Diagnosis of chronic radiating lower back pain without overt focal neurologic deficits: what is the value of segmental nerve blocks?

2. Cervical radicular pain

INTRODUCTION

Cervical radicular pain is pain perceived in the upper limb, caused by irritation or compression of a cervical spine nerve, the roots of the nerve, or both.

METHODS

The literature on the diagnosis and treatment of cervical radicular pain was retrieved and summarized.

RESULTS

The diagnosis is made by combining elements from the patient's history, physical examination, and supplementary tests. The Spurling and shoulder abduction tests are the two most common examinations used to identify cervical radicular pain. MRI without contrast, CT scanning, and in some cases plain radiography can all be appropriate imaging techniques for nontraumatic cervical radiculopathy. MRI is recommended prior to interventional treatments. Exercise with or without other treatments can be beneficial. There is scant evidence for the use of paracetamol, nonsteroidal anti-inflammatory drugs, and neuropathic pain medications such as gabapentin, pregabalin, tricyclic antidepressants, and anticonvulsants for the treatment of radicular pain. Acute and subacute cervical radicular pain may respond well to epidural corticosteroid administration, preferentially using an interlaminar approach. By contrast, for chronic cervical radicular pain, the efficacy of epidural corticosteroid administration is limited. In these patients, pulsed radiofrequency treatment adjacent to the dorsal root ganglion may be considered.

CONCLUSIONS

There is currently no gold standard for the diagnosis of cervical radicular pain. There is scant evidence for the use of medication. Epidural corticosteroid injection and pulsed radiofrequency adjacent to the dorsal root ganglion may be considered. [Correction added on 12 June 2023, after first online publication: The preceding sentence was corrected.].

Human assumed central sensitisation (HACS) in patients with chronic low back pain radiating to the leg (CLaSSICO study)

INTRODUCTION

Patients with chronic low back pain radiating to the leg (CLBPr) are sometimes referred to a specialised pain clinic for a precise diagnosis based, for example, on a diagnostic selective nerve root block. Possible interventions are therapeutic selective nerve root block or pulsed radiofrequency. Central pain sensitisation is not directly assessable in humans and therefore the term 'human assumed central sensitisation' (HACS) is proposed. The possible existence and degree of sensitisation associated with pain mechanisms assumed present in the human central nervous system, its role in the chronification of pain and its interaction with diagnostic and therapeutic interventions are largely unknown in patients with CLBPr. The aim of quantitative sensory testing (QST) is to estimate quantitatively the presence of HACS and accumulating evidence suggest that a subset of patients with CLBPr have facilitated responses to a range of QST tests.The aims of this study are to identify HACS in patients with CLBPr, to determine associations with the effect of selective nerve root blocks and compare outcomes of HACS in patients to healthy volunteers.

METHODS AND ANALYSIS

A prospective observational study including 50 patients with CLBPr. Measurements are performed before diagnostic and therapeutic nerve root block interventions and at 4 weeks follow-up. Data from patients will be compared with those of 50 sex-matched and age-matched healthy volunteers. The primary study parameters are the outcomes of QST and the Central Sensitisation Inventory. Statistical analyses to be performed will be analysis of variance.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee of the University Medical Center Groningen, Groningen, the Netherlands, approved this study (dossier NL60439.042.17). The results will be disseminated via publications in peer-reviewed journals and at conferences.

TRIAL REGISTRATION NUMBER

NTR NL6765.

Predictive Factors for Successful Outcome of Pulsed Radiofrequency Treatment in Patients with Intractable Lumbosacral Radicular Pain

BACKGROUND

In a previous prospective study on pulsed radiofrequency (PRF) treatment adjacent to the lumbar dorsal root ganglion (DRG) for patients with chronic lumbosacral radicular pain, we reported success in 55.4% of the patients at 6 months. Identification of predictors for success after PRF may improve outcome. We assessed the predictors of PRF in patients with chronic intractable lumbosacral radicular pain.

METHODS

Patients with monosegmental chronic lumbosacral radicular pain of L5 or S1 first received a selective nerve root block at the corresponding level. Independent of the result of this block a PRF treatment at the same level was performed. At 6 weeks, 3 months, and 6 months after the procedure the outcome was evaluated.

RESULTS

A positive diagnostic nerve root block and age ≥ 55 were predictive factors for successful outcome at 6 months, while disability was a negative predictor.The use of failed back surgery syndrome, gender, duration of pain, Numerical Rating Scale, level and side of treatment, DN4, and RAND-36 as predictors for success was not supported.

CONCLUSIONS

Successful outcome after PRF adjacent to the DRG, in patients with intractable chronic lumbosacral radicular pain, is more likely in patients ≥ 55 years, with limited disability and after a positive diagnostic nerve root block. A combination of all these factors creates a fair predictive value (AUC: 0.73).

Trigger point-related sympathetic nerve activity in chronic sciatic leg pain: a case study

Sciatica has classically been associated with irritation of the sciatic nerve by the vertebral disc and consequent inflammation. Some authors suggest that active trigger points in the gluteus minimus muscle can refer pain in similar way to sciatica. Trigger point diagnosis is based on Travel and Simons criteria, but referred pain and twitch response are significant confirmatory signs of the diagnostic criteria. Although vasoconstriction in the area of a latent trigger point has been demonstrated, the vasomotor reaction of active trigger points has not been examined. We report the case of a 22-year-old Caucasian European man who presented with a 3-year history of chronic sciatic-type leg pain. In the third year of symptoms, coexistent myofascial pain syndrome was diagnosed. Acupuncture needle stimulation of active trigger points under infrared thermovisual camera showed a sudden short-term vasodilatation (an autonomic phenomenon) in the area of referred pain. The vasodilatation spread from 0.2 to 171.9 cm(2) and then gradually decreased. After needling, increases in average and maximum skin temperature were seen as follows: for the thigh, changes were +2.6°C (average) and +3.6°C (maximum); for the calf, changes were +0.9°C (average) and +1.4°C (maximum). It is not yet known whether the vasodilatation observed was evoked exclusively by dry needling of active trigger points. The complex condition of the patient suggests that other variables might have influenced the infrared thermovision camera results. We suggest that it is important to check if vasodilatation in the area of referred pain occurs in all patients with active trigger points.

11. Lumbosacral radicular pain

Lumbosacral radicular pain is characterized by a radiating pain in one or more lumbar or sacral dermatomes; it may or may not be accompanied by other radicular irritation symptoms and/or symptoms of decreased function. The annual prevalence in the general population, described as low back pain with leg pain traveling below the knee, varied from 9.9% to 25%, which means that it is presumably the most commonly occurring form of neuropathic pain. The patient's history may give a suggestion of lumbosacral radicular pain. The best known clinical investigation is the straight-leg raising test. Final diagnosis is made based on a combination of clinical examination and potentially additional tests. Medical imaging studies are indicated to exclude possible serious pathologies and to confirm the affected level in patients suffering lumbosacral radicular pain for longer than 3 months. Magnetic resonance imaging is preferred. Selective diagnostic blocks help confirming the affected level. There is controversy concerning the effectiveness of conservative management (physical therapy, exercise) and pharmacological treatment. When conservative treatment fails, in subacute lumbosacral radicular pain under the level L3 as the result of a contained herniation, transforaminal corticosteroid administration is recommended (2 B+). In chronic lumbosacral radicular pain, (pulsed) radiofrequency treatment adjacent to the spinal ganglion (DRG) can be considered (2 C+). For refractory lumbosacral radicular pain, adhesiolysis and epiduroscopy can be considered (2 B+/-), preferentially study-related. In patients with a therapy-resistant radicular pain in the context of a Failed Back Surgery Syndrome, spinal cord stimulation is recommended (2 A+). This treatment should be performed in specialized centers.