MULTIPLE SCLEROSIS OR FABRY DISEASE - PROS AND CONS.

- Fabry disease is a rare X-linked inherited lysosomal storage disease affecting multiple organ systems, presenting in the central nervous system (CNS) as white matter lesions with underlying cerebral vasculopathy and autoinflammatory changes of the choroid plexus and leptomeninges. We present a young female patient (age 36 years) admitted to our department due to visual loss on the left eye. Magnetic resonance imaging (MRI) showed demyelinating lesions in the frontal and parietal lobe, periventricularly, in mesencephalon and right cerebellar hemisphere, and left optic neuritis; MR angiography was normal. Her medical history revealed renal dysfunction, hypothyroidism, and miscarriage in the 6th month of pregnancy due to eclampsia and Fabry disease in the family (mother). Cerebrospinal fluid analysis showed mild pleocytosis, normal blood brain barrier function and oligoclonal bands type 3. Visual evoked potentials showed prechiasmal dysfunction of the left optic nerve. Genetical testing for Fabry disease was positive (two heterozygous mutations), with decreased alpha galactosidase activity values and increased Lyso GB3 values. The patient received corticosteroid therapy (methylprednisolone) 1 g for 5 days, which led to regression of visual disturbances on the left eye. After this acute treatment, there was a question of definitive diagnosis and further treatment of the underlying cause. Considering renal dysfunction, miscarriage, arterial hypertension, positive genetic and biochemical testing for Fabry disease, as well as MRI findings showing lesions in posterior circulation, we concluded that the patient probably had Fabry disease with autoinflammatory changes in the CNS and should be treated with enzyme replacement therapy. Still, there was a question of optic neuritis on the left eye and positive oligoclonal bands favoring the diagnosis of multiple sclerosis. Therefore, further clinical and neuroradiological follow up was needed to distinguish multiple sclerosis and Fabry disease in this patient.