Acute cerebral infarcts in multiple arterial territories associated with cardioembolism
The etiology of cerebral infarcts must be determined to prevent recurrence. Diffusion weighted imaging (DWI) is sensitive to acute ischemic lesions and valuable as to etiologic considerations 1. For visualization of ischemic lesions within the first hour after the onset of symptoms, DWI is the optimal modality. Furthermore, it allows differentiation between acute and chronic lesions in most cases 3. Some patients have multiple acute cerebral infarcts (MACI) occurring in more than one arterial territory. This suggests that MACI represent embolic mechanism and stroke neurologists generally believe that cardioembolism (CE) is often the main cause besides other potential sources of embolism, for example, from the aorta, major extracranial and intracranial vessels, fetal type of PCA or due to cross‐flow mechanism, coagulation disturbances, hyperhomocysteinemia, etc. 3. However, the number of DWI‐based studies supporting this concept is surprisingly low, and previous results are conflicting 7. Furthermore, most studies have used different methods and have been retrospective with too small sample sizes 7.
TOAST classification divides cardiac sources into high‐risk and medium‐risk groups according to the probability of cardioembolic stroke. Evidence of previous transitory ischemic attack (TIA) or stroke in more than one vascular territory or systemic embolism supports a cardiogenic mechanism 9. The mechanisms behind multiple acute lesions in a single territory must be distinguished from those which occur in more than one territory. Most multiple brain infarcts in a single territory are probably caused by early fragmentation of one thrombus or embolus, whereas MACI are probably caused by CE or ICA stenosis 3. We present the data on MACI in a prospective study including a large number of patients. We hypothesized that MACI are associated with CE.