tomography revealed the ischemic infarction of the right anterior cerebral artery territory and an associated anterior communicating artery aneurysm was suspected. MRI confirmed the presence of a thrombosed anterior communicating artery saccular aneurysm with associated infarct (Fig. 3).
Complete thrombosis of a cerebral aneurysm after rupture is a well-known event that can be related to hypotension, vasospasm and local damage to the arterial wall [2,14]. The reported incidence is 1% to 2% and may rise to 3% in patients treated with antifibrinolytic agents [14–16]. Spontaneous intra-aneurysmal thrombosis is also a well-documented phenomenon that has been noted in approximately 50% of giant intracranial aneurysms [10] however; the incidence of complete aneurysm occlusion is significantly lower and ranges between 13% and 20% [17]. The occurrence of this phenomenon in non-giant saccular aneurysms has been rarely reported [2,7,11]. Spontaneous aneurysm thrombosis may present with ischemic stroke. Parent artery occlusion due to local extension of the luminal thrombi [2,3,7], distal embolic occlusion secondary to dislodgement of intra-aneurysmatic thrombus (aneurysm-to-distal arteries emboli) [4–6] or increased mass effect [1,12] has been described as possible pathogenic mechanisms. The high incidence of thrombus formation in giant aneurysms has been related mainly to the ratio between aneurysmal volume and aneurysmal neck size; in aneurysms with a relatively small neck, intraluminal thrombosis may occur [2,13]. Other biophysiological parameters such as the age of the aneurysm, hemodymanics in the parent artery, direct distortion of the parent artery by the aneurysmal sac, endothelial damage due to intrasaccular turbulent flow, increased coagulability and the angiographic procedure itself have been also proposed [2,4,6,7,10–13]. The presented cases represent a rare but important complication of unruptured intracranial aneurysms. Clinical and imaging correlation provides evidence that saccular aneurysms may thrombose and originate transient ischemic attacks or stroke. No consensus exists regarding management of thrombosed aneurysms. Mass effect lesions are currently decompressed and clipped. Considering that even completely thrombosed aneurysms may recanalize [11,18] the need of close neuroimaging follow-up should be strongly recommended. References [1] Schaller B, Lyrer P. Focal neurological deficits following spontaneous thrombosis of unruptured giant aneurysms. Eur Neurol 2002;47: 175–82. [2] Brownlee RD, Tranmer BI, Sevick RJ, et al. Spontaneous thrombosis of an unruptured anterior communicating artery aneurysm. Stroke 1995;26:1945–1949. [3] Whittle IR, Williams DB, Halmagyi GM, et al. Spontaneous thrombosis of a giant intracranial aneurysm and ipsilateral internal carotid artery. Care report. J Neurosurg 1982;56:287–9. [4] Sasaki T, Kinugawa K, Tanigake T, et al. Embolism from intracranial aneurysms. J Neurosurg 1980;53:300–4. [5] Fisher M, Davidson RI, Marcus EM. Transient focal cerebral ischemia as a presenting manifestation of unruptured cerebral aneurysms. Ann Neurol 1980;8:367–72.
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[6] Hoffman WF, Wilson CB, Townsend JJ. Recurrent transient ischemic attacks secondary to an embolizing saccular middle cerebral artery aneurysm. J Neurosurg 1979;51:103–6. [7] Ohta H, Sakai N, Nagata I, et al. Spontaneous total thrombosis of distal superior cerebellar artery aneurysm. Acta Neurochir (Wien) 2001;143: 837–43. [8] Morley TP, Barr HWK. Giant intracranial aneurysms: diagnosis, course and management. Clin Neurosurg 1969;16:73–94. [9] Artmann H, Vonofakos D, Muller H, et al. Neuroradiologic and neuropathologic findings with growing giant intracranial aneurysms. Review of the literature. Surg Neurol 1984;21:391–401. [10] Whittle IR, Dorsch NW, Besser M. Spontaneous thrombosis in giant intracranial aneurysms. J Neurol Neurosurg Psychiatry 1982;45: 1040–7. [11] Cohen JE, Rajz G, Umansky F, et al. Thrombosis and recanalization of symptomatic non-giant saccular aneurysm. Neurol Res 2003;25: 857–9. [12] Batjer HH, Purdy PD. Enlarging thrombosed aneurysm of the distal basilar artery. Neurosurgery 1990;26:695–700.
[13] Black SPW, German WJ. Observation on the relationship between volume and size of the orifice of experimental aneurysms. J Neurosurg 1960;17:984–90. [14] Hamilton MG, Dold O. Spontaneous dissapearance of an intracranial aneurysm after subarachnoid hemorrhage. Can J Neurol Sci 1992;19: 389–91. [15] Edner G, Forster DMC, Steiner L, et al. Spontaneous healing of intracranial aneurysm after subarachnoid hemorrhage. J Neurosurg 1978;48:450–4. [16] Fodstad H, Liliequist B. Spontaneous thrombosis of ruptured intracranial aneurysms during treatment with tranexamic acid. Acta Neurochir (Wien) 1979;49:129–44. [17] Pozzati E, Nuzzo G, Gaist G. Giant aneurysm of the pericallosal artery: case report. J Neurosurg 1982;57:566–9. [18] Lee KC, Joo JY, Lee KS, et al. Recanalization of completely thrombosed giant aneurysm: case report. Surg Neurol 1999;51:94–8.
Short communication
Spontaneous thrombosis of cerebral aneurysms presenting with ischemic stroke José E. Cohen a,c , Eyal Yitshayek a , John Moshe Gomori c , Savvas Grigoriadis a,⁎, Guy Raphaeli b , Sergei Spektor a , Gustavo Rajz d a
Department of Neurosurgery, Hadassah Hebrew University Hospital, Jerusalem, Israel Department of Neurology, Hadassah Hebrew University Hospital, Jerusalem, Israel c Department of Radiology, Hadassah Hebrew University Hospital, Jerusalem, Israel d Department of Neurosurgery, Sheba Medical Center, Tel Hashomer, Israel
b
Received 28 September 2006; accepted 13 December 2006 Available online 26 January 2007
Abstract Complete spontaneous thrombosis of an unruptured cerebral aneurysm is a rare event that can be discovered incidentally on advanced neuroradiologic studies. Occasionally, this phenomenon may be symptomatic and can present as an ischemic stroke. The presumed mechanism is probably due to extension of the thrombi to the parent vessel, embolization of intra-aneurysmatic thrombi to distal arteries or arterial compression due to increased aneurysm mass effect. We present documented cases of this unusual entity and review the literature. © 2006 Elsevier B.V. All rights reserved. Keywords: Cerebral aneurysm; Spontaneous thrombosis; Ischemic stroke; Subarachnoid hemorrhage; Cerebral vessels; Aneurysmal thrombus
1. Introduction Cerebral aneurysms usually present with subarachnoid hemorrhage. Less frequently, they present with ischemic stroke secondary to different mechanisms [1–7]. Giant saccular and fusiform aneurysms have a variable component of endoluminal thrombus. These partially or more rarely completely thrombosed aneurysms are considered unstable and dynamic structures that may either grow, recanalize, bleed, compress or give rise to thromboembolic events [1,8– 11]. In non-giant unruptured cerebral aneurysms, the process of spontaneous endosaccular thrombosis (occurring not in relation with previous aneurysm rupture) has been described rarely and in general, is poorly understood [2,7,11]. Several factors (i.e., geometrical configuration of the aneurysm neck and fundus, hemodynamic, biological) have been implicated
⁎ Corresponding author. Hadassah Ein Kerem, Jerusalem, 91120, Israel. Tel.: +972 302310345365; fax: +972 306948362726, +972 302310314952. E-mail address: [email protected] (S. Grigoriadis). 0022-510X/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.jns.2006.12.008
in the delicate balance between thrombogenesis and thrombolysis within the aneurysm lumen [9–12]. This event can be either asymptomatic, mimic a cerebral tumor, provoke seizures or present with ischemic stroke [1–7]. We describe three cases of spontaneous thrombosis of saccular aneurysms presenting with ischemic stroke and review the pathogenic mechanisms and management implications. 2. Clinical cases 2.1. Patient 1 A 51-year-old woman was admitted to our neurosurgical department for a diagnostic cerebral angiography. Patient past medical history was unremarkable except for mild hypertension and smoking for more than ten years. One month prior to admission, she suffered an episode of sudden onset frontal headache, associated with dizziness and nausea that persisted for two weeks. Neurological examination revealed horizontal nystagmus, trunk ataxia, gait imbalance and left dysmetria. She underwent a head magnetic resonance imaging that
96
J.E. Cohen et al. / Journal of the Neurological Sciences 254 (2007) 95–98
Fig. 1. A: Axial T2-weighted scan through the inferior posterior fossa shows the thrombosed left PICA aneurysm and a small infarction of the associated tonsil. B: Anteroposterior digital subtraction angiography of the left vertebral artery confirms thrombosis of the aneurysm and left PICA.
Fig. 2. A: Axial FLAIR image shows a left thalamic infarction. B: Axial T1-weighted image shows subacute thrombosis of a left posterior communicating artery (PComA) aneurysm. C: Axial T2-weighted image shows subacute thrombosis of a left PComA aneurysm. D: Axial T2-weighted image shows contraction of the chronically thrombosed left PComA aneurysm.
J.E. Cohen et al. / Journal of the Neurological Sciences 254 (2007) 95–98
97
3. Discussion
Fig. 3. Axial T2-weighted MRI shows a right anterior cerebral artery (ACA) infarction associated with a thrombosed ACA aneurysm.
showed a complete thrombosis of a left saccular posterior inferior cerebellar artery (PICA) aneurysm (Fig. 1A). Cerebral angiography revealed a small neck remnant of the PICA aneurysm (Fig. 1B). Follow-up angiogram after one year showed persistent occlusion of the aneurysm. 2.2. Patient 2 A 27-year-old man, cocaine and ecstasy abuser was admitted for a right hemispheric sensorimotor transient ischemic attack after use of ecstasy. One year ago he was admitted for an episode of tonicoclonic seizures that was managed with chronic oral carbamazepine. Two weeks after he presented sudden onset mild hemiparesis and complained of associated hemiparesthesia. Brain MRI revealed an acutely thrombosed posterior communicating artery saccular aneurysm with associated thalamic infarct (Fig. 2A–C). Cerebral angiography confirmed the complete exclusion of the aneurysm. One-year follow-up MRI and MRA confirmed stable occlusion of the aneurysm which had decreased in size (Fig. 2D). 2.3. Patient 3 A 76-year-old man, with multiple vascular risk factors presented to the emergency room with sudden onset frontal headache and isolated left leg weakness. Computed tomography revealed the ischemic infarction of the right anterior cerebral artery territory and an associated anterior communicating artery aneurysm was suspected. MRI confirmed the presence of a thrombosed anterior communicating artery saccular aneurysm with associated infarct (Fig. 3).
Complete thrombosis of a cerebral aneurysm after rupture is a well-known event that can be related to hypotension, vasospasm and local damage to the arterial wall [2,14]. The reported incidence is 1% to 2% and may rise to 3% in patients treated with antifibrinolytic agents [14–16]. Spontaneous intra-aneurysmal thrombosis is also a well-documented phenomenon that has been noted in approximately 50% of giant intracranial aneurysms [10] however; the incidence of complete aneurysm occlusion is significantly lower and ranges between 13% and 20% [17]. The occurrence of this phenomenon in non-giant saccular aneurysms has been rarely reported [2,7,11]. Spontaneous aneurysm thrombosis may present with ischemic stroke. Parent artery occlusion due to local extension of the luminal thrombi [2,3,7], distal embolic occlusion secondary to dislodgement of intra-aneurysmatic thrombus (aneurysm-to-distal arteries emboli) [4–6] or increased mass effect [1,12] has been described as possible pathogenic mechanisms. The high incidence of thrombus formation in giant aneurysms has been related mainly to the ratio between aneurysmal volume and aneurysmal neck size; in aneurysms with a relatively small neck, intraluminal thrombosis may occur [2,13]. Other biophysiological parameters such as the age of the aneurysm, hemodymanics in the parent artery, direct distortion of the parent artery by the aneurysmal sac, endothelial damage due to intrasaccular turbulent flow, increased coagulability and the angiographic procedure itself have been also proposed [2,4,6,7,10–13]. The presented cases represent a rare but important complication of unruptured intracranial aneurysms. Clinical and imaging correlation provides evidence that saccular aneurysms may thrombose and originate transient ischemic attacks or stroke. No consensus exists regarding management of thrombosed aneurysms. Mass effect lesions are currently decompressed and clipped. Considering that even completely thrombosed aneurysms may recanalize [11,18] the need of close neuroimaging follow-up should be strongly recommended. References [1] Schaller B, Lyrer P. Focal neurological deficits following spontaneous thrombosis of unruptured giant aneurysms. Eur Neurol 2002;47: 175–82. [2] Brownlee RD, Tranmer BI, Sevick RJ, et al. Spontaneous thrombosis of an unruptured anterior communicating artery aneurysm. Stroke 1995;26:1945–1949. [3] Whittle IR, Williams DB, Halmagyi GM, et al. Spontaneous thrombosis of a giant intracranial aneurysm and ipsilateral internal carotid artery. Care report. J Neurosurg 1982;56:287–9. [4] Sasaki T, Kinugawa K, Tanigake T, et al. Embolism from intracranial aneurysms. J Neurosurg 1980;53:300–4. [5] Fisher M, Davidson RI, Marcus EM. Transient focal cerebral ischemia as a presenting manifestation of unruptured cerebral aneurysms. Ann Neurol 1980;8:367–72.
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J.E. Cohen et al. / Journal of the Neurological Sciences 254 (2007) 95–98
[6] Hoffman WF, Wilson CB, Townsend JJ. Recurrent transient ischemic attacks secondary to an embolizing saccular middle cerebral artery aneurysm. J Neurosurg 1979;51:103–6. [7] Ohta H, Sakai N, Nagata I, et al. Spontaneous total thrombosis of distal superior cerebellar artery aneurysm. Acta Neurochir (Wien) 2001;143: 837–43. [8] Morley TP, Barr HWK. Giant intracranial aneurysms: diagnosis, course and management. Clin Neurosurg 1969;16:73–94. [9] Artmann H, Vonofakos D, Muller H, et al. Neuroradiologic and neuropathologic findings with growing giant intracranial aneurysms. Review of the literature. Surg Neurol 1984;21:391–401. [10] Whittle IR, Dorsch NW, Besser M. Spontaneous thrombosis in giant intracranial aneurysms. J Neurol Neurosurg Psychiatry 1982;45: 1040–7. [11] Cohen JE, Rajz G, Umansky F, et al. Thrombosis and recanalization of symptomatic non-giant saccular aneurysm. Neurol Res 2003;25: 857–9. [12] Batjer HH, Purdy PD. Enlarging thrombosed aneurysm of the distal basilar artery. Neurosurgery 1990;26:695–700.
[13] Black SPW, German WJ. Observation on the relationship between volume and size of the orifice of experimental aneurysms. J Neurosurg 1960;17:984–90. [14] Hamilton MG, Dold O. Spontaneous dissapearance of an intracranial aneurysm after subarachnoid hemorrhage. Can J Neurol Sci 1992;19: 389–91. [15] Edner G, Forster DMC, Steiner L, et al. Spontaneous healing of intracranial aneurysm after subarachnoid hemorrhage. J Neurosurg 1978;48:450–4. [16] Fodstad H, Liliequist B. Spontaneous thrombosis of ruptured intracranial aneurysms during treatment with tranexamic acid. Acta Neurochir (Wien) 1979;49:129–44. [17] Pozzati E, Nuzzo G, Gaist G. Giant aneurysm of the pericallosal artery: case report. J Neurosurg 1982;57:566–9. [18] Lee KC, Joo JY, Lee KS, et al. Recanalization of completely thrombosed giant aneurysm: case report. Surg Neurol 1999;51:94–8.