Features of branch occlusive disease-type intracranial atherosclerotic stroke in young patients.

Background: Young ischemic stroke patients are common while classification and analysis based upon imaging characteristics are rarely reported. We intend to compare the clinical and MRI characteristics of cerebral stroke induced by intracranial atherosclerosis between young patients with branch occlusive disease (BOD) and those with non-branch occlusive disease (non-BOD) or small artery disease (SAD).

Methods: A total of 151 subjects with acute infarction within the middle cerebral artery (MCA) territory were included and patients with ipsilateral internal carotid artery stenosis or cardioembolism were excluded. Based on the distribution characteristics of infarction and the presence of ipsilateral MCA stenosis, the patients were divided into three groups: BOD-striatocapsular area infarction with ipsilateral MCA stenosis; non-BOD -infarction size exceeds the striatocapsular area and accompanied by ipsilateral MCA stenosis; SAD. The clinical and MCA stenosis characteristics of the three groups were compared.

Results: The number of BOD patients with hypertension was significantly higher than that of SAD (92.9% vs 53.7%, p = 0.000) and non-BOD (92.9% vs 57.1%, p = 0.001); subjects with smoking history significantly exceeded that of SAD (50% vs 26.9%, p = 0.03) and subjects with family history of cardiovascular disease was significantly less than that of non-BOD (14.3% vs 41.1%). Baseline NIHSS scores and mRS scores at discharge in patients with BOD were significantly lower than those with non-BOD (p = 0.000, p = 0.001). Majority of patients in non-BOD group displayed severe MCA stenosis (39 cases, 69.6%) while that in BOD group displayed mild stenosis (26 cases, 92.9%), and the difference was statistically significant (p = 0.000). Compared with non-BOD group, the stenosis in BOD group located at a relatively distal end in the M1 segment of MCA (S/M1, 58% vs 40%, p = 0.000) and was more localized (stenosis level/ (SL/M1), 1.86 (1.35-2.6) vs 2.9 (2.0-5.0), p = 0.002).

Conclusion: BOD in young patients with ischemic stroke induced by intracranial atherosclerosis is not rare (33.3%) and its clinical manifestations and prognosis are similar to those of SAD. This may be related to the mild localized stenosis at the distal end in the M1 segment of MCA. Control of hypertension might play a positive role in secondary prevention.