The piriformis syndrome appears to be more common because it is often underdiagnosed and undertreated. This syndrome is caused by compression or irritation of the sciatic nerve by the piriformis muscle as it passes through the sciatic notch. This entrapment neuropathy presents as pain, numbness, paresthesias, and associated weakness in the distribution of the sciatic nerve. In this article. we present the clinical symptoms, anatomy of the piriformis muscle, and the technique and result of the injection therapy with local anesthetics and steroid.

A 72-year-old woman presented with 7 days history of severe pain in the right buttock, hip, numbness of the right thigh. Previous management had included non-steroidal anti-inflammatory drug and physical therapy in local orthopedic clinic. Her past medical history was unremarkable. Her right side buttock was tender and discomfort was increased by right hip flexion, adduction and internal rotation with pain radiating to the anterior thigh. The her leg lenghts were equal, the strenght of right hip abductors and abduction was normal. Also low back range of motion and neurological examination were normal. Radiographs of the lumbosacral spine, pelvis and the hip joint were unremarkable. The she didn't respond to conservative treatment including physcal theraphy combined with the use antiimflammatory drugs, analgesics and muscle relaxants.

One week later she received an injection of 0.5% mepibacaine HCI 8cc and methyl-predanisolone(Depomedrol) 40mg into the medal right piriformis muscle. She reported that the 3 days after the injection, her right buttock pain had resolved and 7 days after the injection the pain resolved completely and she resumed normal activities and continued pain free.

We reviewed the literature on piriformis syndrome and its signs, symptoms and treat-ments. In an isolated piriforms syndrome, the major finding include buttock tenderness from the sacrum to the greater trochanter, piriformis tenderness on rectal or vaginal examination. The patient with piriformis syndrome usually does not have neurologic deficits Through complete history, physical and neurologic examinations, the other causes of low back pain and sciatica should be eliminated. Patients who do not respond to conservative therapy are candidates for local anesthetics and steroid injection. We injected methyl prednisolone 40mg and 0.5% mepibacaine HCl 8cc into the medial right piriformis muscle. 3 days after injection, her pains of right buttock and trochanter had resolved and 7 days after the injection, she resumed normal activites and consumed free. In order to improve the reliability of proper needle placement and allow for definite and treatment, EMG-assisted or MRI guidance may utilize.

Inflammatory response may play role in symptomatic nerve irritation that is associated herniated disc. Steroids decrease neurogenic inflamation, inhibit phospholipase A2 and produce membrane stabilization that result in pain relief. Local anesthetics are believed to break the cycle of pain that exists between local pain and a secondary muscle spasm. Epidural block with steroid combined with local anesthetics(EBSL) are recommended in patients with sign and symptoms of nerve root irritation. The purpose of this study was to asses of ESBL.

A retrospective study undertaken of 20 patients who received ESBL from May 2004 to November 2005 at the pain clinic of Mokdong Hospital Ewha Womans Medical Center. The mean age of the patients was 52, with range from 18-82 years. Nine patients was male, eleven were female. The etiologies of the pain were low back strain(3 patients), bulging disc(9 patients), degenerative disc(4 patients), lumbar stenosis(2 patients) and spondylolisthesis(2 patients). Diagnostic workouts were history, physical and neurologic examinations, and labo-rative studies including simple X-ray and magnetic resonance image. The steroid preparation usedis methylprednisolone and the use of dilute local anesthetics Is mepibacaine. The method of technique of EBSL was median approach with loss of resistance technique. The clinical responsefall into four categories, 6 months follow up after therapy. An excellent response was defined ascomplete resolution of presenting symptoms. A good response was judged to greater than 75%improvement in symptoms with full resumption of the patients life style. A fair response was defined as improvement in the patients condition, whereas a poor response indicated little or noimprovement. The total numbers of blocks were 48 in 20 patients and 2.4/per patient. The duration symptoms within one month were 8 patients and the other 12 patients over one month.

A detailed follow-up of 20 patients with EBSL showed a successful rate(good to excellent) 65%, fair 25%, and poor 10%. The effective responses of EBSL were depend on the etiologies, duration of pains and patients age. All patients of low back strain with one month duration or less have a response rate of very successful excellent. Also all patient with bulging disc who present with pain within one month have a response rate of excellent 3(60%), good 2(40%) and the patient who present with pain of over one month or more have a response rate excellent 1(25%), fair 2(50%) and poor 1(25%). All patients of degenerative disc present with pain of over one month have 50% relative success rate and good 2 patients. The response rate of two patients of spinal stenosis and two patients of spondylolisthesis present pain of long time(2-6 months) and response rate showed fair 3, poor 1, and 0% of successful rate.

EBSL can safely performed and its efficacy has been established in patients with low back strain and bulging disc. The success of this therapeutic procedure depends on attention to selected of patient etiologies and concomitant therapies. In addition, well controlled studics are needed to evaluate any effectivness of EBSL on back pain and radiculopathy.

Of all the chronic pain syndromes postherpetic neuralgia ranks the most refractory to treatment. The eight postherpetic neuralgia patients have been treated with nerve blocks or neurolysis and obtained good result. We evaluate the therapeutic effect of nerve blocks for postherpetic neuralgia and reviewed the pathology, clinical consideration, treatments and prevention.

Eight patients with established postherpetic neuralgia enrolled in pain clinic of Mokdong Hospital of Ewha Womans University from March,2004 to December. Average age at 58 and about 63% of patients were over 68 years. Affected area of forehead was two patients. They have been treated with stellate ganglion block (SCB), two times supraorbital and supratrochlear nerves blocks and neurolysis with absolute alcohol. Face affected patient has was one and has been treated with 5 times SGB, 2 times supraorbital and supratrochlear nerves blocks, infraorbital and mental nerves blocks, and then 2times maxillary and mandibular nerves blocks. Chest affected two patients were treated with intercostal nerve blocks. Thoracic wall affected one patient received 2 times thoracic epidural blocks and thoracic nerve block. Scapalur and thoracic wall affected patient has been treated with SGB and 2 times thoracic epidural block. The chest and thoracic wall affected patient received 10 times intercostal blocks,2 times thoracic epidural blocks,3 times thoracic root block and neurolysis of intercostal nerves with absolute alcohol. The injected agents were 1% mepibacaine or 0.25% mercain heavy and methylprednisolone succinated, and at weekly intervals the agents were injected.

All patient having been treated with nerve blocks were free of pain at 3-9 months.

Although no controlled trial has been done of nerve blocks to treat postherpetic neuralgia, this technique is safe in experienced hands and, if effected, may be repeated. It suggested that local anesthetics and steroid are the effective components in nerve blocks. Data on the relief of acute pain with nerve blocks, however cannot be extrapolated to predict the prevention of postherpetic neuralgia. The best way to prevent herpes zoster becasuse of post herpetic neuralgia is so difficult to treat.