New developments in imaging in ALS.

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• Recent neuroimaging studies offer significant insights into Amyotrophic Lateral Sclerosis (ALS).
• These studies demonstrate early, genotype-specific topological brain changes preceding clinical symptoms.
• They characterize longitudinal propagation patterns and radiological underpinnings of various ALS clinical phenomena.

Purpose of the Study:

• To review recent advancements in neuroimaging for ALS and related motor neuron diseases (MNDs).
• To highlight the shift from focal brain changes to network and connectivity alterations.
• To discuss the implications for understanding ALS as a network disease.

Main Methods:

• Application of advanced neuroimaging techniques, including 7 Tesla MRI.
• Utilisation of clustering approaches for disease subtype identification.
• Development of machine-learning models for patient classification and prediction.

Main Results:

• Demonstrated genotype-specific topological changes and propagation patterns in ALS.
• Elucidated the neuroimaging basis of ALS clinical features and extra-motor manifestations.
• Identified progressive cortico-cortical, cortico-basal, cortico-cerebellar, cortico-bulbar, and cortico-spinal disconnection as drivers of decline.

Conclusions:

• Neuroimaging has redefined ALS as a network or circuitry disease.
• Connectivity alterations are the primary drivers of clinical decline in ALS.
• Quantitative neuroimaging is increasingly applied to non-ALS MNDs.