Related Experiment Videos
Early effects of nucleus pulposus application on spinal nerve root morphology and function
G Byröd1, B Rydevik, C Nordborg
1Department of Orthopaedics, Sahlgren University Hospital, Gothenburg University, Sweden.
Summary
Early nerve root damage occurs within 3 hours of nucleus pulposus application, but functional deficits are not yet apparent. This study investigates early inflammatory and cellular changes in nerve roots following epidural nucleus pulposus exposure.
Area of Science:
- Neuroscience
- Pathology
- Surgical Research
Background:
- Epidural application of nucleus pulposus (NP) is known to cause nerve root damage.
- The timeline for the onset of these functional and structural changes is not well-established.
Purpose of the Study:
- To determine the earliest onset of nerve root functional and histological changes following epidural NP application.
- To evaluate these changes within a reduced 3-hour exposure period.
Main Methods:
- Autologous nucleus pulposus was applied epidurally to the cauda equina in 10 pigs.
- Nerve function was monitored via muscle action potentials (MAP) for 3 hours.
- Histological assessment of nerve roots was performed post-exposure.
- Some animals received additional nerve root compression (50 mm Hg).
Main Results:
- No reduction in muscle action potential (MAP) amplitude was observed, indicating no functional nerve deterioration.
- Histological analysis revealed epidural accumulation of leukocytes and mast cells.
- Minor axonal and Schwann cell changes were noted in NP-exposed and NP+compression groups compared to controls.
Conclusions:
- Morphological changes, including inflammation and minor axonal/Schwann cell damage, occur within 3 hours of epidural NP application.
- Despite early structural changes, functional nerve root deterioration is not detectable within this 3-hour timeframe.