Current evidence of arterial spin labeling in amyotrophic lateral sclerosis: A systematic review.

Objective: This study aimed to evaluate the utility of arterial spin labeling (ASL) in assessing cerebral blood flow (CBF) changes in amyotrophic lateral sclerosis (ALS), and its potential as a biomarker for early diagnosis.

Methods: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies that employed ASL to compare CBF between ALS patients and healthy controls were included.

Results: Seven studies were included. A consistent finding across these studies was hypoperfusion in both the motor and non-motor regions, particularly in the frontotemporal cortex. Hypoperfusion in motor regions was correlated with functional impairment and was observed prior to structural changes, suggesting its potential as an early biomarker. There is limited evidence to suggest that monitoring changes in CBF patterns in the brain. Besides, limited findings showed initial hyperperfusion in regions not yet involved in the pathological process, and progressing hypoperfusion in regions with increasing pathological burden.

Conclusions: This review highlights the potential of ASL as a valuable tool for understanding the neurovascular dysfunction in ALS. Further research is required to validate its clinical utility for diagnosing ALS and monitoring disease progression.