WASTEOSOME DISTRIBUTION SUGGESTS SELECTIVE GLYMPHATIC VULNERABILITY IN DIFFERENT REGIONS OF THE SPINAL CORD

Wasteosomes, also known as corpora amylacea, are polyglucosan structures that accumulate in specific regions of the brain and spinal cord, increasing with normal aging as well as in certain neurodegenerative diseases. These bodies act as waste containers and have recently been proposed as markers of chronic glymphatic insufficiency. While their distribution in the human brain has been extensively studied, their presence and significance within the spinal cord remain poorly explored. The objective of the present study is to examine the distribution of wasteosomes in the human spinal cord to identify critical regions of the glymphatic system at the spinal level.

We examined postmortem human spinal cord sections obtained from 23 donors. From each donor, 4 haematoxylin and eosin-stained sections were selected, corresponding to the cervical, thoracic, lumbar, and sacral levels. Within each section, the number of wasteosomes was quantified across 6 distinct regions: fasciculus gracilis, dorsolateral fasciculus, lateral corticospinal tract, ventral horn, anterior corticospinal tract, and pericentral canal area. Statistical analyses were performed using variance analysis.

Results showed that wasteosomes consistently accumulated in the thoracic segment compared with the cervical, lumbar, and sacral levels. In addition, a marked posterior predominance was observed across all spinal levels, with the highest numbers of wasteosomes detected in the fasciculus gracilis and dorsolateral fasciculus.

The preferential accumulation of wasteosomes at specific spinal cord levels and regions suggests a segment- and region-specific vulnerability to impaired waste clearance, reinforcing the importance of expanding glymphatic system research to the spinal cord.