Rinsho Shinkeigaku (Clinical Neurology)

Original Article

Clinical features, neuroimaging and prognosis of adult patients with clinically diagnosed acute-onset encephalitis treated at a teaching neurology center in the Toyama area of Japan

Nobuhiro Dougu, M.D.1), Shutaro Takashima, M.D.1), Yoshiharu Taguchi, M.D.1), Etsuko Sasahara, M.D.1), Hiroshi Inoue, M.D.2) and Kortaro Tanaka, M.D.1)

1)Department of Neurology, Toyama University Hospital
2)The Second Department of Internal Medicine, Faculty of Medicine, Toyama University

Although acute viral encephalitis (AVE) and acute disseminated encephalomyelitis (ADEM) are etiologically and pathologically distinct, a differential diagnosis between these two disorders is often difficult, especially if the patient exhibits a disturbance in consciousness. To identify useful clinical differences enabling a differential diagnosis to be made at an early stage, we retrospectively analyzed patients who had been admitted to our hospital within the past seven years because of acute-onset encephalitis with a disturbance in consciousness. Eleven adult patients were classified as having AVE, and 8 adult patients were classified as having ADEM within this period. The clinical characteristics of the two groups were then compared. Patients with AVE exhibited a disturbance in consciousness as their first neurological sign, whereas patients with ADEM initially showed focal signs like spastic paralysis, urinary disturbance and ataxia, which were followed by a disturbance in consciousness. ADEM is usually preceded by infection or vaccination, but obtaining a medical history from patients with disturbed consciousness is often difficult. Based on the present analysis, the initial manifestation of focal neurological signs may be very useful for distinguishing ADEM from AVE.

(CLINICA NEUROL, 46: 533－539, 2006)
key words: acute viral encephalitis, acute disseminated encephalomyelitis (ADEM), convulsive status epilepticus, limbic encephalitis, brain MRI

(Received: 22-Jul-05)