Twig-like Middle Cerebral Artery Research Articles

Twig-like middle cerebral artery as a variety of isolated middle cerebral artery disease with new vessel formation: illustrative case.

Twig-like middle cerebral artery (T-MCA) is reported as a rare vascular anomaly characterized by reconstitution of the M1 segment of the middle cerebral artery (MCA) by a plexiform network of small vessels. Although it is generally believed that the etiology of T-MCA is an embryological persistence, some investigators have suggested that T-MCA may be a secondary consequence. Here, the authors report a second case of de novo T-MCA formation and reconsider the concept of T-MCA in connection with isolated MCA disease. A 40-year-old man's brain magnetic resonance imaging (MRI) checkup showed moderate stenosis of the M1 segment of the left MCA. Annual MRI follow-up was planned, and when performed 1 year later, it showed occlusion of the M1 segment of the left MCA. Cerebral angiography revealed occlusion of that M1 segment with abnormal arterial networks. This case was diagnosed as de novo T-MCA. The patient has remained asymptomatic for 2 years. The reports of de novo T-MCA indicate that acquired factors may be involved in the pathogenesis of T-MCA. We suggest that T-MCA should be defined as a variety of isolated MCA disease with new vessel formation.

Twig-like Middle Cerebral Artery: Case Series in a European Population

Twig-like middle cerebral artery (MCA) is a rare anomaly where the M1 MCA is partially or completely replaced by a plexiform network. It has been described in angiographic series from Asian and South-American cohorts, but has not yet been reported in a European population. The digital subtraction angiograms (DSAs) of adult patients referred to a single neurovascular center for a diagnostic hypothesis of moyamoya arteriopathy (MMA) from 2018 to 2023 were prospectively and retrospectively checked by experienced neuroradiologists for identifying patients with twig-like MCA. The angioarchitecture of twig-like MCA was systematically evaluated and described. Five of 30 (16.7%) male patients (mean age 55.8+ 14.7 years) of European ancestry were identified as having twig-like MCA. The clinical presentations were ischemic stroke (2 of 5), hemorrhagic stroke (1 of 5), and headache (2 of 5). All patients showed a unilateral involvement on DSA and in 1 of 5 (20%) an intracranial aneurysm was found. DSA was used to confirm the diagnosis of twig-like MCA and define the angioarchitecture and associated anomalies. An accessory MCA and recurrent artery of Heubner were found in 3 of 5 (60%) cases, feeding the network together with the anterior choroidal artery (4 of 5, 80%). Twig-like MCA is a rare vascular anomaly, but it seems to be less rare than expected among adult European patients with suspected MMA on noninvasive neuroimaging studies. DSA is fundamental for a reliable differential diagnosis and should not be omitted in these patients.

Current state and confusion of twig-like middle cerebral artery.

A twig-like middle cerebral artery (MCA) is an uncommon lesion in which a plexiform network of small vessels replaces the M1 segment of the MCA. Currently, we have insufficient information for twig-like MCAs. Therefore, a review of the literature using PubMed was conducted. In this review of twig-like MCAs, the following were discussed: the definition, pathogenesis, hemodynamics, associated aneurysm, clinical manifestations, imaging examinations, therapeutic strategies, therapeutic complications and prognosis. In addition, we proposed a reasonable grading system for twig-like MCAs, which is significant. For a twig-like MCA, the pathogenesis is unclear, and congenital and acquired factors can be involved. A twig-like MCA disturbed cerebral hemodynamics. An associated aneurysm can occur in patients with twig-like MCAs. Twig-like MCAs can present subclinically and without clinical symptoms, hemorrhage, or ischemic strokes. Of all the available imaging examinations, digital subtracted angiography is the gold standard. When treating a twig-like MCA, it is feasible to target the associated aneurysm, and extracranial-intracranial bypass can be effective in reducing the risk of strokes, but more evidence is needed. Now, the decision to perform surgery for twig-like MCAs should be made on a case-by-case basis.

Anomalous origin of a middle cerebral artery from anterior cerebral artery with no association to an accessory or duplicated middle cerebral artery

The middle cerebral artery (MCA) is one of the major paired intracranial arteries involved in the formation of the circle of Willis. MCA is the most complex of the intracranial arteries mainly because it supplies the cerebral neocortex, which has been significantly developed in humans. The MCA is a recent phylogenetic acquisition and can be considered as a collateral branch of the anterior cerebral artery (ACA). Anomalies of the middle cerebral artery are less commonly reported than other intracranial arteries. Previously, described anomalies include accessory MCA, duplicated MCA, fenestration of MCA and variations of the branching patterns. Recently, several reports have been published describing unfused or twig-like MCA, in which the single MCA trunk is substituted by a collateral plexiform arterial network. This manuscript would like to report our unique case of an anomalous MCA origin from the anterior cerebral artery unassociated with duplication or accessory MCA.

Moyamoya Vasculopathy: Cause, Clinical Manifestations, Neuroradiologic Features, and Surgical Management

In moyamoya disease, the progressive occlusion of the distal portion of the internal carotid artery and its major branches is typically responsible for the formation of an extensive network of collateral vessels at the base of the brain. When moyamoya collateral network develops in association with various systemic or acquired diseases, the term moyamoya syndrome is used to denote this phenomenon. Sudden changes in the supraclinoid internal carotid artery and middle cerebral artery can be recognized with noninvasive neurovascular imaging techniques, which also allow a differential diagnosis with similar diseases such as degenerative steno-occlusive disease, cerebral vasculitis, and twig-like middle cerebral artery. Once the diagnosis is established, the definitive treatment for moyamoya disease is surgical revascularization, with the goal of increasing cerebral blood flow and preventing recurrent stroke. We provide a comprehensive review of the clinical and radiologic features in moyamoya vasculopathy along with its surgical management.

Twig-like Middle Cerebral Artery: Considerations of Twig Structure and Stroke Onset in Asymptomatic Cases

Twig-like Middle Cerebral Artery: Considerations of Twig Structure and Stroke Onset in Asymptomatic Cases

Ring finger protein 213 c.14576G>A mutation is not involved in internal carotid artery and middle cerebral artery dysplasia

The ring finger protein 213 (RNF213) susceptibility gene has been detected in more than 80% of Japanese and Korean patients with moyamoya disease (MMD), a bilateral internal carotid artery (ICA) occlusion. Furthermore, RNF213 has been detected in more than 20% of East Asians with atherosclerotic ICA stenosis. In this study, we evaluated the frequency of RNF213 mutations in congenital occlusive lesions of the ICA system. This case series was conducted jointly at four university hospitals. Patients with a family history of MMD, quasi-MMD, or related diseases were excluded. Ten patients were diagnosed with abnormal ICA or middle cerebral artery (MCA) angiogenesis. Patients with neurofibromatosis were excluded. Finally, nine patients with congenital vascular abnormalities were selected; of these, five had ICA deficiency and four had twig-like MCA. The RNF213 c.14576G > A mutation was absent in all patients. Therefore, the RNF213 c.14576G > A mutation may not be associated with ICA and MCA congenital dysplasia—rare vascular anomalies making it difficult to study a large number of cases. However, an accumulation of cases is required for accurate determination. The results of this study may help differentiate congenital vascular diseases from MMD.

Twig-like middle cerebral artery: a rare condition not to be confused with Moyamoya disease.

Twig-like middle cerebral artery: a rare condition not to be confused with Moyamoya disease.

Preventive Effect of Bypass Surgery on Rebleeding in Patients with Hemorrhagic Twiglike Middle Cerebral Artery

Aplastic or twiglike middle cerebral artery (Ap/T-MCA) is a rare cerebrovascular anomaly correlated to stroke. The most common characteristic of the disease is intracerebral hemorrhage. However, treatment measures that can prevent rebleeding have not yet been established. We sought to validate whether extracranial-intracranial (EC-IC) bypass is effective in preventing recurrent intracerebral hemorrhage in patients with Ap/T-MCA. Ap/T-MCA was defined on the basis of the following criteria: 1) M1 occlusion with plexiform vessels, 2) unilateral MCA involvement without progression to the contralateral side, 3) no significant stenosis in the M2 segment, and 4) no stenoocclusive lesions in other intracranial major arteries. The clinical features, surgical procedures, radiologic changes, and treatment outcomes of patients with Ap/T-MCA who presented with ipsilateral intracerebral hemorrhage at our institution from April 2004 to December 2019 were retrospectively reviewed. Seven patients fulfilled the criteria for hemorrhagic Ap/T-MCA. Female preponderance was observed, and the mean age at the time of onset was 38 (range: 28-47) years. Three patients presented with pure intraventricular hemorrhage and 4 with intraparenchymal hemorrhage. Of the 4 patients, 2 had intraventricular extension. All patients underwent EC-IC bypass and did not present with stroke during the follow-up period (median: 36 [range: 5-140] months). Follow-up magnetic resonance imaging revealed regression of the twiglike vessels or periventricular choroidal anastomosis within 1 year after surgery in all patients. EC-IC bypass may be a treatment option that can prevent rebleeding in patients with hemorrhagic Ap/T-MCA.

Asymptomatic “twig-like” middle cerebral artery embryological anomaly

Introduction. Anomalies of the middle cerebral artery (MCA) are very rare. ?Rete MCA,? ?twig-like MCA? (T-MCA), ?aplastic MCA,? ?unfused MCA,? and others are all synonyms for unilateral embryological anomaly of the M1 segment of the MCA, where, due to an unknown cause, fusion of primordial arteries of the M1 segment did not happen. As a result, the M1 segment of the affected side consists of a mesh of small arteries from which arise normal perforators and cortical branches. Moyamoya disease, moyamoya-like syndrome, atherosclerotic steno-occlusive disease, vasculitis, and dissection of the MCA should be considered in differential diagnosis. Case outline. We present a 60-year-old female patient with twig-like left MCA, incidentally diagnosed due to persistent headaches six days prior to admission. Non-contrast computed tomography head examination was without peculiarities. Computed tomography angiography showed a network of small vessels in place of the left M1 segment, bridging internal carotid artery terminus with branches of the MCA bifurcation and giving rise to lenticulostriate arteries. Fourteen months later, on physical examination, the patient was in good general condition, without a neurological deficit, with occasional episodes of headache no stronger than 3?4/10 on the visual analogue scale. Conclusion. We report a patient with extremely rare variation of the M1 segment of the left MCA, incidentally diagnosed due to headaches.

Aplastic or Twig-like Middle Cerebral Artery with a Tiny Ruptured Aneurysm in the Collateral Network Treated Using Bypass Surgery and Parent Artery Occlusion: A Case Report

Aplastic or Twig-like Middle Cerebral Artery with a Tiny Ruptured Aneurysm in the Collateral Network Treated Using Bypass Surgery and Parent Artery Occlusion: A Case Report

Twig-like middle cerebral arteries: Clinical and radiological findings

Background and purposeAplastic or twig-like middle cerebral artery (MCA) is a rare vascular anomaly characterized by replacement of the M1 segment by a plexiform network of small vessels. Though rare, familiarity with this entity and ability to differentiate it from radiological mimics such as moyamoya changes and steno-occlusive diseases are important. We review the clinical and radiological manifestations of patients diagnosed with twig-like MCA on cerebral angiograms over a five-year period. Materials and methodsRetrospective review of all patients diagnosed with twig-like MCA on cerebral angiograms was performed from January 2015 to January 2020. This was the inclusion criterion for this retrospective study. For each patient, demographic data, clinical presentation, imaging findings and management strategies were reviewed. Results and conclusionsBetween January 2015 and January 2020, three patients with twig-like MCA were identified from 657 patients who underwent four-vessel diagnostic cerebral angiograms (0.45%). In all three cases, the involvement was unilateral (two left-sided and one right- sided). Two patients were male, and one was female. Patients ages were 25, 26 and 46 years. Two of the three patients presented with headache and the third patient with pulsatile tinnitus. There were otherwise no ischemic or hemorrhagic changes. No other vascular anomaly was identified. Twig-like MCA is a rare anatomical variant in which a plexiform network of small vessels replaces the M1 segment of the MCA. Accurate diagnosis and distinguishing this entity from radiological mimics such as moyamoya and steno-occlusive diseases are important for appropriate management and to prevent unnecessary investigations.

Hemorrhagic events associated with unfused or twig-like configuration of the Middle cerebral artery: A rare vascular anomaly with clinical relevance.

Twig-like middle cerebral artery configuration (Tw-MCA) is a rare and commonly misdiagnosed vascular anomaly characterized by a plexiform arterial network that replaces the normal M1 segment. The prevalence and clinical relevance of this anomaly is not fully established. We sought to explore the prevalence of Tw-MCA in patients clinically referred to digital angiography in a single academic comprehensive endovascular center and evaluated the radiological and clinical findings among patients with hemorrhagic events. From 2011 to 2020, a total of 10,234 patients underwent a cerebral angiography at our institution. During this period, 9 (0.088%) Tw-MCAs were identified. Out of these, 5 patients (62.5%) were admitted due to an intracranial hemorrhage. Two patients had a ruptured intracranial aneurysm on the anterior communicating artery, one with multiple brain aneurysms; two patients presented an intraparenchymal hematoma (IPH) due to the presence of a periventricular anastomosis and one patient an intraventricular hemorrhage with unclear origin. Tw-MCA is a very rare vascular anomaly associated with hemorrhagic events. Adequate identification of this anomaly is essential in order to avoid misdiagnosis as steno-occlusive disorders.

A case of aplastic or twig-like middle cerebral artery associated with a ruptured A1 aneurysm at the origin of the anomalous collateral artery

症例は60 歳女性．無症候性右中大脳動脈狭窄症として他施設で経過観察中，頭痛／意識障害で発症した．CT で右前頭葉脳内血腫を伴うくも膜下出血（SAH）を認め，CTA（computed tomographic angiography）/DSA ではM1 が描出されず，A1 より分岐後M1 欠損部を迂回し網状血管塊を介してM2 へ連続する側副血行がみられた．起始部に破裂瘤を認めコイル塞栓した．網状側副血行路を伴う特発性中大脳動脈閉塞症は，近年発生異常に伴う原始血管系の遺残（twig-like MCA）と考えられている．最近その1 亜型として，A1/A2 からM1 部を迂回し末梢へ至る破格側副血行路内に網状血管が遺残するtype が提示された．本例もこれに相当する構造と思われる．起始部に発生したA1 動脈瘤6 例はすべて5 mm 以下であるが，5 例はSAH で発症している．血行動態的/構造的な脆弱性が示唆されており，本type の瘤は小型でも積極的治療適応に入る可能性がある．

Anomalies of the Middle Cerebral Artery

There are several anomalies of the middle cerebral artery (MCA) in humans, such as accessory MCA, duplicated MCA, fenestration of MCA, and duplicated origin of MCA. Recently, unfused or twig-like MCA, which indicates MCA trunk occlusion with collateral plexiform arterial network, have been reported. During the embryonic stage, MCA is thought to generate from plexiform arterial twigs arising from the anterior cerebral artery, and these twigs form the definitive MCA by fusion and regression at the end of the development stage. Any interruption during the fusion of the arterial twigs may result in MCA anomalies, and the unfused or twig-like MCA, especially, is hypothesized to be the persistent primitive arterial twigs. Clinically, it is challenging to differentiate the unfused or twig-like MCA from unilateral moyamoya disease, in which stenotic change begins at the MCA. The knowledge of the anomalies of the MCA is important to perform a safe surgical or endovascular intervention.

Unfused or twig-like middle cerebral artery

IntroductionThe knowledge of anatomic variations of the cerebral arterial circulation may be important to decide on the safest surgical or endovascular treatment method. Variations in the middle cerebral artery (MCA) territory seems to be less frequent than the other intracranial arteries. During the embryonic stage the primitive MCA is hypothesized to be made up of arterial twigs and these twigs will generate the definitive MCA at the end of the development stage. As in our cases, an early interruption in this period will prevent the evolution of MCA normally and a plexiform arterial network will create the M1 segment of MCA which is the so-called extremely rare unfused or twig-like (Uf/Tw) MCA variation. Our aim is to define and evaluate the angiographical features of Uf/Tw MCA. MethodsThe diagnosis of Uf/Tw MCA was evaluated in a total of 4855 diagnostic cerebral catheter angiograms, retrospectively. The coexisting intracranial pathologies were also interpreted with former radiological examinations. A review of the literature is provided. ResultsA total of six cases of Uf/Tw MCA was identified on angiograms accompanying ipsilateral internal carotid artery (ICA) occlusion and contralateral ICA supraclinoid segment aneurysm in one case, and cingulate gyrus AVM in the other. In two different cases, CT or MRI examinations revealed coexisting subarachnoid hemorrhage and misdiagnosis of forniceal AVM in one case, and temporal arachnoid cyst and parenchymal hematoma in the other. ConclusionLack of data and knowledge about the Uf/Tw MCA variation may cause misdiagnosis and unnecessary treatment attempts.

脳出血で発症したAplastic or twig-like middle cerebral arteryの小児例

Patients presenting with angiographic demonstration of missing main trunk of middle cerebral artery (MCA) from the vicinity of its origin and multiple plexiform arterial networks along the normal route of M1 segment of MCA have been reported as “Spontaneous middle cerebral artery occlusion with moyamoya phenomenon (MCAO-Mo),” MCA aplasia/dysplasia, or twig-like MCA. It has been suggested that such vascular conditions are distinct from moyamoya disease and degenerative steno-occlusive diseases of MCA such as atherosclerosis. More recently, aplastic or twig-like MCA (Ap/T-MCA) has been proposed as a term that comprehensively defines a diagnosis for such anomalous conditions. We recently experienced a pediatric case of Ap/T-MCA presenting with intracerebral and intraventricular hemorrhage, which was successfully treated with ventricular drainage and conservative management for Ap/T-MCA. Since this juvenile case had neither angiographic findings that suggested arterial dissection nor a medical history that might cause such a cerebrovascular condition, this case would support the above-mentioned putative congenital etiology of Ap/T-MCA. We also summarized the data from reported cases of MCAO-Mo and Ap/T-MCA, and evaluated their clinical/radiological characteristics and disease, including eight pediatric cases, to identify characteristics findings for these anomalous conditions that might point to an optimal therapeutic approach.

Clinical and Radiological Features of Patients With Aplastic or Twiglike Middle Cerebral Arteries

An aplastic or twiglike middle cerebral artery (Ap/T-MCA) is an extremely rare congenital anomaly related to interference in the normal embryonic development of the MCA. To evaluate the clinical and radiological features of patients with an Ap/T-MCA. A total of 1749 conventional cerebral angiography procedures were performed in 1282 patients from January 2005 to July 2011 at Daegu Fatima Hospital. The images were evaluated for cerebral arterial anomalies. The radiological features of an Ap/T-MCA, coexisting anomalies, and clinical manifestations were recorded. These prospectively maintained databases were analyzed retrospectively. Ap/T-MCAs were found in 15 patients (1.17% angiographic incidence). The anomalies were confined to unilateral M1 segment, and no stenoses were seen in the adjacent major arteries. Of 15 patients, 6 (40%) had hemorrhagic strokes, 5 (33.3%) had ischemic strokes, and 4 (26.7%) had no symptoms. Aneurysms were found in 5 patients (33.3%). Coexisting cerebral arterial anomalies were seen in 12 patients (80%). Ten patients underwent conservative treatments, and the remaining 5 underwent surgical treatments, such as hematoma aspiration, indirect revascularization, and clipping or coiling of aneurysms. An Ap/T-MCA is a rare anomaly and should be differentiated from moyamoya conditions and degenerative steno-occlusive diseases of the middle cerebral artery. Coexisting anomalies of the anterior or middle cerebral arteries are frequent. This anomaly is vulnerable to both hemorrhagic and ischemic strokes.

Aneurysms in Twig-Like Middle Cerebral Artery

Background: We report a vascular abnormality of the middle cerebral artery (MCA) that has not been described in the literature before. Methods: Two patients (1 male and 1 female; age 44 and 67 years, respectively) were found to have a vascular abnormality in which the main trunk of the MCA had a twig-like form. Both patients presented with intracranial hemorrhage. Results: In these 2 patients, the abnormality was seen before the genu of the MCA. They had an intracranial hemorrhage due to an associated aneurysm inside the twigs. The twig appeared to be a network between the bifurcation of internal carotid artery and insular segment of MCA, and it was different from the collateral circulation due to acquired occlusion or moyamoya disease. Conclusion: This new type of vascular lesion of the MCA is not benign. It appears to be associated with the occurrence of an aneurysm, an important clinical aspect.