Abstracts

Rationale: There has been increased recognition of the role of the immune system, including neuronal autoantibodies and neuroinflammation, in epileptogenesis. Seizures are a common feature of encephalitis, present in over 50% of cases and reported with both autoimmune (AE) and infectious (IE) etiologies. While there is robust literature on the association between epilepsy and various psychosocial outcomes, very little is known about the psychosocial outcomes of encephalitis. In this study, we survey individuals with AE and IE to determine long-term psychosocial functioning in these patients. Methods: Individuals who self-report as having AE or IE were asked to participate in the study via a website link distributed to members of the UK-based Encephalitis Society. To be included, participants had to recall their diagnosis and presence of a specific autoantibody (AE) or infectious agent (IE). The survey included non-identifying demographic questions and the Patient-Reported Outcomes Measurement Information System (PROMIS) Psychosocial Illness Impact - Negative - Short Form. This tool assesses negative psychosocial outcomes by capturing changes in participant responses to statements before and after illness (e.g., “I feel worthless”). The administered PROMIS tool raw scores were normalized to generate T-scores using the available control dataset of a national sample enriched for chronic illnesses. Results: 137 eligible participants aged 16-76 years from 18 countries were included in analyses. 67% were male, and 33% were female. Average age of symptom onset was 39 years (range: 1-74 years, standard deviation 16.6 years), and average duration since onset was 9.4 years. 25% reported antibody-positive AE, most commonly with anti-NMDA receptor antibodies (52% of AE cases). 69% reported IE with a known infectious agent, most commonly with HSV (75% of IE cases). 6% reported both AE and IE. 48% of participants with AE or IE who were employed/in school prior to encephalitis onset have been unable to return to work/school since their illness. 31% of those who have returned to work/school require accommodations, and 59% of those who have not returned to work/school receive governmental assistance due to illness-related disabilities. 31% of participants who drove before encephalitis have been unable to drive since their illness, and 94% of them report encephalitis-related reason(s) (e.g., ongoing seizures, cognitive limitations, fear of symptoms returning). The mean score on the administered PROMIS tool in participants with AE or IE (mean: 60.3; standard deviation: 8.6) was higher (worse) than that of the control dataset of individuals with other chronic illnesses (p<0.0001). Scores on all individual items were higher after illness than before illness (p<0.0001). The three items with the greatest changes in mean scores from before to after illness were: “Worry about my health interferes with my life,” “I feel disconnected from others,” and “I feel isolated from others” (p<0.0001). There was no difference between AE and IE participants on any administered assessment. Conclusions: Encephalitis is associated with a decline in long-term psychosocial function, supporting the need for more comprehensive support for this population. Increased awareness of the specific areas affected should inform the design of targeted psychosocial interventions in future studies. Funding: None