Deep cerebral infarcts extending to the subinsular region

We sought to determine the clinical and radiological features and pathogenesis of deep cerebral infarcts extending to the subinsular region (DCIs).

- We defined DCIs as subcortical infarcts extending between the lateral ventricle and the subinsular region with a paraventricular extent >1.5 cm and a subinsular extent of at least one third of the anteroposterior extent of the insula. We identified patients by review of imaging records and noted the clinical information, risk factors, and investigations. We compared risk factors and clinical features between DCIs and "internal border zone" infarcts restricted to the paraventricular region.

- Eight patients were studied. The typical clinical features of DCIs were hemiparesis, aphasia, dysarthria, and dysphagia. Aphasia was seen in 3 of 5 patients with left-sided infarcts. Six of 8 patients (75%) had hypoperfusion as a possible pathogenetic factor (carotid occlusion in 4, surgical clipping of MCA in 1, low ejection fraction in 1), and 3 patients (38%) had cardioembolism as a possible pathogenetic factor (atrial fibrillation in 2, low ejection fraction in 1). One patient (12%) had no cause for stroke. Clinical features were similar to those for paraventricular infarcts. Carotid occlusion was more frequent (P=0.04), and there was a trend toward a higher frequency of hypertension (P<0.1) and smoking with DCIs than with paraventricular infarcts. DCIs were located in a deep vascular border zone.

- The clinical features and pathogenesis of DCIs overlap with those of internal border zone paraventricular infarcts. Hypoperfusion may give rise to DCIs since large-artery occlusion is their main risk factor. The larger size of DCIs compared with paraventricular infarcts may relate to a poorer collateral blood supply.