Neuropathic pain is defined as a painful condition caused by neurological lesions or diseases. Sometimes, neurological disorders may also be associated with neuropathic pain, which can be challenging to manage. For example, multiple sclerosis (MS) may cause chronic centralized painful symptoms due to nerve damage. Other chronic neuropathic pain syndromes may occur in the form of post-stroke pain, spinal cord injury pain, and other central pain syndromes. Chronic neuropathic pain is associated with dysfunction, disability, depression, disturbed sleep, and reduced quality of life. Early diagnosis may help improve outcomes, and pain control can be an important factor in restoring function. There are more than 100 different types of peripheral neuropathy and those involving sensory neurons can provoke painful symptoms. Accurate diagnosis of peripheral neuropathy is essential for pain control. Further examples are represented by gluten neuropathy, which is an extraintestinal manifestation of gluten sensitivity and presents as a form of peripheral neuropathy; in these unusual cases, neuropathy may be managed with diet. Neuropathic pain has been linked to CoronaVirus Disease (COVID) infection both during acute infection and as a post-viral syndrome known as long COVID. In this last case, neuropathic pain relates to the host’s response to the virus. However, neuropathic pain may occur after any critical illness and has been observed as part of a syndrome following intensive care unit hospitalization.

Background: Neuropathic pain (NP) in head and neck cancer (HNC) patients represents a treatment challenge. Most studies investigating drugs against NP are conducted in patients suffering with diabetic neuropathy or postherpetic neuralgia, while data are limited in cancer pain management. Additionally, regarding cancer therapy-related NP, most of the studies do not focus on HNC patients. The aim of this review is to identify the studies on systematically administered medication for NP management that included HNC patients under radiotherapy. Methods: A systematic literature search was performed, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, in PubMed, Cochrane Library, Web of Science and ClinicalTrials.gov on 30 October 2021. The medical subject heading (MeSH) terms were (“head and neck cancer” OR “tumor”) AND “neuropathic pain” AND “medication” AND “radiotherapy.” The Cochrane Collaboration tool was used for quality assessment. Results: The search identified 432 articles. Three more articles were identified after searching the reference lists of the retrieved articles. A total of 10 articles met the eligibility inclusion criteria and were included in this review; 6 on gabapentin, 1 on pregabalin, 1 on nortriptyline, 1 on methadone, and 1 on ketamine. Statistically significant results in pain reduction compared to placebo or standard pain medication were found in the studies on pregabalin (p = 0.003), methadone (p = 0.03), ketamine (p = 0.012), and in two out of six gabapentin studies (p < 0.004). Two of the studies (both concerning gabapentin) had no comparison arm. Conclusions: Treatments including pregabalin, methadone, ketamine, and gabapentin were found to provide pain relief against HNC NP. While there is a plethora of pharmacological treatments available for the management of NP, only a few studies have been conducted regarding the pharmacological management of therapy-related NP in HNC patients. More studies should be conducted regarding the pharmacological approaches in HNC therapy-related NP so that specific treatment algorithms can be developed.

Purpose: The Patient Neurotoxicity Questionnaire (PNQ) represents a diagnostic tool concerning patients with chemotherapy-induced peripheral neuropathy (CIPN). The application of such a tool in the Greek clinical praxis requires validation. Methods: Validation consists of three stages - translation, reverse translation, and patient application. Hundred oncologic patients were assessed by comparing the PNQ to the National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) at the chemotherapy onset and second, fourth, and sixth sessions. The diagnostic tool's specific requirements (compliance, validity, concordance, sensitivity, specificity, reliability) were statistically evaluated. Results: Differences between translated texts and between the reverse translation and the original were considered negligible. At the second, fourth, and sixth session compliance was 98%, 95%, and 93% while Cronbach’s α was 0,57 0,69, and 0,81, respectively. Cohen’s weighted κ was 0,67 and 0,58, Spearman’s ρ was 0,7 and 0,98, while the area under the curve (AUC) of the receiver operating characteristic (ROC) was 1 and 0,9 for the sensory and the motor part, respectively. The variance’s linear regression analysis confirmed CIPN worsening over time (P<0.0001). Discussion: The Greek version remains close to the original English version. Compliance rates reflect easy PNQ applications. Cohen’s κ values highlight the physicians’ tension to underestimate the patients’ condition. Spearman’s ρ, Cronbach’s α, and AUC values reflect good validity, reliability, and specificity of the PNQ respectively. Finally, the linear analysis confirmed the PNQ sensitivity over time. Conclusions: The PNQ validation in Greek adds a crucial tool to the physicians' armamentarium. It can now delineate the necessary information to modify the chemotherapy and analgesic treatment regimens at both preventive and acute levels.

The diagnosis of chronic neuropathic pain requires a laborious process and can be a very long journey for the patients, one that can be characterized as an “odyssey.” Our aim was to describe the “diagnostic odyssey” associated with chronic neuropathic pain in the Greek context. Specialized clinicians working at dedicated chronic pain and palliative care centers were asked to participate in a survey regarding the diagnostic process in Greece. In total, 44 respondents provided information on the organization of their centers, the diagnostic process, and the perceived obstacles involved in the diagnosis of chronic neuropathic pain. Most respondents reported that their centers were not fully or efficiently organized and believed that additional specialized healthcare personnel should be employed. Raising public awareness about the existence of such centers was also considered key. The two main obstacles in reaching a diagnosis were the difficulty non-experts had in recognizing chronic neuropathic pain and the lack of acknowledgement that chronic neuropathic pain is a condition that needs to be addressed. When considering these responses in light of the extended socioeconomic burden associated with chronic neuropathic pain, efforts should be made to limit the “diagnostic odyssey” of chronic neuropathic pain in Greece. The aim of this study is to explore the experience of patients with chronic neuropathic pain in Greece from the viewpoint of pain specialists. A better organization of pain and palliative care centers, facilitation of communication with previously treating clinicians, increased personnel, utilization of a chronic pain registry, and guidelines development can aid in this venture. Keypoints: The diagnosis of chronic neuropathic pain in Greece is a laborious and time-consuming process that needs to be refined; Greek clinicians believe that their centers were not fully or efficiently organized and think that additional specialized healthcare personnel should be employed; Patient comorbidities and retards in visiting a clinic at the onset of symptoms delay the diagnosis of neuropathic pain and may complicate subsequent care; The diagnostic delay has been reported as three years between the onset of symptoms and seeking general medical help and another nine years before a referral to a pain specialist; Neuropathic pain is associated with patient distress and socioeconomic burdens, and diagnostic delays prolong the condition, may allow it to worsen, and utilize valuable healthcare resources without providing effective solutions.