Upper Motor Neuron Disorders: Primary Lateral Sclerosis, Upper Motor Neuron Dominant Amyotrophic Lateral Sclerosis, and Hereditary Spastic Paraplegia

Following the exclusion of potentially reversible causes, the differential for those patients presenting with a predominant upper motor neuron syndrome includes primary lateral sclerosis (PLS), hereditary spastic paraplegia (HSP), or upper motor neuron dominant ALS (UMNdALS). Differentiation of these disorders in the early phases of disease remains challenging. While no single clinical or diagnostic tests is specific, there are several developing biomarkers and neuroimaging technologies which may help distinguish PLS from HSP and UMNdALS. Recent consensus diagnostic criteria and use of evolving technologies will allow more precise delineation of PLS from other upper motor neuron disorders and aid in the targeting of potentially disease-modifying therapeutics.

Automated summary

After ruling out potentially reversible causes, differential diagnosis for patients with a predominant upper motor neuron syndrome includes PLS, HSP, and UMNdALS. Distinguishing between these disorders in the early phases remains challenging, but emerging biomarkers and neuroimaging technologies may be helpful for differentiation. Consensus diagnostic criteria and evolving technologies can improve the precise delineation of PLS from other upper motor neuron disorders and aid in targeted therapeutics for potential disease modification.