Advanced neuroimaging approaches in amyotrophic lateral sclerosis: refining the clinical diagnosis

ABSTRACT

Introduction: In the last decade, multiparametric magnetic resonance imaging (MRI) has achieved tremendous advances in applications to amyotrophic lateral sclerosis (ALS) to increase the understanding of the associated pathophysiology. The aim of this review is to summarize recent progress in the development of MRI-based techniques aiming to support the clinical diagnosis in ALS.

Areas covered: The review of structural and functional MRI applications to ALS and its variants (restricted phenotypes) is focused on the potential of MRI techniques which contribute to the diagnostic work-up of patients with the clinical presentation of a motor neuron disease. The potential of specific MRI methods for patient diagnosis and monitoring is discussed, and the future design of clinical MRI applications to ALS is conceptualized.

Expert opinion: Current multiparametric MRI allows for the use as a clinical biological marker and a technical instrument in the clinical diagnosis of patients with ALS and also of patients with ALS variants. Composite neuroimaging indices of specific anatomical areas derived from different MRI techniques might guide in the diagnostic applications to ALS. Such a development of ALS-specific MRI-based composite scores with sufficient discriminative power versus ALS mimics at an individual level requires standardized advanced protocols and comprehensive analysis approaches.

KEYWORDS:

• Amyotrophic lateral sclerosis
• diffusion tensor imaging
• magnetic resonance imaging
• motor neuron disease
• neurodegenerative disease
• neuropathological staging

Article highlights

• multiparametric MRI protocol has to be defined which addresses all the needs for an individual refinement of the diagnosis in a given ALS patient.

• The tract-of-interest-based staging categorization allows for the individual analysis of predefined tract structures, making it possible to image in vivo the neuropathological disease stages in ALS.

• Standardization of MRI acquisition and postprocessing protocols on the basis of multi-center initiatives will guide in the goal of personalized diagnostic procedures in ALS.

• As a prerequisite for the definition of the single MRI-based components with clinical diagnostic use in ALS, future activities will make use of the improved opportunities of data sharing between sites.

• Composite MRI indices derived from different MRI techniques and different anatomical regions might guide in the computerized diagnostic applications to ALS, both for brain and for spinal cord MRI.

• The development of ALS-specific MRI-based composite scores with sufficient discriminative power at an individual level requires standardized advanced protocols and unbiased analysis approaches.

Acknowledgments

The authors like to thank David Ewert for help with the graphical design of the figures.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.