Differential Vascular Pathophysiologic Types of Intracranial Atherosclerotic Stroke: A High-Resolution Wall Magnetic
Sookyung Ryoo1, Mi Ji Lee1, Jihoon Cha1
1From the Departments of Neurology (S.R., M.J.L., O.Y.B.) and Radiology (J.C., P.J.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Insights
Branch occlusive disease (BOD) and non-BOD are distinct forms of intracranial atherosclerotic stroke (ICAS). High-resolution MRI reveals different vascular remodeling and plaque characteristics between BOD and non-BOD, indicating unique pathophysiologies.
Area of Science:
- Neurology
- Vascular Medicine
- Radiology
Background:
- Intracranial atherosclerotic stroke (ICAS) encompasses diverse mechanisms, including branch occlusive disease (BOD) and non-BOD.
- BOD involves infarcts in subcortical areas due to parent artery disease affecting perforators.
- Non-BOD involves infarcts beyond subcortical areas, often from artery-to-artery embolism.
Purpose of the Study:
- To investigate distinct vascular pathophysiologies between BOD and non-BOD ICAS.
- To compare high-resolution magnetic resonance imaging (MRI) characteristics of BOD versus non-BOD ICAS.
Main Methods:
- Eighty patients with acute ICAS (36 BOD, 44 non-BOD) of the middle cerebral artery or basilar artery were analyzed.
- Exclusion criteria included carotid/cardiac embolic sources and nonatherosclerotic causes.
- Steno-occlusive intracranial arteries were assessed for vascular remodeling and wall enhancement using high-resolution MRI.
Main Results:
- BOD exhibited milder stenosis and lower wall area index compared to non-BOD.
- Positive remodeling was more frequent in non-BOD (P=0.005).
- Plaque enhancement was nearly universal in non-BOD but present in only one-fourth of BOD patients (P=0.003), with BOD enhancement often localized to perforator origins.
Conclusions:
- Branch occlusive disease (BOD) represents a common and distinct subtype of intracranial atherosclerotic stroke (ICAS).
- BOD and non-BOD exhibit differing vascular pathophysiologies, evident in vascular remodeling and plaque characteristics.
- High-resolution MRI is crucial for differentiating these ICAS subtypes.
Background And Purpose:
Intracranial atherosclerotic stroke (ICAS) has various stroke mechanisms, including branch occlusive disease (BOD), subcortical infarcts caused by parent arterial disease occluding the perforator's orifice, and non-BOD, infarcts beyond the subcortical area caused by artery-to-artery embolism. To test whether these 2 types of ICAS had different vascular pathophysiologies, we compared the high-resolution magnetic resonance imaging characteristics between BOD and non-BOD ICAS.
Methods:
Eighty patients with acute infarcts caused by ICAS of proximal middle cerebral artery or basilar artery without carotid/cardiac embolic sources or nonatherosclerotic causes were enrolled (36 BOD and 44 non-BOD patients). The steno-occlusive intracranial artery at the maximal stenosis was analyzed for vascular remodeling and wall enhancement.
Results:
BOD had distinct radiological features in terms of vascular morphology and enhancement. BOD showed a milder stenosis than non-BOD (P<0.001). Positive remodeling was more frequently observed in non-BOD than in BOD (P=0.005). Wall area index was also lower in BOD. Plaque enhancement was observed in all but one non-BOD patient and in one fourth of BOD patients (P=0.003). Although both types showed an eccentric enhancement, this enhancement was more frequently distributed in the BOD group on the side where the perforators arose. As the number of asymptomatic intracranial stenosis increased, the degree of stenosis (rho=0.513, P=0.003) increased in the BOD group, whereas enhanced plaque area (rho=0.343, P=0.030) increased in the non-BOD group.
Conclusions:
Our data indicate that BOD is a common and unique form of ICAS, distinct from non-BOD. These 2 types of ICAS have different vascular pathophysiologies in terms of vascular remodeling and plaque characteristics.
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