Delayed myelopathy induced by chronic compression in the rat spinal cord

Area of Science:

• Neurology
• Experimental Medicine
• Pathophysiology

Background:

• Cervical myelopathy is a frequent cause of neurological disability in the elderly.
• The precise mechanisms driving its insidious and progressive deterioration are not fully understood.

Purpose of the Study:

• To develop and validate an experimental model that replicates the natural course of cervical myelopathy.
• To investigate the pathophysiology of cervical myelopathy using this novel model.

Main Methods:

• A polymer-induced spinal cord compression model was created in rats at the C5-C6 laminae.
• Motor function was assessed over 25 weeks using voluntary exercise and treadmill tests.
• Stereological counting of motor neurons was performed on serial sections.

Main Results:

• Rats with spinal cord compression exhibited a significant decline in forced running capability after a 17-week latent period.
• Motor neuron density decreased by 20.3% at 9 weeks and 35.5% at 25 weeks post-compression.
• Voluntary exercise activity remained comparable between compressed and control groups.

Conclusions:

• The developed rat model effectively reproduces key features of clinical cervical myelopathy, including delayed motor deficits.
• Insidious motor neuron loss precedes the onset of observable motor symptoms in this model.
• This model provides a valuable tool for studying cervical myelopathy pathophysiology and testing potential interventions.