Diagnostic Challenges and Treatment Approach to Seronegative Autoimmune Encephalitis.

Seronegative autoimmune encephalitis (AE) is a rare, immune-mediated inflammatory syndrome that presents with a wide spectrum of neuropsychiatric symptoms, such as cognitive impairment, seizures, psychosis, focal neurological defects, and altered consciousness. This disease process presents with no identifiable autoimmune antibodies, which leads to uncertain diagnosis, delayed treatment, and prolonged hospital admissions. Early diagnosis and prompt treatment of AE should not be delayed, as early recognition and treatment leads to improved outcomes and disease reversibility for these patients. In this study, we present a case report of a 77-year-old male who presented with acutely altered mental status. This patient underwent an extensive workup and demonstrated no signs of clinical improvement throughout a prolonged hospital admission. The diagnostic challenges and treatment obstacles encountered during our care of this patient are described in this case report, along with recommendations for early diagnosis and prompt treatment for patients with suspected seronegative AE.