Neurodegeneration with Brain Iron Accumulation

The term NBIA encompasses a heterogeneous group of inherited disorders characterized clinically by progressive extra pyramidal syndrome and pathologically by excessive iron deposition in brain, primarily affecting the basal ganglia (globus pallidus mainly). The hallmark of this syndrome is the age specific phenotypic presentation and intraphenotypic heterogeneity. NBIAs at present include ten subtypes with genes identified in nine subtypes. They form an important differential diagnosis for the phenotype of global developmental delay in infancy/childhood to dystonia-parkinsonism or isolated parkinsonism at all ages and also for the isolated craniocervical dystonia of adult onset. There needs to be a high index of clinical suspicion for this syndrome and the evaluation includes MRI brain T2* weighted imaging which reveal symmetrical iron deposition in bilateral globus pallidi and other basal ganglia. The T2* imaging pattern of iron deposition varies amongst the different subtypes and the combination of clinical phenotype and MRI signature makes it easier to confidently make a diagnosis of NBIA and to recommend genetic testing. The treatment to date is mostly symptomatic with targeted therapies on the horizon.