Nerve blocks are a common treatment for nerve pain caused by radiculopathy. Radiculopathy is defined as any disease involving a spinal nerve root. Sciatica is one form of radiculopathy.
Nerve injections do have some risks. The numbing agent can spread to other spinal levels giving false information. This can misdirect treatment.
More seriously, paralysis and death can occur if the steroid is injected into the blood vessels to the spinal cord. Some doctors have changed the way they do this procedure. Safer and more accurate methods of steroid injection are being studied.