55-year old gentleman, known diabetic and hypertensive presented with symptoms of right hemiplegia and aphasia of three hours duration. He was evaluated for possible thrombolytic treatment.
CT brain done (3.5 hours after stroke symptom onset) showed a dense (also referred to as hyperdense) MCA sign (yellow arrow in the 1st image). Thrombosis of middle cerebral artery (MCA) in sylvian fissure is responsible for hyperdense MCA sign.
Whenever we notice dense MCA sign, it usually suggests a malignant MCA territory infarction in the involved cerebral hemisphere. This sign usually develops within 90 minutes of symptom onset.
Subtle or early signs of MCA territory infarct: Infarct in brain CT is usually seen as hypodensity in the affected area, however, this finding may be missing in the hyperacute or early phase. In this phase, the following signs should be looked for on the CT brain:
1. Loss of gray-white matter differentiation, 2. Effacement of cerebral sulci, 3. Attenuation of lentiform nucleus. These findings can be seen in second CT image.
Dense MCA sign indicates a large hemispheric infarct, and is usually associated with poorer outcomes. In our patient, we thrombolysed with intravenous tissue plasminogen activator. Patient showed clinical improvement after thrombolytic therapy.