Non-aneurysmal subarachnoid hemorrhage in aplastic or twig-like middle cerebral artery: A case report and literature review.

BACKGROUND: Aplastic or twig-like middle cerebral artery (Ap/T-MCA) is a rare vascular anomaly that can cause hemorrhagic and ischemic stroke. Ap/T-MCA can induce aneurysms due to the fragility of the vessel wall, consequently leading to subarachnoid hemorrhage. Herein, we report a case of Ap/T-MCA with subarachnoid hemorrhage without an aneurysm. CASE PRESENTATION: A 67-year-old man presented to our hospital with a sudden onset of headache. Computed tomography of the head revealed subarachnoid hemorrhage (SAH) in the left Sylvian fissure; however, no aneurysm was observed on digital subtraction angiography. Following conservative treatment, follow-up imaging showed no aneurysm or no recurrent stroke. CONCLUSION: Non-aneurysmal SAH is a possible indication of vessel wall fragility in Ap/T-MCA; however, a standardized treatment strategy for this condition remains to be established.

Triplicated middle cerebral arteries (duplicated and ipsilateral accessory) associated with triplicated anterior cerebral arteries (accessory) diagnosed by magnetic resonance angiography.

PURPOSE: To describe a case of duplicated middle cerebral artery (MCA) combined with ipsilateral accessory MCA, forming a triplicated MCA, associated with the accessory anterior cerebral artery (ACA), forming a triplicated A2 segment of the ACA detected incidentally on magnetic resonance (MR) angiography. METHODS: A 70-year-old woman with internal carotid artery (ICA) stenosis at the origin, which was detected by ultrasound, underwent cranial MR imaging and MR angiography of the intracranial region for an evaluation of brain and cerebral arterial lesions. The MR machine was a 3-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique. RESULTS: Multiple ischemic white matter lesions are observed. No significant stenotic lesions were observed in intracranial arteries. The right duplicated MCA was originated from right distal ICA. And main MCA was originated from right ICA bifurcation. Right accessory MCA was arisen from the A2 segment of the right ACA. Thus, the right MCA was triplicated. There was also an accessory ACA forming a triplicated ACA at its A2 segment. These findings were clearly identified on partial volume-rendering (VR) images. CONCLUSION: We herein report a case of triplicated MCA associated with triplicated ACA. MCA variations are relatively rare, and this is the third case of triplicated MCA reported in relevant English-language literature. To identify multiple cerebral arterial variations, creating partial VR images using MR angiographic source images is useful.

Combined duplicate origin and early bifurcated middle cerebral artery diagnosed by magnetic resonance angiography.

PURPOSE: To describe a case of combined duplicate origin and early bifurcated middle cerebral artery (MCA) incidentally diagnosed using magnetic resonance (MR) angiography. METHODS: A 51-year-old woman with an unruptured left MCA aneurysm underwent cranial MR angiography with a 3-Tesla scanner for presurgical evaluation. MR angiography was performed using a standard 3-dimensional time-of-flight technique. RESULTS: An unruptured left MCA aneurysm at the M1-M2 junction was identified. The maximum aneurysm diameter was 9 mm. Two almost equally sized right MCAs arose from the terminal segment of the right internal carotid artery. These two channels soon anastomosed, and the temporal branch arose from the inferior channel. The aneurysm was successfully treated with coil embolization. CONCLUSION: We herein report a case of a combined duplicate origin and early bifurcated MCA. This variation can also be regarded as anastomosis between the main MCA and the duplicated MCA. This variation has been previously reported as segmental duplication of the MCA. This is the third case of this rare MCA variation reported in the relevant English-language literature. The term "segmental duplication" may be confused with duplicate origin of the MCA, in which only one artery is located distal to the fusion.

An "over-fused middle cerebral artery" anomaly: a case report.

BACKGROUND: MCA has several anomalies, such as accessory MCA, duplicated MCA and twig-like MCA, up to now all these reported anomalies were hypothesized to due to the failure in fusion of the primitive arterial network. No anomaly of over fused MCA has been reported. CASE PRESENTATION: A 59- year- old male was hospitalized with a history of paroxysmal slurred speech and left side headache for a week, his blood pressure was 160/80 mmHg and he manifested mild incomplete motor aphasia at the time of admission. The head and neck CTA and DSA all presented a huge and tortuous left MCA, we diagnosed it an anomaly and termed it over-fused MCA. The patient's speech impairment and headache were relieved by controlling his blood pressure. CONCLUSIONS: Such an anomaly of over-fused MCA is reported for the first time, it's not needed to put special intervention on the anomaly of the patient temporarily, but more observation are needed.

Duplicated Middle Cerebral Artery Aneurysms Treated by Coil Embolization; A Report of Two Cases and Literature Review.

BACKGROUND: Duplication of the middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery (ICA). Aneurysms at the origin of a DMCA have been reported; however, most have been treated with clipping surgery. Here, we describe two cases of aneurysms at the origin of a DMCA treated with coil embolization. CASE PRESENTATION: Case 1: A seventy-three year-old man presented with severe headache and was diagnosed with subarachnoid hemorrhage (SAH). Digital subtraction angiography (DSA) and 3-dimensional (3-D) DSA showed an aneurysm arising from a DMCA. Coil embolization was performed with DMCA patency. The patient had an uneventful postoperative course. CASE 1: A 44-year-old woman presented with a history of clipping for an IC-anterior choroidal artery (AchA) aneurysm 8 years prior. Magnetic resonance imaging (MRI) showed regrowth of the aneurysm. 3-D DSA showed an IC-DMCA aneurysm located laterally and distal to the AchA. The DMCA arose from the bottom of the aneurysm. Coil embolization was performed without DMCA occlusion and showed no postoperative ischemic changes. CONCLUSION: An IC-DMCA aneurysm is rare and may be misdiagnosed as an AchA aneurysm. Clinicians should perform a 3D-DSA evaluation if the aneurysm arises from the lateral wall of the IC to obtain a precise diagnosis and to preserve the DMCA during coil embolization.

A1 Segment Unruptured Aneurysm of Persistent Primitive Olfactory Artery Coexisted with Accessory Middle Cerebral Artery.

A persistent primitive olfactory artery (PPOA) is a rare anomaly of anterior cerebral artery (ACA), which generally arises from the internal carotid artery (ICA), runs along the olfactory tract, and makes a hairpin bend to supply the territory of the distal ACA. PPOA is also associated with cerebral aneurysms. An accessory MCA is a variant of the middle cerebral artery (MCA) that arises from either the proximal or distal portion of the A1 segment of the ACA, which runs parallel to the course of the MCA and supplies some of the MCA territory. We experienced a rare case of coexistence of PPOA with an unruptured aneurysm and accessory MCA. Three-dimensional computed tomographic angiography (3D-CTA) has an excellent picture of the spatial relationship of the surrounding bony and vascular structure.

Correlation between multiple cerebral aneurysms and a rare type of segmental duplication of the middle cerebral artery.

BACKGROUND: Connection between the duplication of the middle cerebral artery (DMCA) and the presence of multiple aneurysms has been described in a small number of cases. CASE PRESENTATION: The presence of a rare type of DMCA associated with cerebral aneurysms was diagnosed in 56 year old woman after a rupture of an aneurysm on the dorsal segment of the DMCA. .. The presence of equal diameters of branches of the DMCA and anterior cerebral artery (ACA) could be recorded as trifurcation of the carotid internal artery (ICA). However, due to the anastomosis of the DMCA branches in the area of the M2 segment, the recorded anatomical change represented a segmental duplication of MCA. Three aneurysms that were directly related to the segmental DMCA were diagnosed. CONCLUSIONS: Anatomical variation by type of segmental DMCA is a rare subtype of DMCA. The presence of multiple aneurysms associated with this type of anatomical variation in MCA indicates their high hemodynamic instability.

Revascularization for Aplastic or Twiglike Middle Cerebral Artery: A Case Report.

An aplastic or twiglike middle cerebral artery (Ap/T-MCA) is a congenital anomaly related to interference of normal embryonic development of the middle cerebral artery (MCA). This condition may cause ischemic and hemorrhagic strokes as a result of hypoperfusion, vulnerable collateral circulation, and associated aneurysms. We reported a case of Ap/T-MCA with transient ischemic attack, which was successfully treated with revascularization. A 19-year-old woman with a history of transient left upper limb hemiparesis, dysesthesia, and headache visited our hospital. Digital subtraction angiography showed an occlusion in the M1 segment of the MCA and abnormal vascular networks distal to the occlusion site. The patient underwent direct and indirect revascularizations, including superficial temporal artery-to-MCA bypass and encephalomyosynangiosis. She was discharged home without any neurological deficit. Magnetic resonance angiography at 12 months after revascularization showed regression of blood flow signals at the twigs network. In spite of congenital anomaly, revascularization for an Ap/T-MCA may be useful to reduce collateral stress in microvascular networks and to prevent future stroke in selected patients.

Duplication of the middle cerebral artery in a neonate: case report.

The middle cerebral artery, a terminal branch of the internal carotid artery, participates greatly in the blood supply of the cerebral cortex and basal nuclei. The aim of this paper is to present a case of middle cerebral artery duplication in a 3-day-old neonate. A brief literature overview in this paper serves to summarize the research on the middle cerebral artery duplication. Also, possible etiology of this anatomical variation will be discussed, together with the embryology of the middle cerebral artery. The arteries of the circle of Willis are affected by numerous neurovascular diseases and the knowledge of these anatomical variations is important in the diagnostic and therapeutic interventions in this field.

[A Rare Case of a Ruptured De Novo Aneurysm Arising from the Twig-like Networks of an Anomalous Collateral Artery Associated with Hypoplasia of the M1 Segment of the Middle Cerebral Artery 4 Years after the Rupture of an A1 Aneurysm at the Origin of the Collateral Artery].

We report a rare case of a de novo ruptured aneurysm arising from the twig-like networks(TLN)of an anomalous collateral artery associated with an aplastic or twig-like middle cerebral artery(Ap/T-MCA). A 65-year-old woman with a decreased level of consciousness, who had been diagnosed with a right Ap/T-MCA and was treated with coil embolization for a ruptured A1 aneurysm at the origin of the anomalous collateral artery 4 years ago, was transferred to our hospital. Head CT revealed an intracerebral hematoma extending from the right frontal lobe to the caudate nucleus with intraventricular hemorrhage. Subsequent 3D-rotational angiograms revealed a ruptured de novo aneurysm arising from the TLN and regrowth of the residual neck of the coiled aneurysm. The two aneurysms were successfully treated by surgical clipping combined with superficial temporal artery middle cerebral artery anastomosis in the subacute phase. To our knowledge, only 11 cases of this type of aneurysm have been reported, including our case, and this is the first report of a de novo aneurysm within the TLN so far. Although all previously reported aneurysms were small(<5-6mm), 10 of them(91%)ruptured. These data may indicate the vulnerability of this type of aneurysm to rupture despite their small size, probably due to hemodynamic stress and the fragile nature of their immature walls. To prevent recurrence of hemorrhage in these cases, revascularization may be necessary in addition to surgical clipping. Whether this concept is correct is an open question. Further studies are necessary to examine this issue.

Pial Arteriovenous Fistula and Capillary Malformation-Arteriovenous Malformation Associated with RASA1 Mutation: 2 Pediatric Cases with Successful Surgical Management.

We present case reports of 2 pediatric patients who were both found to have pial arteriovenous fistulas (AVFs) with subsequent genetic analysis revealing mutations in the RASA1 gene. Considering their family history of distinct cutaneous lesions, these mutations were likely inherited as opposed to de novo mutations. Patient 1 had large capillary malformations on the left side of the face and neck, associated with macrocephaly, and presented at the age of 32 months with speech delay, right-sided weakness, and focal seizures involving the right side of the body. Patient 2 presented with proptosis at the age of 9 months, but was otherwise neurologically intact. Given the chance for definitive single-stage control of vascular shunt (obviating chances for radiation exposure with endovascular treatment) and surgically accessible location of these intracranial lesions, both patients were treated with surgery with excellent clinical and radiological outcome. In general, given the high mortality secondary to severe congestive heart failure when treated conservatively, the goal of treatment in cortical AVF in young children, even when asymptomatic, is rapid control of the shunt. This was achieved successfully in our cases - both patients experienced significant symptomatic improvement following surgery and remained neurologically stable in the subsequent follow-up visits.

Anastomosis between accessory middle cerebral artery and middle cerebral artery diagnosed by magnetic resonance angiography.

The accessory middle cerebral artery (MCA) is a common variation of the MCA that arises from the anterior cerebral artery. We report a patient with anastomosis of the accessory MCA with the main MCA, an extremely rare variant that we diagnosed by magnetic resonance (MR) angiography. Both partial maximum-intensity-projection and partial volume-rendering MR angiographic images obtained at 3 T are useful to identify such rare vascular variation.

Stenosis in Middle Cerebral Artery Duplication: Assessment With Transcranial Color-Coded Duplex Sonography.

Duplication of the middle cerebral artery is an unusual anatomic variant. Stenosis of one of its branches can be an exceptional cause of stroke and is very difficult to diagnose with transcranial duplex sonography. We report 2 patients with duplication of the middle cerebral artery in whom stenosis of one of its branches led to ischemic stroke and describe the sonographic findings in comparison to other neuroimaging modalities. These cases highlight the utility of adding a coronal insonation plane on top of the traditional axial plane to avoid identification pitfalls in patients with anatomic variants.

Nonaneurysmal Subarachnoid Hemorrhage Due to Unfused or Twiglike Middle Cerebral Artery Rupture: Two Case Reports.

BACKGROUND: An unfused or twiglike middle cerebral artery (MCA) is a congenital anomaly related to the abnormal development of the MCA. An unfused or twiglike MCA can cause both ischemic and hemorrhagic strokes. Previous reports have shown that an unfused or twiglike MCA with coexisting aneurysms can cause subarachnoid hemorrhage (SAH). CASES: Two patients presented with nonaneurysmal SAH due to an unfused or twiglike MCA. Both patients had stenosis of the proximal M1 segment of the left MCA and abnormal vascular nets distal to the stenotic lesion. Vasculature distal to the abnormal vascular nets remained grossly normal. These findings were not evident in computed tomography or magnetic resonance angiography. CONCLUSION: An unfused or twiglike MCA can cause nonaneurysmal SAH. Digital subtraction angiography is necessary for accurate diagnosis.

Complete middle cerebral artery block without brain infarction.

We report a patient with progressive supranuclear palsy and incidentally detected the absence of right middle cerebral artery (MCA) without any old or acute infarct in its territory. The magnetic resonance angiography and computed tomography angiography failed to detect any significant collateral circulation. We discuss the embryogenesis of brain circulation and offer a possible explanation for the nonvisualization of the right MCA in our patient.

Morning Glory Syndrome with Carotid and Middle Cerebral Artery Vasculopathy.

PURPOSE: To report a case of incidental asymptomatic atypical morning glory syndrome (MGS) with concomitant ipsilateral carotid and middle cerebral dysgenesis. CASE REPORT: A 6-year-old child was discovered to have incidental findings of MGS, with atypia. All visual functions were normal including vision and stereopsis. Neuroimaging revealed ipsilateral carotid and middle cerebral vascular narrowing without associated collateral vessels or cerebral ischemia commonly seen in Moyamoya disease. Subsequent annual examinations have been stable, without signs of progression. CONCLUSIONS: This case demonstrates disparity between structural aberrations and final visual and neurological function and reinforces the association between MGS and intracranial vascular disruption. Full ancillary ophthalmic and neuroimaging studies should be performed in all patients with MGS with interval reassessments, even when the patient is asymptomatic and functionally intact.

Transcranial color-coded duplex sonography of the middle cerebral artery: more than just the M1 segment.

OBJECTIVES: Routine sonography of the middle cerebral artery in acute ischemic stroke usually focuses on the main stem (M1 segment). However, stenoses and occlusions affect not only proximal but also more distal vessel branches, such as the M2 segments. Transcranial color-coded duplex sonography allows visualization of these segments; however, a formal analysis and description of normal blood flow values are missing. The purpose of this study was to analyze middle cerebral artery branching patterns with transcranial color-coded duplex sonography and to establish reference flow velocity values in the detectable M2 branches as well as the early temporal M1 branch. METHODS: Transcranial color-coded duplex sonography in the axial and coronal planes was performed in 50 participants without vascular disease and with a good temporal bone window (ie, fully visible M1 middle cerebral artery segment and A1 anterior cerebral artery segment). We analyzed the course and branching pattern of the M1 segment, including anatomic variants such as an early temporal M1 branch, and measured the length and flow parameters of the detectable M2 branches. RESULTS: Assessment of 100 hemispheres allowed classification into 3 anatomic patterns: M1 bifurcation (63%), M1 trifurcation (32%), and medial M1 branching into 2 major segments (2%). A clear distinction was not possible in 3 cases (3%). An early temporal M1 branch was detected in the coronal plane in 26%. CONCLUSIONS: Transcranial color-coded duplex sonography is a useful tool for analyzing anatomic variants and branching patterns of the middle cerebral artery as well as flow characteristics of M2 segments. Therefore, it also has potential to increase the diagnostic yield for the detection of middle cerebral artery disease in these vessel segments.

Maternal food restriction modulates cerebrovascular structure and contractility in adult rat offspring: effects of metyrapone.

Although the effects of prenatal undernutrition on adult cardiovascular health have been well studied, its effects on the cerebrovascular structure and function remain unknown. We used a pair-fed rat model of 50% caloric restriction from day 11 of gestation to term, with ad libitum feeding after birth. We validated that maternal food restriction (MFR) stress is mediated by glucocorticoids by administering metyrapone, a corticosterone synthesis inhibitor, to MFR mothers at day 11 of gestation. At age 8 mo, offspring from Control, MFR, and MFR + Metyrapone groups were killed, and middle cerebral artery (MCA) segments were studied using vessel-bath myography and confocal microscopy. Colocalization of smooth muscle α-actin (SMαA) with nonmuscle (NM), SM1 and SM2 myosin heavy-chain (MHC) isoforms was used to assess smooth muscle phenotype. Our results indicate that artery stiffness and wall thickness were increased, pressure-evoked myogenic reactivity was depressed, and myofilament Ca(2+) sensitivity was decreased in offspring of MFR compared with Control rats. MCA from MFR offspring exhibited a significantly greater SMαA/NM colocalization, suggesting that the smooth muscle cells had been altered toward a noncontractile phenotype. MET significantly reversed the effects of MFR on stiffness but not myogenic reactivity, lowered SMαA/NM colocalization, and increased SMαA/SM2 colocalization. Together, our data suggest that MFR alters cerebrovascular contractility via both glucocorticoid-dependent and glucocorticoid-independent mechanisms.

Anatomical Variations and Anomalies of the Middle Cerebral Artery.

OBJECTIVE: Intracranial arteries have a high rate of variation, but a clear schematic overview is lacking. In this pictorial review we classify and depict all the variations and anomalies within the middle cerebral artery (MCA). METHODS: PubMed was searched with the MeSH-term "Middle Cerebral Artery." Articles were selected based on their description of variants within the MCA. Cross-referencing was used to broaden the range of articles. The anatomical variants were then schematically drawn using the anteroposterior and lateral view during angiography of the internal carotid artery. RESULTS: A total of 29 unique medical illustrations were made, depicting variation in number of vessels; variation in vessel origin; and variation in morphology. CONCLUSIONS: The MCA provides vital blood supply to the frontal, parietal, temporal, and central brain structures. An overview of these variations is important to diagnose and treat patients with MCA-related pathology correctly and safely. They can aid in distinguishing pathology from normal anatomical variance; aid neurosurgeons during aneurysmal clipping or arteriovenous malformation resections; and aid interventional radiologists during thrombectomy or coiling. This article provides a summary regarding current knowledge of anatomical variations within the MCA, their prevalence and clinical relevance. A total of 29 unique illustrations were made, depicting currently known variants. We encourage all who diagnose, treat, and study the MCA to use this overview for a uniform and better understanding of its anatomy.