Longitudinal quantitative magnetic resonance imaging in adrenomyeloneuropathy

Area of Science:

• Neurology
• Radiology
• Genetics

Background:

• Adrenomyeloneuropathy (AMN) is a common metabolic hereditary spastic paraplegia primarily affecting the spinal cord.
• Quantifying AMN progression is challenging due to limitations in clinical scales and lack of biomarkers.

Purpose of the Study:

• To investigate if quantitative MRI of the spinal cord and brain can detect structural changes in AMN over a short period.
• To explore potential surrogate outcome measures for AMN progression.

Main Methods:

• A longitudinal observational study involving six AMN patients and six age-matched controls.
• Assessed total cord areas (TCAs) and diffusion tensor imaging (DTI) metrics of the cervical spinal cord and corticospinal tracts.
• Follow-up was conducted at a mean of 22.6 months.

Main Results:

• AMN patients showed a significant reduction in mean TCA at the T1-T2 level (-3.79%) and a trend at lower cervical levels.
• Significant changes in DTI metrics (fractional anisotropy, mean diffusivity, radial diffusivity) were observed at the C2-C3 level in AMN patients.

Conclusions:

• Spinal cord TCAs and DTI metrics show promise as surrogate outcome measures for AMN.
• Focusing on the cervical-thoracic junction and upper cervical cord is recommended for AMN assessment.
• Findings are valuable for future AMN clinical trials and other spinal cord diseases.