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  1. Chapter 016. Back and Neck Pain (Part 9) Neoplasms (See also Chap. 374) Back pain is the most common neurologic symptom in patients with systemic cancer and may be the presenting symptom. The cause is usually vertebral metastases. Metastatic carcinoma (breast, lung, prostate, thyroid, kidney, gastrointestinal tract), multiple myeloma, and non-Hodgkin's and Hodgkin's lymphomas frequently involve the spine. Cancer-related back pain tends to be constant, dull, unrelieved by rest, and worse at night. By contrast, mechanical low back pain usually improves with rest. Plain x-rays may or may not show destructive lesions in one or several vertebral bodies without disk space involvement. MRI, CT, and CT-myelography are the studies of choice when spinal metastasis is suspected. MRI is preferred, but the most rapidly available procedure is best because the patient's condition may worsen quickly. Fewer than 5% of patients who are nonambulatory at the time of diagnosis ever regain the ability to walk, thus early diagnosis is crucial.
  2. Infections/Inflammation Vertebral osteomyelitis is usually caused by staphylococci, but other bacteria or tuberculosis (Pott's disease) may be responsible. The primary source of infection is usually the urinary tract, skin, or lungs. Intravenous drug use is a well- recognized risk factor. Whenever pyogenic osteomyelitis is found, the possibility of bacterial endocarditis should be considered. Back pain exacerbated by motion and unrelieved by rest, spine tenderness over the involved spine segment, and an elevated ESR are the most common findings in vertebral osteomyelitis. Fever or an elevated white blood cell count is found in a minority of patients. Plain radiographs may show a narrowed disk space with erosion of adjacent vertebrae; however, these diagnostic changes may take weeks or months to appear. MRI and CT are sensitive and specific for osteomyelitis; CT may be more readily available in emergency settings and better tolerated by some patients with severe back pain. Spinal epidural abscess (Chap. 372) presents with back pain (aggravated by movement or palpation) and fever. Signs of nerve root injury or spinal cord compression may be present. The abscess may track over multiple spinal levels and is best delineated by spine MRI. Lumbar adhesive arachnoiditis with radiculopathy is due to fibrosis following inflammation within the subarachnoid space. The fibrosis results in nerve root adhesions, and presents as back and leg pain associated with motor,
  3. sensory, or reflex changes. Causes of arachnoiditis include multiple lumbar operations, chronic spinal infections, spinal cord injury, intrathecal hemorrhage, myelography (rare), intrathecal injection of glucocorticoids or anesthetics, and foreign bodies. The MRI shows clumped nerve roots located centrally or adherent to the dura peripherally, or loculations of cerebrospinal fluid within the thecal sac. Clumped nerve roots may also occur with demyelinating polyneuropathy or neoplastic infiltration. Treatment is usually unsatisfactory. Microsurgical lysis of adhesions, dorsal rhizotomy, and dorsal root ganglionectomy have been tried, but outcomes have been poor. Dorsal column stimulation for pain relief has produced varying results. Epidural injections of glucocorticoids have been of limited value. Metabolic Causes Osteoporosis and Osteosclerosis Immobilization or underlying conditions such as osteomalacia, hyperparathyroidism, hyperthyroidism, multiple myeloma, metastatic carcinoma, or glucocorticoid use may accelerate osteoporosis and weaken the vertebral body, leading to compression fractures and pain. The most common causes of nontraumatic vertebral body fractures are postmenopausal (type 1) or senile (type 2) osteoporosis (Chap. 348). Compression fractures occur in up to half of patients with severe osteoporosis, and those who sustain a fracture have a 4.5-fold increased risk for recurrence. The sole manifestation of a compression fracture
  4. may be localized back pain or radicular pain exacerbated by movement and often reproduced by palpation over the spinous process of the affected vertebra. The clinical context, neurologic signs, and x-ray appearance of the spine establish the diagnosis. Antiresorptive drugs including bisphosphonates (e.g., alendronate), transdermal estrogen, and tamoxifen have been shown to reduce the risk of osteoporotic fractures. Fewer than one-third of patients with prior compression fractures are adequately treated for osteoporosis despite the increased risk for future fractures; rates of primary prevention among individuals at risk, but without a history of fracture, are even less. Compression fractures above the midthoracic region suggest malignancy; if tumor is suspected, a bone biopsy or diagnostic search for a primary tumor is indicated. For a complete discussion of diagnosis and management of osteoporosis, see Chap. 348. Interventions [percutaneous vertebroplasty (PVP), kyphoplasty] exist for osteoporotic compression fractures associated with debilitating pain. Candidates for PVP have midline back pain, palpation tenderness over the spinous process of the affected vertebral body,
  5. migration of cement into paraspinal veins. Approximately three-quarters of patients who meet selection criteria have reported enhanced quality of life. Relief of pain following PVP has also been reported in patients with vertebral metastases, myeloma, or hemangiomas. Osteosclerosis, an abnormally increased bone density often due to Paget's disease, is readily identifiable on routine x-ray studies and may or may not produce back pain. Spinal cord or nerve root compression may result from bony encroachment. For further discussion of these bone disorders, see Chaps. 347, 348, and 349.
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