Biophysics of Frequency-Dependent Variation in Paresthesia and Pain Relief during Spinal Cord Stimulation.

The neurophysiological effects of spinal cord stimulation (SCS) for chronic pain are poorly understood, resulting in inefficient failure-prone programming protocols and inadequate pain relief. Nonetheless, novel stimulation patterns are regularly introduced and adopted clinically. Traditionally, paresthetic sensation is considered necessary for pain relief, although novel paradigms provide analgesia without paresthesia. However, like pain relief, the neurophysiological underpinnings of SCS-induced paresthesia are unknown. Here, we paired biophysical modeling with clinical paresthesia thresholds (of both sexes) to investigate how stimulation frequency affects the neural response to SCS relevant to paresthesia and analgesia. Specifically, we modeled the dorsal column (DC) axonal response, dorsal column nucleus (DCN) synaptic transmission, conduction failure within DC fiber collaterals, and dorsal horn network output. Importantly, we found that high-frequency stimulation reduces DC fiber activation thresholds, which in turn accurately predicts clinical paresthesia perception thresholds. Furthermore, we show that high-frequency SCS produces asynchronous DC fiber spiking and ultimately asynchronous DCN output, offering a plausible biophysical basis for why high-frequency SCS is less comfortable and produces qualitatively different sensation than low-frequency stimulation. Finally, we demonstrate that the model dorsal horn network output is sensitive to SCS-inherent variations in spike timing, which could contribute to heterogeneous pain relief across patients. Importantly, we show that model DC fiber collaterals cannot reliably follow high-frequency stimulation, strongly affecting the network output and typically producing antinociceptive effects at high frequencies. Altogether, these findings clarify how SCS affects the nervous system and provide insight into the biophysics of paresthesia generation and pain relief.

Characteristics of spinal and bulbar muscular atrophy in South Korea: a cross-sectional study of 157 patients.

Spinal and bulbar muscular atrophy, namely Kennedy disease, is a rare progressive neurodegenerative disorder caused by the expansion of a CAG repeat in the first exon of the androgen receptor gene on the X chromosome. We assessed the clinical history, laboratory findings, functional scales and electrophysiological data, as well as the levels of luteinizing hormone, follicle-stimulating hormone and testosterone, in 157 Korean patients with genetically confirmed spinal and bulbar muscular atrophy (mean age at data collection = 56.9 years; range = 33-83 years). Hand tremor was the first symptom noticed by patients at a median age of 35 years, followed by gynaecomastia, orofacial fasciculation, cramps and fatigability in ascending order. Clinical symptoms such as paraesthesia and dysphagia appeared during the later stages of the disease. Cane use during ambulation began at a median age of 62 years. There were statistically significant differences between patients and controls in the results of sensory nerve studies, motor conduction velocity, and distal latencies. Furthermore, among the hormone markers analysed, the level of luteinizing hormone exhibited a negative correlation with the spinal and bulbar muscular atrophy functional rating scale, Korean version. However, among the patients with a disease duration of ≤5 years, the levels of luteinizing hormone showed a significant correlation with assessments using the amyotrophic lateral sclerosis functional rating scale-revised, spinal and bulbar muscular atrophy functional rating scale, Korean version and the 6-minute walk test. In conclusion, our findings provide clinical information from a substantial number of patients with spinal and bulbar muscular atrophy in Korea that accorded with that of patients with this disease worldwide but with updated clinical features.

Device-Related Complications Associated with Cylindrical Lead Spinal Cord Stimulator Implants: A Comprehensive Review.

PURPOSE OF REVIEW: Spinal cord stimulation (SCS) is an increasingly utilized therapy for the treatment of neuropathic pain conditions. Though minimally invasive and reversable, there are several important device-related complications that physicians should be aware of before offering this therapy to patients. The aim of this review is to synthesize recent studies in device-related SCS complications pertaining to cylindrical lead implantation and to discuss etiologies, symptoms and presentations, diagnostic evaluation, clinical implications, and treatment options. RECENT FINDINGS: Device-related complications are more common than biologic complications. Device-related complications covered in this review include lead migration, lead fracture, lead disconnection, generator failure, loss of charge, generator flipping, hardware related pain, and paresthesia intolerance. The use of SCS continues to be an effective option for neuropathic pain conditions. Consideration of complications prior to moving forward with SCS trials and implantation is a vital part of patient management and device selection. Knowledge of these complications can provide physicians and other healthcare professionals the ability to maximize patient outcomes.

Investigation of the efficacy of two different laser types in the treatment of lower lip paresthesia after sagittal split ramus osteotomy.

Orthognathic surgery involves invasive and major surgical procedures commonly used to correct maxillofacial deformities. Bilateral sagittal split ramus osteotomy (BSSO) is often used to treat dentofacial anomalies related to the mandible, but it can result in various complications, the most common of which is inferior alveolar nerve damage. Nerve damage-induced paresthesia of the lower lip significantly affects patient comfort. Medical treatments such as steroids and vitamin B, low-level laser therapy (LLLT), and platelet-rich fibrin (PRF) can be used as supportive therapies for nerve regeneration after damage. This study aimed to investigate the effectiveness of two different types of lasers in treating lower lip paresthesia after BSSO. This clinical trial was a controlled, single-center, prospective, single-blind, randomized study. Thirty patients were included in the study and randomly assigned to three groups: Group I (laser GRR, n = 10) received transcutaneous and transmucosal GRR laser treatment, Group II (Epic10 laser, n = 10) received transmucosal and transcutaneous Epic10 laser treatment, and Group III (vitamin B, n = 10) received B-complex vitamin tablets orally once a day. Two-point and brush tests were performed six times at specific intervals, and a visual analog scale was used to evaluate pain and sensitivity. Both vitamin B and laser therapies accelerated nerve regeneration. The contribution of the laser groups to the healing rate was better than that of the vitamin B group. Although there was no statistically significant difference between the two laser groups, clinical observations indicated better results in the GRR laser group.

Defining the Boundaries of Patient Perception in Spinal Cord Stimulation Programming.

OBJECTIVES: Recent developments in spinal cord stimulation (SCS) programming have initiated new modalities of imperceptible stimulation. However, the boundaries of sensory perception are not well defined. The BEnchtop NEuromodulation Following endIng of Trial study aimed to create a map of perceptual threshold responses across a broad range of SCS parameters and programming to inform subperception therapy design. MATERIALS AND METHODS: This multicenter study was conducted at seven US sites. A total of 43 patients with low back and/or leg pain who completed a percutaneous commercial SCS trial were enrolled. Test stimulation was delivered through trial leads for approximately 90 minutes before removal. SCS parameters, including amplitude, frequency, pulse width (PW), electrode configuration, cycling, and multifrequency stimulation were varied during testing. Paresthesia threshold (PT), comfort level (CL), perceptual coverage area, and paresthesia quality (through patient selection of keywords) were collected. Differences were evaluated with analysis of variance followed by post hoc multiple comparisons using t-tests with Bonferroni correction. RESULTS: PT was primarily determined by PW and was insensitive to frequency for constant frequency stimulation (range: 20 Hz-10 kHz; F(1284) = 69.58, p < 0.0001). For all tests, CL was approximately 25% higher than PT. The dominant variable that influenced paresthesia quality was frequency. Sensations described as comfortable and tingling were most common for frequencies between 60 Hz and 2.4 kHz; unpleasant sensations were generally more common outside this range. Increasing distance between active electrodes from 7 mm to 14 mm, or cycling the SCS waveform at 1 Hz, decreased PT (p < 0.0001). Finally, PT for a low-frequency stimulus (ie, 60 Hz) was unaffected by mixing with a sub-PT high-frequency stimulus. CONCLUSIONS: In contrast to previous work investigating narrower ranges, PW primarily influenced PT, independently of frequency. Paresthesia quality was primarily influenced by pulse frequency. These findings advance our understanding of SCS therapy and may be used to improve future novel neuromodulation paradigms.

Ninety-Hz Spinal Cord Stimulation-Induced Analgesia Is Dependent on Active Charge Balance and Is Nonlinearly Related to Amplitude: A Sham-Controlled Behavioral Study in a Rodent Model of Chronic Neuropathic Pain.

BACKGROUND: Ninety-Hz active-recharge spinal cord stimulation (SCS) applied at below sensory-threshold intensity, as used with fast-acting subperception therapy spinal cord stimulation, has been shown clinically to produce significant analgesia, but additional characterization is required to better understand the therapy. This preclinical study investigates the behavioral effect of multiple 90-Hz SCS variants in a rodent model of neuropathic pain, focusing on charge balance and the relationship between 90-Hz efficacy and stimulation intensity. MATERIALS AND METHODS: Rats (n = 24) received a unilateral partial sciatic nerve ligation to induce neuropathic pain and were implanted with a quadripolar lead at T13. Mechanical hypersensitivity was assessed before, during, and after 60 minutes of SCS. After a prescreen with 50-Hz SCS 67% motor threshold ([MT], the positive control), rats underwent a randomized-crossover study including sham SCS and several 90-Hz SCS paradigms (at 40% MT or 60% MT, either using active or pseudopassive recharge) (experiment 1, n = 16). A second, identical experiment (experiment 2) was performed to supplement data with 90-Hz SCS at 20% and 80% MT (experiment 2, n = 8). RESULTS: Experiment 1: At 40% MT, 90-Hz active-recharge SCS produced a significantly larger recovery to baseline than did 90-Hz pseudopassive SCS at both tested intensities and sham SCS. Experiment 2: Only the 90-Hz SCS active recharge at 40% MT and 50-Hz SCS positive control caused mean recovery to baseline that was statistically better than that of sham SCS. CONCLUSIONS: The degree to which 90-Hz SCS reduced mechanical hypersensitivity during stimulation depended on the nature of charge balance, with 90-Hz active-recharge SCS generating better responses than did 90-Hz pseudopassive recharge SCS. In addition, our findings suggest that the amplitude of 90-Hz active-recharge SCS must be carefully configured for efficacy.

Spinal Cord Stimulation Trial Electrodes Rapidly Produce Epidural Scarring, Impeding Surgical Paddle Lead Placement.

OBJECTIVES: After a successful percutaneous cylindrical electrode five-to-seven-day trial of spinal cord stimulation, subsequent permanent surgical paddle lead (SPL) placement can be impeded by epidural scar induced by the trial leads (TLs). Our goal was to determine whether a delay between TL and subsequent SPL placement provokes enhanced epidural scarring with an increased need for laminotomy extension required for scar removal for optimal SPL placement. MATERIALS AND METHODS: Using a prospectively maintained data base, a single-facility/surgeon retrospective study identified 261 patients with newly placed thoracolumbar SPLs from June 2013 to November 2023. Data were obtained from the patients' charts, including, but not limited to, timing between TL and SPL, operative time, and need for extension of laminotomy. RESULTS: We found that the need for laminotomy extension due to TL epidural scarring and longer operative times was not required in our patients if the SPL was placed within ten days of placement of the TL (0/26), leading to shorter operative times in those with SPL placed after ten days (122.42 ± 10.72 minutes vs 140.75 ± 4.72 minutes; p = 0.005). We found no association with other medical comorbidities that may be confounding factors leading to epidural scarring/extension of laminotomy or association with level of SPL placement, size of the spinal canal, or indication for SPL placement. CONCLUSIONS: TL placement leads to scarring in the epidural space that appears to mature after ten days of its placement. In approximately 34% of patients, this leads to prolonged operative time owing to the need for extension of laminotomy and subsequent clearing of epidural scar for optimal SPL placement.

Paramedian versus midline approach of spinal anesthesia: a systematic review and meta-analysis with trial sequential analysis.

PURPOSE: Midline approach of spinal anesthesia has been widely used for patients undergoing surgical procedures. However, it might not be effective for obstetric patients and elderly with degenerative spine changes. Primary objective was to examine the success rate at the first attempt between the paramedian and midline spinal anesthesia in adults undergoing surgery. METHODS: Databases of MEDLINE, EMBASE, and CENTRAL were searched from their starting date until February 2023. Randomized clinical trials (RCTs) comparing the paramedian versus midline approach of spinal anesthesia were included. The primary outcome was the success rate at the first attempt of spinal anesthesia. RESULTS: Our review included 36 RCTs (n = 5379). Compared to the midline approach, paramedian approach may increase success rate at the first attempt but the evidence is very uncertain (OR: 0.47, 95% CI 0.27-0.82, ρ = 0.007, level of evidence:very low). Our pooled data indicates that the paramedian approach likely reduced incidence of post-spinal headache (OR: 2.07, 95% CI 1.51-2.84, ρ < 0.00001, level of evidence:moderate). The evidence suggests that the paramedian approach may result in a reduction in the occurrence of paresthesia (OR: 1.61, 95% CI 1.06-2.45, ρ = 0.03, level of evidence:low). CONCLUSIONS: Our meta-analysis of 36 RCTs showed that paramedian approach may result in little to no difference in success rate at the first attempt owing to its very low level of evidence. However, given the low level of evidence and studies with small sample sizes, these findings need to be interpreted with caveat. CLINICAL TRIAL REGISTRATION NUMBER: CRD42023397781.

[Emergency management of a young patient with ponytail syndrome]. / Prise en charge en urgence d'un patient jeune victime du syndrome de la queue-de-cheval.

A 31-year-old man was brought to the emergency department because, for the past two days, he had been experiencing paresthesia-like sensory disturbances in his lower limbs, with dorsal pain that was not relieved by analgesics, as well as the appearance of sphincter disturbances and increasing difficulty in mobilization due to balance disturbances and pain. Presentation of this clinical case.

Identifying trajectories and predictors of chemotherapy-induced peripheral neuropathy symptoms, physical functioning, and falls across treatment and recovery in adults treated with neurotoxic chemotherapy: the PATTERN observational study protocol (NCT05790538).

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating and dose-limiting side effect of systemic cancer therapy. In many cancer survivors, CIPN persists after treatment ends and is associated with functional impairments, abnormal gait patterns, falls, and diminished quality of life. However, little is known regarding which patients are most likely to develop CIPN symptoms that impair mobility and increase fall risk, when this risk develops, or the optimal timing of early intervention efforts to mitigate the impact of CIPN on functioning and fall risk. This study will address these knowledge gaps by (1) characterizing trajectories of symptoms, functioning, and falls before, during, and after treatment in adults prescribed neurotoxic chemotherapy for cancer; and (2) determining the simplest set of predictors for identifying individuals at risk for CIPN-related functional decline and falls. METHODS: We will enroll 200 participants into a prospective, observational study before initiating chemotherapy and up to 1 year after completing chemotherapy. Eligible participants are aged 40-85 years, diagnosed with stage I-III cancer, and scheduled to receive neurotoxic chemotherapy. We perform objective assessments of vibratory and touch sensation (biothesiometry, tuning fork, monofilament tests), standing and dynamic balance (quiet stance, Timed-Up-and-Go tests), and upper and lower extremity strength (handgrip dynamometry, 5-time repeated chair stand test) in the clinic at baseline, every 4-6 weeks during chemotherapy, and quarterly for 1 year post-chemotherapy. Participants wear devices that passively and continuously measure daily gait quality and physical activity for 1 week after each objective assessment and self-report symptoms (CIPN, insomnia, fatigue, dizziness, pain, cognition, anxiety, and depressive symptoms) and falls via weekly electronic surveys. We will use structural equation modeling, including growth mixture modeling, to examine patterns in trajectories of changes in symptoms, functioning, and falls associated with neurotoxic chemotherapy and then search for distinct risk profiles for CIPN. DISCUSSION: Identifying simple, early predictors of functional decline and fall risk in adults with cancer receiving neurotoxic chemotherapy will help identify individuals who would benefit from early and targeted interventions to prevent CIPN-related falls and disability. TRIAL REGISTRATION: This study was retrospectively registered with ClinicalTrials.gov (NCT05790538) on 3/30/2023.

Neurological Complications of the Lower Extremities After Femoral Cannulated Extracorporeal Membrane Oxygenation: A Systematic Review.

BACKGROUND: Femoral cannulated extracorporeal membrane oxygenation (ECMO) has been associated with neurologic complications in the lower extremity ipsilateral to the cannulation. There is uncertainty about the prevalence of these complications and their mechanisms of development. OBJECTIVE: Aim of this systematic review was to investigate the prevalence of neurological complications after ECMO and to describe possible underlying mechanisms. METHOD: A systematic literature search was performed in Medline-Ovid, Embase, Cochrane Library, CINAHL, and PEDro until April 2021 for clinical trials in English or German language which quantified neurologic complications in the lower extremity ipsilateral to the ECMO cannulation of adults. The complications had to be delimitable to intensive care unit-acquired weakness. Methodological quality was assessed by 2 independent investigators using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the National Heart, Lung, and Blood Institute. RESULTS: Eight observational studies were included in the synthesis. Study quality was good to fair in 88% of the papers. Overall, 47 of 202 patients (23.3%; ranging from 3% to 48% across studies) with femoral ECMO cannulation showed neurologic complications of the lower extremity ipsilateral to the cannulation. Peripheral ischemia and compression of nerves by the ECMO cannula are discussed as mechanisms of injury. CONCLUSION: The occurrence of neurological complications after ECMO was common and can lead to long-term impairment. The mechanisms are largely unknown but currently there is no sufficient evidence for the involvement of ECMO. Standardized assessments are needed to systematically screen for neurological complications early after ECMO, to enable countermeasures and prevent further complications.

Meralgia paresthetica mimic after Moderna COVID­19 vaccine.

This report describes the case of a 56-year-old male who developed unilateral right anterior thigh numbness which began 16 hours after receiving his second Moderna COVID-19 vaccine in the left deltoid. The numbness persisted and after one week a circular, raised, painless area with a red border appeared in the center of the anterior thigh which resolved after 2 weeks spontaneously. There was no clinical history or risk factors consistent with meralgia paresthetica. At his 6 month follow up the patient reported that his symptoms spontaneously resolved. While many other non-specific neurologic side effects of COVID-19 vaccines have been documented, this is the first case of meralgia paresthetica documented after a vaccine without any other risk factors for the syndrome. COVID vaccines should be considered as a potential cause of very localized peripheral neuropathy.

Trigeminal trophic syndrome in a pediatric patient with diffuse intrinsic pontine glioma.

A 13-year-old girl with a history of diffuse intrinsic pontine glioma (DIPG) suffered from progressively worsening facial ulcerations secondary to paresthesia-induced self-excoriation. She was diagnosed with trigeminal trophic syndrome (TTS) induced by DIPG and struggled to heal her lesions in the background of this excoriation disorder. A multidisciplinary approach that included mood disorder management with sertraline and amitriptyline helped diminish paresthesia, improve her quality of life, and promote healing of the ulcers despite the progression of her DIPG. This case highlights the multifactorial complexity of TTS in pediatric patients and the need for successful management strategies.

The Anatomy and Clinical Significance of Sensory Disturbance in Parkinson's Disease.

The clinical features of Parkinson's disease (PD) include tremors and rigidity. However, paresthesia has not drawn clinical attention. PD involves the whole body and begins with gastrointestinal lesions, which do not start in the midbrain substantia nigra, but from the beginning of the medulla oblongata of the glossopharyngeal nerve nuclei, to the motor nerve dorsal nucleus of the vagus nerve, to the pons and midbrain, and finally to the neocortex. The human eye, ear, nose, tongue, and body perceive the external world. (1) Visual impairment in patients with PD can be easily confused with senile eye disease. This change in retinal pigment cells has many similarities to the degeneration of dopaminergic neurons in the substantia nigra in PD. (2) Selective high-frequency hearing impairment can cause a certain degree of communication barriers, only understanding the son's bass but not the daughter's soprano, and there is a certain relationship between hearing and body postural balance. (3) Olfactory loss is one of the earliest signs of PD and an important indicator for the early screening of PD. (4) Taste disorders, including loss of taste and taste memory, can cause cognitive impairment. (5) The body's sense of touch, pressure, pain, temperature, and position abnormalities interfere with the motor symptoms of PD and seriously affect the quality of life of patients. This article discusses vision, hearing, smell, taste, touch, and analyses of neuroanatomy and pathology, revealing its clinical significance.

Laser acupuncture in the treatment of neuropathies in dentistry: a systematic review.

Laser acupuncture can be used to treat neurosensory alterations and motor disorders caused by dental treatments. This study aimed to review the existing literature on the effects of laser acupuncture on neuropathies in the context of dentistry and to search for treatment modalities in which this technique is used. This systematic review was conducted in accordance with the Cochrane Collaboration guidelines and the PICOS strategy. Randomized clinical trials that evaluated laser acupuncture as a primary intervention for facial neuropathy were included. We searched the database for relevant studies and manually searched the gray literature until April 2022, and finally included four studies. The study was considered eligible if it included patients with paresthesia, facial paralysis, or neuralgia, neuropathies within dentistry, and referred to the application of laser acupuncture as a treatment method. The risk of bias was assessed using the RoB 2 tool. It was observed that the recommended wavelengths ranged from 790 nm to 810 nm, with a frequency of at least two applications per week, and to a greater or lesser degree, all evaluated studies obtained an improvement in sensory or motor recovery of the facial nerves. The use of laser acupuncture presented itself as a viable alternative in dentistry for the treatment of paresthesia and facial paralysis due to its therapeutic potential in neuropathic treatment (CRD42022344339).

Mental and Lingual Nerve Paresthesia Following Infiltration Anesthesia for Dental Implant Placement in a Patient With Guillain-Barré Syndrome.

Guillain-Barré syndrome (GBS) is a rare rapid onset autoimmune peripheral polyneuropathy, most commonly characterized by inflammatory demyelination of peripheral nerves. Patients with GBS are considered higher risk for anesthetic-induced neurotoxicity caused by demyelination. In the present report, a case is described of a 56-year-old man with GBS who experienced mental and lingual nerve paresthesia following infiltration anesthesia for dental implant placement in the posterior mandible. The pareshesia lasted 5 months postoperatively and subsided spontaneously without any intervention. The patient was successfully restored with fixed partial dental prosthesis without any other complication. This is considered the first report of such complication in patient with GBS after local anesthesia in the oral and maxillofacial region. Possible pathogenic mechanism of the complication and clinical implications are discussed.

[Globus pharyngeus : etiologies, diagnosis and management. A narrative review]. / Globus pharyngé : étiologies, diagnostic et prise en charge. Revue narrative de la littérature.

Globus pharyngeus is a very common symptom in the general population. It is defined as a sensation of lump or foreign body in the throat, generally not accompanied by pain and relieved by eating. This last notion makes the differential diagnosis with dysphagia, which requires a different management. Its possible etiologies are complex and multiple, both organic and psychological, and many of them are still debated. Therefore, there is no consensus on the management and the treatment of globus pharyngeus. The purpose of this narrative review of the literature is to synthesize the current evidence regarding the causes, diagnostic strategy, and therapeutic management of globus pharyngeus.

Le globus pharyngé est un symptôme très fréquent dans la population générale. Il est défini comme une sensation de boule ou de corps étranger dans la gorge généralement, non accompagnée de douleurs et soulagée par l'alimentation. Cette dernière notion fait le diagnostic différentiel avec la dysphagie qui relève d'une mise au point et de traitements différents. Ses étiologies possibles sont complexes et multiples, aussi bien organiques que psychologiques et nombre d'entre elles restent débattues. Par conséquent, il n'existe aucun consensus sur la mise au point du globus pharyngé ni sur son traitement. Cette revue narrative de la littérature a pour objectif de synthétiser les données actuelles concernant les causes, la mise au point et la prise en charge thérapeutique du globus pharyngé.

[Microanatomy features in third molars roots adjacent to mandibular canal]. / Osobennosti anatomii kornei tret'ikh molyarov i nizhnechelyustnogo kanala pri ikh tesnom prileganii.

THE PURPOSE: Of the study is to reduce the risk of postoperative neuropathy of the inferior alveolar nerve by improving diagnostic methods, assessment of individual topographic and anatomical features and extraction technique of impacted teeth adjacent to the mandibular canal. MATERIALS AND METHODS: According to the CBCT examination, orthopantomography and macroscopic examination of removed third molars roots (n=140) the relative position of the mandibular canal and the roots of the third molars were studied. RESULTS: Three variants of close mandibular canal and third molars position have been identified. In the lateral and apical nerve position, the root surface depressions were detected. With inter-radicular position fit, the mandibular canal and the nerve bundle form a «bed¼ in between impacted tooth roots. CONCLUSION: The injury of neurovascular bundle prognosis during extraction with an interadicular mandibular position depends on roots anatomy and their convergence degree. If the interradicular distance is less than the diameter of the mandibular canal, nerve injury during tooth extraction is inevitable, in such cases coronectomy is indicated.

[Classification of lower impacted third molars position and their interrelationship with mandibular canal]. / Klassifikatsii vidov retentsii nizhnikh tret'ikh molyarov i ikh anatomicheskogo vzaimoraspolozheniya s nizhnechelyustnym kanalom.

Classification of lower Impacted third molars position and their interrelationship with mandibular canal have a great scientific, theoretical and practical importance. An attempt to systematize and classify all anatomical impacted third molars position has been made by many authors. Based on our scientific literature search, we found: 8 impacted third molars classifications, 7 third molars and mandibular canal interposition classifications, as well as 5 classifications of mandibular canal anatomical branching variants. Most classifications are proposed by the author to predict third molar eruption perspective, determine level of operation complexity and prevent mandibular canal damage. New clinical classification development of impacted third molars interrelationship with mandibular canal, which combined the radiological PR, CBCT criteria, neurovascular bundle trauma prognosis, and operative technic choice can be actual.

Pruritus, Pain, and Depression Associated with the Most Common Skin Diseases: Data from the French Study "Objectifs Peau".

BACKGROUND: The prevalence and impact of pruritus, pain, and other sensory symptoms in skin diseases are poorly known. OBJECTIVE: To assess the frequency of these symptoms with dermatoses and their association with depression using data from the "Objectifs Peau" survey. METHODS: A representative sample of 20,012 French individuals was created using the usual quota method. RESULTS: When patients suffered from both pruritus and skin pain, they had a higher relative risk of psychological suffering (2.9) than those who suffered only from pruritus (1.4) or skin pain (1.2). Pruritus was reported in 48.55% of patients with acne, 43.24% with mycoses, 44.35% with warts, and 36.51% with rosacea. For skin pain, the results were 11.22%, 27.59%, and 16.13% for atopic dermatitis, acne, and warts, respectively. Other unpleasant sensations, such as tingling or burning, were also frequently reported. CONCLUSION: Pruritus, pain, or other sensory symptoms were found to be common not only in classic pruritic skin diseases but also in acne, rosacea, or warts. The association of pruritus and pain dramatically increased psychological suffering. These symptoms must be systematically searched for in patients, especially since new therapeutic possibilities are emerging for the symptomatic treatment of pruritus.