Spinal infusion involves placing a tiny catheter into the spinal sac or epidural space. These spaces around the spinal sac are separated only by a thin membrane called the dura mater which includes a layer called the arachnoid membrane. Spinal or subarachnoid infusions place medicine inside the spinal sac (inside the dura mater) where the medicine can spread out in the cerebral spinal fluid (CSF) and affect wide areas of pain. Epidural ( above the dura ) medicines flow into the epidural space where the fluid spread is much more restricted by the epidural contents (epidural fat and blood vessels). Where the catheter is placed, and the kind of medicine infused depends on the patient, the type of pain, the duration of infusion, and many other factors.
High dosages of oral corticosteroids taken daily for prolonged periods of time can have serious systemic side effects including bone loss ( osteoporosis), increased risk of infections and diabetes and cataracts, thinning of skin, stretch marks, increased facial/body hair growth, acne, fluid retention, weight gain with redistribution of fat (fat deposits on back and face, thinning of limbs), muscle weakness, decreased resistance to infections, stomach ulcers, mood swings, insomnia, suppression of the body's own production of cortisol, etc.