@sveta25, I see @kobebeef2026 provided some helpful links with information about limbic encephalitis.

As per Mayo Clinic For some people, autoimmune encephalitis is triggered by certain cancers or infections or by some medicines.

When cancer related, it's known as paraneoplastic utoimmune encephalitis. It sounds like your husbands care team is taking care to determine the underlying cause so that he can get the right treatment. Read more here: https://www.mayoclinic.org/diseases-conditions/autoimmune-encephalitis/diagnosis-treatment/drc-20576406