Rapid improvement of tick-borne encephalitis after treatment with corticosteroids Tick-borne encephalitis (TBE) is a viral disease transmitted by ticks. The virus is divided into three subtypes named Western, Siberian and Far Eastern TBE virus (TBEV). Western TBEV is endemic in parts of Europe and Sweden and typically causes a biphasic illness with influenza-like symptoms followed by neurological symptoms ranging from mild meningitis to severe meningoencephalitis and death. Despite an effective vaccine, TBE is increasing in Sweden and Europe. The pathogenesis of TBE is poorly understood; direct infection of neurons as well as immunological reactions mediated by T-cells have been implicated. In some endemic areas, such as Lithuania, patients with TBE are given corticosteroids based on the clinical experience that it results in rapid improvement. However, existing retrospective studies have failed to show beneficial effects of corticosteroids compared to symptomatic treatment in patients with TBE. This case report describes how an elderly man with meningoencephalitis and cranial nerve palsy due to TBE rapidly improved after administration of high dose corticosteroids.