Adult-Onset Genetic Leukoencephalopathies With Movement Disorders

Genetic leukoencephalopathies (GLEs) are a group of white matter abnormalities with heterogeneous radiological and phenotypic features. Although these conditions have mostly been described in children, adult-onset cases are increasingly recognized owing to the widespread use of neuroimaging and advances in molecular genetic testing. The disease course is often progressive with a varied spectrum of presentations, trapping neurologists in the dilemma of differential diagnosis. Movement disorders are among the most common symptoms, and their diversity makes diagnosis challenging. In this review, we focus on adult-onset GLEs with movement disorders and offer a step-by-step diagnostic approach by clarifying the phenomenology of movement, advising investigations for acquired causes, describing the clinical and radiological clues to each disease, emphasizing the limitations of advanced molecular testing, and discussing the future application of artificial intelligence. We provide a list summarizing the leukoencephalopathies associated with different categories of movement disorders. In addition to guiding clinicians on how to narrow the list of differential diagnoses with the tools currently available, another aim of this review is to emphasize the inevitable trend toward applying advanced technology in diagnosing these difficult diseases.