Protectin DX Attenuates Lumbar Radicular Pain of Non-compressive Disc Herniation by Autophagy Flux Stimulation via Adenosine Monophosphate-Activated Protein Kinase Signaling

Background: Neuroinflammation plays a crucial role in initiating and sustaining lumbar radicular pain (LRP). Protectin DX (PDX) has been experimentally verified to possess pro-resolving properties and anti-inflammatory effects. This study aimed to observe the analgesic effects of PDX and its potential mechanisms in LRP rats with non-compressive lumbar disc herniation (NCLDH).Method: Only male rats were selected to avoid gender-related interferences. Rat models of NCLDH were established, and rats were randomly divided into four groups: the sham group, the vehicle group, the PDX (10 ng PDX) group, and the PDX (100 ng PDX) group. Changes in the mechanical withdrawal threshold and thermal withdrawal latency were observed for 7 days. The mRNAs of pro-inflammatory and anti-inflammatory mediators were evaluated via real-time polymerase chain reaction, whereas western blot and immunohistochemistry were separately conducted to assess the expression levels of autophagy-related proteins and adenosine monophosphate-activated protein kinase (AMPK) signaling.Results: Intrathecal delivery of PDX reduced interleukin (IL)-6 and IL-1β mRNA levels and facilitated mRNA transcription of transforming growth factor-β1, with attenuation of mechanical and thermal hyperalgesia in LRP rat models. With the application of nucleus pulposus to the dorsal root ganglion, autophagy flux and AMPK signaling were severely disrupted in the spinal dorsal horns, and intrathecal treatment with PDX could dose-dependently restore the dysfunction of autophagy flux and AMPK signaling.Conclusion: These data suggest that PDX possesses pro-resolving properties and exerts potent analgesic effects in LRP by affecting autophagy flux via AMPK signaling.

Disentangling ‘sciatica’ to understand and characterise somatosensory profiles and potential pain mechanisms

Objectives The study aimed to investigate if patients with lumbar radicular pain only and those with combined lumbar radicular pain + radiculopathy differ in their somatosensory profiles and pain experiences. Methods Quantitative sensory testing (QST) was performed in 26 patients (mean age 47 ± 10 years, 10 females) with unilateral leg pain in the L5 or S1 distribution in their main pain area (MPA) and contralateral mirror side, in the relevant foot dermatome on the symptomatic side and in the hand dorsum. Pain experience was captured on the painDETECT. Results Eight patients presented with lumbar radicular pain only and 18 patients with combined radicular pain + radiculopathy. Patients with radicular pain only demonstrated widespread loss of function (mechanical detection) bilaterally in the MPA (p<0.003) and hand (p=0.002), increased heat sensitivity in both legs (p<0.019) and cold/heat sensitivity in the hand (p<0.024). QST measurements in the dermatome did not differ compared to HCs and patients with radiculopathy. Patients with lumbar radiculopathy were characterised by a localised loss of function in the symptomatic leg in the MPA (warm, mechanical, vibration detection, mechanical pain threshold, mechanical pain sensitivity p<0.031) and dermatome (mechanical, vibration detection p<0.001), consistent with a nerve root lesion. Pain descriptors did not differ between the two groups with the exception of numbness (p<0.001). Patients with radicular pain did not report symptoms of numbness, while 78% of patients with radiculopathy did. Conclusions Distinct differences in somatosensory profiles and pain experiences were demonstrated for each patient group, suggesting differing underlying pain mechanisms.

Pulsed Radiofrequency Dorsal Root Ganglion-Fluoroscopy Guide for Lumbar Radicular Pain

Background: Lumbosacral radicular pain is the most common neuropathic pain. Pulsed Radio Frequency (PRF) is a method that believes to be safe and effective for reducing pain. Case: A 43-year-old woman experiences chronic right lumbar radiculopathy due to Herniated nucleus pulposus (HNP) L4-5. Anamnesis and physical examination show a sign of neuropathic pain. The MRI examination shows a paracentral disc protrusion L4-5 that compresses the transversing nerve L5. The conservative management did not produce a satisfying result indicated by the patient still experience pain with the Numeric Rating Scale (NRS) 4-5. Patient unable to do activity properly. We perform pain management using the dorsal root ganglion L5 pulsed radiofrequency-fluoroscopy (PRF) and producing a positive outcome. Patients experience a decrease in pain intensity with NRS 1. The examination on one and two months post-intervention show an improvement. Patient able to do the daily activity with NRS 1-2. Conclusion: Pulsed radiofrequency dorsal root ganglion-fluoroscopy guide that relatively safe, minimum complications, and minimal side effects, making it the preferred treatment for chronic lumbar radicular pain.

Evidence for the BUAS-test ability to diagnose lumbar radicular pain

Background: Differential diagnosis of low back pain (LBP) is complex and a prominent issue at all health-care levels; guidance may come from patients’ history cues and clinical examination signs. Human and animal studies report that diagnosis of lumbar radicular pain (LRP) may come from evaluating subjective responses of injured lumbar nerves to a strain applied at the buttock. The Buttock Applied Strain (BUAS-test) test may guide the differential diagnosis of LBP. Following an ex-adiuvantibus criterion, clinical improvement of LRP, diagnosed with the BUAS-test and congruently treated, may support this test diagnostic ability. Methods: Among 258 LRP patients, who, upon first visit (V1), tested positive on the BUAS-test (with/without positive Straight Leg Raising Test, SLRT), the effect of gabapentin prescription on painDETECT (PD) questionnaire and Brief Pain Inventory (BPI) outcomes was quantified in the follow-up visit (V2). To support BUAS-test diagnostic ability, we hypothesized that, at V2, >50% of the sample would present negative PD outcome, significant ( t-test) and ⩾2 points V2-V1 differences for each of the BPI-item’s score. We used multinomial logistic regression (MLR) and χ2 analyses to evaluate the PD-V2 outcomes’ dependence upon independent variables. Results: Of the sample, 77% reported a negative PD-V2 outcome. V2-V1 differences of all BPI items were significant and >2 points. PD-V2 outcomes showed significant associations with SLRT-V1 and PD-V1, respectively, but not with gender, age group or pain site. MLR showed a significant relationship between SLRT-V1 and PD-V2 outcomes. Conclusion: Among LRP patients, diagnosed by the BUAS-test and treated with gabapentin, all prespecified endpoints were reached. These results may be considered a piece of ex-adiuvantibus evidence for the BUAS-test ability to diagnose LRP. While positive BUAS-test implies potential LRP, the co-presence with positive SLRT may imply a severer LRP condition. Further prospective research, in different settings and direct clinical measures, is needed.

Topiramate and Pregabalin in Lumbar Radicular Pain. Is Topiramate a better option?

Objective: To compare the efficacy of two anticonvulsant drugs topiramate and pregabalin on lumbar radicular pain and to find out whether topiramate is a better option or not. Study design: Experimental study. Place and Duration: Department of Neurosurgery, Combined Military Hospital Lahore. January 2020 - March 2020. Patients and Methods: 60 patients of both gender divided in two groups of 30 each were included. Patients were assessed based on subjective impairment scale of oswestry disability index. Maximum score was calculated in percentage with higher score pointing to greater disability. Both drugs were given in low starting once daily dose, 75 mg for pregabalin and 25 mg for topiramate for two weeks followed by twice daily dose for two more weeks in patients not getting pain relief. Results: Male to female ratio of 4:1 in both groups. Age range of 27-77 years (41.5+12.45) for pregabalin and 22-74 years (41.6+14.6) for topiramate group. Baseline demographics and pre drug pain measurement index were identical amongst two groups. Oswestry disability index was 49.2+18.3 pre drug and post drug 41+16.4 for pregabalin (p<0.01). For topiramate it was 43.6+37.9 pre drug and 37.9+17.3 post drug (p <0.01). Conclusion: Both pregabalin and topiramate are effective in radicular pain management, and topiramate is not better but still a viable option as an alternative to pregabalin.