Options. You have multiple options, the mainstay of treatment are interdisciplinary and include physical therapy, acupuncture, medications (anti-inflammatories, nerve pain agents) and epidural steroid injections. Depending on your response surgery may need to be considered. There continue to be emerging technologies to treat sciatica in a minimally invasive fashion.
Stretching. Many times acute sciatic pain will resolves after stretching the area abit. The muscles will loosen up and help resolve pain. If not, then consider further imaging studies to see which exact nerve in your spine is getting pinched for further treatment options.
Varied. Sciatica is a symptom, a pattern of pain, for which there are various causes. Therefore there is no one best treatment, it depends on the cause. In most of my cases is due to sacroiliac joint dysfunction, i.e., hypermobility due to injury. Between 10 & 30% of persons with chronic low back pain have pain generation from this joint. Stabilization of the joint is foremost, via a fusion procedure.
What is the best treatment for "severe" sciatica pain. My last resort for my mother is neuromuscular release technique with poss. Nerve block.
Surgery. If sciatica is severe and unresponsive to pt or steroids/nerve blocks, surgery may be required to release the compression from a disk herniation or bone spur.
Depends. The best treatment depends on the cause of the sciatica. Until that is known there is no best treatment. If it is from a herniated disc then physical therapy, exercise and anti inflammatory medication is a good start. If it does not improve I would consider an epidural injection within 3 months of the pain onset.
Spine Pain Options. This chronic pain in the distribution as you suggested is the result of an irritated nerve or facet joints or other injury typically in the lumbar spine (low back) which are caused by herniated disks, spinal stenosis or degenerative disc disease, etc requiring further evaluation by a spine specialist and may be candidate for facet injections/radiofrequency ablation and epidural steroid injection.