Normal Sensation Research Articles

Isolation and Purification of Primary Rodent Schwann Cells.

Schwann cells are the main glial cells of the peripheral nervous system (PNS) and play key roles in peripheral nerve development and function, including providing myelin that is essential for normal movement and sensation in the adult. Schwann cells can be readily destabilized by a wide variety of distinct conditions that range from nerve injury to immune assaults, metabolic disturbances, microbial infections, or genetic defects, leading to the breakdown of myelin (demyelination) and a subsequent switch in phenotypic states. This striking feature of Schwann cells forms the cornerstone of several debilitating and even fatal PNS neurological disorders that include the demyelinating neuropathies Guillain Barré syndrome (GBS) and Charcot-Marie-Tooth disease (CMT), and PNS cancers, including Neurofibromatosis.Primary Schwann cell cultures have proved a valuable tool to dissect key mechanisms that regulate proliferation, survival, differentiation, and myelination of these glial cell types. In this chapter, we describe the steps involved in the isolation and purification of Schwann cells from rodent peripheral nerves and the use of these cultures to model myelination in vitro.

Retrospective Analysis of 20 Patients With Schwannomas: Magnetic Resonance Imaging Characteristics, Pain, and Outcomes Following Excision.

A Tinel's sign, a percussion-induced, painful sensation, has been reported as the most useful sign for diagnosing a schwannoma. On magnetic resonance imaging, schwannomas often exhibit a split fat sign and a target sign. The typical treatment for schwannomas is surgical excision; however, excision often results in high rates of neurological deficit. The authors retrospectively reviewed 20 patients who underwent excision of a schwannoma from 2007 to 2015. Twenty patients presented with a split fat sign and 12 patients presented with a Tinel's sign on magnetic resonance imaging. Only 3 patients presented with a target sign on magnetic resonance imaging. The operative approach involved removing the schwannoma, preserving the nearby nerve fascicles, and leaving the epineurium open. Follow-up ranged from 3 to 91 months (average, 29 months). At final follow-up, all patients were pain free. Nineteen patients had normal sensation and full function of their affected limb. One patient developed postoperative posterior interosseous nerve palsy. A Tinel's sign, preoperative pain, and a split fat sign on preoperative magnetic resonance imaging are the clinical symptoms most useful for diagnosing a schwannoma. Schwannomas can be safely removed via intracapsular surgical excision with minimal complications, yielding eradication of preoperative pain, normal sensation, and full function. [Orthopedics. 2017; 40(6):e1036-e1043.].

A Case of Acquired Hepatocerebral Degeneration Presenting as Hemichorea Post-Liver Transplant

Acquired hepatocerebral degeneration (AHCD) is a rare but morbid neurological manifestation of decompensated cirrhosis. Portosystemic shunting leads to manganese deposition in the basal ganglion which is identified as bilateral hyperintense signals on T1-weighted MRI. The resulting neuronal loss leads to involuntary movements, cognitive dysfunction, Parkinsonism, or cerebellar ataxia in the absence of hepatic encephalopathy. We present a case of AHCD with several unique features: 1) initial presentation post-liver transplant (OLT), 2) no clinical or radiographical evidence of portosystemic shunting, and 3) unilateral basal ganglia hyperintensity. A 57-year-old man with hypertension and chronic kidney disease (stage III) underwent OLT for hepatitis C and alcoholic cirrhosis 3 years prior to presentation. His post-transplant course was complicated by continued alcohol abuse, steroid-induced hyperglycemia, and acute cellular rejection without fibrosis 4 months prior. Prescriptions included tacrolimus, mycophenolate mofetil, prednisone, nifedipine, and insulin with questionable adherence. He had no personal or family history of movement disorders. His chief complaint was one month of progressive, uncontrollable right-sided arm and leg movements in a writhing, non-rhythmic pattern. He was afebrile. Physical exam was notable for right-sided hemichorea with normal strength, finger-to-nose test, reflexes, and sensation. He displayed no altered-mental status, asterixis, nystagmus, hepatosplenomegaly or ascites. Labs were notable for total bilirubin 1.3 mg/dL, Alk Phos 43 U/L, AST/ALT 117/65 U/L, blood alchohol level 103 mg/dL. INR 1.0 and platelets 141 x103/μL. Electrolytes, glucose and creatinine were normal. HgbA1c 6.0%. Tacrolimus level undetectable. Serum iron, zinc, lead, and manganese levels were normal. MRI brain notable for T1 hyperintensities in the left globus pallidus without evidence of hemorrhage or acute ischemia (Figure 1). He was treated with haloperidol 1mg twice daily which mildly suppressed the hemichorea and allowed discharge with close neurology follow-up. Symptoms of ACHD often improve with resolution of portosystemic shunting post-OLT. However, we present a case of new onset ACHD in a post-transplant patient without evidence of portosystemic shunting. This illustrates that ACHD remains a poorly understood disorder that should be considered in patients with typical findings and a history of cirrhosis, even after liver transplantation.Figure: T1 weighted magnetic resonance imaging (MRI) of the brain without contrast in axial view (A) and sagittal view (B) of hyperintensity in the left globus without evidence of hemorrhage or acute ischemia.

Comparing the sensation of common donor site regions for autologous breast reconstruction to that of a healthy breast

Autologous breast reconstruction has become the standard care for breast cancer patients. Although excellent cosmetic results can be achieved, most reconstructed breasts fail to regain normal sensation. Nerve coaptation of the flap has been suggested to improve sensation; the effect of the donor flap native sensory threshold on the degree of sensory restoration is yet to be determined. The aim of this study is to evaluate the differences in sensation between various potential donor site regions in comparison to the sensation of the healthy breast. A cross-sectional study in healthy women was performed in the Maastricht University Medical Centre. Monofilaments were used to measure sensation in the breast and at different flap donor sites: deep inferior epigastric perforator (DIEP), lateral thigh perforator (LTP), profunda artery perforator (PAP), superior gluteal artery perforator (SGAP) and transverse musculocutaneous gracilis (TMG) flaps. The Wilcoxon signed rank test was used to analyse statistical significance in sensation. Fifty women with a mean age of 49 ± 2.72 years and mean BMI of 26.14 ± 0.89 kg/m2 were included in the study. The median monofilament value of the normal breasts was 2.97(2.56-3.55). The median monofilament value of each donor site and p value when compared to the healthy breast were as follows: DIEP flap, 2.62 (2.36-3.22) p < 0.01; LTP flap, 3.61 (2.83-4.08) p <0.01; PAP flap, 3.09 (2.67-3.5) p = 0.97; SGAP flap, 3.22 (2.64-3.87) p = 0.01; and TMG flap, 3.03 (2.6-3.47) p = 0.69. There is a significant difference in sensation between the various donor site regions for breast reconstruction and the healthy breast. This may be taken into consideration for donor site selection.

Myasthenia Gravis and Crisis: Evaluation and Management in the Emergency Department

BackgroundMyasthenia gravis (MG) is an uncommon autoimmune disorder affecting the neuromuscular junction and manifesting as muscle weakness. A multitude of stressors can exacerbate MG. When symptoms are exacerbated, muscle weakness can be severe enough to result in respiratory failure, a condition known as myasthenic crisis (MC). ObjectiveThis review discusses risk factors, diagnosis, management, and iatrogenic avoidance of MC. DiscussionMC can affect any age, ethnicity, or sex and can be precipitated with any stressor, infection being the most common. MC is a clinical diagnosis defined by respiratory failure caused by exacerbation of MG. Muscle weakness can involve any voluntary muscle. MC can be differentiated from other neuromuscular junction diseases by the presence of normal reflexes, normal sensation, lack of autonomic symptoms, lack of fasciculations, and worsening weakness with repetitive motion. Treatment should target the inciting event and airway support. All acetylcholinesterase inhibitors should be avoided in crisis, including edrophonium testing and corticosteroids initially. Respiratory support can begin with noninvasive positive-pressure ventilation, as this has been successful even in patients with bulbar weakness. If intubation is necessary, consider avoiding paralytics or use a reduced dose of nondepolarizing agents. ConclusionsMC should be in the differential of any patient with muscular weakness and respiratory compromise. Emergency department management of MC should focus on ruling out infection and respiratory support. Strong consideration should be given to beginning with noninvasive positive-pressure ventilation for ventilatory support. Corticosteroids, depolarizing paralytics, and acetylcholinesterase inhibitors should be avoided in patients with MC in the emergency department.

Microbiota regulates visceral pain in the mouse.

The perception of visceral pain is a complex process involving the spinal cord and higher order brain structures. Increasing evidence implicates the gut microbiota as a key regulator of brain and behavior, yet it remains to be determined if gut bacteria play a role in visceral sensitivity. We used germ-free mice (GF) to assess visceral sensitivity, spinal cord gene expression and pain-related brain structures. GF mice displayed visceral hypersensitivity accompanied by increases in Toll-like receptor and cytokine gene expression in the spinal cord, which were normalized by postnatal colonization with microbiota from conventionally colonized (CC). In GF mice, the volumes of the anterior cingulate cortex (ACC) and periaqueductal grey, areas involved in pain processing, were decreased and enlarged, respectively, and dendritic changes in the ACC were evident. These findings indicate that the gut microbiota is required for the normal visceral pain sensation.

Immunoengineering nerve repair

Injuries to the peripheral nervous system are major sources of disability and often result in painful neuropathies or the impairment of muscle movement and/or normal sensations. For gaps smaller than 10 mm in rodents, nearly normal functional recovery can be achieved; for longer gaps, however, there are challenges that have remained insurmountable. The current clinical gold standard used to bridge long, nonhealing nerve gaps, the autologous nerve graft (autograft), has several drawbacks. Despite best efforts, engineering an alternative "nerve bridge" for peripheral nerve repair remains elusive; hence, there is a compelling need to design new approaches that match or exceed the performance of autografts across critically sized nerve gaps. Here an immunomodulatory approach to stimulating nerve repair in a nerve-guidance scaffold was used to explore the regenerative effect of reparative monocyte recruitment. Early modulation of the immune environment at the injury site via fractalkine delivery resulted in a dramatic increase in regeneration as evident from histological and electrophysiological analyses. This study suggests that biasing the infiltrating inflammatory/immune cellular milieu after injury toward a proregenerative population creates a permissive environment for repair. This approach is a shift from the current modes of clinical and laboratory methods for nerve repair, which potentially opens an alternative paradigm to stimulate endogenous peripheral nerve repair.

Pattern of Neurological Improvements in Patient with Lumbar Disc Herniation after Microdiscectomy: Experience at the Fourth Oldest Western Medical Facility in South Asia

The pattern of improvement in Neurological status after disc surgery is different. The chronology of improvement in Medical Research Council (MRC) scores, sensory status and improvement in Straight Leg Raise (SLR) test degrees is beneficial in management part to surgeons, relatives and the patients.To assess pattern of neurological outcomes in patients with lumbar disc herniation after microdiscectomy in terms of muscle power, sensory status and SLR.A Quasi experimental study comprising 70 consecutive cases though non-probability purposive sampling technique of both the sexes admitted in Neurosurgery department, Mayo Hospital operated for the 1st time for any disc pathology with no other spinal lesions giving consent themselves or though legal guardians was conducted. Pain for leg and back was measured pre and post-operatively was done by VAS which had 42 days of follow up. Standard Neurological examinations were conducted pertaining to muscle power (by MRC), sensory status and SLR test pre and post-operatively. Variables according to their nature were expressed in the form of Mean±SD, Median (Range) and Frequency (percentage). Mc Neumer’s chi square test and paired t test were used to see association between preoperative and post-operative Neurological status depending on their nature viz: qualitative or quantitative respectively in SPSS version 15.Out of 70 patients 74% were male and 26% were females. Mean±SD of patients was 37.6±13.0 years. Majority were Laborers after housewives. Illiterates, Poor lifting techniques were the most common characteristics in the respective headings of education and employment. Most common level of disc herniation was L4-L5, L5- S1 level (96%) where Prolapse and extrusion were most common MRI findings. As compared to pre-operative (3.4) muscle power 1st and 42nd day power were respectively 4.0 and 4.7 (p=0.001). Pre-operatively only 32 (45.7%) had normal sensation which improved to 38 (54.3%) and 51 (72.9%) respectively in 1st and 42nd day of surgery (p=0.001). Pre-operative mean SLR improved to 98.6 degrees in 1st POD and continued to be the same till 42nd day (p=0.001). All the MRC findings, sensory status and SLR values in each post-operative days were statistically significant with the baseline by paired t test (p=0.001). MRC and Sensory status had same pattern of improvement (r=0.0. p=0.04) unlike SLR which total improvements were see in 1st POD itself.In conclusion, muscle power and sensory improvement follows same improvement pattern whereas maximum SLR improves in the 1st POD itself.Nepal Journal of Neuroscience, Vol. 14, No. 2, 2017 Page: 8-15

17 yo Football Player with Central Cord Syndrome after Negative Initial Neck Exam

HISTORY: A 17 year old HS football receiver was injured when he sustained a hit from the opposing safety. Reported mechanism by opposing player was shoulder to head impact. He fell to the ground in the prone position. He was immediately evaluated on the field by the nearby opposing athletic trainers. He had no LOC, no neck pain on the field, and he denied tenderness to palpation. He complained of having the wind knocked out of him. He reported that he got hit in the back of the leg and it felt odd. He had an ACL brace on his right knee. Care was transitioned to his team athletic trainers. He was turned supine and his helmet was removed. Afterwards, his right arm was noted to be in an awkward position. He could not move his arms or his legs. He had good sensation but had tingling in his upper and lower extremities. He had no prior history of weakness, neck pain, or concussion. His neck was immobilized. He regained motion in the upper extremity, but continued to demonstrate weakness in grip strength. He could not move his lower extremity. On EMS arrival he was spine boarded, and then taken to the ED for further management. PHYSICAL EXAMINATION: He was AO x 3. He had no tenderness over the cervical spinous processes and paraspinal muscles. He had normal sensation of his bilateral extremities. After being turned supine and having his helmet removed, he developed weakness of his upper and lower extremities, but no sensory deficit. Respiratory and Cardiovascular exams were normal. DIFFERENTIAL DIAGNOSIS: 1. Central Cord Syndrome 2. Anterior Cord Syndrome 3. Posterior Cord Syndrome 4. Brown-Sequard Syndrome 5. Concussion 6. Intracranial Hemorrhage 7. Acute disk herniation 8. Epidural Hematoma 9. Syringomyelia TEST AND RESULTS:CT Head, XR C, T, L spine: No fracture or bleed MR C-spine: Congenital stenosis of the spinal canal, with endplate osteophytes/protrusions moderately narrowing the spinal canal to 8 mm at C3-4, with expansile T2 signal suggestive of edema within the cervical spinal cord at C3-4 levels. FINAL/WORKING DIAGNOSIS: Traumatic Cervical Myelopathy superimposed on Congenital Stenosis of Spinal Canal TREATMENT AND OUTCOMES: 1. Immobilization with Miami J Collar 2. Admitted to the hospital for observation. 3. Sensory and strength deficits improved during stay. 4. Transferred to an intensive inpatient activity based rehabilitation facility.

Quantitative Thermal Testing Profiles as a Predictor of Treatment Response to Topical Capsaicin in Patients with Localized Neuropathic Pain.

There are no reliable predictors of response to treatment with capsaicin. Given that capsaicin application causes heat sensation, differences in quantitative thermal testing (QTT) profiles may predict treatment response. The aim of this study was to determine whether different QTT profiles could predict treatment outcomes in patients with localized peripheral neuropathic pain (PeLNP). We obtained from medical records QTT results and treatment outcomes of 55 patients treated between 2010 and 2013. Warm sensation threshold (WST) and heat pain threshold (HPT) values were assessed at baseline at the treatment site and in the asymptomatic, contralateral area. Responders were defined as those who achieved a > 30% decrease in pain lasting > 30 days. Two distinct groups were identified based on differences in QTT profiles. Most patients (27/31; 87.1%) with a homogenous profile were nonresponders. By contrast, more than half of the patients (13/24, 54.2%) with a nonhomogenous profile were responders (p = 0.0028). A nonhomogenous QTT profile appears to be predictive of response to capsaicin. We hypothesize patients with a partial loss of cutaneous nerve fibers or receptors are more likely to respond. By contrast, when severe nerve damage or normal cutaneous sensations are present, the pain is likely due to central sensitization and thus not responsive to capsaicin. Prospective studies with larger patient samples are needed to confirm this hypothesis.

Effectiveness and safety of phentolamine mesylate in routine dental care

BackgroundPhentolamine mesylate (PM) is widely used to reverse local anesthesia after dental procedures. Limited knowledge is available regarding effectiveness and safety in routine dental practice. MethodsThe authors conducted 2 national, prospective, noninterventional, postauthorization effectiveness studies (OraVerse Post-Authorization Efficacy Study [ORAPAES] controlled, OraVerse Non-Interventional Study [ORANIS] uncontrolled) in patients receiving a local anesthetic as part of their dental treatment. They investigated time to recovery of normal sensation and function and the frequency of adverse events (AEs). The authors used Kaplan-Meier methods to analyze times to recovery; in ORAPAES, they used hazard ratios based on Cox models using the control group as a reference. ResultsIn ORAPAES (n = 856), PM reduced the time to recovery of normal sensation and function with a difference in the median time of 70 and 79 minutes, respectively, with similar results observed in ORANIS (n = 445). In ORAPAES, patients in the PM group had, at any time point, a 2.77-fold higher chance of recovery to normal sensation (hazard ratio, 2.77; 95% confidence interval [CI], 2.35-3.26; P < .001) and for normal function 2.94-fold higher chance of recovery to normal sensation (95% CI, 2.49-3.47; P < .001) than in the control group. The observed incidence of AEs with PM treatment was 8.4% in ORAPAES (95% CI, 6.2-10.9) and 9.7% (95% CI, 7.1-12.7) in ORANIS. No serious AEs occurred. ConclusionsPM substantially reduced the time to recovery of normal sensation and function after local anesthesia in routine dental treatment. The results confirm the effectiveness, safety, and tolerability of PM used in patients with routine dental conditions in Germany, and that PM augments the safety of dental treatments. Practical ImplicationsThe authors determined that PM is well suited to reverse local anesthesia after routine dental procedures.

Quantitative validation of sensory mapping in persistent postherniorrhaphy inguinal pain patients undergoing triple neurectomy.

Neurectomy of the inguinal nerves may be considered for selected refractory cases of chronic postherniorrhaphy inguinal pain (CPIP). There is to date a paucity of easily applicable clinical tools to identify neuropathic pain and examine the neurosensory effects of remedial surgery. The present quantitative sensory testing (QST) pilot study evaluates a sensory mapping technique. Longitudinal (preoperative, immediate postoperative, and late postoperative) dermatomal sensory mapping and a comprehensive QST protocol were conducted in CPIP patients with unilateral, predominantly neuropathic inguinodynia presenting for triple neurectomy (n=13). QST was conducted in four areas on the affected, painful side and in one contralateral comparison site. QST variables were compared according to sensory mapping outcomes: (o)/normal sensation, (+)/pain, and (-)/numbness. Diagnostic ability of the sensory mapping outcomes to detect QST-assessed allodynia or hypoesthesia was estimated through calculation of specificity and sensitivity values. Preoperatively, patients exhibited mechanical hypoesthesia and allodynia and pressure allodynia and hyperalgesia in painful areas mapped (+) (p<.05); sensory mapping outcome (+) demonstrated high ability to detect mechanical allodynia [sensitivity 0.74 (95% CI 0.61-0.86), specificity 0.94 (0.84-1.00)] and pressure allodynia [sensitivity 0.96 (0.89-1.00), specificity 1.00 (1.00-1.00)], but not thermal allodynia. Postoperatively, mapped areas of numbness (-) were associated with mechanical and thermal hypoesthesia (p<.05); (-) showed high sensitivity and specificity to detect mechanical and cold hypoesthesia. Sensory mapping provides an accurate clinical neuropathic assessment with strong correlation to QST findings of preoperative mechanical and pressure allodynia, and postoperative mechanical and thermal hypoesthesia in CPIP patients undergoing neurectomy.

Effect of Nerve Stimulation Use on the Success Rate of Ultrasound-Guided Subsartorial Saphenous Nerve Block: A Randomized Controlled Trial.

Ultrasound-guided subsartorial saphenous nerve block is commonly used to provide complete surgical anesthesia of the foot and ankle in combination with a popliteal sciatic nerve block. However, in part owing to its small caliber and absence of a prominent vascular landmark in the subsartorial plane distal to the adductor canal, the saphenous nerve is more difficult to reliably block than the sciatic nerve in the popliteal fossa. Although the saphenous nerve is a sensory nerve only, neurostimulation can be used to elicit a "tapping" sensation on the anteromedial aspect of the lower leg extending toward the medial malleolus. Our objective was to test the hypothesis that the addition of nerve stimulation use to an ultrasound (US)-guided technique will increase the success rate of subsartorial saphenous nerve block. With institutional human ethics board approval and participants' written informed consent, we enrolled 80 patients undergoing foot and ankle surgery in a randomized, single-blinded, parallel-group clinical trial. Patients were randomly assigned to receive US-guided subsartorial saphenous nerve block either alone (US group) or with the use of additional nerve stimulation (NS group; time limit, 5 minutes). For saphenous nerve blockade, all patients received 10 mL of 0.5% ropivacaine. The primary end point was complete absence of sensation to pinprick at 30 minutes at two different anatomic areas in the distribution of the saphenous nerve (2 cm proximal to the medial malleolus and 10 cm distal to the medial tibial condyle). Secondary end points included decreased sensation at 30 minutes and block failure (normal sensation) at 30 minutes. This trial was registered at ClinicalTrials.gov: NCT02382744. All 80 patients completed the trial (40 patients in each group). Twenty-two patients (55%) in the NS group versus 18 (45%) in the US group had complete absence of sensation to pinprick at 30 minutes at both anatomic areas of assessment (Fisher exact test, P = 0.25 [one sided]; 95% confidence interval of difference in proportions, -11.9% to 31.9%). The percentages of patients with any evidence of block (decreased or complete absence of sensation) at both areas at 30 minutes were 92.5% (NS) and 97.5% (US), respectively (P = 0.62 [two sided]); corresponding failure rates (normal sensation) were 7.5% (NS) and 2.5% (US). In the NS group, no response in the saphenous nerve distribution was elicited within 5 minutes of stimulation time limit in 20% of patients (n = 8). All of the patients in the NS group with normal sensation at 30 minutes (n = 3) were among this subcohort. The addition of the use of nerve stimulation did not improve the success rate of US-guided subsartorial saphenous nerve block. However, in the NS group, an inability to elicit a "tapping" sensation in the saphenous nerve distribution was associated with block failure.

Reduction mammaplasty with the modified round block technique in Chinese patients and its anatomy study

Background: Although reduction mammaplasty is one of the most common procedures in plastic surgery, it is associated with some serious complications, especially in cases of severe hypertrophy or advanced ptosis, including necrosis of the nipple and areola, absence of normal sensation of the nipple-areolar complex, and loss of lactational function for future nursing. A thorough understanding of the breast anatomy is vital for successful reduction mammaplasty. This article describes the blood supply and innervation of the breasts, and introduces a modified round block technique for reduction mammaplasty based on this anatomy.Methods: Six adult female cadavers were used to assess the vasculature of the anterior thorax and the nerve distribution of the breasts according to vascular perfusion and autopsy. Based on this anatomical study, a modified round block technique was designed for reduction mammaplasty, which was performed in 40 Chinese patients with breast hypertrophy.Results: Würinger’s horizontal septum was observed in all six cadavers. In the superficial layer, the main sources of blood are the second and third intercostal perforating branches of the internal thoracic artery, which run along the medial ligaments, and the branches of the lateral thoracic artery, which run along the lateral ligaments. In the deep layer, the main sources of blood are the fourth and fifth intercostal artery perforators, which run along Würinger’s horizontal septum. Innervation of the nipple-areolar complex is achieved mainly by the lateral branches of the fourth intercostal nerve, which also run along Würinger’s horizontal septum toward the nipple-areolar complex. The 40 patients with breast hypertrophy underwent successful reduction mammaplasty using our modified round block technique, except for one case, which developed necrosis of the nipple-areolar complex.Conclusions: Reduction mammaplasty using our modified round block technique can maximally preserve the blood supply to the remaining gland as well as the innervation to the nipple-areolar complex, while maintaining the advantages of the traditional technique, such as an invisible scar and good projection.

Pinprick Testing Will Identify Pudendal Neuropathy in Patients with Chronic Pelvic Pain Syndrome

This retrospective analysis discusses 25 consecutive males and 25 females, who had consulted at a clinical practice that focuses on chronic pelvic pain, beginning January 2, 2010. Sensory evidence of neuropathy was sought using response to light pinprick touch in the pudendal territory. Confirmation of neuropathy utilized neurophysiologic testing (not a part of this paper). Purpose: To report the ease of diagnosing pudendal neuropathy by searching for sensory response to light touch with a safety pin. Methods: Both genders were examined for pudendal neuropathy using light touch with a safety pin. Normal sensation at the thigh (lumbar territory) was compared to the six pudendal branches (sacral territory). Six test sites are the glans (clitoris) the posterior scrotum (posterior labia) and the posterior anal skin. These sites evaluate the dorsal nerve of the penis (clitoris), the perineal nerve and the inferior rectal nerve. With each touch patients are asked to compare whether the pudendal response is the same as the thigh, has more pinprick sensation, less sensation, or none. Several additional neuropathic pelvic pain generators are also sought. Two neurophysiologic tests were performed; a warm temperature threshold detection test and a pudendal nerve terminal motor latency test. Main findings: Pinprick sensation is abnormal at one or more pudendal branches in 92% of males and 92% of females. Bilateral neuropathy is almost universal. Addition of the two neurophysiologic tests increased the diagnosis of pudendal neuropathy to 100%. 64% of the patients had additional neuropathic pelvic pain generators. Principal conclusions: Pinprick testing can identify pudendal neuropathy in 92% of CPP patients. Changes from normal include chiefly hyperalgesia but also hypoalgesia and analgesia. These findings refute the erroneous declarations of the Nantes Criteria [1]. The presence of additional neuropathic pain generators in 64% of patients emphasizes the complexity of the CPP syndrome.

Central Poststroke Pain Can Occur With Normal Sensation.

In view of the paucity of studies on central poststroke pain (CPSP), in this hospital-based prospective study, we evaluated the frequency, the spectrum, imaging, and quantitative sensory testing in a cohort of stroke patients with CPSP. Stroke patients who developed CPSP at onset or during follow-up were included. Patients were subjected to clinical evaluation and sensory testing. The severity of stroke was defined by the Modified Rankin Scale and disability by the Barthel Index. Quantitative sensory testing included monofilament testing and evaluation for static and dynamic mechanical allodynia, punctuate hyperalgesia, temporal summation, cold allodynia, and cold hyperalgesia. Sleep, anxiety, and depression were also evaluated. Patients were treated with pregabalin 150 to 600 mg/d and good response was defined as >50% improvement in the VAS score. CPSP symptoms were correlated with demographic information, sensory findings, and imaging findings. A total of 319 patients with stroke were evaluated. CPSP occurred in 66 (20.7%) of them. The median age of the CPSP patients was 55 years (range, 25 to 80 y). About 31.8% patients were female. The onset, the duration, and the distribution of pain were variable. The severity of symptoms did not correlate with demographic variables and the site of lesion. Spinothalamic sensations were normal in 42.3% patients. On treatment with pregabalin (150 to 600 mg), half of the patients had a good response. CPSP was present in 20.7% of the stroke patients. Spinothalamic tract dysfunction may not be necessary for the development of CPSP, and it can also be seen with normal spinothalamic sensation. The location of the stroke, its type and quality, and the severity of CPSP were not related.

Sensory Topography of Oral Structures

Sensory function in the oral cavity and oropharynx is integral to effective deglutition and speech production. The main hurdle to evaluation of tactile consequences of upper aerodigestive tract diseases and treatments is access to a reliable clinical tool. We propose a rapid and reliable procedure to determine tactile thresholds using buckling monofilaments to advance care. To develop novel sensory testing monofilaments and map tactile thresholds of oral cavity and oropharyngeal structures. A prospective cross-sectional study of 37 healthy adults (12 men, 25 women), specifically without a medical history of head and neck surgery, radiation, or chemotherapy, was carried out in an academic tertiary medical center to capture normative data on tactile sensory function in oral structures. Cheung-Bearelly monofilaments were constructed by securing nylon monofilament sutures (2-0 through 9-0) in the lumen of 5-French ureteral catheters, exposing 20 mm for tapping action. Buckling force consistency was evaluated for 3 lots of each suture size. Sensory thresholds of 4 oral cavity and 2 oropharyngeal subsites in healthy participants (n = 37) were determined by classical signal detection methodology (d-prime ≥1). In 21 participants, test-retest reliability of sensory thresholds was evaluated. Separately in 16 participants, sensory thresholds determined by a modified staircase method were cross-validated with those obtained by classical signal detection. Buckling forces of successive suture sizes were distinct (P < .001), consistent (Cronbach α, 0.99), and logarithmically related (r = 0.99, P < .001). Test-retest reliability of sensory threshold determination was high (Cronbach α, >0.7). The lower lip, anterior tongue, and buccal mucosa were more sensitive than the soft palate, posterior tongue, and posterior pharyngeal wall (P < .001). Threshold determination by classical signal detection and modified staircase methods were highly correlated (r = 0.93, P < .001). Growth of perceptual intensity was logarithmically proportional to stimulus strength (P < .01). Topography of normal oral cavity and oropharyngeal tactile sensation is organized in accordance to decreasing sensitivity along the anteroposterior trajectory and growth of perceptual intensity at all subsites is log-linear. Cheung-Bearelly monofilaments are accessible, disposable, and consistent esthesiometers. This novel clinical tool is deployable for quantitative sensory function assessment of oral cavity and oropharyngeal structures.

Ultrasound guided K-wire reduction of irreducible femoral neck fractures

Objective To evaluate the effect of ultrasound-guided K-wire reduction of irreducible femoral neck fractures. Methods A retrospective analysis was made on 21 patients with irreducible femoral neck fractures hospitalized from January 2011 to January 2014. There were 13 males and 8 females, aged 23-60 years (mean, 41.5 years). The fractures of nine patients were caused by road traffic accidents, seven by slipping, and five by fall from the height. According to the Garden classification, four patients were classified as type Ⅱ, eleven type Ⅲ, and six type Ⅳ. Patients were placed in traction bed for limb traction. After 3-times unsuccessful reduction with limb traction, the patients were performed ultrasound-guided localization of superficial femoral artery, vein and nerve in the hip, marked and stabilized with two K-wires into the surface markers. Position relations of femoral artery, vein and nerve with the femoral head were determined under fluoroscopic guidance. After operation, the part with K-wire insertion was routinely reviewed by ultrasound, the anterior and lateral positions of the hip joint were routinely reviewed, and the sensorimotor function of the area of femoral nerve and sense function of the anterolateral femoral cutaneous nerve were routinely examined. Quality of reduction was assessed with the Garden index. Hip function was assessed with Harris score. Results All patients were followed up for mean 18 months (range, 6-28 months), which showed satisfactory reduction. No major vascular or nerve injury occurred intraoperatively. Postoperative ultrasound examination revealed no local hematoma formation, normal functions of the femoral nerve and normal superficial sensibility of the anterolateral femoral cutaneous nerve. No deep vein thrombosis of the lower limb occurred postoperatively. According to the Garden index, reduction was reached grade Ⅰ in fourteen patients and grade Ⅱ in seven patients. Harris hip score was excellent in 14 patients, good in six and poor in one, with the excellent-good rate of 95%. One patient underwent total hip arthroplasty for the postoperative femoral head necrosis, and none had screw displacement and implant loosening. Conclusion Ultrasound guided K-wire reduction of irreducible femoral neck fractures is associated with simple equipment, high repeatability, safe and effective results, and decreased iatrogenic injury. Key words: Ultrasonography; Femoral neck fractures; Reduction

HCN2 ion channels: basic science opens up possibilities for therapeutic intervention in neuropathic pain.

Nociception - the ability to detect painful stimuli - is an invaluable sense that warns against present or imminent damage. In patients with chronic pain, however, this warning signal persists in the absence of any genuine threat and affects all aspects of everyday life. Neuropathic pain, a form of chronic pain caused by damage to sensory nerves themselves, is dishearteningly refractory to drugs that may work in other types of pain and is a major unmet medical need begging for novel analgesics. Hyperpolarisation-activated cyclic nucleotide (HCN)-modulated ion channels are best known for their fundamental pacemaker role in the heart; here, we review data demonstrating that the HCN2 isoform acts in an analogous way as a 'pacemaker for pain', in that its activity in nociceptive neurons is critical for the maintenance of electrical activity and for the sensation of chronic pain in pathological pain states. Pharmacological block or genetic deletion of HCN2 in sensory neurons provides robust pain relief in a variety of animal models of inflammatory and neuropathic pain, without any effect on normal sensation of acute pain. We discuss the implications of these findings for our understanding of neuropathic pain pathogenesis, and we outline possible future opportunities for the development of efficacious and safe pharmacotherapies in a range of chronic pain syndromes.

Somatic Symptom Disorder in Semantic Dementia: The Role of Alexisomia

Semantic dementia (SD) is a neurodegenerative disorder characterized by loss of semantic knowledge. SD may be associated with somatic symptom disorder due to excessive preoccupation with unidentified somatic sensations. To evaluate the frequency of somatic symptom disorder among patients with SD in comparison to comparably demented patients with Alzheimer׳s disease. A retrospective cohort study was conducted using clinical data from a referral-based behavioral neurology program. Fifty-three patients with SD meeting criteria for imaging-supported semantic variant primary progressive aphasia (another term for SD) were compared with 125 patients with clinically probable Alzheimer disease. Logistic regression controlled for sex, age, disease duration, education, overall cognitive impairment, and depression. The prevalence of somatic symptom disorder was significantly higher among patients with SD (41.5%) compared to patients with Alzheimer disease (11.2%) (odds ratio = 6:1; p < 0.001). Somatic symptom disorder was associated with misidentification and preoccupation with normal bodily sensations such as hunger, bladder filling, borborygmi, rhinorrhea, and reflux; excessive concern over the incompletely understood meaning or source of pain or other symptoms; and Cotard syndrome or the delusion that unidentified somatic symptoms signify death or deterioration. SD, a disorder of semantic knowledge, is associated with somatic symptom disorder from impaired identification of somatic sensations. Their inability to read and name somatic sensations, or "alexisomia," results in disproportionate and persistent concern about somatic sensations with consequent significant disability.