Clinical and Radiological Evaluation of Neuromyelitis Optica in Children: Report on a Case Series

Abstract

Objective: To describe patterns for conventional magnetic resonance imaging (MRI) of the cranium in pediatric patients with neuromyelitis optica (NMO). Methods: A retrospective, descriptive study of cephalic lesions and classification of abnormality patterns on MRI of the cranium in pediatric patients with NMO was conducted using the criteria established by Wingerchuck and colleagues, 2006. There viewed cases were from patients treated between 1999 and 2015 at the Center for Demyelinating Disease in Rio de Janeiro, Brazil. Results: Of 55 patients treated for NMO at our center, 12 (21.8%) had their first neurological symptoms before the age of 18 and were thus included in this study. Nine (75.0%) were female and of African descent. IgG-NMO test were positive in 8 patients (66.7%) and negative in 4 (33.3%). The average age of the onset of neurological problems was 11 years old. Transverse myelitis was documented in 7 patients (58.3%), unilateral optic neuritis (ON) in 3 (25.0%), and bilateral ON in 2 (16.6%). The types of MRI patterns were: Absence of a lesion in the cerebral hemispheres and brain stem - The only patient AQP4-seropositive (8,3%) without a lesion detected by head MRI. Unespecific hemispheric lesions - They were found in 2 patients AQP4-seropositive (16,6%). Lesions in the ependyma infratentorial, brainstem and bulbomedular junction associated were present in only one. Hemispheric lesions similar to MS in conjunction with lesions specific to NMO - They were found in 2 patients (16,6%), one was AQP4-seropositive and the other  AQP4-seronegative. Lesions in the ependyma supratentorial and brainstem were associated in both cases. Lesions specific to NMO – This type was revealed by MRI in 5 patients (41,6%). Two patients had no lesions in the cerebral hemispheres, but the brainstem was involved in both. In patient AQP4-seronegative there was lesion in the medulla oblongata and the patient AQP4 seropositive there was an extensive lesion in the brainstem, area postrema and infratentorial ependyma. In 3 patients there were lesions in corticospinal tract and the brainstem. Lesion in the ependima supratentorial was found in only one.  Extensive hemispheric lesions were demonstrated by MRI in 2 patients AQP4-seronegative (16.7%). Others lesions in 1 patients were found in medulla oblongata and bulbomedular junction. Conclusion: We observed five patterns of conventional head MRI findings in pediatric patients with NMO. Typical signs of NMO, using current criteria, were found with in all of the imaging patterns and were present in patients regardless of their AQP4 status. This case series showed a wide range of clinical and imaging MRI presentations of NMO. Conventional MRI protocols for the study of the brainstem, optic nerves and corticospinal tract showed specific signs and should be included in routine NMO diagnosis protocols.