Introduction: The most common forms of familial ALS are due to the C9ORF72 and SOD1 genes. Pathology studies have demonstrated patients with C9ORF72 ALS tend to develop more protein aggregates in the cerebellum and temporal lobes, while SOD1 patients develop more protein aggregates in the frontal and temporal lobes. (REF). Other means of looking for these signs are not established. Currently, we use brain MRI quantitative susceptibility mapping analysis (QSM) to examine susceptibility in the

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... or cortex, which is typically increased in motor neuron disease, correlating with the clinical syndrome. We designed a study to retrospectively assess the MRI/QSM in genetic ALS patients for specific regional changes.Methods: We retrospectively reviewed all genetic ALS patients seen in Neurology at Hospital for Special Surgery from 2013 through 2018 who had MRI with QSM. Our neuroradiologist carefully examined the scans of each patient.Results: We found no distinguishing abnormalities in the brain MRIs of the genetic ALS patients reviewed. QSM of the motor cortices and corticospinal tracts showed increase in susceptibility, which is not unique to any specific type of ALS.Discussion: MRI/QSM may not be useful in distinguishing ALS patients with the C9ORF72 or SOD1 mutations. This could reflect that the amount of protein aggregation may not be directly related to axonal loss, or that they affect certain neurons/tracts more than others.