Bilateral temporal lobe disease: looking beyond herpes encephalitis

Abstract: The temporal lobes have unique architecture, and functionality that makes them vulnerable to certain disease processes. Patients presenting with bilateral temporal lobe disease are often confused and have altered consciousness, and are therefore unable to provide cogent histories. For these reasons, imaging plays an important role in their workup and management. Disease entities causing bilateral temporal lobe involvement can be infectious, metabolic, neoplastic, and degenerative aetiologies, as well as trauma and cerebrovascular events. We will first describe the structural and functional anatomy of the temporal lobes and explain the mechanisms that underlie bilateral temporal lobe disease, and then show and discuss the different disease entities and differential diagnosis. Teaching points: • Bilateral temporal lobe disease is a unique pattern with specific differential diagnosis. • Patients presenting with bilateral temporal lobe disease are often confused. • Radiologists should be familar with the variety of disease processes that cause bitemporal disease.