Autoimmune Encephalitis in Rural Central Illinois

Encephalitis may be defined as “An acute inflammatory global neurologic dysfunction”, characterized by altered mental status with protracted clinical course and high risk of significant morbidity. Timely therapeutic intervention is paramount to insure a good outcome”. The most common endemic infectious encephalitis in immune-competent hosts involves several types of herpes virus infections, frequently herpes simplex virus (HSV). We may add to this group the less common epidemic-regional, arbovirus encephalitis. In recent years however, identification of novel auto-antibodies lead to the classification of autoimmune encephalitis in two clinical settings: 1.A paraneoplastic disorder (PNS) with either an overt or an occult neoplasm driving the dysimmune response 2. Antibodies directed against specific neuronal receptor channels in patients without underlying malignancy. In both groups, the initial management involves search for a possible occult neoplasm as a trigger of the autoimmune response and the expeditious initiation of immunosuppressive therapy. Autoimmune non-paraneoplastic encephalitis is the focus in this chapter. We will discuss four cases with autoimmune encephalitis diagnosed on our service in recent years. The clinical phenotype, work up results and treatment will be reported. A management algorithm will also be proposed (Figure 1). All four patients were residents of either rural or small urban Illinois communities. These cases illustrate how familiarity with these disorders and increasing comfort with immune-suppression represent a needed skill in the practice of General Neurology.