{
  "abstract": "Background Autoimmune encephalitis is an uncommon disorder characterised by antibody-mediated brain inflammation with presentations ranging from distinct clinical syndromes to less specific neurologic and psychiatric disturbances. Early diagnosis is difficult but may be aided by specific abnormalities such as the ‘extreme delta brush’ EEG pattern, which is characteristic of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.Methods We describe a unique case of anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis with extreme delta brush pattern on EEG, and conducted a literature review to identify any other cases of extreme delta brush observed in non-NMDAR encephalitis.Results A 47-year-old male presented with a first convulsive seizure following a subacute neuropsychiatric syndrome. MRI and lumbar puncture were non-contributory, but serum and cerebrospinal fluid antibody testing eventually returned positive anti-LGI1 antibodies. EEG revealed bursts of frontal-predominant high amplitude rhythmic delta activity with superimposed low amplitude fast activity, suggestive of extreme delta brush. Response to immunomodulatory therapies was excellent, which contrasts the poor outcomes typically seen in anti-NMDAR encephalitis associated with extreme delta brush. A literature review identified six other cases of extreme delta brush in non-NMDAR autoimmune encephalitis, with highly variable outcomes.Conclusion This case highlights the potential utility of extreme delta brush when observed outside the context of anti-NMDAR encephalitis. Publication of future cases of non-NMDAR encephalitis with unique EEG biomarkers including extreme delta brush should be encouraged.",
  "authors": [
    {
      "affiliations": [
        "Department of Neurology, Launceston General Hospital, Launceston, TAS, Australia",
        "Neurodegeneration Unit – Neurogenetics and Movement Disorders, Neuroscience Research Australia (NeuRA), Randwick, NSW, Australia"
      ],
      "name": "Michael Li"
    },
    {
      "affiliations": [
        "Department of Neurology, Launceston General Hospital, Launceston, TAS, Australia",
        "Launceston Clinical School, University of Tasmania, Launceston, TAS, Australia"
      ],
      "name": "Aaron De Souza"
    }
  ],
  "title": "3565 Extreme delta brush EEG pattern in anti-LGI1 encephalitis; a case report and literature review",
  "uid": "7e8428e3-9b70-5b84-9967-396ffdd23411"
}