Pain classification by course
Back pain is classified depending on the duration of the pain syndrome:
- Acute pain: lasts up to 6 weeks.
- Subacute pain: lasts from 6 to 12 weeks.
- Chronic pain: persists for 12 weeks or more.
Causes of pain syndrome
All causes of dorsalgia can be divided into two large groups.
Nonspecific pain (80–90% of cases):
- Musculoskeletal pain.
- Myofascial pain syndromes.
- Discogenic radiculopathy (occurs less frequently than previously thought, only 3–5%).
- Fibromyalgia (up to 10% of chronic pain).
Specific causes (5–10% of cases):
- Tumors and other spinal cord diseases (e.g., syringomyelia).
- Infections (tuberculous spondylitis, epidural abscess).
- Dysmetabolic disorders (osteoporosis, Paget's disease).
- Spinal fractures.
- Ankylosing spondylitis (Bechterew's disease).
- Referred pain from internal organs (heart, kidneys, pelvic organs).
Pathogenesis of disc herniation
Historically, back pain was associated with osteochondrosis. Intervertebral disc degeneration occurs due to microtrauma, overloads, and age-related changes. The process goes through several stages:
- Dehydration: the nucleus pulposus (nucleus pulposus) dries out, losing its cushioning properties.
- Damage to the annulus fibrosus: the annulus fibrosus thins, and cracks appear.
- Protrusion: the nucleus shifts toward the cracks.
- Herniation (extrusion): the annulus fibrosus ruptures completely.
Hernias directed backward and laterally can compress the nerve root (radix nervi), causing radiculopathy, or the spinal cord (myelopathy, more common in the cervical region).
Muscle pain
Most often, back and neck pain is of muscular (myogenic) origin. It occurs due to non-physiological postures, "unprepared" movements, and muscle micro-tears.
Two main mechanisms are distinguished:
- Muscle-tonic syndrome: reflex muscle spasm in response to issues in the osteoligamentous apparatus.
- Myofascial syndrome: the appearance of local painful indurations, so-called myogeloses.
If the muscle is given rest, such pain can resolve in a few days. However, stress and repeated overloads contribute to chronification.
Briefly: answers to topical questions
What symptoms are considered "red flags" in dorsalgia, indicating a specific cause of pain?
"Red flags" in back pain include signs that require ruling out malignancies, infectious processes, and somatic diseases.
Among them are:
- Onset of pain at age 50 or older.
- Atypical pain pattern (no relation to movement, unusual localization, worsening at rest).
- Recent back trauma.
- Fever, infectious disease, symptoms of intoxication.
- Unexplained weight loss.
- Malignant neoplasm (current or history of).
- Symptoms of spinal cord involvement, pelvic organ dysfunction.
- Corticosteroid use, manifestations of osteoporosis, dysimmune disorders.
What instrumental imaging methods are used to confirm discogenic radiculopathy?
The following instrumental methods are used to diagnose discogenic radiculopathy:
- Magnetic resonance imaging — allows visualization of the intervertebral disc herniation and determination of its traumatic or degenerative etiology.
- Computed tomography — used to establish the cause of radiculopathy.
- Contrast-enhanced MRI — indicated when planning revision surgery, as well as when tumor or infectious etiology is suspected.
- Electrodiagnostic studies — used to rule out peripheral neuropathy as a cause of symptoms in the extremities.
- Radiography can reveal narrowing of the intervertebral space, flattening of the lumbar or cervical lordosis, and spondylosis.
What clinical syndromes develop with compression of the spinal cord at the cervical level (cervical myelopathy)?
Compression of the spinal cord at the cervical level leads to transverse lesion syndromes, depending on the level of compression.
- Upper cervical level — often leads to fatal outcome due to respiratory failure associated with the loss of function of the phrenic and intercostal nerves.
- Lower cervical region — characterized by peripheral paresis of the arms and spastic paralysis of the legs.
- Pain and sensory loss in the intercostal nerve segments, respiratory failure, and pelvic organ dysfunction are possible.
Class and exam questions
What is the difference between specific and nonspecific back pain?
Nonspecific pain is mainly related to muscles and ligaments, accounting for the vast majority of cases. Specific pain is caused by serious conditions (tumors, infections, fractures) and requires a completely different treatment approach.
What is a Schmorl's node and how dangerous is it?
Schmorl's node is a herniation of the disc into the cancellous bone of the vertebral body itself. Unlike posterior hernias, it is clinically insignificant and usually asymptomatic.
How is back pain classified by duration?
Pain lasting up to 6 weeks is considered acute, from 6 to 12 weeks is subacute, and pain lasting 12 weeks or more is chronic.
What else to study on this topic
- Anatomy of the intervertebral disc: annulus fibrosus and nucleus pulposus
- Mechanism of myelopathy development in cervical hernias
- Spondylolisthesis: types and clinical presentation
- Spinal stenosis and cauda equina root ischemia
- Osteoporosis and vertebral compression fractures
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