Teaching Neuro Images : Basal ganglia involvement in facio-brachial dystonic seizures associated with LGI1 antibodies

Abstract

A 30-year-old man developed right faciobrachial dystonic seizures (FBDS).1 Ictal and interictal EEGs were normal. CSF analysis was unremarkable. Brain MRI revealed a gadolinium-enhancing lesion involving the left caudate and globus pallidus (figure 1). Leucine-rich glioma inactivated protein 1 (LGI1) antibodies were detected in the serum. Total-body CT scan revealed no malignancies. The patient underwent 5 cycles of plasmapheresis followed by long-term steroid therapy with complete benefit. A brain MRI performed after 5 months showed reduction of contrast enhancement (figure 2). LGI1, a secreted protein complexed with voltage-gated potassium channels, is highly expressed in the neocortex and hippocampus.2 LGI1 mutations have been described in patients with autosomal dominant partial epilepsy with auditory features (ADPEAF). Our patient had no clinical features of ADPEAF. Whether FBDS can be classified as epilepsy or dystonia is a matter of debate.3 The involvement of basal ganglia described in our patient can be relevant to the ongoing debate.