ABSTRACT
Chronic compression models attempt to simulate mass lesions which gradually compress the spinal cord such as osteophytes, ossification of the posterior longitudinal ligament (OPLL), herniated intervertebral discs, and spinal tumors. This chapter discusses these chronic compression models. Clinical neurological evaluation such as Tarlov’s scale or its modifications may be easier to perform on larger animals. Tarlov developed a method of gradual spinal cord compression in dogs by slowly inflating an extradural balloon. The model of cervical spondylotic myelopathy allowed control of the spinal cord compression, an assessment of neurologic deficits, imaging evaluations like magnetic resonance imaging, somatosensory evoked potentials recordings, spinal cord blood flow measurements, and postmortem histopathologic examinations. Because some bone morphogenetic proteins have bone-inducing potentials, they may be causative factors in the development and growth of OPLL and ossification of ligamentum flavum. Evaluation of outcome is an extremely important aspect of models of spinal cord compression.
