Aneurysm — Kazunari
OKA,
of the Lenticulostriate
Artery
Report of Four Cases— Fumiaki
MAEHARA*
and
Masamichi
TOMONAGA
Departments of Neurosurgery and *Radiology, School of Medicine, Fukuoka University, Fukuoka
Abstract Four rare cases of aneurysm of the lenticulostriate artery (LSA) are presented. LSA aneurysms were located at the origin in three patients and distally in one. Two cases were of multiple aneurysms, one was associated with hypertensive intracerebral hematoma (putaminal hemorrhage), and the other with moyamoya disease. Two patients were successfully treated by microsurgical procedures. The occur rence of LSA aneurysm suggests that aneurysm formation and growth are accentuated by hemo dynamic alteration and stress. Key words:
cerebral
aneurysm,
lenticulostriate
Introduction Aneurysms of the lenticulostriate artery (LSA) are very rare and may be associated with hypertensive in tracerebral hematoma,1 2) arteriovenous malforma tion (AVM),',`) systemic lupus erythematosus (SLE),5) and moyamoya disease."') The proposed etiology for intracranial aneurysms is the develop ment of congenital defects in the arterial wall in response to arteriosclerosis and hypertension.',',",") Few studies of LSA aneurysm have been made to in vestigate the pathogenesis of aneurysm formation and growth. Here, we report four cases of LSA aneurysm and discuss possible mechanisms of aneu rysm formation. Case
artery,
hypertension,
moyamoya
disease
was due to rupture of the AComA aneurysm. This was successfully clipped 25 days after SAH. The LSA aneurysm was wrapped at the same time. She has since remained well. Case 2: A 59-year-old female had a sudden onset of headache accompanied by neck stiffness in 1984. Computed tomographic (CT) scans revealed SAH. Cerebral angiograms demonstrated aneurysms at the origins of the left ophthalmic artery (OphA), the left anterior choroidal artery (AChA), and the left
Reports
Case 1: A 59-year-old female had a sudden onset of severe headache associated with vomiting and neck stiffness in 1978. A lumbar puncture found bloody cerebrospinal fluid (CSF). Carotid angiograms demonstrated an aneurysm at the origin of the anterior communicating artery (AComA) with hy poplasia of A, portion of the right anterior cerebral artery, and another at the origin of the right lateral LSA (Fig. 1). The subarachnoid hemorrhage (SAH) Received 1990
June
18,
1990;
Accepted
December
17,
Fig. 1
Case 1. Right (left) and left (right) carotid angiograms, showing aneurysms at the origins of the right lateral LSA (arrow) and AComA (arrowheads).
lateral LSA (Fig. 2 upper). The three aneurysms were clipped 4 days after SAH. The ruptured AChA aneurysm appeared macroscopically to have caused SAH. Postoperative cerebral angiograms revealed in complete clipping of the ruptured AChA aneurysm (Fig. 2 lower). However, she has not complained of headache or vomiting for 4 years. Case 3: A 44-year-old hypertensive female developed headache, transient loss of consciousness, and right hemiparesis in 1980. Neurological examination revealed stupor, neck stiffness, early papilledema, and right hemiparesis. CT scans demonstrated left putaminal hematoma associated with SAH (Fig. 3). The hematoma was removed completely through a craniotomy. Carotid angiograms showed an aneu rysm at the distal portion of the left lateral LSA (Fig. 4). She refused another operation. there has been no rebleeding for 8 years.
Fig. 3
Case 3. CT scans, showing putaminal hemor rhage on the left side and SAH (arrowheads) in the Sylvian fissure.
However,
Fig. 4 Case 3. Left carotid angiograms, early (left) and late (right) arterial phases, showing an aneurysm (arrow) at the distal portion of the lateral LSA.
Case 4: A 32-year-old male developed sudden, severe headache associated with neck stiffness in 1978. A lumbar puncture found bloody CSF. Four-vessel angiograms demonstrated occlusion at the terminal portions of bilateral internal carotid arteries, moyamoya vessels, and an aneurysm at the origin of the left medial LSA (Fig. 5). He was treated conser vatively. He has presented no neurological deficits for 10 years. Discussion Fig. 2
Case 2. upper: Preoperative left carotid angiogram, showing aneurysms at the origins of the lateral LSA (arrow), AChA, and OphA. lower: Postoperative left carotid angiogram, showing incomplete clipping of the ruptured AChA aneurysm.
The rupture of intracerebral microaneurysms (mili ary aneurysms) is well-known to cause hypertensive intracerebral hematoma. Cole and Yates'.2) stated that the microaneurysms formed during the aging process of arterial walls and that this was accen
Fig. 5
Case 4. Right (left) and left (right) carotid angiograms, showing occlusion at the terminal portions of the internal carotid arteries, moyamoya vessels, and an aneurysm (arrow) at the origin of the left medial LSA.
tuated by hypertension. The intracerebral hematoma observed might have resulted from ruptured micro aneurysms. Our Case 3 demonstrated a small LSA aneurysm on postoperative angiograms, associated with hypertensive intracerebral hematoma. Possibly, the cause was rupture of the microaneurysm and, subsequently, aneurysmal bulging occurred because the arterial wall was composed of connective tissue and muscular remnant only. Previous authorss,s,9,",14) have reported intracere bral microaneurysm of the LSA associated with AVM, SLE, and moyamoya disease. The patho genesis of moyamoya disease remains unclear. His tologically, stenosis or occlusion results from in traluminal proliferation of loose fibrous connective tissue associated with variable intimal elastofibro sis. The conspicuous wavy internal elastic lamina reflects the narrowing of the artery. Oka et al.") reported 19 fatal cases of moyamoya disease, 14 of which demonstrated fresh, massive cerebral hemor rhage. Two patients also had microaneurysms of the cerebral arteries in the subarachnoid space. However, no rupture of the perforating arteries in the subarachnoid space occurred and no micro aneurysms were found in the brain tissue. Okuma et al.") and Murakami et al." reported intracerebral hemorrhage due to rupture of microaneurysms of the distal Heubner artery and the distal LSA. Kodama et al.') also described intracranial hemor rhage in moyamoya disease. In these three cases, carotid angiograms demonstrated microaneurysms at the distal portion of the posterior choroidal ar teries. The aneurysm shadow was adjacent to the
upper lateral edge of the lateral ventricle, but disap peared completely on follow-up angiograms. The microaneurysms were therefore considered to be pseudo-aneurysms, indicating focal bleeding in the brain tissue. However, Murakami et al.') suggested that the microaneurysm is a true aneurysm histo logically and occurs on the moyamoya vessels de veloped as collateral circulation. They concluded that the hemodynamic mechanism might cause in tracerebral aneurysm with moyamoya disease. This mechanism may have occurred in our Case 4, which demonstrated a saccular aneurysm at the origin of the medial LSA causing SAH. Yasargil15) described 14 cases of small aneurysm at the origin of the LSA, including six (42.9%) with multiple aneurysms. However, no further informa tion was given. Crompton') examined 154 cases of ruptured aneurysm, 37 (24%) of which arose from the middle cerebral artery (MCA). Seven of these oc curred at the origin of the early branches of the MCA. Our Case 1 demonstrated SAH due to a rup tured aneurysm at the origin of the AComA and Case 2 at the AChA. Both cases had unruptured small aneurysms at the origin of the LSA. Such aneurysms are frequently multiple and demonstrate a remarkable difference in size between parent and perforating arteries. Crompton') examined 101 ar terial forks of the MCA in both sexes, with and without aneurysms. He found medial defects at al most all forks in both sexes and in aneurysmal and nonaneurysmal groups. Most authors' 4,12,13) consider that saccular aneurysms form in the region of the medial gap. Aging of the arterial wall due to hemodynamic stress is an important factor in adults. Two of our four patients received surgical treat ment for unruptured LSA aneurysm. Case 1 was treated by gauze wrapping and Case 2 by neck clip ping. After surgery, clipping was complete and no kinking and obstruction of the LSA were found. Crompton3) and Krayenbuhl and Yasargil') pointed out that operative approaches to aneurysms at the origin of the early MCA branch might cause traction on perforating arteries already grossly insulted by the rupture of the closely adjacent aneurysm, and therefore extremely sensitive to further trauma. We found that direct microsurgery can be safely and suc cessfully performed. References 1)
2)
Cole FM, Yates PO: The occurrence and significance of intracerebral micro-aneurysms. J Path Bact 93: 393-411, 1967 Cole FM, Yates PO: Intracerebral microaneurysms
and small cerebrovascular 1967
3)
4)
5)
6)
7) 8)
9)
lesions.
Brain
90: 759-768,
Crompton MR: The pathology of ruptured middle cerebral aneurysms with special reference to the differences between the sexes. Lancet 2: 421-425, 1962 Crompton MR: Mechanism of growth and rupture in cerebral berry aneurysms. Brit Med J 1: 1138-1142, 1966 Kidoguchi J, Chiba M, Murakami T, Saiki I, Kanaya H, Tazawa M, Tamura M: A case of systemic lupus erythematosus associated with aneurysm of len ticulostriate artery. No Shinkei Geka 15: 1221-1225, 1987 (in Japanese) Kodama N, Mineura K, Suzuki J, Kitaoka Y, Kurashima Y, Takahashi S: Cerebrovascular moyamoya disease associated with aneurysm at the peripheral portion of the posterior choroidal artery. No Shinkei Geka 4: 985-991, 1976 (in Japanese) Krayenbiihl H, Yasargil MG: Cerebral Angiography, ed 2. Stuttgart, Georg Thieme, 1982, pp 253-509 Murakami H, Mine T, Nakamura T, Aki T, Suzuki K: Intracerebral hemorrhage due to rupture of true aneurysms of the lenticulostriate artery in moyamoya disease. Case report. Neurol Med Chir (Tokyo) 24: 794-799, 1984 (in Japanese) Ohta H, Ito Z, Nakajima K, Fukasawa H, Uemura K: A case report of ruptured lenticulostriate artery aneurysm with arteriovenous malformation. No To Shinkei 32: 839-846, 1980 (in Japanese)
10)
11)
12)
13)
14)
15)
Oka K, Yamashita M, Sadoshima S, Tanaka K: Cerebral haemorrhage in moyamoya disease at autop sy. Virchows Arch [Pathol Anat] 392: 247-261, 1981 Okuma A, Oshita H, Funakoshi T, Shikinami A,. Yamada H: A case of an aneurysm in the cerebral moyamoya vessel: Aneurysmal rupture during cerebral angiography and spontaneous regression of the aneurysm. No Shinkei Geka 8: 181-185, 1980 (in Japanese) Pakarinen S: Incidence, aetiology, and prognosis of primary subarachnoid haemorrhage. Acta Neurol Scand [Suppl] 29: 9-128, 1967 Sheffield EA, Weller RO: Age changes at cerebral artery bifurcations and the pathogenesis of berry aneurysms. J Neurol Sci 46: 341-352, 1980 Tognetti F, Limoni P, Testa C: Aneurysm growth and hemodynamic stress. Surg Neurol 20: 74-78, 1983 Yasargil MG: Microneurosurgery. II Clinical Con siderations, Surgery of the Intracranial Aneurysms and Results, ed 3. Stuttgart, Georg Thieme, 1984, pp 124-164
Address reprint requests to: K. Oka, M.D., Department of Neurosurgery, School of Medicine, Fukuoka Univer sity,
7-45-1
01, Japan.
Nanakuma,
Jonan-ku,
Fukuoka
814
OKA,
of the Lenticulostriate
Artery
Report of Four Cases— Fumiaki
MAEHARA*
and
Masamichi
TOMONAGA
Departments of Neurosurgery and *Radiology, School of Medicine, Fukuoka University, Fukuoka
Abstract Four rare cases of aneurysm of the lenticulostriate artery (LSA) are presented. LSA aneurysms were located at the origin in three patients and distally in one. Two cases were of multiple aneurysms, one was associated with hypertensive intracerebral hematoma (putaminal hemorrhage), and the other with moyamoya disease. Two patients were successfully treated by microsurgical procedures. The occur rence of LSA aneurysm suggests that aneurysm formation and growth are accentuated by hemo dynamic alteration and stress. Key words:
cerebral
aneurysm,
lenticulostriate
Introduction Aneurysms of the lenticulostriate artery (LSA) are very rare and may be associated with hypertensive in tracerebral hematoma,1 2) arteriovenous malforma tion (AVM),',`) systemic lupus erythematosus (SLE),5) and moyamoya disease."') The proposed etiology for intracranial aneurysms is the develop ment of congenital defects in the arterial wall in response to arteriosclerosis and hypertension.',',",") Few studies of LSA aneurysm have been made to in vestigate the pathogenesis of aneurysm formation and growth. Here, we report four cases of LSA aneurysm and discuss possible mechanisms of aneu rysm formation. Case
artery,
hypertension,
moyamoya
disease
was due to rupture of the AComA aneurysm. This was successfully clipped 25 days after SAH. The LSA aneurysm was wrapped at the same time. She has since remained well. Case 2: A 59-year-old female had a sudden onset of headache accompanied by neck stiffness in 1984. Computed tomographic (CT) scans revealed SAH. Cerebral angiograms demonstrated aneurysms at the origins of the left ophthalmic artery (OphA), the left anterior choroidal artery (AChA), and the left
Reports
Case 1: A 59-year-old female had a sudden onset of severe headache associated with vomiting and neck stiffness in 1978. A lumbar puncture found bloody cerebrospinal fluid (CSF). Carotid angiograms demonstrated an aneurysm at the origin of the anterior communicating artery (AComA) with hy poplasia of A, portion of the right anterior cerebral artery, and another at the origin of the right lateral LSA (Fig. 1). The subarachnoid hemorrhage (SAH) Received 1990
June
18,
1990;
Accepted
December
17,
Fig. 1
Case 1. Right (left) and left (right) carotid angiograms, showing aneurysms at the origins of the right lateral LSA (arrow) and AComA (arrowheads).
lateral LSA (Fig. 2 upper). The three aneurysms were clipped 4 days after SAH. The ruptured AChA aneurysm appeared macroscopically to have caused SAH. Postoperative cerebral angiograms revealed in complete clipping of the ruptured AChA aneurysm (Fig. 2 lower). However, she has not complained of headache or vomiting for 4 years. Case 3: A 44-year-old hypertensive female developed headache, transient loss of consciousness, and right hemiparesis in 1980. Neurological examination revealed stupor, neck stiffness, early papilledema, and right hemiparesis. CT scans demonstrated left putaminal hematoma associated with SAH (Fig. 3). The hematoma was removed completely through a craniotomy. Carotid angiograms showed an aneu rysm at the distal portion of the left lateral LSA (Fig. 4). She refused another operation. there has been no rebleeding for 8 years.
Fig. 3
Case 3. CT scans, showing putaminal hemor rhage on the left side and SAH (arrowheads) in the Sylvian fissure.
However,
Fig. 4 Case 3. Left carotid angiograms, early (left) and late (right) arterial phases, showing an aneurysm (arrow) at the distal portion of the lateral LSA.
Case 4: A 32-year-old male developed sudden, severe headache associated with neck stiffness in 1978. A lumbar puncture found bloody CSF. Four-vessel angiograms demonstrated occlusion at the terminal portions of bilateral internal carotid arteries, moyamoya vessels, and an aneurysm at the origin of the left medial LSA (Fig. 5). He was treated conser vatively. He has presented no neurological deficits for 10 years. Discussion Fig. 2
Case 2. upper: Preoperative left carotid angiogram, showing aneurysms at the origins of the lateral LSA (arrow), AChA, and OphA. lower: Postoperative left carotid angiogram, showing incomplete clipping of the ruptured AChA aneurysm.
The rupture of intracerebral microaneurysms (mili ary aneurysms) is well-known to cause hypertensive intracerebral hematoma. Cole and Yates'.2) stated that the microaneurysms formed during the aging process of arterial walls and that this was accen
Fig. 5
Case 4. Right (left) and left (right) carotid angiograms, showing occlusion at the terminal portions of the internal carotid arteries, moyamoya vessels, and an aneurysm (arrow) at the origin of the left medial LSA.
tuated by hypertension. The intracerebral hematoma observed might have resulted from ruptured micro aneurysms. Our Case 3 demonstrated a small LSA aneurysm on postoperative angiograms, associated with hypertensive intracerebral hematoma. Possibly, the cause was rupture of the microaneurysm and, subsequently, aneurysmal bulging occurred because the arterial wall was composed of connective tissue and muscular remnant only. Previous authorss,s,9,",14) have reported intracere bral microaneurysm of the LSA associated with AVM, SLE, and moyamoya disease. The patho genesis of moyamoya disease remains unclear. His tologically, stenosis or occlusion results from in traluminal proliferation of loose fibrous connective tissue associated with variable intimal elastofibro sis. The conspicuous wavy internal elastic lamina reflects the narrowing of the artery. Oka et al.") reported 19 fatal cases of moyamoya disease, 14 of which demonstrated fresh, massive cerebral hemor rhage. Two patients also had microaneurysms of the cerebral arteries in the subarachnoid space. However, no rupture of the perforating arteries in the subarachnoid space occurred and no micro aneurysms were found in the brain tissue. Okuma et al.") and Murakami et al." reported intracerebral hemorrhage due to rupture of microaneurysms of the distal Heubner artery and the distal LSA. Kodama et al.') also described intracranial hemor rhage in moyamoya disease. In these three cases, carotid angiograms demonstrated microaneurysms at the distal portion of the posterior choroidal ar teries. The aneurysm shadow was adjacent to the
upper lateral edge of the lateral ventricle, but disap peared completely on follow-up angiograms. The microaneurysms were therefore considered to be pseudo-aneurysms, indicating focal bleeding in the brain tissue. However, Murakami et al.') suggested that the microaneurysm is a true aneurysm histo logically and occurs on the moyamoya vessels de veloped as collateral circulation. They concluded that the hemodynamic mechanism might cause in tracerebral aneurysm with moyamoya disease. This mechanism may have occurred in our Case 4, which demonstrated a saccular aneurysm at the origin of the medial LSA causing SAH. Yasargil15) described 14 cases of small aneurysm at the origin of the LSA, including six (42.9%) with multiple aneurysms. However, no further informa tion was given. Crompton') examined 154 cases of ruptured aneurysm, 37 (24%) of which arose from the middle cerebral artery (MCA). Seven of these oc curred at the origin of the early branches of the MCA. Our Case 1 demonstrated SAH due to a rup tured aneurysm at the origin of the AComA and Case 2 at the AChA. Both cases had unruptured small aneurysms at the origin of the LSA. Such aneurysms are frequently multiple and demonstrate a remarkable difference in size between parent and perforating arteries. Crompton') examined 101 ar terial forks of the MCA in both sexes, with and without aneurysms. He found medial defects at al most all forks in both sexes and in aneurysmal and nonaneurysmal groups. Most authors' 4,12,13) consider that saccular aneurysms form in the region of the medial gap. Aging of the arterial wall due to hemodynamic stress is an important factor in adults. Two of our four patients received surgical treat ment for unruptured LSA aneurysm. Case 1 was treated by gauze wrapping and Case 2 by neck clip ping. After surgery, clipping was complete and no kinking and obstruction of the LSA were found. Crompton3) and Krayenbuhl and Yasargil') pointed out that operative approaches to aneurysms at the origin of the early MCA branch might cause traction on perforating arteries already grossly insulted by the rupture of the closely adjacent aneurysm, and therefore extremely sensitive to further trauma. We found that direct microsurgery can be safely and suc cessfully performed. References 1)
2)
Cole FM, Yates PO: The occurrence and significance of intracerebral micro-aneurysms. J Path Bact 93: 393-411, 1967 Cole FM, Yates PO: Intracerebral microaneurysms
and small cerebrovascular 1967
3)
4)
5)
6)
7) 8)
9)
lesions.
Brain
90: 759-768,
Crompton MR: The pathology of ruptured middle cerebral aneurysms with special reference to the differences between the sexes. Lancet 2: 421-425, 1962 Crompton MR: Mechanism of growth and rupture in cerebral berry aneurysms. Brit Med J 1: 1138-1142, 1966 Kidoguchi J, Chiba M, Murakami T, Saiki I, Kanaya H, Tazawa M, Tamura M: A case of systemic lupus erythematosus associated with aneurysm of len ticulostriate artery. No Shinkei Geka 15: 1221-1225, 1987 (in Japanese) Kodama N, Mineura K, Suzuki J, Kitaoka Y, Kurashima Y, Takahashi S: Cerebrovascular moyamoya disease associated with aneurysm at the peripheral portion of the posterior choroidal artery. No Shinkei Geka 4: 985-991, 1976 (in Japanese) Krayenbiihl H, Yasargil MG: Cerebral Angiography, ed 2. Stuttgart, Georg Thieme, 1982, pp 253-509 Murakami H, Mine T, Nakamura T, Aki T, Suzuki K: Intracerebral hemorrhage due to rupture of true aneurysms of the lenticulostriate artery in moyamoya disease. Case report. Neurol Med Chir (Tokyo) 24: 794-799, 1984 (in Japanese) Ohta H, Ito Z, Nakajima K, Fukasawa H, Uemura K: A case report of ruptured lenticulostriate artery aneurysm with arteriovenous malformation. No To Shinkei 32: 839-846, 1980 (in Japanese)
10)
11)
12)
13)
14)
15)
Oka K, Yamashita M, Sadoshima S, Tanaka K: Cerebral haemorrhage in moyamoya disease at autop sy. Virchows Arch [Pathol Anat] 392: 247-261, 1981 Okuma A, Oshita H, Funakoshi T, Shikinami A,. Yamada H: A case of an aneurysm in the cerebral moyamoya vessel: Aneurysmal rupture during cerebral angiography and spontaneous regression of the aneurysm. No Shinkei Geka 8: 181-185, 1980 (in Japanese) Pakarinen S: Incidence, aetiology, and prognosis of primary subarachnoid haemorrhage. Acta Neurol Scand [Suppl] 29: 9-128, 1967 Sheffield EA, Weller RO: Age changes at cerebral artery bifurcations and the pathogenesis of berry aneurysms. J Neurol Sci 46: 341-352, 1980 Tognetti F, Limoni P, Testa C: Aneurysm growth and hemodynamic stress. Surg Neurol 20: 74-78, 1983 Yasargil MG: Microneurosurgery. II Clinical Con siderations, Surgery of the Intracranial Aneurysms and Results, ed 3. Stuttgart, Georg Thieme, 1984, pp 124-164
Address reprint requests to: K. Oka, M.D., Department of Neurosurgery, School of Medicine, Fukuoka Univer sity,
7-45-1
01, Japan.
Nanakuma,
Jonan-ku,
Fukuoka
814
