Lacunar infarction in type 2 diabetes is associated with an elevated intracranial arterial pulsatility index

The arterial pulsatility index (PI) is measured by transcranial Doppler ultrasonography (TCD) and is postulated to reflect the vascular resistance distal to the artery being examined. An increased PI of the intracranial artery is often reported with diabetes mellitus (DM), old age, hypertension, intracranial hypertension, vascular dementia, and small artery disease. Microvascular complication of DM, which may contribute to cerebral infarction, involves the small perforating artery and may influence the PI of the proximal artery.

We performed a TCD examination in patients with type 2 DM with acute lacunar infarction (DML, n=35), type 2 DM without cerebral infarction (DMO, n=69), and in control cases with no DM or cerebral infarction (control group, n=41). We then compared the TCD findings among these groups.

The PI was significantly higher in the DML and DMO groups than in the control group (1.05, 0.93, 0.73. respectively, for the right middle cerebral artery; 1.04, 0.90, 0.73, respectively, for the left middle cerebral artery; 0.97, 0.89, 0.70, respectively, for the basilar artery). The PI was also significantly higher in the DML group than in the DMO group for both middle cerebral arteries. The flow velocity was comparable among the three groups.

The elevated PI of the intracranial arteries may reflect diabetic cerebral microvascular complications. The PI measurement using TCD may be a useful predictor of lacunar infarction in type 2 DM patients.