Benmoh Y, Hamid M, Arrami A, Alaoui MY, Satte A, Mounach J, Bichra MZ, Elfenni J and Bourazza A
Introduction: Neurmyelitis Optica Spectrum Disorders (NMOSD) is a rare central nervous demyelinating autoimmune disease. Posterior Reversible Encephalopathy Syndrome (PRES) is a reversible subcortical vasogenic brain edema with acute neurological symptoms and specific radiologic findings. We report a rare case associating both NMOSD and PRES as revealing form.
Case Report: A 50 years old woman, with previous history of 3 neurologic episodes made of visual loss, lower limb weakness and paraethesia, regressing spontaneously in the past 3 years. 7 days before her admission, she presented rapidly progressive weakness of both lower limbs, followed by urinary retention, headache and fluctuant awareness. Clinical examination found symmetric flaccid paraparesis, with sensory level at D6. Spinal cord MRI showed thoracic longitudinally extensive transverse myelitis compatible with NMOSD pattern. Cerebral MRI showed increased signal intensity in T2 and FLAIR weighted images localized in: subcortical dominant in parieto-occipital regions and holohemispheric watershed pattern compatible with PRES. Cerebrospinal fluid study objectified pleocytosis to neutrophils, and Visual evocked potential study found bilateral demyelinating optic neuritis. The Aquaporin4-specific IgG was positive, with large negative paraclinical tests eliminating alternative etiologies or association. The fail of initial bolus methyprednisolone, leaded to a cure of human immunoglobulin and cyclophosphamide with favorable course. Cerebral MRI control was performed 3 months and 12 months later, and showed complete regression of signal abnormalities. Spinal cord MRI control showed thoracic spine atrophy.
Conclusion: Severe impairment in blood brain barrier water channels by aquaporin4-specific IgG cause a knockout phenotype with an increase of brain edema. This suggests that NMOSD acute attack and PRES may co-occur like in our case. Few cases are reported over the literature, for this association, especially as a revealing form. When the precipitating cause is treated or eliminated, PRES lesions are usually reversible. Thus, in PRES associated to NMOSD, the treatment refers to immunotherapy.