We present the case of an 18-year-old male with a ventriculoperitoneal (VP) shunt for hydrocephalus who experienced right shoulder pain. The patient was thoroughly investigated for gastrointestinal disease, including abdominal ultrasound and upper endoscopy, which revealed no abnormalities that could explain his symptoms. X-ray imaging subsequently revealed that the shunt\'s distal peritoneal tubing was positioned in a supra-hepatic subdiaphragmatic location. Surgical shortening and repositioning of the peritoneal tubing successfully alleviated the patient\'s shoulder pain. A review of the literature uncovered four articles, comprising a total of six patients, who exhibited similar symptoms of shoulder pain linked to their VP shunts. Given the rarity of this complication, it can be easily overlooked or misdiagnosed. It is crucial for physicians to consider this possibility when evaluating patients with VP shunts who present with shoulder pain to ensure prompt and effective treatment.

Patients who present with acute or chronic posterior dental pain but cannot identify the tooth from which the pain originates may suffer from a common but often unrecognized condition. The present article introduces a new term for this disorder, ectopic sulcular pain (ESP), derived from its unusual presentation, location, and defining symptom. It is tempting to call ESP an infection, but this has not been confirmed. In ESP, oral examination reveals no visual abnormalities, and there are no evident fractures, caries, periodontitis, attachment loss, traumatic occlusion, or periapical abscesses. This confusing symptomatology often leads to incorrect diagnosis and, consequently, treatment that fails to relieve the patient\'s pain. This article discusses ESP and reports 13 cases in which the condition was identified via intraligamental or topical application of an anesthetic agent to numb the gingiva. In 12 patients, ESP was successfully treated with meticulous oral hygiene, chlorhexidine rinses, and, in some cases, oral antibiotics.

BACKGROUND: Myofascial trigger points (TrPs) are hypersensitive points located in a tight band of muscle that, when palpated, produce not only local pain but also referred (distant) pain. The role of TrPs in patients with cervical dystonia (CD) has not been investigated.
OBJECTIVE: To identify the presence of TrPs in patients with isolated idiopathic CD and their association with pain.
METHODS: Thirty-one patients (74.2% women; age: 61.2 years, SD: 10.1 years) participated. TrPs were explored in the sternocleidomastoid, upper trapezius, splenius capitis, levator scapulae, anterior scalene, suboccipital, and infraspinatus muscles. Clinical features of CD were documented as well as the presence of pain. The severity of dystonia and its consequences were assessed using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS).
RESULTS: The mean number of TrPs for each patient was 12 (SD:3), with no differences between patients with pain (n = 20) and those without pain (n = 11). Active TrPs were only found in patients with pain (mean: 7.5, SD:4). Latent TrPs were found in both groups but were more prevalent (P < 0.001) in patients without pain (mean: 11, SD:3.5) than in those with pain (mean: 5, SD:3.5). The number of active TrPs or latent TrPs was positively associated with the TWSTRS disability subscale and the TWSTRS total score. The number of active, but not latent, TrPs was associated with worse scores on the TWSTRS pain subscale.
CONCLUSIONS: Active TrPs were present in patients with CD reporting pain, while latent TrPs were present in all CD patients, irrespective of their pain status. The numbers of active/latent TrPs were associated with disability. TrPs could act as pain generators in CD and also contribute to the involuntary muscle contractions characteristic of dystonia.

BACKGROUND: Symptomatic irreversible pulpitis often results in heightened reactions to thermal stimuli such as pain evoked by a cold stimulus, and spontaneous odontogenic pain (unprovoked pain).
OBJECTIVE: This study primarily compared the clinical manifestations of odontogenic spontaneous pain and pain provoked by cold stimulus specifically focusing on their sensory discriminative characteristics (intensity, duration and quality) between symptomatic irreversible pulpitis patients with and without referred pain.
METHODS: Twenty-three patients with symptomatic irreversible pulpitis with referred pain and 12 patients without referred pain were included in this cross-sectional study. The following outcomes were assessed: odontogenic spontaneous pain and its descriptors; pain evoked by cold stimulus and qualitative sensory testing before and after local anaesthesia; referred pain location; use of analgesic medication; complementary anaesthesia efficacy. T-test, chi-squared and McNemar tests were applied to the data (p < .50).
RESULTS: Patients with referred pain presented a greater odontogenic pain intensity (p < .05) when considered the average of the last 24 h. These patients also showed higher pain rating and pain descriptors (p < .05). Intensity and duration of the pain evoked by cold stimulus in the non-affected contralateral tooth at baseline were higher for patients with referred pain (p < .05).
CONCLUSIONS: Symptomatic irreversible pulpitis patients with referred pain present greater odontogenic spontaneous pain and a heightened pain sensitivity. Therefore, patients with referred pain seem more complex from a pain severity perspective, supporting the clinical utility of discriminating symptomatic irreversible pulpitis with and without referred pain.

BACKGROUND: The temporal tendon is a structure often compromised in patients suffering from temporomandibular disorders (TMD), yet its intraoral location makes a standardised assessment difficult.
OBJECTIVE: To evaluate the variability and accuracy to target force of a newly designed intraoral extension for a palpometer device (Palpeter, Sunstar Suisse) when compared to manual palpation, in addition to clinically assessing the mechanical sensitivity and referred sensations of the temporal tendon in healthy individuals.
METHODS: Experiment 1: 12 individuals were asked to target on a scale 0.5, 1 and 2 kg, for 2 and 5 s by using five different methods (Palpeter, Palpeter with three different extension shapes and manual palpation). Experiment 2: 10 healthy participants were recruited for a randomised double-blinded assessment by applying pressure of 0.5, 1 and 2 kg to the right temporal tendon with the three extensions and manual palpation. Participants rated the intensity of their sensation/pain on a 0-50-100 numeric rating scale (NRS), unpleasantness on a 0-100 NRS, and if present, they rated and drew the location of referred sensations. Repeated measures analysis of variance (ANOVA) was used in both experiments to compare differences between palpation methods. Tukey\'s HSD tests were used for the post hoc comparisons, and p values below .05 were considered significant.
RESULTS: Experiment 1: The extensions showed no significant differences between them regarding reliability and accuracy for all forces and durations (p > .05). The manual method was significantly less reliable and accurate when compared to the other methods (p < .05). Experiment 2: There were no significant differences between the Palpeter extensions regarding pain intensity or unpleasantness NRS scores (p > .05), but all the extensions had significantly increased pain intensity and unpleasantness when compared to manual palpation (p < .05). Similarly, the frequency of referred sensations was similar between extensions but increased when compared to manual palpation.
CONCLUSIONS: The new Palpeter extensions proved to be significantly more accurate and have lower test-retest variability than the manual method in a non-clinical setting. Clinically, they showed no significant differences in NRS scores for pain intensity nor unpleasantness, with no major differences in referred sensations, making any of the extensions suitable for clinical testing of the temporal tendon in future studies.

Tension-type headache is the most prevalent type of headache and is commonly associated with myofascial pain syndrome and the presence of active myofascial trigger points. This randomized controlled trial aimed to assess the impact of dry needling on the total number of active trigger points, pain intensity, and perceived clinical change in tension-type headache subjects. Thirty-two subjects were randomly assigned to the control and dry needling groups. The presence of active trigger points in 15 head and neck muscles, the headache intensity, and the perceived clinical change were evaluated. A single dry needling technique was administered at each active trigger point across three sessions. Significant differences were observed in the post-treatment measures favouring the dry needling group, including reductions in the headache intensity scores (p = 0.034) and the total number of active trigger points (p = 0.039). Moreover, significant differences in the perception of clinical change were found between the control and treatment groups (p = 0.000). Dry needling demonstrated positive effects in reducing the number of active trigger points and improving the short-term headache intensity in tension-type headache patients. A single dry needling session applied in the cranio-cervical area resulted in a self-perceived improvement compared to the control subjects.

Clinical studies have shown that there may be a certain relationship between pathological changes of the myodural bridge complex (MDBC) and chronic headaches of unknown cause. But there is still a lack of experimental evidence to explain the possible mechanism. This study aims to further confirm this relationship between MDBC and chronic headaches and explore its potential occurrence mechanism in rats. Bleomycin (BLM) or phosphate-buffered saline (PBS) was injected into the myodural bridge fibers of rats to establish the hyperplastic model of MDBC. After 4 weeks, the occurrence of headaches in rats was evaluated through behavioral scores. The immunohistochemistry staining method was applied to observe the expression levels of headache-related neurotransmitters in the brain. Masson trichrome staining results showed that the number of collagen fibers of MDBC was increased in the BLM group compared to those of the other two groups. It revealed hyperplastic changes of MDBC. The behavioral scores of the BLM group were significantly higher than those of the PBS group and the blank control group. Meanwhile, expression levels of CGRP and 5-HT in the headache-related nuclei of the brain were increased in the BLM group. The current study further confirms the view that there is a relationship between pathological changes of MDBC and chronic headaches of unknown cause. This study may provide anatomical and physiological explanations for the pathogenesis of some chronic headaches of unknown cause.

With a wide range of etiologies, low back pain (LBP) presents a true clinical challenge, finding its origins both in intrinsic spinal and systemic conditions, as well as referred ones. This review categorizes the LBP into these three groups and aims to offer a comprehensive look at the tools required to diagnose and differentiate them. The intrinsic etiologies are based on conditions that affect the musculoskeletal components of the lumbar spine, such as intervertebral disc disease, stenosis, muscular imbalance, and facet joint degeneration. The systemic causes usually extend beyond local structures. Such are the cases of neoplasia, infections, and chronic inflammation. The diagnosis is rendered even more complex by adding the referred pain, which only manifests in the lower back yet arises in more distant locations. By synthesizing the literature that encompasses the problem, this review aims to augment the understanding of the differential diagnoses of LBP by showcasing the subject\'s nuances. This categorization provides a structured approach to a patient-centered diagnosis, which could facilitate the medical practitioners\' efforts to navigate this pathology more effectively.

The most superficial layer of the spinal dorsal horn, lamina I, is a key element of the nociceptive processing system. It contains different types of projection neurons (PNs) and local-circuit neurons (LCNs) whose functional roles in the signal processing are poorly understood. This article reviews recent progress in elucidating novel anatomical features and physiological properties of lamina I PNs and LCNs revealed by whole-cell recordings in ex vivo spinal cord. This article is part of the Special Issue on \"Ukrainian Neuroscience\".

Nociplastic pain is a non-specific, regional pain lasting more than three months, characterised by the onset of hypersensitivity, despite no clear evidence of tissue damage. It is a relatively new classified type of pain. As a result, there has not yet been much work describing its precise modelling. The mechanism of its formation needs to be clearly explained. Authors point out that the occurrence of myofascial trigger points (MTrPs) can lead to this type of pain as one possibility. This paper summarises the available literature on modelling nociplastic pain and MTrPs. It complies with studies describing animal model creation and presents the results of performed experiments. The literature search was conducted in December 2022 and included the following databases: PubMed, Scopus, and Web of Science. In this scoping review, six studies were included. Two described the creation of animal models of nociplastic pain, one adapted old models to nociplastic pain, and three described the modelling of MTrPs. This is the first paper pointing in the possible direction of detecting and studying the correlation between MTrPs and nociplastic pain in animal models. However, there is currently insufficient evidence to describe MTrPs as nociplastic, as few studies with animal models exist.