Tertiary damage: Hippocampal and brain changes after spinal cord injury

JURE, IGNACIO; LABOMBARDA, F

Spinal Cord Injury: Cellular Mechanisms to Medical Management

Elsevier

Año: 2023;

Spinal cord injury (SCI) drives to permanent motor,sensory and autonomic dysfunction. The mechanic impact leads to a primarydamage followed by its propagation through the contiguous spinal segments,which is known as secondary damage. In this chapter we propose the termtertiary damage to describe the alterations that distal parts of the brain sufferafter SCI. Traditionally, SCI investigation was focused on pathophysiologicalchanges in the spinal cord with efforts being made in order to recoversensorimotor function and relieve neuropathic pain. In this regard, severalstudies have shown anterograde and retrograde axonal degeneration which leadsto the atrophy of the deafferentated sensorimotor cortex. However, studiesconsidering brain areas other than the sensorimotor system are scarce althoughhumans suffer from cognitive and emotional impairment. Interestingly, animalmodels have shown that SCI results in cognitive deficits and depressive-likebehavior, which correlate with hippocampal neurodegeneration, neurogenesisreduction and neuroinflammation. Furthermore, neuroinflammation response andneurodegeneration after SCI reach other brain areas related to the processingof pain. The mechanisms underlying the tertiary damage are unknown, but therelease of chemokines induced by axonal injury at distance sites and thesystemic response of the immune system and the stress axis could be involved inthe process. Finally, we consider the impact that implies the inclusion oftertiary damage in rehabilitation and therapeutic strategies.