Background Antibodies to myelin oligodendrocyte glycoprotein (MOG) are being increasingly detected in patients with non-MS demyelination many of whom have the neuromyelitis optica spectrum disorders (NMOSD) phenotype. Cortical involvement or seizures are rare in AQP4 IgG NMO. Having encountered one MOG IgG+ve patient with seizures we systematically reviewed all our patients.
Method Retrospective review of the clinical and MRI data of all MOG IgG +ve cases (n=28) and 100 patients with AQP4 IgG+ve NMOSD for seizures and cortical lesions.
Results Only 1/100 NMOSD with AQP4 IgG had seizures (1%)-a 43-year old woman with epilepsy, her first seizure 5 years before the onset of NMOSD. Brain MRI was normal. 4/28 patients with MOG IgG had seizures (14%) that occurred along with an episode of demyelination. All 4 had cortical lesions and relapsing demyelination and are on immunosuppressants. 3 continue on antiepileptic drugs.
Conclusion Patients with MOG IgG associated disease are more likely to have seizures (P<0.008, Fisher's test) and cortical MRI changes compared to AQP4IgG +ve cases. This may further support the view that the two are different diseases.