Sciatica Q&A

Richard HughesMr Shuaib Karmani, Consultant Spinal Surgeon at BMI Goring Hall Hospital, explains what is sciatica, how it affects our lives and we can treat it.

Mr Karmani has a special interest in sciatica and lower back pain, and has pioneered the use of minimally invasive spine surgery. He specialises in all disorders of the spine including neck pain, sciatica, trauma and tumours of the spine, degenerative disc disease, sponylolisthesis and scoliosis. Mr Karmani is active in research and teaching, and the development of new techniques to treat spinal disorders.

Mr Shuaib Karmani
Sciatica is a painful condition, causing back pain that radiates down your leg to your ankle. It can be associated with numbness in the leg and weakness in the foot. The distribution of the pain is along the course of the sciatic nerve.

Mr Shuaib Karmani
Sciatica affects adults between 30 to 50 years, most commonly. It causes huge disability, back pain being the the most common musculoskeletal problem to affect people.

Mr Shuaib Karmani
Sciatica is due to compression of one or more of the roots of the sciatic nerve in the spine. The levels of the spine most commonly affected are the L5/S1 and L4/5 levels.

The most common cause is a disc prolapse. This is when the nucleus pulposus herniates through annulus of the disc. This causes compression of the adjacent nerve root and a very painful acute inflammatory reaction in the nerve. Less commons causes for sciatica are a facet joint cyst, infection and tumours.

Mr Shuaib Karmani
Compression of the roots of the sciatic nerve in the lumbar spine causes pain in the lumbar spine extending down the leg below the knee. The patient feels a tightness in the leg and a cramping sensation in the calf and ankle. Sleep can be disturbed and the patient’s leg can be restless. There is paraesthesia  and/or numbness in the leg.

If the L5 root is compressed the disturbed sensation affects the shin and dorsum of the foot, particularly the big toe. If the S1 nerve root is effected the disturbed sensation affects the calf and lateral aspect of the foot. Lastly there can be weakness in the leg, this can effect ankle dorsiflexion (L5) and ankle plantarflexion (S1).

In severe cases with a large central disc prolapse, patients can complain of bowel and bladder problems. There can be numbness affecting the perineum. The particular problems with the bladder are insensate incontinence. This is where the patient is not aware of their bladder filling and emptying, and this can also be the case with bowel function. These symptoms suggest cauda equine syndrome and an urgent referral to A+E is needed.

Mr Shuaib Karmani
In most cases of sciatica, patients settle with rest analgesics and time. It can take 6-8 weeks to settle.
In patients whose pain is difficult to manage, whose neurological deficit (numbness and weakness) is dense, further treatment is needed. This can be either a nerve root block, when a powerful steroid is injected under Xray guidance around the affected nerve root to reduce the painful inflammation. This can control the pain, while time is given for the disc bulge to heal naturally.

If the pain is resistant to a nerve root block, if there is weakness causing difficulty walking then surgery is indicated. Surgery involves removal of the disc prolapse compressing the affected nerve root. Surgery is performed under a general aneasthetic and can be done minimally invasively. This usually involves a one night stay in hospital.