Establishment of intramedullary spinal cord glioma model in rats

Treating intramedullary spinal cord gliomas is a big challenge because of limited options, high recurrence rate and poor prognosis. An intramedullary glioma model is prerequisite for testing new treatments. This paper describes the establishment of a rodent intramedullary glioma model and presents functional progression, neuroimaging and histopathological characterization of the tumour model.

Fischer344 rats (n = 24) were randomized into two groups. Group 1 (n = 16) received a 5 µl intramedullary implantation of 9L gliosarcomal (10⁵) cells. Group 2 (n = 8) received a 5 µl intramedullary injection of Dulbecco's modified Eagle medium. The rats were anesthetized, the spinous process of the T₁₀ vertebra and the ligamentum flavum were removed to expose the T₁₀₋₁₁ intervertebral space and an intramedullary injection was conducted into the spinal cord. The rats were evaluated preoperatively and daily postoperatively for neurological deficits using the Basso, Beattie and Bresnahan scale. High resolution magnetic resonance images were acquired preoperatively and weekly postoperatively. When score equal to 0, rats were sacrificed for histopathological examination.

Rats implanted with 9L gliosarcoma cells had a statistically significant median onset of hind limb paraplegia at (16.0 ± 0.4) days, compared with rats in the control group in which neurological deficits were absent. Imaging and pathological cross sections confirmed intramedullary 9L gliosarcoma invading the spinal cord. Rats in the control group showed no significant functional, radiological or histopathological findings of tumour.

Rats implanted with 9L cells regularly develop paraplegia in a reliable and reproducible manner. The progression of neurological deficits, neuroimaging and histopathological characteristics of intramedullary spinal cord gliomas in rats is comparable with the behaviour of infiltrative intramedullary spinal cord gliomas in patients.