Prognosis of symptomatic and asymptomatic middle cerebral artery occlusion
Bong-Su Kang1, Hyung-Min Kwon, Wi-Sun Ryu
1Department of Neurology, Seoul National University and Seoul National University Boramae Hospital, Seoul, South Korea.
Insights
Patients with middle cerebral artery occlusion (MCAO) have a better prognosis than previously thought. Asymptomatic MCAO is benign, with low risks of stroke or death when managed with optimal medical therapy.
Area of Science:
- Neurology
- Vascular Neurology
- Neuroimaging
Background:
- Middle cerebral artery stenosis carries a >10% annual risk of stroke or cardiovascular events.
- Prognosis for middle cerebral artery occlusion (MCAO) is not well-defined.
- This study investigated cardiovascular event/death risk in symptomatic vs. asymptomatic MCAO patients.
Purpose of the Study:
- To clarify the prognosis of patients diagnosed with middle cerebral artery occlusion (MCAO).
- To compare the risk of cardiovascular events and death between symptomatic and asymptomatic MCAO patients.
Main Methods:
- 48 MCAO patients (37 symptomatic, 11 asymptomatic) diagnosed via Doppler sonography and MRA were followed for a mean of 2.8 years.
- Medical records and telephone interviews assessed composite outcomes: ipsilateral stroke, hemorrhagic stroke, overall stroke, myocardial infarction (MI), vascular death, and nonvascular death.
- Comparison focused on symptomatic vs. asymptomatic MCAO patients with prior ischemic stroke or TIA in the same territory.
Main Results:
- 13 patients experienced cardiovascular events or death; 1 in the asymptomatic group, 12 in the symptomatic group.
- Annual rates for composite outcomes (2.2% vs. 13.2%) and overall stroke (0.0% vs. 6.6%) were significantly lower in asymptomatic MCAO patients (p=0.041 and p=0.048, respectively).
- Asymptomatic MCAO patients showed significantly lower risks for stroke, MI, and death.
Conclusions:
- The overall prognosis of MCAO is comparable to middle cerebral artery stenosis or internal carotid artery stenosis.
- Asymptomatic MCAO appears to be a benign condition.
- Optimal medical therapy significantly reduces the risk of subsequent stroke, MI, or death in asymptomatic MCAO patients.
Background:
The annual risk of stroke or cardiovascular events has been reported to be over 10% in middle cerebral artery stenosis. However, the prognosis of patients with middle cerebral artery occlusion (MCAO) remains unclear. We investigated the risk of cardiovascular events or death in patients with symptomatic or asymptomatic MCAO.
Methods:
Consecutive patients with MCAO demonstrated by transcranial Doppler sonography and magnetic resonance angiography were enrolled. Medical records were reviewed during the follow-up period and a telephone interview was conducted using a preformed questionnaire, comparing asymptomatic and symptomatic patients who had a history of ischemic stroke or transient ischemic attack in the same vascular territory. The composite outcome of ipsilateral stroke, hemorrhagic stroke, overall stroke, myocardial infarction (MI), any vascular death and nonvascular death was evaluated during the follow-up period.
Results:
Thirty-seven of the 48 patients were symptomatic and 11 were asymptomatic. During the mean follow-up period of 2.8 years, cardiovascular events or death occurred in a total of 13 patients: 1 from the asymptomatic group and 12 from the symptomatic group (overall stroke, 6; MI, 2; vascular death, 1; nonvascular death, 5). The annual rates of composite outcome (2.2 vs. 13.2%, p = 0.041) and overall stroke (0.0 vs. 6.6%, p = 0.048) were significantly lower in the asymptomatic group.
Conclusion:
These results suggest that the overall prognosis of MCAO is not worse than previously reported for patients with middle cerebral artery stenosis or internal carotid artery stenosis. Asymptomatic MCAO seems to be a benign condition associated with a low risk of subsequent stroke, MI or death under the optimal medical therapy.
