Back and Neck Pain
Allan H. Ropper
LOW BACK PAINBackground
1. Back pain is ubiquitous, with half of all adults having experienced mild to moderate back pain at some time and many having been unable to work because of it.
2. The majority of low back pain has a mechanical basis in the joints, discs, bones, or adjacent muscles; that is, it is spinal and not the result of neurologic disease.
3. Many practitioners including general physicians, orthopaedists, osteopaths, physical therapists, chiropractors, and various derivative practices such as musculoskeletal therapists see patients with back pain prior to and after the care of a neurologist.
4. The examination is generally unrevealing, and a specific diagnosis for back pain is usually not apparent. The history, however, generally exposes the more serious causes.
History
1. Chronic back pain
a. The typical symptom is acute or chronic “aching” in the low back, most often in the region of the L3 through L5 vertebral bodies, in the adjacent paraspinal muscles, in the upper ramus of the iliac crests, or over the sacrospinal ligaments or sacroiliac joints.
b. There are two patterns of nondescript aching pain, one worse on awakening and the other increasing through the day with activity or after prolonged sitting. Both are characteristic of benign “arthritic” or “mechanical” causes.
c. Aching pain across the low back and waist is also characteristic of a benign mechanical musculoskeletal disorder.
d. Chronic degenerative low back pain displays little in the way of limitation of motion, but it may have broad areas of tenderness over the muscles, ligaments, and joints throughout the low back.
e. Severe osteoporosis or osteopenia may also give rise to vague, relatively constant low back pain, but the majority of patients with this bone disease do not have pain.
f. Nocturnal pain, especially awakening the patient in the middle of the night, suggests metastatic disease in the spinal column and should not be attributed to mechanical or arthritic back pain.
g. Fever, night sweats, weight loss, recent bacteremia, HIV, or pulmonary tuberculosis suggests spinal osteomyelitis or lymphomatous infiltration of the spine.
h. Lumbar back pain accompanies rupture of the annulus surrounding a disc, but this is the sole cause in only a few cases of pain.
i. Sciatica has special significance as a sign of lumbar disc disease (see below).
j. The special case of ankylosing spondylitis produces progressively severe low back pain with limitation of motion.
k. Degenerative lumbar stenosis (see further on) is a disease of the older population, mainly men, characterized by aching back pain and claudication-type walking-induced sciatic and leg pain.
l. Persistent and increasing lumbar pain of recent onset without a history of recurrent discomfort earlier in life, acute injury, or known arthritic disease in the spine compels consideration of retroperitoneal disease including renal cell cancer, pancreatic cancer, duodenal ulcer, abdominal aortic dissection, and retroperitoneal hematoma.
2. Acute back pain
a. Sudden mechanical injury from awkward positioning, being thrown or falling, lifting, trauma elsewhere in the body (and occasionally acute disc rupture) are the main causes of acute back pain, called “strain.” Pain may be delayed by hours after the inciting event.
b. Focal paraspinal pain suggests disease in the facet joints.
c. In acute low back strain, there is a disinclination to bend, twist, or extend the lower torso and the paraspinal muscles, the assumption of protective postures of the trunk, and there may be palpable muscle spasm.
d. In adolescents, acute low lumbar pain after minor injury may indicate spondylolysis, a congenital weakness of the pars interarticularis, that is prone to fracture usually of L5.
e. Focal low thoracic or lumbar back pain may be the result of a compression fracture. Usually there has been a fall on the buttock or back, but injury is not necessary if the bones are osteopenic.
f. Severe pain after direct trauma to the spinal column or head is a more serious matter of specialized nature because of disruption of the ligaments and supporting bony structures that result in instability of the spinal column.
g. Bladder dysfunction indicates compression of the spinal cord or cauda equina and is not consistent with the nondescript types of back pain discussed here.
h. Disc disease can cause projected pain: for example, L5 rupture is typically perceived in the L5-S1 facet joint.
Pathophysiology
1. The pain-sensitive structures that generate low back pain include free nerve endings in the capsule of the facet joints and of the annulus surrounding the disc.
2. The periosteum is a source of pain when there is invasion of spinal bones by tumor or with osteomyelitis or bony collapse of a compression fracture.
3. Pain referred to a distant site from bony or disc disease is termed “sclerotogenous” and has a distribution different from that of neurogenic “referred” pain.
4. Much back pain is described as “muscular” and is located in the paraspinal muscles, and it has been presumed that pain receptors in the muscle contribute to discomfort.
5. A relationship of chronic low back pain with posture, abdominal girth, and fatigue of muscles has long been proposed but without definite basis.
6. The origin of much chronic low back pain is osteoarthritis involving the paired facet joints and degeneration of the adjacent ligaments. The role of inflammation in back pain has not been established but some treatments are oriented to that component.
7. Degenerative arthritic changes lead to hypertrophy of the bone surrounding the facet joints and, in advanced cases, loosening of the structural elements that maintain alignment of the spine.
8. The resultant instability may lead to spondylolisthesis, or slippage of one vertebral segment upon an adjacent one. This results in narrowing of the spinal canal and compression of the cauda equina roots that may itself cause pain.
Prognosis
1. Most nonmalignant acute back pain is self-limited but certain individuals are prone to repeated acute injury or chronic discomfort.
2. Most large studies show about 50% improvement in acute pain level by 1 month, continued slower improvement over the following 2 months, and persistent pain in those who have not improved by that time.
3. The risk of recurrence within 3 months of an acute episode is about 25% and within a year, about 75%.
4. The prognosis of infectious inflammatory or malignant low back pain is determined by the nature and treatment responsiveness of the underlying process.
Diagnosis
1. Straight leg raising and derivative maneuvers and the motor, reflex, and sensory examination are most useful in detecting lumbar root compression and degenerative spondylosis as described further on. A search for a cause of back pain that is more serious than mechanical and arthritic disease is made if there are abnormal findings on these tests.
2. Imaging of the lumbar spine with x-ray, computed tomography (CT), or magnetic resonance imaging (MRI) is not required in cases that conform by history to musculoskeletal or acute mechanical low back pain (“sprain”).
3. Pain that persists for more than several weeks and is not explained by preceding bouts of acute injury should have imaging to exclude cancer, fracture, osteomyelitis, and spondylolisthesis from degenerative disease.
4. Plain lumbar spine films—lateral, anteroposterior, and oblique—are adequate if the anticipated diagnosis is degenerative arthritis and the neurologic examination is normal.
5. Degenerative changes of the joints and disc spaces on imaging studies are very common with aging and are usually asymptomatic. Therefore, their presence does no more than affirm that it may be a cause of low back pain.
6. In cases of otherwise unexplained deep lower mid lumbar pain or flank pain, imaging of the structures of the retroperitoneal space and abdomen is advisable.
7. Sedimentation rate, C-reactive protein, blood cultures, immunoelectrophoresis, and imaging are required to exclude infection and cancer in appropriate cases.
Treatment
1. Many symptomatic treatments are used for acute low back pain with no clear superiority of one over the other.
2. Patients with acute low back strain may be obliged to rest in bed or easy chair, but beyond symptomatic relief, there is no evidence that rest speeds improvement. The patient can determine the most comfortable position—lying with pillows under or between the knees or decubitus position may reduce pain.
3. Stretching of the low back muscles, heat applied externally or through diathermy, massage, and nonsteroidal inflammatory and analgesic drugs are helpful. Traction was favored in the past but is currently not conventionally used. Immobilization with corset-like devices was also at one time popular but has also been discouraged.
4. Muscle relaxants and diazepines have an ambiguous role and have not been shown to be particularly effective, but they are still widely used.
5. Chiropractic adjustment may speed the return to functional capacity after low back strain. Low-velocity distraction and ballottement administered by qualified physical therapists are probably as helpful. Compression fracture, cancer, or infection is a reason to avoid adjustments.
6. Instructions in proper biomechanics of sitting, lifting, bending, and carrying are helpful to individuals who have recurrent or postural low back strain. Weight support belts for workers may reduce injury.
7. Changes in mattress firmness and automobile seats that provide back support are helpful in individual cases.
8. A few patients have chronic low back pain as part of a depressive-chronic pain syndrome that may respond to tricyclic antidepression medications. This diagnosis should be made sparingly.
9. In the special circumstances of low back pain due to degenerative spondylolisthesis, pain may be improved by surgery with fusion, but cases must be selected with great care. It has become clear over the last 40 years that more harm than good is done by ill-considered low back surgery (see below).
10. Back pain from bulging discs and nondescript degenerative changes at the disc spaces and facet joints is not aided by surgery (see below).
SCIATICABackground
1. This term refers to sharp and aching pain that originates in the buttock or gluteal fold and radiates down the back or lateral aspect of the thigh. There may, or may not, be associated low back pain.
2. Unlike the types of nondescript low back pain described above, sciatica usually indicates L4, L5, or S1 nerve root compression by ruptured disc, osteoarthritic encroachment on the neural foramen, spondylolisthesis from lumbar stenosis, or less common lesions such as synovial cysts or nerve sheath tumors.
3. The combination of paraspinal lumbar pain followed in hours or days by sciatica is characteristic of lumbar disc rupture.
4. Most sciatica does not have acute precipitating events but lifting, twisting, or back injury may precede the symptom.
5. Bilateral sciatica usually signifies severe degenerative spinal disease.
History
1. The patient describes regional pain beginning in or around the buttock on one side and radiating to the posterior or posterolateral thigh. Radiation below the knee or into the foot does occur but is uncommon.
2. The severity of the pain varies, but at its extreme, it is very disabling and prevents either sitting, standing or walking.
3. A few patients with sciatica have additional neurologic symptoms, specifically numbness in the foot, foot drop, or weakness of foot plantar flexion.
4. Chronic low back pain and limitation of lumbar motion when associated with sciatica suggest the diagnosis of lumbar stenosis (see below).
5. Facet pain is focal and worsened by change in position that distracts the joint.
6. Urinary incontinence with (usually bilateral) sciatica indicates compression of the cauda equina, an emergency.
Pathophysiology
