Capsaicin 8% Patch for Spinal Cord Injury Focal Neuropathic Pain, a Randomized Controlled Trial

Pain in the Context of Sensory Deafferentation

Pain that accompanies deafferentation is one of the most mysterious and misunderstood medical conditions. Prevalence rates for the assorted conditions vary considerably but the most reliable estimates are greater than 50% for strokes involving the somatosensory system, brachial plexus avulsions, spinal cord injury, and limb amputation, with controversy surrounding the mechanistic contributions of deafferentation to ensuing neuropathic pain syndromes. Deafferentation pain has also been described for loss of other body parts (e.g., eyes and breasts) and may contribute to between 10% and upwards of 30% of neuropathic symptoms in peripheral neuropathies. There is no pathognomonic test or sign to identify deafferentation pain, and part of the controversy surrounding it stems from the prodigious challenges in differentiating cause and effect. For example, it is unknown whether cortical reorganization causes pain or is a byproduct of pathoanatomical changes accompanying injury, including pain. Similarly, ascertaining whether deafferentation contributes to neuropathic pain, or whether concomitant injury to nerve fibers transmitting pain and touch sensation leads to a deafferentation-like phenotype can be clinically difficult, although a detailed neurologic examination, functional imaging, and psychophysical tests may provide clues. Due in part to the concurrent morbidities, the physical, psychologic, and by extension socioeconomic costs of disorders associated with deafferentation are higher than for other chronic pain conditions. Treatment is symptom-based, with evidence supporting first-line antineuropathic medications such as gabapentinoids and antidepressants. Studies examining noninvasive neuromodulation and virtual reality have yielded mixed results.

Novel therapeutical approaches based on neurobiological and genetic strategies for diabetic polyneuropathy - A review

BACKGROUND

Neuropathy is among the most often reported consequences of diabetes and the biggest cause of morbidity and mortality in people suffering from this life-long disease. Although different therapeutic methods are available for diabetic neuropathy, it is still the leading cause of limb amputations, and it significantly decreases patients' quality of life.

AIM

This study investigates potential novel therapeutic options that could ameliorate symptoms of DN.

METHODOLOGY

Research and review papers from the last 10 years were taken into consideration.

RESULTS

There are various traditional drugs and non-pharmacological methods used to treat this health condition. However, the research in the area of pathogenic-oriented drugs in the treatment of DN showed no recent breakthroughs, mostly due to the limited evidence about their effectiveness and safety obtained through clinical trials. Consequently, there is an urgent demand for the development of novel therapeutic options for diabetic neuropathy.

CONCLUSION

Some of the latest novel diagnostic methods for diagnosing diabetic neuropathy are discussed as well as the new therapeutic approaches, such as the fusion of neuronal cells with stem cells, targeting gene delivery and novel drugs.

A Silver Lining of Neuropathic Pain: Predicting Favorable Functional Outcome in Spinal Cord Injury

Background

Neuropathic pain (NP) is a common and severe problem following spinal cord injury (SCI). However, its relationship with functional outcome remains unclear.

Methods

A retrospective explorative analysis was performed on SCI patients admitted to a tertiary academic medical center between January 2018 and June 2022. The candidate predictor variables, including demographics, clinical characteristics and complications, were analyzed with logistic and linear regression. Spinal Cord Independence Measure (SCIM) scores at discharge and mean relative functional gain (mRFG) of SCIM were as outcome parameters.

Results

A total of 140 SCI patients included for the final analysis. Among them, 44 (31.43%) patients were tetraplegics, and 96 (68.57%) patients were paraplegics; 68 (48.57%) patients developed NP, and 72 (51.43%) patients did not. Logistic and linear regression analyses of SCIM at discharge both showed that NP [OR=3.10, 95% CI (1.29,7.45), P=0.01; unstandardized β=11.47, 95% CI (4.95,17.99), P<0.01; respectively] was significantly independent predictors for a favorable outcome (SCIM at discharge ≥ 50, logistic regression results) and higher SCIM total score at discharge (linear regression results). Besides, NP [unstandardized β=15.67, 95% CI (8.94,22.41), P<0.01] was also independently associated with higher mRFG of SCIM scores. Furthermore, the NP group had significantly higher mRFG, SCIM total scores and subscales (self-care, respiration and sphincter management, and mobility) at discharge compared to the non-NP group. However, there were no significant differences in mRFG, SCIM total score or subscales at discharge among the NP subgroups in terms of locations (at level pain, below level pain, and both) or timing of occurrence (within and after one month after SCI). This study also showed that incomplete injury, lumbar-sacral injury level and non-anemia were significantly independent predictors for a favorable outcome, and higher mRFG of SCIM scores (except for non-anemia).

Conclusion

NP appears independently associated with better functional recovery in SCI patients, suggesting the bright side of this undesirable complication. These findings may help to alleviate the psychological burden of NP patients and ultimately restore their confidence in rehabilitation.

Novel Drug Targets and Emerging Pharmacotherapies in Neuropathic Pain

Neuropathic pain is a debilitating condition characterized by abnormal signaling within the nervous system, resulting in persistent and often intense sensations of pain. It can arise from various causes, including traumatic nerve injury, neuropathy, and certain diseases. We present an overview of current and emerging pharmacotherapies for neuropathic pain, focusing on novel drug targets and potential therapeutic agents. Current pharmacotherapies, including tricyclic antidepressants, gabapentinoids, and serotonin norepinephrine re-uptake inhibitors, are discussed, as are emerging treatments, such as ambroxol, cannabidiol, and N-acetyl-L-cysteine. Additionally, the article highlights the need for further research in this field to identify new targets and develop more effective and targeted therapies for neuropathic pain management.

Perineural Invasion in Pancreatic Ductal Adenocarcinoma: From Molecules towards Drugs of Clinical Relevance

Pancreatic ductal adenocarcinoma is one of the most threatening solid malignancies. Molecular and cellular mediators that activate paracrine signalling also regulate the dynamic interaction between pancreatic cancer cells and nerves. This reciprocal interface leads to perineural invasion (PNI), defined as the ability of cancer cells to invade nerves, similar to vascular and lymphatic metastatic cascade. Targeting PNI in pancreatic cancer might help ameliorate prognosis and pain relief. In this review, the modern knowledge of PNI in pancreatic cancer has been analysed and critically presented. We focused on molecular pathways promoting cancer progression, with particular emphasis on neuropathic pain generation, and we reviewed the current knowledge of pharmacological inhibitors of the PNI axis. PNI represents a common hallmark of PDAC and correlates with recurrence, poor prognosis and pain in pancreatic cancer patients. The interaction among pancreatic cancer cells, immune cells and nerves is biologically relevant in each stage of the disease and stimulates great interest, but the real impact of the administration of novel agents in clinical practice is limited. It is still early days for PNI-targeted treatments, and further advanced studies are needed to understand whether they could be effective tools in the clinical setting.