skip to main content

Anti-CASPR2 Encephalitis – Thymoma Screening — SCE Neurology MCQ

Instant feedback + full explanation. One question, done properly.

ModerateEpilepsy & Seizure DisordersAnti-CASPR2 Encephalitis – Thymoma ScreeningSCE Neurology

A 55-year-old man with epilepsy presents with subacute progressive encephalopathy and refractory seizures over 8 weeks. MRI brain shows bilateral mesial temporal T2/FLAIR hyperintensity with hippocampal swelling. CSF shows 20 lymphocytes/µL. Extensive infectious workup is negative. Serum anti-CASPR2 antibodies are positive. What associated conditions should be screened for?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Thymoma

Anti-CASPR2 antibodies are associated with autoimmune limbic encephalitis, neuromyotonia, and Morvan syndrome. They are less strongly associated with malignancy than some other paraneoplastic antibodies, but when a tumour is found, it is most commonly a thymoma. CT chest should be performed to exclude thymoma. Anti-CASPR2 encephalitis is more common in men (unlike anti-NMDAR, which is female-predominant). A: Ovarian teratoma is associated with anti-NMDAR antibodies. C: Lung cancer is more associated with anti-Hu. D: Testicular cancer is associated with anti-Ma2. E: Breast cancer is associated with anti-Ri and anti-amphiphysin.

Reference: ABN Autoimmune Encephalitis Guidelines; Graus et al. Lancet Neurol (2016)