Researchers exploring the evolution of brain perfusion and its association with primary progressive multiple sclerosis (PPMS) discovered that it had a putative association with various MS disease mechanisms, as published in the European Journal of Neurology.
PPMS is a subtype of MS that has shown to be more neurodegenerative than relapsing-remitting MS. The progression of disability in patients with PPMS is characterized by inflammation and neurodegeneration, and both of these mechanisms are thought to alter brain perfusion. This theory has been strengthened by studies that demonstrated brain lesions in patients with PPMS.
Brain perfusion assessment via magnetic resonance imaging (MRI) has already been hailed as a potential biomarker in MS. Arterial spin labeling (ASL) is a functional imaging technique that can assess brain perfusion without the need for gadolinium. Existing medical literature suggests a link between PPMS disability and brain perfusion; hence, the researchers decided to investigate the association between brain perfusion, neurodegeneration, and disability by studying an exclusive longitudinal cohort of patients with PPMS.
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They recruited participants from the Institute of Neuroimmunology and MS at the University Medical Centre Hamburg-Eppendorf in Germany who had been diagnosed with PPMS and had an Expanded Disability Status Scale (EDSS) score of ≤7.0. These participants were recruited between 2012 and 2015, with the understanding that there would be annual follow-up visits over the following 5 years.
Follow-up visits included the following:
- Brain MRI with an ASL perfusion sequence
- EDSS assessment
- Assessment using a modified version of the Multiple Sclerosis Functional Composite
The results demonstrated that with disease duration, EDSS disability increased, while brain perfusion decreased. Lower global perfusion was correlated with higher disability scores in the various disability assessments used. In addition, regional associations with key disability metrics appeared to represent both adaptive and maladaptive functional reorganization.
“Decreasing perfusion indicates a putative association with MS disease mechanisms such as neurodegeneration, reduced metabolism, and loss of resilience,” the research team concluded. “A low alteration rate limits its use in clinical practice, but regional association patterns might provide a snapshot of adaptive and maladaptive functional reorganization.”
Testud B, Delacour C, El Ahmadi AA, et al. Brain grey matter perfusion in primary progressive multiple sclerosis: mild decrease over years and regional associations with cognition and hand function. Eur J Neurol. Published online February 15, 2022. doi:10.1111/ene.15289