Infection and Encephalitis

Abstract

Magnetic resonance spectroscopy (MRS) serves as a powerful tool in narrowing the differential diagnosis in pediatric brain disorders. Unfortunately, the literature provides only a limited number of case reports and larger patient series employing this technique in the diagnosis and monitoring of infectious and inflammatory conditions. For these conditions producing encephalitis, MRS often demonstrates a more benign spectral appearance, with minor changes in metabolite levels, which contrasts to the typically more dramatic and often aggressive spectral features recognized in neoplasms and metabolic disorders. One key exception is frank abscess, as this process depletes the metabolites found in normal brain parenchyma and replaces them with distinct amino acids. This chapter first describes some practical and technical concerns associated with conducting neurological MRS studies in the pediatric patients to confirm the diagnosis of an infectious and/or inflammatory process. A brief description of infectious disorders and inflammatory conditions with illustrative imaging and spectroscopy examples from our center and the literature will provide important information in diagnosing these conditions.