Amy M. Stubbs
EPIDEMIOLOGY
Neck and back pain are common complaints and account for approximately 2% of all physician office visits.
Myelopathy is the most common cause of spastic paraparesis in patients >55 years old.
In the majority of atraumatic neck and back pain cases, no specific cause can be identified.
Patients <18 years old or >50 years old with back pain are more likely to have serious underlying pathology.
PATHOPHYSIOLOGY
Nontraumatic neck and back pain are often due to nonspecific musculoskeletal causes.
Radiculopathy is caused by compression of a single spinal nerve root.
Myelopathy is seen with spinal cord dysfunction, which may be caused by a lesion, stenosis, or compression.
Knowledge of spinal anatomy, specific dermatomes, and spinal nerve innervations may guide the examiner to a particular cause or location of pathology.
CLINICAL FEATURES
Neck pain patients can be classified into two groups: (1) those with pain from joint or muscular components, and (2) those with signs of radiculopathy or myelopathy. Symptoms and historical features of these groups are summarized in Table 179-1.
Back pain can be divided into groups based on duration of symptoms: acute (<6 weeks), subacute (between 6 and 12 weeks), and chronic (>12 weeks).
A positive straight leg raise test causes radicular pain of the affected leg radiating to below the knee (see Fig. 179-1).
Signs and symptoms of radiculopathy include sensory abnormalities (paresthesias or numbness), motor weakness, and diminished reflexes in a dermatomal distribution.
Signs and symptoms of cervical and lumbar radicu lopathy are summarized in Table 179-2 and Fig. 179-2.
Thoracic nerve root compression may result in pain that radiates to the chest or abdomen.
Insidious onset of pain, impaired fine motor movements, gait disturbances, hyperreflexia or clonus, and sexual or bladder dysfunction may be seen with mye-lopathy. A positive Babinski sign may also be observed.
Urinary retention, with or without overflow incontinence, is the most common finding in cauda equina syndrome. Other common findings include diminished rectal tone and saddle anesthesia (numbness over the buttocks, upper posterior thighs, and perineal regions).
Specific physical examination findings that are characteristic of spinal pathology are summarized in Table 179-3.
Many patients with neck and back pain complain of localized stiffness and decreased range of motion. Often the pain is worsened with certain movements or positions.
Pain in conjunction with systemic complaints such as fever, night sweats, or weight loss is concerning for malignancy, infection, or rheumatologic disease. Night pain or unremitting pain is also suggestive of serious pathology.
Pain from disc herniation is often exaggerated by coughing, valsalva, or sitting.
Pain from spinal stenosis is characterized by bilateral sciatic pain exacerbated by walking, standing, or back extension. It may be relieved by rest or flexion of the spine.
TABLE 179-1 Historical Clues to Differentiate Muscular Neck Pain from Nerve Root or Spinal Cord Related Pain
FIG. 179-1. Straight leg raise testing. Instructions for the straight leg raising test. 1. Ask the patient to lie as straight as possible on a table in the supine position. 2. With one hand placed above the knee of the leg being examined, exert enough firm pressure to keep the knee fully extended. Ask the patient to relax. 3. With the other hand cupped under the heel, slowly raise the straight limb. Tell the patient “If this bothers you, let me know, and I will stop.” 4. Monitor for any movement of the pelvis before complaints are elicited. True sciatic tension should elicit complaints before the hamstrings are stretched enough to move the pelvis. 5. Estimate the degree of leg elevation that elicits complaint from the patient. Then determine the most distal area of discomfort: back, hip, thigh, knee, or below the knee. 6. While holding the leg at the limit of straight leg raising, dorsiflex the ankle. Note whether this aggravates the pain. Internal rotation of the limb can also increase the tension on the sciatic nerve roots
DIFFERENTIAL AND DIAGNOSIS
The majority of patients with nontraumatic neck and back pain do not require imaging or laboratory tests.
For patients with history of recent trauma and cervical spine pain, the National Emergency X-Radiography Utilization Study (NEXUS) criteria are useful to determine the need for imaging (see Chapter 163for further reading on spinal trauma).
Plain radiographs of the spine have low sensitivity but may be of use in some subsets of patients. Three views of the cervical spine may be useful in patients with chronic neck pain with or without history of trauma, neck pain, and history of malignancy or prior neck surgery, or those with neck pain and known spinal disorders. Anterior-posterior and lateral radiographs of the thoracic and/or lumbar spine should be considered if suspicion exists for tumor, infection, or fracture.
Abnormal plain radiographs or neurologic deficits on examination should prompt further imaging.
Flexion-extension films of the cervical spine may help identify spinal instability.
CT scanning is valuable in diagnosing bony pathology, but insensitive for nerve root or spinal cord disorders.
MRI is the test of choice for patients with neck or back pain and neurologic deficits.
CT myelography is an alternative when MRI is contraindicated.
If serious pathology (eg, malignancy, infection) is suspected, a complete blood count (CBC), erythro-cyte sedimentation rate (ESR), and urinalysis should be ordered. ESR has a sensitivity of 90% to 98% for infectious causes of spinal pain.
Bowel or bladder incontinence in conjunction with back pain should raise concern for epidural compression. A post-void residual (determined by cath-eterization or bedside ultrasound) of >100 mL suggests incomplete bladder emptying (and therefore suggests that any incontinence is overflow incontinence).
Mechanical disorders may result in acute or chronic neck pain; the majority of cases arise from motor vehicle collisions, falls, sports injuries, and work-related injuries. (See Chapter 163 for further discussion of spinal injuries.)
Cervical disc herniation, spondylosis, or spinal stenosis may result in radiculopathy or myleopathy. Herniation and spondylosis are most common at levels C5-C6 and C6-C7.
The risk of cervical myelopathy increases if the spinal canal diamter is reduced to <13 mm; this may occur from congenital narrowing, osteophyte formation, or buckling of the ligamentum flavum.
The differential diagnosis for nontraumatic neck pain includes metastatic cancer, myofascial pain syndrome, temporal arteritis, and ischemic heart disease.
Thoracic compression fractures are seen in the elderly, and in patients with osteoporosis.
Patients with sciatica generally complain more of radicular symptoms than back pain.
Ninety-five percent of lumbar disc herniations occur at the L4-L5 or L5-S1 levels.
Spinal cord compression, cauda equina syndrome, and conus medullaris syndrome comprise epidural compression syndromes and may initially present in a similar fashion (weakness, sensory changes, and autonomic dysfunction).
Epidural compression may be caused by malignancy, abscess, or massive midline disc herniation. Compression due to hemorrhage or hematoma should also be considered in patients at risk for coagulopathy.
Spinal infections such as discitis, osteomyelitis, and epidural abscess should also be considered, especially in the setting of immunocompromise or intravenous drug abuse. The ESR will typically be elevated. MRI is preferred for diagnosis.
Transverse myelitis, ruptured aortic aneurysm, pancreatitis, posterior lower lobe pneumonia, herpetic neuralgia, and renal colic or infarct should be included in the differential for back pain.
TABLE 179-2 Signs and Symptoms of Cervical Radiculopathy
FIG. 179-2. Testing for lumbar nerve root compromise.
TABLE 179-3 Examination Findings Associated with Spinal Pathology
EMERGENCY DEPARTMENT CARE AND DISPOSITION
Patients with neck or back pain accompanied by significant or progressive neurologic deficits require emergent imaging (ideally MRI), and admission to the appropriate service.
For suspected epidural compression, dexamethasone 10 milligrams IV should be given prior to imaging.
For patients with suspected spinal infection, broad-spectrum intravenous antibiotics, such as pipera-cillin-tazobactam (3.375 grams) and vancomycin (1 gram), should be given unless directed otherwise by consultants.
Patients with nonspecific neck and back pain or a stable, mild radiculopathy may be managed conservatively and discharged with pain medication, explicit return precautions for worsening symptoms, and instructions to return to routine activity. Those who fail conservative management may require MRI and surgical referral.
Pain management options include acetaminophen (650-975 milligrams every 4-6 hours) alone or in combination with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (800 milligrams twice a day) or naproxen (250-500 milligrams twice a day). NSAIDs should be used with caution (if at all) in the elderly, patients with kidney disease, or those with peptic ulcer disease.
Muscle relaxants such as diazepam 5 to 10 milligrams every 6 to 8 hours may also provide relief.
A short course of opioids may be prescribed for moderate to severe pain, but long-term use is not beneficial in the setting of chronic or nonspecific neck and back pain.
For further reading in Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th ed., see Chapter 276, “Neck and Back Pain,” by William J. Frohna and David Della-Giustina.