I would put it off unless the consenses is universal. Something doesn't make sense. Myelograms by nature are not without risks. Superficially, makes sense to consider a myelogram, if surgery is eminent, based on what what you say about a deep indent in your spine around your lower back. Except for one problem: the spinal cord ends at L1, roughly, so root compression below that level (the rest of the lumbar spine) would cause depressed or absent reflexes of the lower limbs, not "active" (I assume you mean hyperactive). If you had cord compression above L1 (central cord issue), then hyperreflexia makes sense. It is really only the dinosaurs from the paleolithic era that still order myelograms because they don't believe the MRI's. Maybe change neurologists?