A Complex Solution of Radicular Pain
17. 3. 2017
The prevalence of back pain varies between 60–85% and, globally, it escalates. After an acute infection of the upper respiratory ways, it ranks the second most often cause of incapacity to work in people younger than 45 years. The radicular syndrome (RS) is, together with headache, the most frequent cause of a visit to the neurologist in adults. The incidence of the RS is 10 % in the age group of 55 to 65 years old men; in women it is the highest after 65 years (5 %). Some studies mention 9.9–25% in the population.
RS is characterised by a set of symptoms like one-sided sharp pain, burning, prickling, tightness, tingling or weakness of hand, leg or trunk (in the area of the path of an affected nerve) that were caused by suppression, irritation, or inflammation of nerve roots extending from the spinal canal. According to the International Association for the Study of Pain it isthe”feeling of pain originating and proceeding along an extremity or trunk, caused by an ectopic activation of nociceptive afferent fibres of the spinal nerves or roots, or other neuropathic mechanisms“.
Suppression, mechanical damage to the nerve root or both is the main cause of pain origin. Suppression (except for disc hernia itself) is caused by inflammation, ischemia, and oedema. Several studies proved the presence of the inflammation mediatorsin the site of disc damage – hernia (TNF-α, phospholipasis A2, prostaglandin E2, NO, leukotrienes, immunoglobulines, pro-inflammatory cytokines – IL-1α, IL-1β, IL-6) and autoimmune reactions (IL-1β produced by macrophages, intracellular adhesive molecules). Penetration of such substances and compounds into the surrounding causes irritation of nociceptors (β4 leukotrien and β2 tromboxane), direct damage to the nerve, intraneural and perineural inflammation; ischemia and oedema – set of such factors causes RADICULAR PAIN.
The most often cause of the RS is hernia of intervertebral discs (lumbosacral area is affected in 90% of all radiculopathies, 20–40 times more often incidence than in the neck area; the most often is hernia of L5/S1; 90% of hernias affects the L4, L5, and S1 roots; in the neck area it is 75% of hernias in the C6/C7, and C5/C6 segments, predominantly in the 4th and 5th decade of life. In the chest area the incidence is 0.5% out of all hernias of intervertebral discs. From other causes spondylotic changes are significant – arthrosis of facet joints, formation of osteophytes, reduction of intervertebral discs (most often from the 6th to the 7th decade of life) and stenosis of spinal channel. From other causes it is necessary to mention FBSS, primary and secondary tumours of the spine, spinal cord coverings, spine a roots; trauma spine (vertebrae fracture with fragments dislocation); spine inflammatory disease of infectious nature, spondylitis, spondylodiscitis, post-surgery adhesive arachnoitis (together with epidural fibrosis); epidural haematoma, abscess, osteoporosis, root disease (herpes zoster, Lyme Borreliosis), diabetic radiculopathy (most often affecting the chest segments).
The clinical picture has typically three symptoms – local pain with a disorder of the spine function (posture, locomotion disorder); sensitive dermatome symptoms (pain or paresthesia radiating in the appurtenant dermatome, sharply localized, invoked by provocation manoeuvres) and segmentally motoric symptoms (muscle weakness with hypotonia in the given myotome – it is missing at an isolated affection of rear sensitive roots).
Diagnostics is based upon medical history, physical examinations (clinical tests) and auxiliary imaging methods (MRI). MRI has a low specificity, 20–36 % of hernia discs detected in an asymptomatic part of population. Clinical tests at cervical radiculopathy are: cervical compression (pressure in the axial plane), the Spurling’s test (pressure in the axial plane connected with extension and head rotation to the side with pain), test of the cervical traction (pulling of chin and occipital area with pain relief), test of the passive abduction in elbow relieves pain in two thirds of the patients. At lumbosacral radiculopathy: the Lasègue’s manoeuvre (“straight leg raising test“) passive flexion in the loins with the extension in knee joint causes a radicular pain to 60° (L5 and S1), reverse Lasègue’s manoeuvre – rear stretching test (on abdomen, flexion in knee L4) and the Bragard’s test: at positive Lasègue’s manoeuvre decrease flexion by 5–10 %. This should result in relief; subsequent dorsal leg flexion in ankle joint causes the root pain.
Therapy in acute (subacute) condition is started with the conservative approach (anti-inflammatory drugs, physiotherapy, rehabilitation, saving regime of a patient – raising of a heavy load is prohibited), interventional therapy (epidural application of steroids: according to way of administration it is possible caudal, interlaminar a transforaminal one: TFESI, PRT – periradicular therapy: subpedicular, supraneural, retroneural, infraneural), pulse radiofrequency therapy and adhesiolysis using epinavigator, epiduroscopy and surgical procedures – decompressive laminectomy, foraminotomy, discectomy (miniinvasive endoscopic discectomy).
Indication for administration of steroids is pain of a lower extremity caused by an acute hernia of intervertebral disc with a radicular distribution in patients: who do not react on other non-surgical treatment, who need an acute relief from pain, in whom surgical treatment has not been indicated or in whom it is not possible, and in whom the case is the pain having an inflammatory etiology.
Contraindications of conducting the TFESI are broken down to absolute – impossibility to obtain the approval from a patient with the procedure, non-collaborating patient, impossibility to administer the contrast agent (allergy), infection at the site of the procedure and relative – pregnancy (RTG is an absolute contraindication), coagulopathy, systemic infection, immunosuppression, serious respiratory or cardiovascular disease, unfavourable anatomic conditions preventing to carry out a safe procedure.
Having exhausted all the therapeutic possibilities and in situation of persisting pain, it is proper to consider introduction of the SCS (spinal cord stimulator) in patient.
Author: MUDr. L’ubomír Poliak, ©EuroPainClinics®
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