Mineralizing angiopathy presenting with recurrence of basal ganglia stroke following minor head trauma.

Basal ganglia stroke secondary to mineralizing angiopathy of lenticulostriate arteries is a well-recognized clinical entity following minor head trauma in children. Recurrences are uncommon, and the majority of these recurrences occur within a few months of initial insult. We report a 2-year-old boy who developed recurrence of basal ganglia stroke after a latency of 18 months from the time of first unrecognized insult at 6 months of age. The case brings forth the need to recognize the condition of basal ganglia stroke secondary to mineralizing angiopathy considering the risk of recurrence to occur as far as 18 months after the first stroke.

Quantitative assessment of symptomatic intracranial atherosclerosis and lenticulostriate arteries in recent stroke patients using whole-brain high-resolution cardiovascular magnetic resonance imaging.

BACKGROUND: It has been shown that intracranial atherosclerotic stenosis (ICAS) has heterogeneous features in terms of plaque instability and vascular remodeling. Therefore, quantitative information on the changes of intracranial atherosclerosis and lenticulostriate arteries (LSAs) may potentially improve understanding of the pathophysiological mechanisms underlying stroke and may guide the treatment and work-up strategies. Our present study aimed to use a novel whole-brain high-resolution cardiovascular magnetic resonance imaging (WB-HRCMR) to assess both ICAS plaques and LSAs in recent stroke patients. METHODS: Twenty-nine symptomatic and 23 asymptomatic ICAS patients were enrolled in this study from Jan 2015 through Sep 2017 and all patients underwent WB-HRCMR. Intracranial atherosclerotic plaque burden, plaque enhancement volume, plaque enhancement index, as well as the number and length of LSAs were evaluated in two groups. Enhancement index was calculated as follows: ([Signal intensity (SI)plaque/SInormal wall on post-contrast imaging] - [SIplaque/SInormal wall on matched pre-contrast imaging])/(SIplaque / SInormal wall on matched pre-contrast imaging). Logistic regression analysis was used to investigate the independent high risk plaque and LSAs features associated with stroke. RESULTS: Symptomatic ICAS patients exhibited larger enhancement plaque volume (20.70 ± 3.07 mm3 vs. 6.71 ± 1.87 mm3 P = 0.001) and higher enhancement index (0.44 ± 0.08 vs. 0.09 ± 0.06 P = 0.001) compared with the asymptomatic ICAS. The average length of LSAs in symptomatic ICAS (20.95 ± 0.87 mm) was shorter than in asymptomatic ICAS (24.04 ± 0.95 mm) (P = 0.02). Regression analysis showed that the enhancement index (100.43, 95% CI - 4.02-2510.96; P = 0.005) and the average length of LSAs (0.80, 95% CI - 0.65-0.99; P = 0.036) were independent factors for predicting of stroke. CONCLUSION: WB-HRCMR enabled the comprehensive quantitative evaluation of intracranial atherosclerotic lesions and perforating arteries. Symptomatic ICAS had distinct plaque characteristics and shorter LSA length compared with asymptomatic ICAS.

Infantile Basal Ganglia Stroke after Mild Head Trauma Associated with Mineralizing Angiopathy of Lenticulostriate Arteries: An Under Recognized Entity.

Basal ganglia infarction in young children, mostly after mild head trauma, has been repeatedly reported. The pathogenesis and the risk factors are not fully understood. Lenticulostriate vasculopathy, usually referred to as basal ganglia calcification, is discussed as one of them. We describe five young (7-13 months old on presentation) male children who suffered from hemiparesis due to ischemic stroke of the basal ganglia, four of them after minor head trauma. All of them had calcification in the basal ganglia visible on computed tomography or cranial ultrasound but not on magnetic resonance imaging. Follow-up care was remarkable for recurrent infarction in three patients. One patient had a second symptomatic stroke on the contralateral side, and two patients showed new asymptomatic infarctions in the contralateral basal ganglia on imaging. In view of the scant literature, this clinic-radiologic entity seems under recognized. We review the published cases and hypothesize that male sex and iron deficiency anemia are risk factors for basal ganglia stroke after minor trauma in the context of basal ganglia calcification in infants. We suggest to perform appropriate targeted neuroimaging in case of infantile basal ganglia stroke, and to consider prophylactic medical treatment, although its value in this context is not proven.

Lenticulostriate Vasculopathy and Neurodevelopmental Outcomes in Preterm Infants: A Systematic Review.

Objective The objective of this study was to perform a systematic review of all studies that report neurodevelopmental outcomes at 12 months' corrected age or later for preterm infants (< 32 weeks) who are diagnosed with lenticulostriate vasculopathy (LSV) on cranial ultrasound. Study Design This is a systematic review. Results We identified 501 unique publications of which 3 met all prespecified eligibility criteria. Neurodevelopmental outcome data were available for 44 preterm infants with LSV. There were mixed results from the studies: the first reported impairments of mental development; the second reported impairments of motor development only; and finally, the third reported that three of three preterm infants with LSV had mild or moderate developmental delay. Conclusion The available results raise some concern for future impairments in preterm infants with LSV, but they are conflicting and inconclusive. There is insufficient evidence about the neurodevelopmental implications of LSV in preterm infants to inform counseling of parents.

An Electronic Health Record Investigation of Lenticulostriate Vasculopathy Features.

Objective Lenticulostriate vasculopathy (LSV) is characterized by linear hyperechogenicities in the basal ganglia found on the head ultrasounds of infants. We reviewed electronic health records of infants with and without LSV to investigate whether physician dictations indicated symptoms which could reflect subtle basal ganglia injury. Study Design In a case-control study, we analyzed data from 46 infants with LSV and 127 controls. Infants were stratified between term and preterm birth. Odds ratios (ORs) and 95% confidence intervals were calculated for tone abnormalities, apnea, feeding difficulties, seizures, and movement abnormalities in the presence of LSV. Results Both term and preterm infants with LSV showed elevated risks for tone abnormalities (OR: 3.6 and 2.9, respectively). Term infants with LSV showed elevated risks for hypotonia (OR: 4.3), apnea (OR: 2.9), and feeding difficulties (OR: 4.1). Preterm infants with LSV showed elevated risks for truncal hypotonia (OR: 3.9) and hyperreflexia (OR: 3.9). Conclusion Our findings provide some evidence that LSV is associated with an increased risk of early signs of abnormal development, possibly relating to signs of subtle basal ganglia injury. Historically LSV has been considered incidental. The associations identified here suggest that LSV findings are worthy of further study.

Successful Resection of a Growing Distal Medial Lenticulostriate Artery Pseudoaneurysm Presenting with Isolated Intraventricular Hemorrhage.

INTRODUCTION: Distal medial lenticulostriate artery (LSA) aneurysms associated with isolated intraventricular hemorrhage (IVH) are extremely rare. We report a very rare case of the isolated IVH due to the rupture of the distal medial LSA pseudoaneurysm that was not visible at the initial angiography but later emerged and grew. CASE REPORT: A 61-year-old woman with a history of hypertension had sudden onset of severe headache and mild consciousness disturbance. The computed tomography scan revealed the IVH, but the initial angiographies showed no evidence of aneurysm. The follow-up magnetic resonance imaging revealed that an intraventricular mass, arising from the right distal medial LSA, emerged and grew into the right anterior horn. Considering the risk of rebleeding, we resected the mass lesion via the transsulcal transventricular approach. The postoperative imaging showed complete obliteration of the mass lesion. Histopathological analysis indicated the pseudoaneurysm. The patient was discharged without any neurological deficit. CONCLUSIONS: The careful and repetitive follow-up imaging should be done in the cases with isolated IVH even if the initial image evaluations are unrevealing. The transsulcal transventricular approach can be the most minimally invasive surgical option for intraventricular lesion.

Multiple Simultaneous Spontaneous Intracerebral Hemorrhages: A Rare Entity.

BACKGROUND: In hospital databases, multiple simultaneous spontaneous intracerebral hemorrhages (ICH-m) account for 0.7-5.6% of all ICHs. Their long-term outcome has never been systematically and prospectively investigated. We aimed at identifying the long-term outcome of patients with ICH-m. METHODS: We prospectively recruited consecutive adults with ICH-m and followed them up for at least 4.5 years. We classified patients into the following 3 groups: (i) definite or probable cerebral amyloid angiopathy (CAA), (ii) deep perforating vasculopathy (DPV) and (iii) unknown causes. RESULTS: Of 562 consecutive patients with ICH, 32 had ICH-m (5.7%): 8 (25%) with probable CAA, 5 (16%) with DPV and 19 (59%) with ICH-m of undetermined cause. At the last visit (cumulative follow-up of 39.5 person-year), 27 patients (84%) had died, and 3 of the 5 survivors were independent. Late-onset seizures, recurrent ICH-m (symptomatic or not) and new brain microbleeds were mainly found in patients with probable CAA. CONCLUSIONS: ICH-m is a rare but extremely severe expression of ICH. Survivors with CAA are more likely to develop late seizures and new hemorrhagic lesions. Because of low survival rates, large multicenter cohort studies are needed for a better understanding of this rare condition.

Comparison of Functional Outcome between Lacunar Infarction and Branch Atheromatous Disease in Lenticulostriate Artery Territory.

BACKGROUND: Branch atheromatous disease (BAD) is differentiated from lacunar infarction (LI). BAD is often associated with neurological deterioration in the acute stage, but outcome of BAD patients in the chronic stage is unclear. We aimed to explore the outcome of BAD in the lenticulostriate artery (LSA) territory in comparison with those of LI from the viewpoint of activities of daily living (ADLs). METHODS: We retrospectively investigated patients who were admitted within 3 days after stroke onset. The patients underwent daily rehabilitation during hospitalization. BAD in LSA territory was defined by the presence of lesion representing 3 or more consecutive horizontal slices in magnetic resonance imaging. Patients having atrial fibrillation or more than 50% stenosis of the large artery in magnetic resonance angiography were excluded. We retrieved data on clinical characteristics and evaluation from medical records. RESULTS: Subjects were 41 BAD and 35 LI patients. There was little difference in baseline characteristics. The National Institutes of Health Stroke Scale score was significantly higher in BAD patients (P < .05). The Barthel Index (BI) score and the Brunnstrom recovery stage were lower in BAD patients at admission (P < .05 and P < .05). Hospital stay was longer in BAD patients (P < .01), but the BI score at discharge was not different. To ambulate, 8 BAD and 1 LI patients depended on orthoses (P < .05), and 21 BAD and 7 LI patients used canes (P < .01). Multivariable analysis demonstrated that BAD lesion was correlated with AFO use independent of age and sex. CONCLUSIONS: BAD patients can obtain ADLs similar to LI patients. However, many BAD patients require canes and/or orthoses.

Imaging patterns of sonographic lenticulostriate vasculopathy and correlation with clinical and neurodevelopmental outcome.

PURPOSE: To evaluate the relationship between the imaging patterns of lenticulostriate vasculopathy (LSV) and clinical outcomes. METHODS: We performed cranial sonography (US) in 110 neonates and evaluated the patterns of visible lenticulostriate vessels with three grades: 0: no vessel seen; 1 (low grade): one or two thin branches seen; and 2 (high grade): more than three prominent branches seen. Color Doppler US was performed on these vessels to evaluate the presence of flow. Associated underlying diseases and the presence of neurodevelopmental delay on follow-up were reviewed retrospectively. RESULTS: There were 51 neonates with associated underlying diseases, including congenital heart diseases (CHD) (n = 34) and neonatal hypoxia (n = 13). Sonographic LSV was detected in 29.1% cases (22 low- and 10 high-grade cases). Doppler flow was not detected in three patients with CHD (p = 0.028). CHD (odds ratio [OR], 25.73; p < 0.001), neonatal hypoxia (OR, 7.00; p = 0.020), two underlying diseases (OR, 73.232; p < 0.001), high-grade LSV (OR, 16.29; p = 0.005), and absent color Doppler flow (OR, 40.80; p = 0.046) were significantly associated with neurodevelopmental delay in univariate analysis. In multivariate analysis, underlying diseases and absent color Doppler flow were associated with neurodevelopmental delay. Both high LSV grade (area under the receiver operating characteristic curves of 0.901; 95% confidence interval, 0.823-0.979) and absent color Doppler flow (area under the receiver operating characteristic curves of 0.874; 95% confidence interval, 0.803-0.945) had a high predictive power for neurodevelopmental delay. CONCLUSIONS: High-grade sonographic LSV and absent color Doppler flow on lenticulostriate vessels were significantly associated with neurodevelopmental delay.

Impact of albuminuria on early neurological deterioration and lesion volume expansion in lenticulostriate small infarcts.

BACKGROUND AND PURPOSE: Albuminuria, a marker of chronic kidney disease, is associated with an increased risk of incident stroke and unfavorable long-term outcomes. However, the association of albuminuria with short-term outcomes and change in infarct volume in patients with acute small subcortical infarction remains unknown. METHODS: We retrospectively reviewed 85 consecutive patients with acute small subcortical infarcts in the lenticulostriate artery territory who were admitted to our stroke center within 24 hours of symptom onset and underwent serial diffusion-weighted imaging (DWI). Albuminuria was determined based on the urinary albumin-to-creatinine ratio obtained from a first morning spot urine after admission. Infarct volume was measured on axial sections of the initial and follow-up DWI. Early neurological deterioration (END) was defined as an increase of ≥2 points in the National Institutes of Health Stroke Scale score during the first 5 days after admission. RESULTS: Albuminuria (UACR ≥30 mg/g creatinine) was observed in 14 of 18 patients with END (77.8%) and in 25 of 67 patients without END (37.3%), P=0.002. Multivariate logistic regression analysis revealed that albuminuria was associated with END after adjustment for age, low estimated glomerular filtration rate (<60 mL/min per 1.73 m2), and infarct volume on initial DWI (odds ratio, 6.64; 95% confidence interval, 1.62-27.21; P=0.009). In addition, albuminuria was an independent predictor of increase in infarct volume using multivariate linear regression analysis (ß coefficient=0.217; P=0.038). CONCLUSIONS: Our findings suggest that albuminuria is associated with END and infarct volume expansion in patients with small subcortical infarcts in the lenticulostriate artery territory.

High-resolution MRI findings in patients with capsular warning syndrome.

BACKGROUND: Capsular warning syndrome (CWS) is rare (1.5% of TIA presentations) but has a poor prognosis (7-day stroke risk of 60%). Up to date, the exact pathogenic mechanism of CWS has not been fully understood. We report the clinical presentations and high-resolution MRI (HR MRI) findings of two cases with capsular warning symptoms. CASE PRESENTATION: Case 1 was a 63-year-old man with a history of hypertension with recurrent episodes of left hemiparesis and dysarthria lasting 10 ~ 30 minutes. Case 2 was a 54-year-old woman with repetitive episodes of transient left hemiparesis and dysarthria lasting about 10 minutes. Capsular infarctions on DWI were demonstrated in the territory of a lenticulostriate artery in both 2 patients. HR MRI disclosed atherosclerotic plaques on the ventral wall of the MCA where enticulostriate arteries were arisen from, although traditional digital subtraction angiography showed normal. Aggressive medical therapy with dual antithrombotic agents and statin was effective in these two cases. CONCLUSION: Our HR MRI data offer an insight into the pathophysiology of CWS which might be caused by atherosclerotic plaque in non-stenotic MCA wall. HR MRI might be a useful modality for characterizing atherosclerotic plaques in the MCA and detecting the pathophysiology of the CWS.

Post-stroke memory impairment among patients with vascular mild cognitive impairment.

BACKGROUND: The American Stroke Association/American Heart Association recommended the criteria for diagnosis of vascular cognitive impairment and memory impairment (MI) is a feature in the classification of vascular mild cognitive impairment (VaMCI). VaMCI patients with MI may differ in terms of infarct location or demographic features, so we evaluated the clinical characteristics associated with MI in patients with VaMCI. METHODS: A prospective multicenter study enrolled 353 acute ischemic stroke patients who underwent evaluation using the Korean Vascular Cognitive Impairment Harmonization Standard Neuropsychological Protocol at three months after onset. The association between MI and demographic features, stroke risk factors, and infarct location was assessed. RESULTS: VaMCI was diagnosed in 141 patients, and 58 (41.1%) exhibited MI. Proportions of men and of left side infarcts were higher in VaMCI with MI than those without (75.9 vs. 57.8%, P = 0.03, 66.7 vs. 47%, P = 0.02). Multiple logistic analyses revealed that male sex (odds ratio [OR] 3.07, 95% confidence interval [95% CI] 1.12-8.42), left-side infarcts (OR 3.14, 95% CI 1.37-7.20), and basal ganglia/internal capsule infarcts (OR 4.53, 95% CI 1.55-13.22) were associated with MI after adjusting other demographic variables, vascular risk factors, and subtypes of stroke. CONCLUSIONS: MI is associated with sex and infarct location in VaMCI patients.

Mineralizing angiopathy with infantile basal ganglia stroke after minor trauma.

AIMS: The objective of this study was to describe a cohort of infants with basal ganglia stroke associated with mineralization in the lenticulostriate arteries and their clinical outcomes. METHOD: Subcortical strokes occurring in infants during the study period were categorized as arterial ischaemic, venous, or haemorrhagic. A cohort of infants with basal ganglia infarcts and associated mineralization of lenticulostriate arteries were identified. This group was analysed for possible aetiological factors, clinical course, and recurrence rate of the stroke. RESULTS: Of 23 infants with basal ganglia arterial ischaemic stroke, 22 (16 males, six females; mean age 11mo [±SD 4.8mo]) were found to have lenticulostriate artery mineralization. Twenty infants presented with hemiparesis and two presented with recurrent episodes of hemidystonia. Eighteen infants had a history of minor trauma before onset of stroke. No other predisposing factors were identified in this cohort. There were no demonstrable causes for vascular and soft tissue calcification. The mean follow-up was 11 months, during which five infants experienced stroke recurrence. Of the 17 infants who did not experience a recurrent stroke, eight exhibited complete neurological recovery, and nine had mild residual hemiparesis. INTERPRETATION: Acute basal ganglia stroke after minor trauma associated with mineralization of lenticulostriate arteries in infants is a distinct clinicoradiological entity. Investigations for prothrombotic states and vasculopathies are normal. Although neurological outcomes in most children are good, trauma is a risk factor for recurrence of stroke.

A case of lenticulostriate artery infarction presenting with peripheral type facial palsy.

An 82-year-old woman developed a droopy right eyelid with ipsilateral hemiparesis. Her ocular symptom was caused by weakness of the right frontalis, which is usually seen in patients with peripheral facial nerve palsy. However, head MRI showed acute cerebral infarction of the left lenticulostriate artery, and electroneurography did not detect damage to the right facial nerve. To explain the pathophysiology in this patient, asymmetrical bilateral cortex innervation to the right upper face was hypothesized. This case suggested that patients with some hemispheric strokes could develop upper facial weakness mimicking facial nerve palsy, and clinicians should pay attention to this potential pitfall in the differential diagnosis of facial nerve palsy.

Placental pathology associated with lenticulostriate vasculopathy (LSV) in preterm infants.

OBJECTIVE: Our aim was to examine the frequency and type of placental abnormalities in neonates with LSV. STUDY DESIGN: We prospectively reviewed cranial ultrasounds (cUS) from neonates born at ≤32 weeks of gestation at Parkland Hospital between 2012 and 2014. Our cohort included neonates with LSV and gestational age and sex matched controls with normal cUS. We retrieved placental pathology reports retrospectively and compared placental abnormalities in both groups. RESULTS: We reviewed 1351 cUS from a total of 407 neonates. Placental pathology evaluations were complete for 64/65 (98%) neonates with LSV and 68/70 (97%) matched controls. There were no significant differences for any type of placental abnormities between LSV and control groups. However, infants with highest stage LSV were more likely to have large for gestational age (LGA) placentas (p = 0.01). CONCLUSION: The association between LSV and LGA placenta may indicate a shared vascular response to an adverse prenatal environment.

Mineralizing Lenticulostriate Vasculopathy: An Emerging Risk Factor for Basal Ganglia Stroke After Minor Head Trauma in Young Children.

Mineralizing lenticulostriate vasculopathy is a well-recognized risk factor for basal ganglia stroke after minor head trauma in infants and young children; it is diagnosed on head computed tomography by the presence of basal ganglia calcification, seen as punctate hyperdensities on axial and linear hyperdensities on reconstructed coronal and sagittal images. In children with anterior fontanel window, its presence is suggested by branching hyperechogenic stripes in the basal ganglia region on cranial ultrasound. Brain magnetic resonance imaging, including susceptibility-weighted sequences and brain magnetic resonance angiography, fail to detect calcification or vascular abnormalities. Although its etiology remains unknown, mineralizing lenticulostriate vasculopathy is considered to represent end-stage pathology of lenticulostriate vasculopathy, a neonatal radiographic condition detected during routine neonatal cranial ultrasonographic examination and represents nonspecific finding associated with a multitude of etiologies. The significance of mineralizing lenticulostriate vasculopathy lies in the fact that it has emerged as one of the most common risk factors for basal ganglia stroke in Indian children, accounting for one-fourth to one-half of all causes of stroke in some studies. The outcome of stroke in children with mineralizing lenticulostriate vasculopathy appears to be favorable with the majority achieving complete or nearly complete recovery of their motor functions. Stroke recurrence following repeat head trauma is seen in a small proportion of children despite aspirin treatment.

Does lenticulostriate vasculopathy predipose to ischemic brain infarct? A case report.

Lenticulostriate vasculopathy (LSV) is a sonographic finding in infancy with obscure etiology and variable diagnostic and prognostic significance. Ischemic infarct in the territory of the lenticulostriate vessels after mild head trauma is a rare pathology. There are no publications on LSV followed by ischemic infarct. We present the case of an 8-month-old boy who suffered mild head trauma and developed an ischemic brain infarct in the territory of preexisting LSV. It is speculated that LSV might be a predisposing factor for ischemic brain infarct after mild head trauma in infants.

Rotational vertigo associated with putaminal infarction.

A 57-year-old man was admitted because of left hemiparesis. A magnetic resonance imaging scan of the brain revealed a recent infarct from the dorsal side of the right putamen to the corona radiata. Three hours after onset, he complained of rotational vertigo. Truncal ataxia was also found on standing a few days later, which persisted until the chronic phase. Repeat magnetic resonance imaging scans on days 2 and 11 revealed no additional lesions. The present case indicates that rotational vertigo might result from a small, supratentorial, subcortical lesion.

A rare cause of stroke in young children: minor head trauma associated with mineralising lenticulostriate angiopathy in three patients.

Acute basal ganglia infarct following minor head trauma in association with mineralisation of lenticulostriate arteries is an increasingly recognised entity in childhood stroke. Three cases with a classical history and phenotypical features of mineralising angiopathy are described. Case 1 was a 2-year-old girl who presented with acute onset hemiparesis with a same-side upper motor neuron (UMN)-type facial palsy following minor head trauma. Case 2 was a 14-month-old boy who presented with a left side hemiparesis and a left UMN-type facial nerve palsy following a minor fall. Case 3 was an 8-month-old boy who, following a fall from his cot, had a sudden-onset hemiparesis on the right side and deviation of the angle of the mouth to the left. In brain computed tomography, all three cases demonstrated characteristic basal ganglia calcification of the mineralising angiopathy. Magnetic resonance imaging of the brain demonstrated features supportive of acute infarcts in the lentiform nucleus, caudate nucleus and putamen. Two of the patients had iron deficiency anaemia with haemoglobin of 7.0 g/dL and 7.8 g/dL, respectively. On follow-up, Case 1 had mild residual weakness and the other two made a complete recovery. None of the patients had a recurrence of stroke. Basal ganglia stroke with mineralising angiopathy should be considered in toddlers presenting with sudden-onset focal neurological deficits preceded by minor head trauma.Abbreviations: ADC: apparent diffusion coefficient; CT: computed tomography; DWI: diffusion-weighted imaging; Hb: haemoglobin; IDA: iron deficiency anaemia; MRI: magnetic resonance imaging; SLV: sonographic lenticulostriate vasculopathy; SWI: susceptibility weighted imaging; UMN: upper motor neuron.

Cerebral aneurysms in children: are we talking about a single pathological entity?

PURPOSE: The objective of this article is to highlight the fact that cerebral aneurysms in children are heterogeneous unlike in the adult population. MATERIAL AND METHODS: This is a retrospective review of 17 children with intracranial aneurysms who were managed at a single institution from 2004 to 2009. RESULTS: The median age was 12 years (range 10 months-17 years). Sixty-five percent of the aneurysms were saccular and 24% were fusiform. There was one infectious and one distal lenticulostriate aneurysm. Patients with saccular aneurysms were predominantly male and presented more commonly with intracranial hemorrhage (91%). The fusiform aneurysms were dissecting in nature or chronic with intramural thrombus and mass effect. The treatment was dependent upon the type and location of the aneurysm. CONCLUSION: Pedriatic aneurysms are a heterogeneous group of intracranial arterial diseases with different etiologies, diverse morphology, and dissimilar clinical manifestations.