Classification of non-specific back pain
Lower back and sacral pain is divided into several variants depending on the clinical course and the area of radiation:
- Lumbago (acute lumbar pain). Characterized by sharp, shooting pain in the lower back. The main provoking factor is physical exertion (e.g., lifting heavy objects).
- Lumbalgia. Subacute or chronic aching pain syndrome. It develops after physical exertion, an awkward movement, hypothermia, and sometimes without apparent causes. The pain worsens with walking, spinal movements, or prolonged positioning in certain postures. During an acute attack, the patient may freeze in an awkward position, as attempting to move provokes increased pain.
- Lumboischialgia. A pain syndrome where pain is localized in the lower back, buttock, and radiates along the posterolateral surface of the leg. An important differential diagnostic sign: unlike radiculopathy, the pain does not reach the foot and toes. The causes include pathologies of the zygapophysial joints, intervertebral discs, sacroiliac joints, and myofascial syndromes. In the latter variant, the piriformis, iliopsoas, iliocostalis, as well as the gluteus maximus and medius muscles are involved (palpation reveals areas of local tenderness).
Discogenic radiculopathy
Radiculopathy occurs when spinal nerve roots are affected. Clinically, it presents as acute shooting ("stabbing") pain in the lower back and leg, which is significantly more intense than in muscular syndromes.
Characteristic features:
- Radiation: pain spreads in a proximal-to-distal direction, reaching the foot and toes (when the lower lumbar and first sacral roots are affected).
- Pain provocation: symptoms worsen in the upright position, during spinal movements, sneezing, and when bringing the chin to the sternum.
- Neurological deficit: sensory, reflex, and/or motor disturbances are detected within the innervation zone of the affected nerve root.
- Symptoms: a positive Lasegue sign, tension in the back and leg muscles are determined. Scoliosis (spinal curvature) is frequently observed, which noticeably decreases in the horizontal position.
Most commonly, L5 and S1 roots are affected, less commonly L4, and extremely rarely the upper lumbar roots.
Topical diagnosis of L5 and S1 radiculopathies
The clinical picture makes it possible to precisely determine the level of spinal nerve root lesion.
| Sign | S1 radiculopathy | L5 radiculopathy |
|---|---|---|
| Pain localization | Lower back $\rightarrow$ buttock $\rightarrow$ posterior thigh $\rightarrow$ posterolateral lower leg $\rightarrow$ lateral edge of the foot and lateral toes | Lower back $\rightarrow$ buttock $\rightarrow$ lateral thigh and lower leg $\rightarrow$ medial edge of the foot and great toe |
| Hypoesthesia | Lateral lower leg and lateral toes (less frequently, posterior thigh) | Lateral lower leg and great toe |
| Reflexes | Achilles reflex is lost | Preserved |
| Paresis (weakness) | Gastrocnemius muscle (sometimes foot flexors/pronation, toe flexors) | Extensor hallucis longus (less commonly foot dorsiflexors/pronation) |
Briefly: answers to topical questions
What tension signs, besides Lasegue's sign, are detected in lumbosacral radiculopathy?
In lumbosacral radiculopathy, in addition to Lasegue's sign, Wasserman's and Mackiewicz's signs are elicited.
- Wasserman's sign — appearance of pain along the anterior surface of the thigh and in the groin upon extension of the leg at the hip joint in a patient lying prone.
- Mackiewicz's sign — pain in the groin area radiating to the anterior surface of the thigh upon maximal flexion of the lower leg in a patient lying prone.
The purpose of these provocative tests is to elicit reactive pain upon tension of the affected nerve.
Which reflex is lost in L4 spinal nerve root lesion?
In L4 spinal nerve root lesion, the knee jerk reflex is lost.
The neurological status in radiculopathy at this level may also reveal the following changes:
- Sensory disturbances — the area of hypesthesia corresponds to the pain distribution area spreading along the anteromedial surface of the thigh, and also involving areas such as the medial surface of the lower leg and the medial edge of the foot.
- Motor disturbances — weakness of the quadriceps femoris muscle (m. quadriceps femoris) is possible.
The vastus lateralis and vastus medialis muscles (m. vastus lateralm. vastus medialis) and the tibialis anterior muscle (m. tibialis anterior) also serve as indicator muscles for this root.
For quick memorization of topography: an L5 lesion "hits" the great toe and the inner edge of the foot (reflexes preserved), while an S1 lesion affects the little toe and the outer edge of the foot (Achilles reflex is lost).
Class and exam questions
How to distinguish lumboischialgia from radiculopathy?
In lumboischialgia, pain radiates down the leg but never reaches the foot and toes. In discogenic radiculopathy, pain radiates distally right down to the toes.
Does scoliosis change in discogenic radiculopathy?
Yes, scoliosis arising from pain and muscle tension often significantly decreases when the patient assumes a horizontal position.
What is myofascial syndrome in lumboishialgia?
It manifests as involvement of the gluteus maximus and medius, piriformis, iliocostalis, and iliopsoas muscles. Palpation reveals zones of local tenderness.
What else to study on this topic
- Cervical pain syndromes: cervicalgia, cervicocranialgia, and cervicobrachialgia
- C6 and C7 cervical radiculopathies
- Vertebrogenic cervical myelopathy: etiology and clinical stages
- Scapulohumeral periarthropathy and scalene myofascial syndrome
- Nonspecific thoracic pain (thoracalgia)
Master the entire topic in the "Neurology" course
This is a summary. The course covers everything tested in classes and exams.
- Full guide on "Lumbosacral Vertebrogenic Syndromes" and 907 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 32 video lessons for the subject
Other topics in "Chapter 27. Neck, back, and limb pain. Vertebrogenic neurological disorders"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.