| Part 1 Non-moyamoya vessel network formation along steno-occlusive middle cerebral arteryObjective:In this study, we sought to examine the prevalence and clinical relevance of deep tiny flow voids (DTFV) in patients with steno-occlusive middle cerebral artery (MCA) disease on high-resolution magnetic resonance imaging (HRMRI).Methods:We retrospectively reviewed the HRMRI and clinical data of"477 patients with MCA steno-occlusive disease. The presence and distribution of DTFV, defined as three or more flow voids along the affected MCA on at least two consecutive T2-weighted image slices on HRMRI, were observed. The relationships among DTFV, the degree of stenosis (mild, <50%; moderate,50-70%; severe,70-99%; and occlusion), and infarctions were analyzed. To clarify the difference between DTFV and moyamoya collaterals, we compared the HRMRI findings of the patients with DTFV and 102 patients with moyamoya disease.Results:The prevalence of DTFV was 1.4% in mild stenosis,12.8% in moderate stenosis,40.6% in severe stenosis and 50.7% in MCA occlusions. Of the 112 patients with DTFV,57 (50.9%) patients had all the 4 quadrants (superior, inferior, dorsal, and ventral sides) of MCA involved. DTFV were more common in asymptomatic patients than in symptomatic patients with severe stenosis (49.3% vs 30.9%, p=0.025) and occlusions (68.0% vs 41.7%, p=0.033). Obvious flow voids in basal ganglia region were observed in 58 (56.9%) patients with moyamoya disease, but in none of patients with DTFV (p<0.001).Conclusions:DTFV are common in patients with severe steno-occlusive MCA disease, especially in asymptomatic patients. We hypothesize that DTFV originate from new vessel network formation in response to chronic cerebral ischemia.Part 2 Etiology of Middle Cerebral Artery Stenosis in Young Adult PatientsObjective:Using high-resolution magnetic resonance imaging (HRMRI), we sought to observe the vessel wall properties of intracranial stenosis in young patients and investigate the underlying etiology.Methods:We retrospectively studied 122 Chinese young adult patients (from 18 to 45 years old, mean age 36.2±7.5 years) with unilateral middle cerebral artery (MCA) stenosis based on a prospectively established HRMRI database. The eccentricity, degree of stenosis, and remodeling types of MCA lesions were analyzed. The MCA lesions were classified as eccentric (presumed atherosclerosis) or concentric stenosis (presumed non-atherosclerosis). The clinical data and vessel wall properties were compared between the patients> 35 years old and the patients≤35 years old.Results:Eccentric stenosis was observed in 98 (80.3%) patients and concentric stenosis in 24 (19.7%) patients. The patients with eccentric stenosis were older (37.5±6.8 vs.31.4±8.4 years old, p<0.001) and more likely had atherosclerosis risk factors (56.1%vs.25.0%, p=0.006). The patients> 35 years old had higher prevalence (90.1% vs.66.7%, p=0.001) of eccentric stenosis and atherosclerosis factors (60.6% vs.35.3%, p=0.006) than the patients≤35 years old. Most of patients with concentric stenosis were≤35 years old (17/24, 70.8%) and were female (16/24,66.7%). Smoking (OR 3.171,95% CI 1.210-8.314; p=0.019) and remodeling ratio (OR 1.625,95% CI 1.001-2.636; p=0.049) were independent predictive factors for symptomatic stenosis.Conclusions:Atherosclerosis is the most common cause of MCA stenosis in Chinese young patients. Non-atherosclerosis disease is an important etiology in young female, especially in the patients aged 35 years old or younger.
|
PDF Full Text Request