TITLE:
Can Autoimmune Encephalitis Occur with Negative Markers? A Rare Case Report
AUTHORS:
Anas Mahmoud, Ahmed Salem, Nizar Alyassin, Moh’d Azzam
KEYWORDS:
Autoimmune Encephalitis, Seizures, Paraneoplastic Syndrome, Encephalitis, Autoimmune
JOURNAL NAME:
Case Reports in Clinical Medicine,
Vol.12 No.2,
February
6,
2023
ABSTRACT: In our case, we present a case of a 27-year-old male who presented with progressively worsening altered mental status and seizures. Over the course of his admission to the hospital and intensive care unit, laboratory testing failed to find an offending agent to his presentation. Testing did result in the diagnosis of encephalitis, but an underlying cause was not found. After careful exclusion of bacterial, viral, and other types of encephalopathy, autoimmune encephalopathy was diagnosed despite the absence of commonly used markers of autoimmune encephalopathy. The presentation and symptoms of our patient led to a wide range of differentials, and a high index of suspicion was needed throughout his admission in order to obtain the appropriate tests. Although appropriate testing might be ordered, due to the sensitivities and specificities of all laboratory tests, these objective tests do produce false negative results at times. It is in these times that one must weigh the physical exam, clinical judgment, and the process of elimination to diagnose an underlying pathology. Autoimmune Encephalitis diagnosis can be broken down into possible, probable, and definitive diagnoses based on antibody testing results. In this case, we present a patient with probable autoimmune encephalitis that failed to yield positive autoimmune markers after extensive testing of other possible causes of encephalitis.