Correlation between diffusion- and perfusion-weighted MRI and neurological deficit measured by the Scandinavian Stroke Scale and Barthel Index in hyperacute subcortical stroke (< or = 6 hours)

Objective: We used combined diffusion-weighted (DWI) and perfusion-weighted (PWI) MRI to characterize hyperacute infarctions within 6 h of symptom onset with special reference to subcortical infarctions, and investigated the relation between perfusion-diffusion mismatch volume and functional outcome.

Material and methods: Twenty-two patients presenting with symptoms of acute stroke underwent DWI and PWI within 6 h of symptom onset, and follow-up MRI 30 days later. Twelve of these had a subcortical infarction on acute DWI. Lesion volumes were measured by acute DWI and PWI as well as chronic T(2)-weighted MRI (T2WI). Clinical severity was measured by the Scandinavian Stroke Scale (SSS) and the Barthel Index (BI).

Results: In the 12 patients with subcortical infarctions, PWI and especially DWI correlated strongly with acute and chronic neurological SSS score, as well as with final infarct volume. Furthermore, a hyperacute PWI/DWI mismatch in this subgroup predicted lesion growth. There was a weaker correlation between acute DWI/PWI and neurological score among all 22 patients, and patients with a PWI/DWI mismatch larger than 100 ml had a significantly larger lesion growth and a poorer outcome than patients with a smaller mismatch.

Conclusions: Subcortical infarctions may represent a sizeable subgroup of acute stroke patients. Also subcortical infarctions may have a PWI/DWI mismatch and therefore may respond to neuroprotective/thrombolytic therapy. Hyperacute DWI may reflect the acute clinical status and predict the outcome in patients with subcortical infarction.