CADASIL with an unusual presentation of prosopagnosia

Abstract

CADASIL is a rare autosomal dominant arteriopathy due to a NOTCH3 mutation on chromosome 19, known to result in subcortical infarcts and leukoencephalopathy. Here, we present a middle-aged gentleman with an acute onset of prosopagnosia. His MRI brain showed acute infarct of the right fusiform gyri and extensive subcortical leukoencephalopathy with bilateral anterior temporal lobe involvement and was eventually diagnosed with CADASIL. Despite bilateral anterior temporal lobe involvement being a distinctive feature of CADASIL on MRI, there has been no reported case of CADASIL with acute prosopagnosia so far. While CADASIL and prosopagnosia have been extensively studied over the last few decades, this could be the first CADASIL case presented with acute prosopagnosia alone. This case report illustrates the importance of recognizing prosopagnosia to avoid misdiagnosis or a delayed diagnosis of acute stroke.