Assissi loops may be okay, since there's evidence that PEMF can reduce glutamate in the cord. High Joules per sq cm are more likely to help, say above 30. So go with your 50 J treatment.
I talk this fall at the AHVMA about why endothelial nitric oxide may be harmful for these guys once there is cord damage. I sent you the notes to look at ahead of time by email