Innervation Area Research Articles

Effectiveness and Safety of Radiofrequency Thermocoagulation Treatment Guided by Computed Tomography for Infraorbital Neuralgia Following Failed Conservative Treatment: A Retrospective Study.

To evaluate the effectiveness and safety of CT-guided radiofrequency thermocoagulation (RFT) for the treatment of infraorbital neuralgia following the failure of conservative management. This was a single center, retrospective study which included 196 patients between the ages of 37 to 90 years, who suffered from infraorbital neuralgia, and had undergone CT-guided RFT treatment. The medical records of these patients were retrieved between January 7, 2015 and February 5, 2020, and the patients were followed up for 2 years. Follow-up outcomes included Numerical Rating Scale (NRS) scores, dosage of carbamazepine, time to take effect, status of recurrence and side effects. The effective rate was defined as the percentage of patients with postoperative NRS score reduction of >50%. The effective rates were 92.9%, 100%, 100%, 100%, 93.4% and 85.7% onthesame day, week 1, month 1, month 6, year 1 and year 2 after RFT, respectively. After RFT, the postoperative NRS scores and dosage of carbamazepine were significantly reduced than those preoperatively (P < 0.05). The median time to take effect was zero day. Twenty-eight patients with recurrence underwent RFT again and achieved complete pain relief. All patients experienced numbness in the infraorbital nerve innervation area and the numbness scores gradually decreased over time. CT-guided RFT treatment may be an effective and safe technique for pain relief in patients with infraorbital neuralgia following failed results from conservative treatment.

Clinical characteristics of pain in patients with trigeminal neuralgia: data from a neurosurgical clinic

Among the pain syndromes caused by damage to cranial nerves, trigeminal nerve pathology occupies the main place. Trigeminal neuralgia is an exhausting condition characterized by acute shooting recurrent pain in the face. However, according to modern classification of facial pain types, there is also a distinction made for the second type of neuralgia, in which the mentioned pain alternates with dull, burning pain in the area of trigeminal nerve innervation. Numerous clinical and diagnostic criteria which can influence the results of surgical treatment of trigeminal neuralgia are being actively studied. However, the data varies both in terms of the number of criteria considered and the nature of the study, as well as the research outcomes.Objective ‒ to determine the demographic, clinical, and anatomical characteristics of patients with classical trigeminal neuralgia upon their admission in the neurosurgical ward for microvascular decompression of the trigeminal nerve.Materials and мethods. A retrospective analysis of medical data from 92 patients with trigeminal neuralgia, who were admitted to the Regional Clinical Center of Neurosurgery and Neurology from 2011 to 2023 was performed. The data included: patient's gender and age, type of neuralgia according to K. Burchiel and colleagues' classification (2009), involvement of trigeminal nerve branches, duration of pain prior to hospitalization, medication for conservative therapy and its dosage. Results. Trigeminal neuralgia most commonly affects elderly patients. This may be associated with systemic atherosclerotic vessel damage, leading to increased irritation by a denser vessel wall. Another cause of late disease manifestation may be gradual demyelination in the vicinity of the neurovascular conflict. Women are more likely to be affected than men. Right-sided trigeminal nerve involvement and the involvement of lower and upper jaw branches are more characteristic, with pain more frequently being paroxysmal in nature. In seven out of ten patients, the cause of neurovascular conflict is an artery, with the upper cerebellar artery being the most typical conflict.Conclusions. Demographic and clinical-diagnostic indicators vary among patients with trigeminal neuralgia. There are numerous variables that can influence the long-term effects of conservative and surgical treatment in patients with trigeminal neuralgia. A comprehensive assessment of these factors can identify a group of patients who are likely to have the most successful long-term treatment outcomes for trigeminal neuralgia.

Evaluation of the Physical Treatment Success in Patients with Peripheral Nerve Injury Caused by Firearm

Background: All wars bring high incidence of patients with peripheral nerve injuries, and many of today's knowledge about degeneration, regeneration and surgical treatment in this casuistry come from the period of the global world conflict. Such injuries do not endanger life, but the function of the extremities is threatened, which manifests itself in motor and sensory outbursts, as well as negative psychological implications. Objective: The aims of this article were: a) To present the method of monitoring physical treatment in a patient with a peripheral nerve injury; b) To perform a quantitative analysis of nerve lesions caused by firearms (n = 445);; c) To present the effects of physical treatment for this condition;; d) To analyze the time interval from injury to healing (n = 220);; e) Determine the time from injury until the surgery. Results: Anatomical disruption of axons with complete Waler degeneration. The connective tissue network remains intact and the endoneurium can guide the regenerated nerve fibers to their destination. Spontaneous functional recovery can be expected in 12 to 18 months. Clinical evaluation shows a deficit in the innervation area of damaged axons with muscle atrophy and loss of sensitivity. Nerve recovery can be inhibited by scar formations at the site of injury. Complete interruption of the nerve. Functional recovery is not possible without surgical intervention. Paralysis of mm. atrophy, anesthesia and atrophic skin changes are visible. Conclusion: Rehabilitation is a delicate problem and requires long-term treatment and multidisciplinary cooperation, and is carried out in accordance with the principles of peripheral nerve repair. Factors that facilitate successful regeneration are: a) Pre and post-operative physical treatment; b) Younger age; c) Shorter time since injury (&lt;6 months); d) More distal level of the lesion; e) Absence of factors complicating the injury (infection); and f) The first signs of nerve recovery are the return of sweating and pain.

AIRWAY MANAGEMENT WITH RIGID BRONCHOSCOPE IN ADULT PATIENT DURING CERVICAL SPINE SURGERY: A CASE REPORT.

SCIWOCTET is a cervical spine injury (CSI) with objective signs of myelopathy, due to trauma, without evidence of ligament injury or bone fractures on x-ray and computed tomography (CT) images. It is rare, found in about 3% of patients with CSI. Perioperative manipulation of these patients may cause secondary spinal cord injury. The challenge for the anesthesiologist is to manage an airway with as little movement of the patient's head and neck as possible. A patient is presented after a fall from a motorbike. At hospital admission, he had neurological deficit in the innervation area of the cervical spinal cord. Multi-slice CT of the head and cervical spine was without signs of acute bone trauma. Magnetic resonance imaging was performed and the diagnosis met the criteria defining SCIWOCTET. Elective cervical spine surgery under general anesthesia was performed, the patient was intubated with a rigid bronchoscope using manual in-line immobilization. The selection of instruments and procedures is emphasized. Other procedures, techniques and instruments that can be used for airway management and their influence on the movement of the patient's head and neck are listed. It is concluded that rigid bronchoscopy with the application of manual in-line immobilization is suitable for emergency and elective intubation of patients with cervical spine pathology.

Complication of acute Otitis media in pediatrics: a case report

The acute otitis media (AOM) is a frequent bacterial infection in Pediatrics. Despite the advance of antibiotic therapy in the treatment of this infection, there is the possibility of a rare complication, Gradenigo Syndrome (GS). This is a serious complication that should be suspected in a patient with abducens nerve paralysis, pain in the trigeminal innervation area and AOM. The objective of this work was to describe a case report in pediatric regarding to Gradenigo’s Syndrome and reinforce the importance of early diagnosis in the treatment. In addition, a literature review of articles in journals indexed in the following databases was carried out: Pubmed, Lilacs and Scielo. The case report presented is a 7-year-old girl, presenting a typical clinical of GS that evolved satisfactorily with the management based on broad-spectrum antibiotic therapy, without the need for a subsequent surgical approach. Thus, it is clear that the identification of the classic triad of GS, in addition to performing imaging tests, allows for an early diagnosis of the disease, favoring a conservative approach with antibiotic therapy.

Risk Factors, Prevention, and Primary and Secondary Management of Sciatica: An Updated Overview.

Sciatica is a chronic condition causing crippling low back pain radiating down to the sciatic nerve innervation area, which is the posterior thigh. It remains a major public health problem worldwide with significant socio-economic, physical, and psychological impacts. Studies suggested different diagnostic methods due to the lack of consensus on diagnostic and treatment guidelines. When it comes to the management and treatment, there is ambiguous evidence about the use of painkillers, surgical interventions, and alternative options and their effectiveness, with most studies contrasting one another in addition to the lack of high-quality trials. This review presents the available data on the current understanding of sciatica covering clinical manifestations, diagnosis and treatment modalities, prognosis, and complications since a disagreement is observed in the scientific community regarding sciatica, starting with a definition of sciatica, its epidemiological characteristics, to the management and treatment. Our review would help raise knowledge and awareness about sciatica in the health professional community and the general public sincethe prevalence of low back pain is high in most parts of the world and there is insufficient knowledge of sciatica in the literature.

Relationships between the Clinical Test Results and Neurophysiological Findings in Patients with Thoracic Outlet Syndrome.

A thoracic outlet syndrome (TOS) is the type of brachial plexus disorder most difficult to objectively assess using a clinical examination and differential diagnosis. Its symptoms can be frequently misdiagnosed, especially among others with cervical disc-root conflicts, plexopathies, and peripheral neuropathies. In this study, we aim to identify the correlations between positive Doppler ultrasonography results indicating pathological changes in the subclavian flow velocity, clinical tests, and chosen clinical neurophysiology recordings as proposed alternative or supplementary diagnostic tools for evaluating TOS patients. Sixty TOS patients with positive Doppler ultrasonography and Roos test results and sixty healthy people as a control group were bilaterally examined, and the results were compared. Pain intensity was assessed using a visual analogue scale (VAS). Sensory perceptions within C4–C8 dermatomes were assessed with Von Frey filament (FvF) tests. The activity of motor units in the proximal and distal muscles of the upper extremities was evaluated using surface electromyography (sEMG) during maximal contractions before and after a provocative raised hands test (RHT). An electroneurography (ENG) was used to evaluate the transmission of nerve impulses peripherally. Motor evoked potential (MEP) recordings, induced by the over-vertebral magnetic stimulation of the C5–C7 neuromeres, were used to examine motor transmissions from the cervical motor centres to the upper extremities muscles. The results revealed a relationship between positive Doppler test scores and pathological changes in the subclavian flow velocity through the results of the following diagnostic tools: a VAS score of 1.9 was detected on average, superficial sensory perception abnormalities were found in the innervation areas of the ulnar nerves detected by FvF tests, a decrease in the amplitudes of sEMG recordings was seen in distal rather than proximal muscles (especially following the RHT), a decrease in the motor and sensory peripheral transmissions of nerve impulses in the median, ulnar and cutaneous anterobrachial median nerves was seen, as well as MEP amplitudes recorded from the abductor pollicis brevis muscle. The provocative RHT combined with sEMG and MEP recordings can be considered accurate and objective clinical neurophysiology tools that could supplement the commonly used clinical tests. Such an approach may result in a more precise neurogenic TOS diagnostic algorithm.

Double Fascicular Nerve Transfer to Restore Elbow Flexion Following Neuralgic Amyotrophy: A Case Report

Double fascicular nerve transfer (DFNT) involves transferring fascicles from the median and ulnar nerves to the musculocutaneous nerve to restore elbow flexion. We performed this procedure on a patient who was diagnosed with neuralgic amyotrophy (NA) 2 years previously. We aimed to investigate the short-term outcomes and feasibility of DFNT applied to non-traumatic neuropathy. A 63-year-old, right-handed man presented to us with persistent right elbow flexion weakness 24 months after receiving the diagnosis of NA. On examination, biceps strength was 0/5, and shoulder abduction strength was 3/5. Magnetic resonance neurography demonstrated muscle atrophy in the upper trunk. DFNT was considered to restore elbow flexion. The donor and recipient fascicles were then coapted (flexor digitorum superficialis to biceps brachii, flexor carpi ulnaris to brachialis). Postoperatively, paresthesia was reported in the area of ulnar innervation, and the patient complained of hand clumsiness. From postoperative day 10 onward, biceps muscle contracture was identified and on the 14th day, grade 3 elbow flexion strength was observed. We suggest that DFNT may be a safe and effective method to restore elbow flexion in patients with NA.

Results of the study of electroexcitability of the skin in the area of innervation of the lower alveolar nerve

In patients with mandibular fractures, 87.6% of cases showed varying severity damage to the lower alveolar nerve (LAN). So, in most cases, when the displacement of fragments is less than 0.5 cm, a mild degree was noted, when the displacement is from 0.5-1.0 cm - an average degree, and more than 1.0 cm-a severe degree of damage to the LAN. In 3.7% of cases, violations of deep sensitivity were detected. It was revealed that the highest rates of electrical excitability of the skin were noted in 2-the 2nd and 3-3rd zones. So, at admission, the average values in patients with mild severity of damage were noted at the level of 56.5±1.5 mkA, with an average degree - of 115.8±3.1 mkA, with severe-163.8±4.5 mkA. It is noted that the higher the indicators, the more pronounced the violation of sensitivity. The values of indicators in the main group by day 32-40 were 1.6 times less than in the control group.

Trigeminal Neuralgia - What Do We Know about the Causes, Diagnosis and Treatment?

Trigeminal Neuralgia - What Do We Know about the Causes, Diagnosis and Treatment? Abstract. Classical trigeminal neuralgia is typically characterized by a stimulus-evoked, recurrent and intense short-lasting stabbing pain in the innervation area of the trigeminal nerve. Its intensity is among the most severe pain imaginable in humans, and yet it is often misdiagnosed and undertreated. Triggers are common activities of daily life like talking or eating. The classical trigeminal neuralgia is due to a neurovascular compression at the nerve root entry zone. The secondary form is related to an underlying neurological disease (caused for example by multiple sclerosis or compression by a brain tumor); the etiology of the idiopathic trigeminal neuralgia is unknown. Treatment options include both medication (mostly antiepileptic drugs) and escalated interventional approaches (microvascular decompression, neurolesional percutaneous procedures, neuromodulative therapeutic options and radiosurgery).

Reliability of Ulnar Nerve Sensation Tests in Patients with Cubital Tunnel Syndrome and Healthy Subjects.

Static two-point discrimination (2PD) and Semmes–Weinstein monofilament (SWM) tests are commonly used to evaluate sensory disorders in the hand. The aim of this study was to evaluate the reliability of 2PD and SWM tests in the ulnar nerve innervation area in patients with cubital tunnel syndrome (CuTS) and healthy individuals. This was a two-group repeated-measures inter-rater and intra-rater reliability study. Twenty-one patients with CuTS and 30 healthy adults participated. The static 2PD test was performed using a standardized Dellon discriminator, whereas the SWM test was conducted using TOUCH TEST monofilaments. Two examiners performed both tests at the hypothenar eminence and the fourth and fifth digits (ulnar nerve innervation hand territory). First, examiner A conducted three series of 2PD and SWM tests twice with a 15-min rest period (within-day intra-rater reliability). Next, examiner B repeated the same examination 5 min after (inter-rater reliability). Examiner A conducted the same examination 7 days after (between-day intra-rater reliability). For single measurements, the inter-rater reliability and within-day intra-rater reliability in the 2PD was at least 0.81 in patients with CuTS or healthy subjects. The between-days intra-rater reliability for a single measurement varied from 0.56 to 0.95 in CuTS patients and healthy subjects. The between-days intra-rater reliability for mean value from three measurements was above 0.80. The kappa for SWM was above 0.8 and the percentage of agreement was at least 90% for all sessions and trials. In conclusion, the 2PD and SWM tests are reliable for assessing sensation in the ulnar nerve innervation area of the hand in patients with CuTS and healthy subjects.

Differences in central sensitisation between healthy men and women in Switzerland: a single-centre trial

<h2>Abstract</h2><h3>Background</h3> Many chronic pain conditions exhibit differences between men and women regarding prevalence, pain intensity, or treatment effects. Mechanisms underlying these differences are poorly understood. Central sensitisation, defined as an increased responsiveness of nociceptive neurons in the CNS to normal or subthreshold afferent input, is considered an important mechanism that can differ between men and women with chronic pain conditions. We aimed to assess differences in central sensitisation between healthy men and women, with the hypothesis that central sensitisation is more pronounced in healthy women than in men. <h3>Methods</h3> This single-centre trial followed a within-subject design and was conducted at the Balgrist University Hospital in Switzerland after approval by the Cantonal Ethics Board of Zurich. Healthy, pain-free adults aged 18–40 years with a BMI of less than 30 kg/m² and no history of chronic pain were recruited using advertisement and word-of-mouth. Biological sex (male or female) was self-reported. A validated sensitisation protocol was used by applying a contact thermode to the innervation area of the sural nerve on one foot. A sham protocol was used on the other foot. The protocols were performed in counterbalanced order. All participants were masked to the study design and protocols. The primary endpoint before and after the protocols, was the area of secondary hyperalgesia relative to the thermode, serving as a proxy of central sensitisation. Additionally, the nociceptive withdrawal reflex was repeatedly elicited at the sural nerve with two currents (corresponding to 120% and 140% of the individual reflex threshold current) and recorded from the biceps femoris by surface electromyography. The magnitude of the reflex response in the 90 ms to 150 ms post-elicitation interval was compared before and after the protocols. This study was registered with ClinicalTrials.gov, NCT05031286. <h3>Findings</h3> Between April 22, 2021, and Feb 19, 2022, 66 healthy participants were included in the trial. The median age of participants was 26 years (IQR 21–31) and 33 (50%) were women. Following the sensitisation protocol, secondary hyperalgesia was greater in women than men (12·4 cm² [SD 8·41] <i>vs</i> 8·2 cm² [6·90]; two-sided <i>t</i> test p=0·031). The effect of the sensitisation protocol on the magnitude of the biceps femoris nociceptive withdrawal reflex was stronger in women than in men for both currents (Cohen's d 0·32 <i>vs</i> 0·07 for 120% and 0·31 <i>vs</i> 0·15 for 140% reflex threshold current) with 99·6% versus 95·6% probability (Bayesian normal–normal model). No adverse effects were recorded during the trial. <h3>Interpretation</h3> The two tested outcomes (extent of secondary hyperalgesia and magnitude of the nociceptive withdrawal reflex) indicate that central sensitisation processes are more pronounced in healthy women than men. Because central sensitisation is suggested to influence pain chronification, more pronounced central sensitisation processes might constitute a sex-specific risk factor for developing chronic pain. <h3>Funding</h3> The Swiss National Science Foundation.

Application of personalized digital analog assisted acetabular prosthesis precise implantation in Crowe typeⅠand Ⅱ hip dysplasia

To explore the effect of personalized digital analog assisted acetabular prosthesis precise implantation in hip dysplasia. From February 2017 to July 2019, 11 patients(12 hips) with hip dysplasia underwent total hip arthroplasty, including 4 males(5 hips) and 7 females(7 hips), aged from 27 to 61 years old, with an average of (46.64±12.93) years old;Crowe classification:8 hips in typeⅠ and 4 hips in typeⅡ. The preoperative thin-layer CT scan was imported into Mimics 10.01 software. The appropriate size and placement angle of acetabular prosthesis were selected through preoperative simulation, and the acetabular bone defect was understood to determine whether structural bone grafting was needed during the operation. The length of both lower limbs, the anteversion angle of acetabular prosthesis, the abduction angle, the height of acetabular rotation center and the horizontal distance of hip joint center before and after the operation were measured, and the postoperative dislocation, bone graft healing and acetabular cup loosening were observed. The hip Harris score was used to evaluate the joint function. All patients were followed up for 18 to 30 months with an average of (23.45±3.70) months. There was no prosthesis dislocation, loosening and bone graft healing after operation. One case had numbness in the innervation area due to the traction of sciatic nerve during operation, and was treated with neurotrophic drugs and recovered one month after operation. The length difference of both lower limbs decreased from (31.73±5.98) mm before operation to (4.73±1.90) mm 3 months after operation (t=15.268, P<0.01). The anteversion angle of acetabular cup and acetabulum was (17.45±3.62)°and abduction angle was (40.10 ± 2.30)° after operation. In all cases, the abduction angle and anteversion angle were within the safe range of Lewinek. The height of hip rotation center was (20.64±2.58) mm and the horizontal inward displacement of hip was (33.46±3.61) mm. Harris score increased from (45.36±2.34) before operation to (91.27±2.37) 3 months after operation (P<0.05). Through preoperative personalized digital analog reconstruction of acetabulum in patients with hip dysplasia, we can better understand the acetabular defect, help to evaluate the size and placement angle of acetabular prosthesis and whether structural bone grafting is needed, and obtain satisfactory clinical curative effect.

Olfactory Ensheathing Cells Alleviate Facial Pain in Rats with Trigeminal Neuralgia by Inhibiting the Expression of P2X7 Receptor

Trigeminal neuralgia (TN) is a common facial neuropathic pain that is mainly characterized by spontaneous or induced needling or electric shock pain in the innervation area of the trigeminal nerve. It is also referred to as “the cancer that never dies”. The olfactory ensheathing cell (OEC) is a special glial cell in the nervous system that has a strong supportive function in nerve regeneration. Cell transplantation therapy is a useful treatment modality that we believe can be applied in TN management. In this study, OECs were transplanted into the ligation site of the infraorbital nerve of rats. We found that after the OEC transplantation, mechanical pain threshold in the face of the rats was significantly increased. Western blotting, immunofluorescence assay, and reverse transcription-quantitative polymerase chain reaction were performed on the trigeminal ganglia (TG) of model rats. The results revealed a decrease in the expression of P2X7 receptor (P2X7R) in the trigeminal ganglia. Our findings show that OEC transplantation has a good therapeutic effect on TN in rats, and that can reduce the expression of P2X7R in trigeminal ganglia. Therefore, we think that OEC transplantation may be a suitable treatment for TN.

Peripheral Nerve Innervation in Bilateral Cleft Hand Syndrome Elucidated by Ultrasound.

Bilateral cleft hand syndrome is a rare congenital malformation with complex anatomy. Previous reports have mainly focused on the description of bone and soft tissue abnormalities, but information about innervation is scarce. Knowledge of the peripheral nerve anatomy is helpful for surgical treatment, optimizing the reconstruction, and preventing iatrogenic damage. Following clinical assessment and conventional radiologic imaging, we used high-resolution ultrasound of both hands and forearms to image the peripheral nerves in a patient with severe bilateral cleft hand syndrome. The patient presented with two ulnar digits, a deformed thumb on the right, and a rudimentary thumb appendage on the left. In keeping with the tissue elements present and absent, we found a severe bilateral nerve size reduction of the median nerves, sparing the anterior interosseous nerve fascicles. The radial nerve and end branches were intact, and a slightly smaller ulnar nerve was found that ended in two digital branches to a single digit. Our study shows that in cleft hand syndrome the peripheral nervous system anatomy exactly reflects the presence and absence of the corresponding muscle and skin innervation areas. This information is helpful for planning a surgical-reconstructive approach and suggests a potential role for nerve ultrasound in the assessment of complex limb malformations.

Characterization of Electrodes to Record Neural Signals in the Periphery

Appropriately designed electrodes to make in vivo recordings of neural activity have been essential to understanding the nervous system. Recording electrode design has been extensively explored for use in measurement of naturally occurring neural activity in the brain. Recently, recordings of evoked compound action potentials (ECAPs) in the periphery have garnered interest due to their relevance in neuromodulation therapies for determining target engagement and enabling closed‐loop operation. Here, we compare three types of recording electrodes – microelectrodes, cuff electrodes, and intrafascicular electrodes – and their ability to make in vivo recordings of electrically ECAPs, naturally occurring neural activity, and sensory evoked neural activity in the peripheral nerves of a human‐relevant large animal model.The great auricular nerve, innervating the auricle, and cervical vagus nerve of domestic pigs were instrumented with the three recording electrodes. Naturally occurring neural activity, sensory evoked neural activity induced by gentle brushing of the auricle, and electrically ECAPs initiated by non‐invasive and invasive stimulation electrodes were recorded. The study was pre‐registered (https://osf.io/y9k6j).We showed that the recording cuff had superior performance in measuring invasive electrically ECAPs (p &lt; 0.05) while the tungsten microelectrode, routinely used for microneurography in humans, had superior performance in measuring naturally occurring action potentials (p &lt; 0.05). The microelectrode was still able to record electrically ECAPs. Further, we show how choice of reference electrode position may be optimized per application.Microneurography recordings paired with the deployment of a non‐invasive neuromodulation therapy can be used to functionally map sensory innervation areas in patients, allowing individualized placement of stimulation electrodes to achieve on‐target neural fiber activation. These findings provide a basis to select recording electrode type and configuration for measurement of neural signals in the development and deployment of neuromodulation therapies.

Inferior alveolar nerve preservation during resection and reconstruction of the mandible for benign tumors as a factor improving patient's quality of life

This prospective study aimed to evaluate neurosensory disturbance and quality of life in patients who underwent mandibular resection for benign tumors and whose inferior alveolar nerve (IAN) was either preserved or sacrificed. Mandibular resection was indicated owing to the presence of osteoradionecrosis in 25 patients and ameloblastoma in 15 patients. Resection was unilateral in 24 patients and bilateral in 16 patients.The authors assessed the inferior alveolar nerve's sensory dysfunction by measuring the electroexcitability of skin receptors using an electro-odontometer. Study participants' quality of life was estimated with the oral health impact profile (OHIP)-14 and short-form (SF)-36 questionnaire. All the patients in whom the inferior alveolar nerve was sacrificed experienced persistent numbness in the area of innervation with mental nerve on the affected side. The average pain threshold reached preoperative levels (point 1–22.7 ± 2.5, p-value = .025; point 2–25.8 ± 2.7, p-value = .023) 6 months after the operation in patients in whom the IAN was preserved (point 1–23.7 ± 2.3, p-value = .022; point 2–25.4 ± 2.8, p-value = .025). The results of the OHIP-14 and SF-36 showed that patients with preserved IANs had a significantly better quality of life than the patients in whom the IAN was sacrificed. The results of OHIP-14 twelve months after the operation in unilateral resection: control group - 16.0 ± 1.6, p-value = .029; study group - 8.0 ± 0.8, p-value = .029, and in bilateral resection: control group - 26.0 ± 3.2, p-value = .044; study group - 9.0 ± 0.7, p-value = .027. The possibility of sparing the inferior alveolar nerve should not be ignored when planning mandibular resection and reconstruction.

GLOSSOPHARYNGEAL NERVE AS A SOURCE OF OROFACIAL PAIN - DIAGNOSTIC AND THERAPEUTIC CHALLENGES.

Chronic neuropathic orofacial pain along with physical suffering can cause emotional, psychological and social difficulties, which significantly affects the quality of life of patients. Pain in the area of glossopharyngeal nerve innervation, especially chronic neuropathic, is relatively rare, but is significant because of the great suffering it causes to sufferers. It can be life threatening, due to the cardiac arrhythmia, syncope or convulsions it can cause. Drug treatment is often of limited effectiveness and can be fraught with side effects. It is necessary to look for the etiology of the underlying disease, and if possible, to take adequate causal treatment. This review article discusses the etiology, clinical features, differential diagnosis, and treatment modalities of neuropathic pain in the area of glossopharyngeal nerve innervation.

Menthol-induced activation of TRPM8 receptors increases cutaneous blood flow across the dermatome.

Topical menthol-based analgesics increase skin blood flow (SkBF) through transient receptor potential melastatin 8 (TRPM8) receptor-dependent activation of sensory nerves and endothelium-derived hyperpolarization factors. It is unclear if menthol-induced TRPM8 activation mediates a reflex change in SkBF across the dermatome in an area not directly treated with menthol. The purpose of this study was to determine the effects of localized topical menthol application on SkBF across a common dermatome. We hypothesized that SkBF would be increased with menthol at the site of application and across the dermatome (contralateral limb) through a spinal reflex mechanism. In a double blind, placebo controlled, cross-over design, 15 healthy participants (7 men; age=22±1yrs) were treated with direct application (3ml over 8×13cm) of 5% menthol gel (Biofreeze™) or placebo gel on the L4 dermatome, separated by 48h. Red blood cell flux was measured using laser Doppler flowmetry over the area of application, on the contralateral leg of the same dermatome, and in a separate dermatome (L5/S1) to serve as control. Cutaneous vascular conductance was calculated for each measurement site (CVC=flux/MAP). At baseline there were no differences in CVC between menthol and placebo gels, or among sites (all p>0.05). After 30±6min, CVC increased at the treated site with menthol (0.12±0.02 vs. 1.36±0.19flux/mmHg, p<0.01) but not the placebo (0.10±0.01 vs. 0.18±0.04flux/mmHg, p=0.91). There was a modest increase in CVC at the contralateral L4 dermatome with menthol gel (0.16±0.04 vs. 0.29±0.06flux/mmHg, p<0.01), but not placebo (0.11±0.02 vs. 0.15±0.03flux/mmHg, p=0.41). There was no effect on SkBF from either treatments at the L5/S1 control dermatome (both, p>0.05), suggesting the lack of a systemic response. In conclusion, menthol containing topical analgesic gels increased SkBF at the treated site, and modestly throughout the dermatome. These data suggest menthol-induced activation of the TRPM8 receptors induces an increase in SkBF across the area of common innervation through a localized spinal reflex mechanism.

Two clinical cases of unintentionally prolonged sciatic nerve block

This study describes two clinical cases of unexpectedly long duration of motor block after anterior sciatic nerve block. In two patients who underwent total knee replacement, the motor block reversion in the area of sciatic nerve innervation did not occur at the expected time. Ultrasound examination revealed the deposition of a local anesthetic near the sciatic nerve. In these two clinical cases, unintentionally prolonged sciatic nerve blockade was caused by combined age-related factors of reduced tissue perfusion and the vasoconstrictor properties of levobupivacaine. Subsequently, the block was successfully resolved in 3638 h without any neurological consequences.