Anti-SEZ6L2 antibodies in paraneoplastic cerebellar syndrome: case report and review of the literature

Abstract

Seizure Related 6 Homolog Like 2 (SEZ6L2) protein has been shown to have implications in neuronal and especially motor function development. In oncology, overexpression of SEZ6L2 serves as a negative prognostic marker in several tumor entities. Recently, few cases of anti-SEZ6L2 antibody mediated cerebellar syndromes were reported. In this article, we present a case of a 70-year-old woman with subacute onset of gait disturbance, dysarthria and limb ataxia. Serum anti-SEZ6L2 antibodies were markedly increased, and further diagnostic workup revealed left sided breast cancer. Neurological symptoms and SEZ6L2 titer significantly improved after curative tumor therapy. This is a very rare and educationally important report of anti-SEZ6L2 autoimmune cerebellar syndrome with a paraneoplastic etiology. Additionally, we performed a review of the current literature for SEZ6L2, focusing on comparing the published cases on autoimmune cerebellar syndrome.

Fig. 1

Course of the disease in chronological order

Fig. 2

MR image of the patient shows atrophy of cerebellar hemispheres (arrows) in Axial T2-FLAIR images a and coronal T1-weighted images b and vermis atrophy (arrowhead) in sagittal T2-weighted images (c)

Fig. 3

Review of published literature on SEZ6L2