Abstract Colony stimulating factor-1 receptor (CSF1R) encodes for a tyrosine kinase receptor expressed on microglia. CSF1R related disorder is a devastating autosomal dominant leukoencephalopathy caused by CSF1R with variable penetrance in adults. It remains significantly underdiagnosed or misdiagnosed. We report a case of a 43-year-old woman with an insidious onset of neurocognitive decline, alien limb phenomenon, and personality changes over 1 year. In this report we will discuss the clinical approach, differential diagnosis, investigation, and available treatment options for CSF1R related disorder.