COMMENTARY

A New Epilepsy Etiology

Epilepsy Notes

Andrew N. Wilner, MD

Disclosures

January 15, 2013

Introduction

Autoimmune epilepsy is a newly recognized treatable cause of uncontrolled seizures. A retrospective review of patients who presented with uncontrolled seizures to both the epilepsy and neuroimmunology clinics of the Mayo Clinic between 2005 and 2010 identified 32 patients (19 females, 13 males with probable autoimmune epilepsy.[1] Patients presented either exclusively with seizures (n = 11) or with seizures as their predominant symptom (n = 21). After immunotherapy, 67% became seizure free.

Clinical Profile

A history of autoimmune disease was present in 50% of the patients and a family history of autoimmune disease was present in 53%. Most of the patients presented with simple partial seizures and/or auras (27/32 [84%]), complex partial seizures (26/32 [81%]), and secondary generalized tonic-clonic seizures (17/32 [53%]). Twenty-six (81%) had daily seizures. Findings on electroencephalography (EEG) included interictal epileptiform discharges (n = 20), electrographic seizures (n = 15), focal slowing (n = 13), and generalized slowing (n = 12). Three patients had normal EEGs. Probable inflammatory changes were noted in 29 (63%) of MRIs. Cerebrospinal fluid from 30 patients revealed elevated protein in 17 (57%), and elevated leukocytes in 5 (17%), oligoclonal bands in 5 (19%) and was normal in 11 (38%). Neural autoantibodies were present in 29 (91%) of patients. These included voltage-gated potassium channel (VGKC complex) (n = 18; 56%), glutamic acid decarboxylase (GAD65) (n = 7; 22%), collapsin response-mediator protein (CRMP-5) (n = 2; 6%), Ma2 (n = 1; 3%), N-methyl-D-aspartate receptor (NMDAR) (n = 1; 3%), and ganglionic acetylcholine receptor (AChR) (n = 1; 3%). Two patients with VGKC neural autoantibodies had malignancies (thyroid or prostate) and 1 patient with CRMP-5 had recurrent bladder cancer. Eighty-one percent of patients had already tried 2 or more antiepileptic drugs. Two (6%) patients failed epilepsy surgery.

Therapy

Immunotherapy included IV methylprednisolone (n = 12), IVIg (n = 3), and combinations of IV methylprednisolone, IVIg, cyclophosphamide, or plasmapheresis (n = 12). Patients were followed for 3-72 months (median, 17 months). Eighteen patients (67%) became seizure free and 27 (81%) improved.

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