Lumbar Radiculopathy

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Definition/Description

Lumbar radiculopathy occurs in the lower back and causes pain in de lower back and hip radiating down the back of the thigh into the leg. It is caused by damage to the lower spine which causes compression of the nerve roots which exit the spine. The compression can lead to tingling, radiating pain, numbness, paraesthesia and occasional shooting pains. Radiculopathy can occur in any part of the spine, but it is most common in the lower back (lumbar radiculopathy) and in the neck (cervical radiculopathy). It is less commonly found in the middle portion of the spine (thoracic radiculopathy). (1; LOE 1B)
Radiculopathy is not the same as “radicular pain” or “nerve root pain”. Radiculopathy and radicular pain commonly occur toghether, but radiculopathy can occur in the absence of pain and radicular pain can occur in the absence of radiculopathy. (2; LOE 5)
Radiculopathy can be defined as the whole complex of symptoms that can rise from nerve root pathology, including anaesthesia, paresthesia, hypoesthesia, motor loss and pain.
Radicular pain and nerve root pain can be defined as specifically apply of a single symptom (pain) that can arise from one or more spinal nerve roots. (3; LOE 3B) Lumbar radiculopathy is a disorder of the spinal nerve root from L1 to S1.
A variety of conditions can lead to compression of the nerve roots, which means that there are several different approaches to the treatment and management of lumbar radiculopathy.

Epidemiology /Etiology

Lumbar radiculopathy is a disease that commonly arises with significant socioeconomical consequences. The discal origin of a lumbar radiculopathy incidence is around 2%. Out of a 12.9% incidence of low back complaints within working population, 11% is due to lumbar radiculopathy. (9, LOE:5)
The prevalence of lumbosacral radiculopathy has been situated from 9.9% to 25%. (10, LOE:3A)
Risk factors for radiculopathy are activities that place an excessive or repetitive load on the spine. Patients involved in heavy labour or contact sports are more prone to develop radiculopathy than those with a more sedentary lifestyle.  

Radiculopathy is caused by compression or irritation of the nerves with resultant pain, weakness, and/or sensor impairment in the affected nerve root, may be from direct trauma or from chemical irritation to the affected nerve root (10, LOE:3A ). This can be due to mechanical compression of the nerve by a disk herniation, a bone spur (osteophytes) from osteoarthritis, or from thickening of surrounding ligaments. As people age, their spines are subject to increasing degeneration which can cause herniated discs and similar problems, leading to lumbar radiculopathy.
Other less common causes of mechanical compression of the nerves is from a tumour or infection. Either of these can reduce the amount of space in the spinal canal and compress the exiting nerve. Scoliosis can cause the nerves on one side of the spine to become compressed by the abnormal curve of the spine.

Characteristics/Clinical Presentation

Symptoms of lumbar radiculopathy

General symptoms of a spinal nerve root injury:

• Failure of the sensible dermatome. Because of the overlap of the dermatomes there will be never be a total loss of touch by an injury of one nerve root.
• Radiating electric pain, coupled with irritation in the periphery. The pain arises or decreases by pressure increment, stretch (Lasègue) and certain positions. Paravertebral pressure above the nerve root causes pain in the periphery.
• Tendonreflexes are reduced or fall out
• Sometimes there is a motorial loss, where the pain often disappears abruptly

Pain: the description of nature and localisation of the pain is important. Pain drawings are often used for this purpose. The most patients describe their pain as “aching” or “sharp”.

Nerve root pain should not be expected to follow along a specific dermatome. Dermatomal maps and a dermatomal distribution of pain is not a useful historical factor in the diagnosis of radiculopathy. The exception of this is S1 radicular pain, in which the pain does commonly follow the S1 dermatome.

The clinical presentation of lumbar radiculopathy will vary depending on the cause of the radiculopathy and which nerve roots are being affected. Patients will often present with pain in the lumbar region that radiates through one or both legs. This pain is often described as burning, stabbing, or shooting. For this pain to be considered radiculopathy, however, neurological signs must be present such as weakness, numbness, or reflexive changes.

Effectiveness of using weakness and numbness as identifying factors. See test diagnostics page for explanation of statistics.

File:Dermatomes.jpg

Question	+LR (yes)	-LR(no)
Weakness?	1.2	.73
Numbness?	1.0	.94

Clinical presentation for radiculopathy from each lumbar nerve root: 

Nerve Root	Dermatomal area	Myotomal area	Reflexive changes
L1	Inguinal region	Hip flexors
L2	Anterior mid-thigh	Hip flexors
L3	Distal anterior thigh	Hip flexors and knee extensors	Diminished or absent patellar reflex
L4	Medial lower leg/foot	Knee extensors and ankle dorsiflexors	Diminished or absent patellar reflex
L5	Lateral leg/foot	Hallux extension and ankle plantar flexors	Diminished or absent achilles reflex
S1	Lateral side of foot	Ankle plantar flexors and evertors	Diminished or absent achilles reflex

• Dermatomes and myotomes aren't intended as an all-inclusive list, but rather a clinically relevant system to assist in neurological screening. See dermatomal map to the right for further clarification.

Causes of lumbar radiculopathy

The most common causes of radiculopathy:

• lateral canal stenosis
• herniated disk

The leading causes of monoradiculopathy:

• Compression: prolapse of the intervertebral disc, arthrosis with narrowing of the intevertebral foramen, metastasis at the vertebral column
• Infections: Herpes zoster

Spinal cord disorders with a back strand disorder:

• Myelitis transversa (radicular irritation often preceding)
• Myelopathy because of B12- deficiency (arise gradual with gnostic sensibilisation disorders and paresthetics in the legs)
• Multiple sclerosis
• Spinocerebellum degeneration
  

Examination

A complete physical and neurologic examination can reveal defects at specific levels.

Motor, sensory and reflex function should be assessed to determine the affected nerve root level. Specific movements and positions that reproduce the symptoms should be investigated during the examination to help determine the source of the pain and the affected nerve root level.

Clinical evaluation of lumbosacral radiculopathy begins with:

• Medical history (type, location and duration of symptoms, presence of subjective weakness and dysesthesia, current therapy, dermatomal radiation, absence of work)
• and physical examination: dermatomal sensory loss, myotomal weakness, straight leg raise  and reflexes
• X-rays(identify the precence of trauma or osteoarthritis and early signs of tumor or infection)
• EMG: useful in detecting radiculopathies
• MRI: used to see if disc herniation and nerve root compression are present in patients with clinical suspicion of lumbosacral radiculopathy.
• In patients with clinical suspicion of lumbosacral radiculopathy and normal MRI findings, EMG may help in diagnosing nerve root involvement in patients with otherwise unexplained leg pain.
• Significant predictors of radiological nerve root compression (one of the most common causes of radiculopathy) are:
  • dermatomal radiation
  • more pain on coughing, sneezing or straining
  • positive straight leg raise (SLR) and finger-floor distance
  • ongoing denervation on EMG 
    

Diagnostic Procedures

Special Tests:

Straight Leg Raise Test: 

Patient lies supine and raises the leg on the involved side with the knee extended. If pain is produced at 40 degrees or less of hip flexion, the test is positive. Symptoms can be sharpened by adding ankle dorsiflexion to the straight-leg raise. Even if the test is negative, useful information can be gained if symptoms are produced past 40 degrees of hip flexion, assuming that hamstring length is equal. 

Crossed Straight Leg Raise Test:

Patient lies supine and raises the leg on the uninvolved side with the knee extended. If pain is provoked down the involved leg, the test is positive for radiculopathy, and indicates that there is likely a large space-occupying lesion (herniated nucleus pulposus). This test is useful for ruling in radiculopathy, as it is highly specific for it. 

Medical Management

Medical management includes patient education, medications to relieve pain and muscles spasm, cortisone injection around the spinal cord (epidural injection), physical therapy (heat, massage, ultrasound, electrical stimulation), anti-inflammatory medications, or chiropractic treatment, and avoiding activity that strains the neck or back. By research the majority of radiculopathy patients respond well to this conservative treatment, and symptoms often improve within six weeks to three months.

If nerve root compression is persistent discectomy will be considered.

Physical Therapy Management

The more treatable condition of lumbar radiculopathy, however, arises when extruded disc material contacts, or exerts pressure, on the thecal sac or lumbar nerve roots.

The literature support both conservative management and surgical intervention as viable options for the treatment of radiculopathy caused by lumbar disc herniation. Surgical intervention may result in faster relief of symptoms and earlier return to function, although long-term results appear to be similar regardless of type of management. The ultimate decision regarding type of treatment should be bases on a surgeon-patient discussion, in light of proper surgical indications, duration of symptoms, and patient wishes.

Physical therapy can include mild stretching and pain relief modalities, such as ultrasound, whirlpool, ice and heat pack therapy, electrical stimulation, and/or massage  ,active stabilisation, lasertherapy, conditioning exercise and ergonomic program ,
Positional distraction: It can isolate the spinal level to maximally open the effected neuroforamen. The combination of lateral flexion (away from the targeted neuroforamen), lumbar flexion (flexed hips to induce forward bending at targeted segment) and lumbar rotation (patient’s bottom arm is pulled upward) can maximally open a targeted neuroforamen. The intervention is effective when the patient report relief of leg pain shortly after placement in the position. It can be performed in the clinic and at home.

Recent Related Research (from Pubmed)

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