Pharmacogenetic inhibition of lumbosacral sensory neurons alleviates visceral hypersensitivity in a mouse model of chronic pelvic pain

The study investigated the cellular and molecular mechanisms in the peripheral nervous system (PNS) underlying the symptoms of urologic chronic pelvic pain syndrome (UCPPS) in mice. This work also aimed to test the feasibility of reversing peripheral sensitization in vivo in alleviating UCPPS symptoms. Intravesical instillation of vascular endothelial growth factor A (VEGFA) was used to induce UCPPS-like symptoms in mice. Spontaneous voiding spot assays and manual Von Frey tests were used to evaluate the severity of lower urinary tract symptoms (LUTS) and visceral hypersensitivity in VEGFA-instilled mice. Bladder smooth muscle strip contractility recordings (BSMSC) were used to identify the potential changes in myogenic and neurogenic detrusor muscle contractility at the tissue-level. Quantitative real-time PCR (qPCR) and fluorescent immunohistochemistry were performed to compare the expression levels of VEGF receptors and nociceptors in lumbosacral dorsal root ganglia (DRG) between VEGFA-instilled mice and saline-instilled controls. To manipulate primary afferent activity, Gi-coupled Designer Receptors Exclusively Activated by Designer Drugs (Gi-DREADD) were expressed in lumbosacral DRG neurons of TRPV1-Cre-ZGreen mice via targeted adeno-associated viral vector (AAVs) injections. A small molecule agonist of Gi-DREADD, clozapine-N-oxide (CNO), was injected into the peritoneum (i. p.) in awake animals to silence TRPV1 expressing sensory neurons in vivo during physiological and behavioral recordings of bladder function. Intravesical instillation of VEGFA in the urinary bladders increased visceral mechanical sensitivity and enhanced RTX-sensitive detrusor contractility. Sex differences were identified in the baseline detrusor contractility responses and VEGF-induced visceral hypersensitivity. VEGFA instillations in the urinary bladder led to significant increases in the mRNA and protein expression of transient receptor potential cation channel subfamily A member 1 (TRPA1) in lumbosacral DRG, whereas the expression levels of transient receptor potential cation channel subfamily V member 1 (TRPV1) and VEGF receptors (VEGFR1 and VEGFR2) remained unchanged when compared to saline-instilled animals. Importantly, the VEGFA-induced visceral hypersensitivity was reversed by Gi-DREADD-mediated neuronal silencing in lumbosacral sensory neurons. Activation of bladder VEGF signaling causes sensory neural plasticity and visceral hypersensitivity in mice, confirming its role of an UCPPS biomarker as identified by the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) research studies. Pharmacogenetic inhibition of lumbosacral sensory neurons in vivo completely reversed VEGFA-induced pelvic hypersensitivity in mice, suggesting the strong therapeutic potential for decreasing primary afferent activity in the treatment of pain severity in UCPPS patients.

Translumbosacral Anorectal Magnetic Stimulation Test for Fecal Incontinence

BACKGROUND

Neuropathy may cause fecal incontinence and mixed fecal incontinence/constipation, but its prevalence is unclear, partly due to the lack of comprehensive testing of spino-anorectal innervation.

OBJECTIVE

This study aimed to develop and determine the clinical usefulness of a novel test, translumbosacral anorectal magnetic stimulation for fecal incontinence.

DESIGN

This observational cohort study was conducted from 2012 to 2018.

SETTINGS

This study was performed at a tertiary referral center.

PATIENTS

Patients with fecal incontinence, patients with mixed fecal incontinence/constipation, and healthy controls were included.

INTERVENTIONS

A translumbosacral anorectal magnetic stimulation test was performed by using an anorectal probe with 4 ring electrodes and magnetic coil, and by stimulating bilateral lumbar and sacral plexuses, uses and recording 8 motor-evoked potentials at anal and rectal sites.

MAIN OUTCOME MEASURES

The prevalence of lumbar and/or sacral neuropathy was examined. Secondary outcomes were correlation of neuropathy with anorectal sensorimotor function(s) and morphological changes.

RESULTS

We evaluated 220 patients: 144 with fecal incontinence, 76 with mixed fecal incontinence/constipation, and 31 healthy controls. All 8 lumbar and sacral motor-evoked potential latencies were significantly prolonged (p < 0.01) in fecal incontinence and mixed fecal incontinence/constipation groups compared with controls. Neuropathy was patchy and involved 4.0 (3.0) (median (interquartile range)) sites. Lumbar neuropathy was seen in 29% to 65% of the patients in the fecal incontinence group and 22% to 61% of the patients in the mixed fecal incontinence/constipation group, and sacral neuropathy was seen in 24% to 64% and 29% to 61% of these patients. Anal neuropathy was significantly more (p < 0.001) prevalent than rectal neuropathy in both groups. There was no correlation between motor-evoked potential latencies and anal sphincter pressures, rectal sensation, or anal sphincter defects.

LIMITATIONS

No comparative analysis with electromyography was performed.

CONCLUSION

Lumbar or sacral plexus neuropathy was detected in 40% to 75% of patients with fecal incontinence with a 2-fold greater prevalence at the anal region than the rectum. Lumbosacral neuropathy appears to be an independent mechanism in the pathogenesis of fecal incontinence, unassociated with other sensorimotor dysfunctions. Translumbosacral anorectal magnetic stimulation has a high yield and is a safe and clinically useful neurophysiological test. See Video Abstract at http://links.lww.com/DCR/B728.

PRUEBA DE ESTIMULACIN MAGNTICA TRANSLUMBOSACRAL ANORECTAL PARA LA INCONTINENCIA FECAL

ANTECEDENTES:La neuropatía puede causar incontinencia fecal y una combinación de incontinencia fe-cal/estreñimiento, pero su prevalencia no está clara, en parte debido a la falta de pruebas comple-tas de inervación espino-anorrectal.OBJETIVO:Desarrollar y determinar la utilidad clínica de una nueva prueba, estimulación magnética trans-lumbosacral anorrectal para la incontinencia fecal.DISEÑO:Estudio de cohorte observacional del 2012 al 2018.ENTORNO CLINICO:Centro de referencia terciario.PACIENTES:Pacientes con incontinencia fecal, combinación de incontinencia fecal/estreñimiento y controles sanos.INTERVENCIONES:Se realizó una prueba de estimulación magnética translumbosacral anorrectal utilizando una sonda anorrectal con 4 electrodos anulares y bobina magnética, y estimulando los plexos lumbares y sacros bilaterales y registrando ocho potenciales evocados motores las regiones anal y rectal.PRINCIPALES MEDIDAS DE RESULTADO:Se examinó la prevalencia de neuropatía lumbar y/o sacra. Los resultados secundarios fueron la correlación de la neuropatía con las funciones sensitivomotoras anorrectales y cambios morfológi-cos.RESULTADOS:Evaluamos 220 pacientes, 144 con incontinencia fecal, 76 con combinación de incontinencia fe-cal/estreñimiento y 31 sujetos sanos. Las ocho latencias de los potenciales evocadas motoras lum-bares y sacras se prolongaron significativamente (p <0,01) en la incontinencia fecal y el grupo mixto en comparación con los controles. La neuropatía fue irregular y afectaba 4,0 (3,0) (mediana (rango intercuartílico) sitios. Se observó neuropatía lumbar en 29-65% en la incontinencia fecal y 22-61% en el grupo mixto, y neuropatía sacra en 24-64% y 29-61 % de pacientes respectivamen-te. La neuropatía anal fue significativamente más prevalente (p <0,001) que la rectal en ambos grupos. No hubo correlación entre las latencias de los potenciales evocadas motoras y las presio-nes del esfínter anal, la sensación rectal o los defectos del esfínter anal.LIMITACIONES:Sin análisis comparativo con electromiografía.CONCLUSIÓNES:Se detectó neuropatía del plexo lumbar o sacro en el 40-75% de los pacientes con incontinencia fecal con una prevalencia dos veces mayor en la región anal que en el recto. La neuropatía lumbo-sacra parece ser un mecanismo independiente en la patogenia de la incontinencia fecal, no asocia-do con otras disfunciones sensitivomotoras. La estimulación magnética translumbosacral anorrec-tal tiene un alto rendimiento, es una prueba neurofisiológica segura y clínicamente útil. Consulte Video Resumen en http://links.lww.com/DCR/B728.

Nociceptor subtypes are born continuously over DRG development

Sensory neurogenesis in the dorsal root ganglion (DRG) occurs in two waves of differentiation with larger, myelinated proprioceptive and low-threshold mechanoreceptor (LTMR) neurons differentiating before smaller, unmyelinated (C) nociceptive neurons. This temporal difference was established from early birthdating studies based on DRG soma cell size. However, distinctions in birthdates between molecular subtypes of sensory neurons, particularly nociceptors, is unknown. Here, we assess the birthdate of lumbar DRG neurons in mice using a thymidine analog, EdU, to label developing neurons exiting mitosis combined with co-labeling of known sensory neuron markers. We find that different nociceptor subtypes are born on similar timescales, with continuous births between E9.5 to E13.5, and peak births from E10.5 to E11.5. Notably, we find that thinly myelinated Aδ-fiber nociceptors and peptidergic C-fibers are born more broadly between E10.5 and E11.5 than previously thought and that non-peptidergic C-fibers and C-LTMRs are born with a peak birth date of E11.5. Moreover, we find that the percentages of nociceptor subtypes born at a particular timepoint are the same for any given nociceptor cell type marker, indicating that intrinsic or extrinsic influences on cell type diversity are occurring similarly across developmental time. Overall, the patterns of birth still fit within the classical "two wave" description, as touch and proprioceptive fibers are born primarily at E10.5, but suggest that nociceptors have a slightly broader wave of birthdates with different nociceptor subtypes continually differentiating throughout sensory neurogenesis irrespective of myelination.

Thoracolumbar interfascial plane block for postoperative analgesia in spine surgery: A systematic review and meta-analysis

INTRODUCTION

Thoracolumbar interfascial plane (TLIP) block has been discussed widely in spine surgery. The aim of our study is to evaluate analgesic efficacy and safety of TLIP block in spine surgery.

METHOD

We performed a quantitative systematic review. Randomized controlled trials that compared TLIP block to non-block care or wound infiltration for patients undergoing spine surgery and took the pain or morphine consumption as a primary or secondary outcome were included. The primary outcome was cumulative opioid consumption during 0-24-hour. Secondary outcomes included postoperative pain intensity, rescue analgesia requirement, and adverse events.

RESULT

9 randomized controlled trials with 539 patients were included for analysis. Compared with non-block care, TLIP block was effective to decrease the opioid consumption (WMD -16.00; 95%CI -19.19, -12.81; p<0.001; I2 = 71.6%) for the first 24 hours after the surgery. TLIP block significantly reduced postoperative pain intensity at rest or movement at various time points compared with non-block care, and reduced rescue analgesia requirement ((RR 0.47; 95%CI 0.30, 0.74; p = 0.001; I2 = 0.0%) and postoperative nausea and vomiting (RR 0.58; 95%CI 0.39, 0.86; p = 0.006; I2 = 25.1%). Besides, TLIP block is superior to wound infiltration in terms of opioid consumption (WMD -17.23, 95%CI -21.62, -12.86; p<0.001; I2 = 63.8%), and the postoperative pain intensity at rest was comparable between TLIP block and wound infiltration.

CONCLUSION

TLIP block improved analgesic efficacy in spine surgery compared with non-block care. Furthermore, current literature supported the TLIP block was superior to wound infiltration in terms of opioid consumption.

Magnetic resonance tractography of the lumbosacral plexus: Step-by-step

ABSTRACT

MR tractography of the lumbosacral plexus (LSP) is challenging due to the difficulty of acquiring high quality data and accurately estimating the neuronal tracts. We proposed an algorithm for an accurate visualization and assessment of the major LSP bundles using the segmentation of the cauda equina as seed points for the initial starting area for the fiber tracking algorithm.Twenty-six healthy volunteers underwent MRI examinations on a 3T MR scanner using the phased array coils with optimized measurement protocols for diffusion-weighted images and coronal T2 weighted 3D short-term inversion recovery sampling perfection with application optimized contrast using varying flip angle evaluation sequences used for LSP fiber reconstruction and MR neurography (MRN).The fiber bundles reconstruction was optimized in terms of eliminating the muscle fibers contamination using the segmentation of cauda equina, the effects of the normalized quantitative anisotropy (NQA) and angular threshold on reconstruction of the LSP. In this study, the NQA parameter has been used for fiber tracking instead of fractional anisotropy (FA) and the regions of interest positioning was precisely adjusted bilaterally and symmetrically in each individual subject.The diffusion data were processed in individual L3-S2 nerve fibers using the generalized Q-sampling imaging algorithm. Data (mean FA, mean diffusivity, axial diffusivity and radial diffusivity, and normalized quantitative anisotropy) were statistically analyzed using the linear mixed-effects model. The MR neurography was performed in MedINRIA and post-processed using the maximum intensity projection method to demonstrate LSP tracts in multiple planes.FA values significantly decreased towards the sacral region (P < .001); by contrast, mean diffusivity, axial diffusivity, radial diffusivity and NQA values significantly increased towards the sacral region (P < .001).Fiber tractography of the LSP was feasible in all examined subjects and closely corresponded with the nerves visible in the maximum intensity projection images of MR neurography. Usage of NQA instead of FA in the proposed algorithm enabled better separation of muscle and nerve fibers.The presented algorithm yields a high quality reconstruction of the LSP bundles that may be helpful both in research and clinical practice.

Lumbar medial branch cryoneurolysis under ultrasound guidance: initial report of five cases

AIMS

To assess the feasibility and preliminary results of ultrasound guided medial branch cryoneurolysis in the management of facet joint syndrome.

MATERIAL AND METHODS

Between March 2017 and August 2017, a total of 20 patients underwent medial branch blocks, 12 of which were positive. Five patients chose to participate in the study and 8 medial branch cryoneurolysis were performed. The primary endpoint of the study was the feasibility of the procedure. The secondary endpoint was the efficacy on pain assessed over the following year after the procedure.

RESULTS

Technical feasibility of cryoneurolysis under ultrasound guidance was 100%. Accurate needle positioning at the accurate target in the angle between the posterior aspect of the transverse process and the lateral aspect of the facet joint was achieved in all cases. Needle progression could be depicted with US guidance in all cases. Mean pre-procedural Visual Analogue Scale and Oswestry disability Index scores were 6.8 (range 5-8) and 20.6 (range 12- 31), respectively. Follow up showed a decrease of Visual Analogue Scale score at one month (1.75, range 0-7), and at three months (1.75 range 0-3), Mean self-reported improvement at 6 months was 76% (60- 100%) and 77% at 12 months (50-100%). We report one case of failure at one month. No complications were noted during or after the procedure.

CONCLUSION

Our findings suggest that ultrasound is a valid imaging modality to perform lumbar medial branch cryoneurolysis. Initial results show that cryoneurolysis under ultrasound guidance appears as a safe and effective procedure in patients suffering for facet joint pain.

Optical recording reveals topological distribution of functionally classified colorectal afferent neurons in intact lumbosacral DRG

Neuromodulation as a non-drug alternative for managing visceral pain in irritable bowel syndrome (IBS) may target sensitized afferents of distal colon and rectum (colorectum), especially their somata in the dorsal root ganglion (DRG). Developing selective DRG stimulation to manage visceral pain requires knowledge of the topological distribution of colorectal afferent somata which are sparsely distributed in the DRG. Here, we implemented GCaMP6f to conduct high-throughput optical recordings of colorectal afferent activities in lumbosacral DRG, that is, optical electrophysiology. Using a mouse ex vivo preparation with distal colorectum and L5-S1 DRG in continuity, we recorded 791 colorectal afferents' responses to graded colorectal distension (15, 30, 40, and 60 mmHg) and/or luminal shear flow (20-30 mL/min), then functionally classified them into four mechanosensitive classes, and determined the topological distribution of their somata in the DRG. Of the 791 colorectal afferents, 90.8% were in the L6 DRG, 8.3% in the S1 DRG, and only 0.9% in the L5 DRG. L6 afferents had all four classes: 29% mucosal, 18.4% muscular-mucosal, 34% low-threshold (LT) muscular, and 18.2% high-threshold (HT) muscular afferents. S1 afferents only had three classes: 19.7% mucosal, 34.8% LT muscular, and 45.5% HT muscular afferents. All seven L5 afferents were HT muscular. In L6 DRG, somata of HT muscular afferents were clustered in the caudal region whereas somata of the other classes did not cluster in specific regions. Outcomes of this study can directly inform the design and improvement of next-generation neuromodulation devices that target the DRG to alleviate visceral pain in IBS patients.

Anatomical evaluation of lumbar nerves using diffusion tensor imaging and implications of lateral decubitus for lateral transpsoas approach

PURPOSE

Recently, lateral interbody fusion (LIF) has become more prevalent, and evaluation of lumbar nerves has taken on new importance. We report on the assessment of anatomical relationships between lumbar nerves and vertebral bodies using diffusion tensor imaging (DTI).

METHODS

Fifty patients with degenerative lumbar disease and ten healthy subjects underwent DTI. In patients with lumbar degenerative disease, we studied nerve courses with patients in the supine positions and with hips flexed. In healthy subjects, we evaluated nerve courses in three different positions: supine with hips flexed (the standard position for MRI); supine with hips extended; and the right lateral decubitus position with hips flexed. In conjunction with tractography from L3 to L5 using T2-weighted sagittal imaging, the vertebral body anteroposterior span was divided into four equally wide zones, with six total zones defined, including an anterior and a posterior zone (zone A, zones 1-4, zone P). We used this to characterize nerve courses at disc levels L3/4, L4/5, and L5/S1.

RESULTS

In patients with degenerative lumbar disease, in the supine position with hips flexed, all lumbar nerve roots were located posterior to the vertebral body centers in L3/4 and L4/5. In healthy individuals, the L3/4 nerve courses were displaced forward in hips extended compared with the standard position, whereas in the lateral decubitus position, the L4/5 and L5/S nerve courses were displaced posteriorly compared with the standard position.

CONCLUSIONS

The L3/4 and L4/5 nerve roots are located posterior to the vertebral body center. These were found to be offset to the rear when the hip is flexed or the lateral decubitus position is assumed. The present study is the first to elucidate changes in the course of the lumbar nerves as this varies by position. The lateral decubitus position or the position supine with hips flexed may be useful for avoiding nerve damage in a direct lateral transpsoas approach. Preoperative DTI seems to be useful in evaluating the lumbar nerve course as it relates anatomically to the vertebral body.

[Comorbid state in coal miners suffering from lumbosacral radiculopathy]

The authors considered topics of occupational and general comorbidity of occupational lumbosacral radiculopathy in coal miners (2791 examinees) observed over 1976-2014 in occupational center. In patients having lumbosacral radiculopathy without occupational mixed diseases, the occupational disease was diagnosed at the age 3-5 years younger, and 2-4 years earlier from primary visit. Analysis of occurrence of general comorbid conditions with lumbosacral radiculopathy revealed some regularities: patients manifested with symptoms due to vibration have more frequent arterial hypertension than in those with lumbalgia, whereas in risk group of hearing affected by noise IHD was more possible.

[The effects of sacral nerve root electrostimulation on the colon function and its mechanisms in a rat model of spinal cord injury]

OBJECTIVE

To study the effects of sacral nerve root electrostimulation (SNS) on the colon function and its mechanisms in rats with spinal cord injury (SCI).

METHODS

One hundred and four Wistar rats were divided into three groups: A, B and C. A group ( n = 24) was divided into three subgroups (n = 8) for studying the bioelectricity: Normal group (NG), SCI group (SCI) and SCI group with SNS(SNS); B group( n = 24) was divided into three subgroups( n = 8) for studying the colon motility: NG, SCI and SNS. C group( n = 56) were divided into three groups for studying the change of morphology and neurotransmitters(SP and VIP): NG (n = 8), SCI (n = 24), and SNS (n = 24) . In SCI and SNS, included of three subgroups: 24, 48, 72 h after spinal cord injury (n = 8).

RESULTS

In SCI group, the activity of bioelectricity in proximal and distal colon was reduced; the colon motility was lessened, and colon mucosa appeared different degree of damage; cell-cell connections between intestinal epithelial cells were destroyed. The expressions of substance P(SP) and vasoactive intestinal peptide (VIP) in colon were decreased obviously. SNS was found to activate the bioelectricity, promote the colon motility, improve the intestinal mucosal, and increase the expressions of SP and VIP. Conclusion: SNS can activate the peristalsis, rehabilitate the motility of denervated colon, protection of the intestinal mechanical barrier between intestinal epithelial cells and tight junction, rebuild the colon function through activating the bioelectricity and increase the expressions of SP and VIP.

Effects of sacral nerve stimulation on postpartum urinary retention-related changes in rat bladder

OBJECTIVE

To examine the effect of sacral nerve stimulation (SNS) on the urodynamic function and molecular structure of bladders in rats following acute urinary retention (AUR) after parturition.

MATERIAL AND METHODS

Thirty primiparous rats were divided into three groups: postpartum, postpartum+AUR, and postpartum+AUR+SNS. AUR was achieved by clamping the distal urethra of a rat for 60 minutes. The postpartum+AUR+SNS group received electrical stimulation 60 minutes daily for 3 days after AUR. In addition to cystometric studies and external urethral sphincter electromyography, the expression of caveolins and nerve growth factor (NGF) and caveolae number in bladder muscle were analyzed.

RESULTS

The postpartum+AUR group has significantly greater residual volume than the postpartum group, but the residual volume decreased significantly after SNS treatment. The postpartum+AUR group had significantly lower peak voiding pressure, a longer bursting period and lower amplitude of electromyograms of external urethral sphincter activity than the postpartum and postpartum+AUR+SNS groups. The postpartum+AUR rats had higher NGF expression, lower caveolin-1 expression, and fewer caveolae in bladder muscle compared with the postpartum rats. Conversely, the caveolin-1 expression and caveolae number increased, and the NGF expression decreased after SNS treatment.

CONCLUSION

Bladder dysfunction after parturition in a rat model caused by AUR may be restored to the non-AUR structural and functional level after SNS treatment.

[THE APPLICATION OF ANTIHOMOTOXIC DRUG PREPARATIONS IN THE COMPLEX TREATMENT IN PATIENTS WITH NEUROLOGICAL MANIFESTATIONS OF LUMBAR OSTEOCHONDROSIS]

The expediency of application homeosyniatry by preparations of Traumel S and Placenta Compositum after the offered chart in relation to a complex with classic acupuncture and in relation to the group of the generally accepted treatment has been proved in complex treatment patients with reflex syndromes of lumbar osteochondrosis. A similar conclusion was done after the statistically reliable (P < 0.05) dynamics of parameters of endogenous intoxication, liperoxydation and antioxydant systems of the protection (by the level of katalase, superoxyddismutase, SH-groups, ceruloplasmine).

Similarities and differences in cervical and thoracolumbar multisegmental motor responses and the combined use for testing spinal circuitries

STUDY DESIGN

Experimental study.

OBJECTIVE

To determine similarities and differences of C7 and T11-12 multisegmental motor responses (MMR) studies for the upper limbs (UL) and lower limbs (LL).

SETTINGS

Neuroscience Lab, TWU (School of Physical Therapy, TX, USA).

METHODS

C7 and T11-12 percutaneous electrical stimulations were applied while recording muscle action potentials from ULs and LLs.

RESULTS

The procedure of cervical MMR (CMMR) was easier in application than thoracolumbar MMR (TMMR), requiring less current intensities but cause more "jolts" in the trapezius/shoulder complex, due to close proximity of the stimulation electrodes. CMMR evoked large amplitude motor responses in the millivolts range in (UL) muscles, but smaller amplitude signal in (LL) muscles (in microvolts). TMMR evoked large amplitude motor responses in both UL and LL (in millivolts). The MMR amplitude was generally larger in the UL as compared to the LL, in the distal limb muscles more than in the proximal limb muscles. CMMR and TMMR for the UL were comparable in amplitude, latencies and action potential shapes. Signal latencies were longer for distal limb muscles as compared to proximal limb muscles and were slightly longer for LL as compared to UL muscles. MMR signals were either biphasic or triphasic in shape.

CONCLUSION

CMMR and TMMR have similarities and differences in the methods and recording signal that must be considered during its clinical applications. Comparing the signal of the UL muscles with CMMR and TMMR could be a useful test for the integrity of the ascending and descending spinal pathways in patients with spinal cord injuries and diseases.

[Subpopulation of calbindin-immunoreactive interneurons in the dorsal horn of the mice spinal cord]

In the dorsal horn of the spinal cord in the plates I-IV on the thoracic and lumbar levels different subpopulations of interneurons immunoreactive for calbindin 28 kDa (CAB IR), which are specific to each plate. In the area of the medial edge of the dorsal horn, we have found a special subpopulation of CAB IR interneurons whose morphometric characteristics differ from CAB IR interneurons subpopulations of said plates. The number of CAB IR interneurons was maximal in the plate II at all levels of the spinal cord. Leveled differences are more CAB IR interneurons and larger area of the cross sections at the lumbar level.

The effect of lumbar sympathetic ganglion block on gynecologic cancer-related lymphedema

BACKGROUND

Eighteen to 25% of patients after gynecological cancer treatment suffer from lower limb lymphedema (LLL) that decreases the quality of life of gynecological cancer survivors. Lumbar sympathetic ganglion block (LSGB) is widely used in practice for the evaluation and management of sympathetically mediated pain in the lower limbs. Several articles have suggested that sympathetic ganglion block could be an effective treatment for lymphedema.

OBJECTIVES

To investigate the effect of LSGB on patients with secondary lymphedema related to the treatment of gynecologic cancer, who do not respond to a conservative treatment.

STUDY DESIGN

Prospective clinical study.

SETTING

A single academic medical center, outpatient setting.

METHODS

Eighteen patients with stage II lower limb lymphedema who did not response to the conservative treatment were recruited. The patients underwent fluoroscopy-guided LSGB 3 times at 2-week intervals. The circumference of the thigh and calf was measured in the upright position at the first visit and 2 weeks after each session of LSGB. The pain score of the lower limb was checked at the same time by a numeric rating scale (NRS) from 0 to 10. The patients were asked about their satisfaction with the procedure at the last follow-up visit. The Wilcoxon signed rank test was used for data analysis. Significance was accepted at a P-value less than 0.05/3.

RESULTS

The circumferences of affected thighs and calves decreased from 56.38 ± 4.77 and 35.33 ± 3.51 cm to 54.42 ± 5.27 and 34.41 ± 3.35 cm, respectively, in a significant manner after 3 consecutive LSGBs (P < 0.05/3). The maximal decrease after the third LSGB was 4 cm in the thigh and 2 cm in the calf. The pain score also showed a significant decrease after 3 consecutive LSGBs from 2.17 to 1.28. The tightness and heaviness of the affected limb decreased after the first LSGB in 15 patients (83.3%) and after the second LSGB in 2 patients (11.1%). Five of 18 patients (27.8%) answered that the result of the LSGB met their expectations, 10 (55.6%) answered they would undergo the same treatment for the same outcome, 2 (11.1%) answered they did not improve as much as they had hoped, and they would not undergo the same treatment for the same outcome, and only one patient (5.6%) answered the LSGB showed no effect.

LIMITATIONS

This study lacks a placebo control group and has only 18 patients. We did not evaluate the quality of life of the patients.

CONCLUSION

We suggest that LSGB can be one of the treatment options for patients suffering from LLL after gynecologic cancer treatment. Our result could provide a basis for a randomized controlled trial in future investigations. The pain physicians can play an important role as one of the multidisciplinary team for a comprehensive treatment of LLL.

[Study on the area of pain and numbness in cases with lumbosacral radiculopathy]

In the clinical diagnosis of lumbosacral radicular symptoms, dermatome maps are commonly used, by which the segmental location of the affected nerve can be determined. However, the diagnosis is often difficult because the pattern of sensory disturbance does not necessarily match the patterns of classical dermatomes, and there are many dermatome maps made by different methods. The author examined the area of pain and numbness in cases of lumbosacral radiculopathy. Clinical features of pain and numbness in consecutive seventy three cases of lumbosacral radiculopathy were investigated (L3: n=13, L4-S1: n=20). Patients of L3 radiculopathy showed symptoms at the upper buttock and ventral surface of the thighs, knees and upper ventral surface of the legs. Patients of L4 radiculopathy showed symptoms at the ventro-lateral surfaces of the thigh and leg. The distinctive region, defined as the region having 100% superimposition, of L4 radiculopathy was the lateral part of the shin. Patients of L5 radiculopathy showed symptoms at the lateral surfaces of the thigh and leg. The distinctive region was the upper buttock. Patients of S1 radiculopathy showed symptoms at the lower buttock, dorso-lateral part of the leg and lateral part of the foot. The distinctive region was the lateral part of the calf. It was found that the regions of pain and numbness formed a continuous band-like zone from thigh to leg in 8% of L3, 45% of L4 and L5, and 35% of S1 radiculopathy. Using a visual analogue scale, the degree of leg pain was more severe than low back pain in 68% of the patients, but in 5% of patients, low back pain was more severe.

[Correlation study on effects of electroacupuncture on the muscle condition and MNCV in rabbits with lumbar nerve root compression]

OBJECTIVE

To observe the effects of electroacupuncture on the muscle condition and electrophysiology of the muscle in rabbits with lumbar nerve root compression and to explore potential mechanisms.

METHODS

Twenty-four New Zealand white rabbits were randomly divided into a normal group, a model group, a medication group and an electroacupuncture group. The rabbit model with lumbar nerve root compression was established in the model group, the medication group and the electroacupuncture group. The model and the treatment were not produced in the normal group. The medication group was treated with oral administration of Loxoprofen tablets at a dose of 30 mg each day for 14 days. The electroacupuncture group was treated with electroacupuncture at "Jiaji" (EX-B 2) of L5 and L6 for 14 days. The hibateral muscle condition before and after making model and after treatment was detected and the electromyogram and the nerve conduction velocity (NCV) were observed.

RESULTS

The spontaneous potential and the insertion potential were increased in the model group, the medication group and the electroacupuncture group after making model. The value of the activation and the relaxed condition of the strength-creep (ARCSC) in the right muscle was significantly decreased. The motor nerve conduction velocity (MNCV) and the wave amplitude of evoked potential (WAEP) were significantly decreased in the model group, the medication group and the electroacupuncture group after treatment, but the value of MNCV and WAEP in the electroacupuncture group, and ARCSC in the right muscle in the electroacupuncture group and the medicine group were closed to those level in the normal group, among them, the relaxed condition in the electroacupuncture group was more close to the level in the normal group.

CONCLUSION

Electroacupuncture can improve the strength-creep condition of the muscle that damage nerve place controls and the electrophysiology of the muscle can recover the MNCV and the wave amplitude of evoked potential in the compression nerve root.

Can the human lumbar posterior columns be stimulated by transcutaneous spinal cord stimulation? A modeling study

Stimulation of different spinal cord segments in humans is a widely developed clinical practice for modification of pain, altered sensation, and movement. The human lumbar cord has become a target for modification of motor control by epidural and, more recently, by transcutaneous spinal cord stimulation. Posterior columns of the lumbar spinal cord represent a vertical system of axons and when activated can add other inputs to the motor control of the spinal cord than stimulated posterior roots. We used a detailed three-dimensional volume conductor model of the torso and the McIntyre-Richard-Grill axon model to calculate the thresholds of axons within the posterior columns in response to transcutaneous lumbar spinal cord stimulation. Superficially located large-diameter posterior column fibers with multiple collaterals have a threshold of 45.4 V, three times higher than posterior root fibers (14.1 V). With the stimulation strength needed to activate posterior column axons, posterior root fibers of large and small diameters as well as anterior root fibers are coactivated. The reported results inform on these threshold differences, when stimulation is applied to the posterior structures of the lumbar cord at intensities above the threshold of large-diameter posterior root fibers.

Evaluation of lumbosacral nerve root conduction in chickens by electrophysiological testing including high-resolution spinal magnetic stimulation

The value of avian models in peripheral nerve research recently became substantiated by the immunobiological similarity of avian inflammatory demyelinating polyradiculoneuropathy to human Guillain-Barré syndrome providing an alternative animal model for experimental autoimmune neuritis. As electrophysiologic evaluation of nerve roots is essential part of the diagnosis of polyradiculoneuropathies in humans, it would be favourable to have similar research methods available for juvenile chickens. Hence, this study was performed (1) to establish a tool-set that allows for reproducible evaluation of the tibial/sciatic nerve and its nerve roots, (2) to achieve age-matched reference values, and (3) to trace the kinetics of peripheral nerve maturation within chickens. Nine chickens underwent serial electrodiagnostic examinations between the age of 6 and 15 weeks. Several methods of sensory and motor nerve fiber stimulation of the tibial/sciatic nerve were tested and modified or established. Ultimately, scalp-recorded somatosensory evoked potentials, compound muscle action potentials elicited by tibial/sciatic nerve electrical as well as spinal magnetic stimulation and motor nerve conduction velocity were available for tibial/sciatic nerve and nerve root evaluation in chickens. Base values were obtained for all investigations and parameters. Results indicated that the maturation of the nerve fibers is incomplete up to the age of 15 weeks. The methods tested here provide an excellent tool-set for quantitative tibial/sciatic nerve and nerve root assessment in avian polyradiculoneuropathies, especially within the scope of longitudinal monitoring of the disease course.

[Effect of electroacupuncture on expression of ionotropic glutamate receptor subunits and their genes in lumbar segments of spinal cord in rats with neuropathic pain]

OBJECTIVE

To observe the effect of electroacupuncture (EA) on the expression of ionotropic glutamate receptor (iGluR) subunits and their mRNAs in the lumbar segments of spinal cord in rats with neuropathic pain, so as to explore its underlying mechanism in relieving spinal hyperalgesia.

METHODS

Thirty SD rats were randomly divided into control, model, and EA groups, with 10 rats in each. The spared nerve injury (SNI) model was established by ligature of the sural nerve after cutting off the common peroneal nerve and anterior tibial nerve. EA (2 Hz, 1 mA) was applied to "Huantiao" (GB 30) and "Weizhong" (BL 40) for 30 min, once daily for 7 days. Mechanical pain threshold was detected before and after modeling and before and after EA treatment. The expression levels of N-methyl-d-aspartic acid (NMDA) receptor subunits NR1 and NR 2 B,and AMPA receptor subunit GluR 1 of iGluR and their genes were assayed by Western blot and reverse transcription polymerase chain reaction (RT-PCR) separately.

RESULTS

In comparison with control group, the mechanical pain thresholds were decreased significantly on day 2, 7 and day 14 following modeling in the model group (P < 0.05, P < 0.01). While compared with the model group, the pain threshold was increased considerably on day 14 in the EA group (P < 0.01). Compared with the control group, the expression levels of lumbar spinal cord NR 2 B and NR 2 B mRNA in the model group were increased significantly (P < 0.05), and those of lumbar spinal cord NR 1 and NR 1 mRNA, GluR 1 and GluR 1 mRNA in the model group increased slightly (P > 0.05). In comparison with the model group, the expression levels of lumbar spinal cord NR 2 B and NR 2 B mRNA in the EA group were downregulated remarkably (P < 0.05), and those of lumbar spinal cord NR 1 and NR 1 mRNA, GluR 1 and GluR 1 mRNA in the EA group down-regulated slightly (P > 0.05).

CONCLUSION

EA can significantly suppress pain reaction in rats with neuropathic pain probably through down-regulating the expression of lumbar spinal cord NR 2 B protein and NR 2 B mRNA.

[Case of Charcot-Marie-Tooth disease type 1A with increased cerebrospinal fluid proteins and nerve root hypertrophy]

We report herein a 54-year-old man who first noticed muscle weakness of the hands and legs and hypesthesia of the legs at 20-years-old. Symptoms gradually worsened. Charcot-Marie-Tooth disease type 1A (CMT 1A) was diagnosed on the basis of a nerve conduction study and PMP22 gene duplication. Increased levels of cerebrospinal fluid proteins were identified and cervical and lumbosacral nerve root hypertrophy was evident on magnetic resonance imaging (MRI). CMT 1A with increased CSF proteins and nerve root hypertrophy was carefully evaluated clinically and electrophysiologically to rule out other motor sensory neuropathies such as CIDP. Increased levels of CSF proteins in this case might have resulted from circulatory disturbance of CSF in hypertrophic nerve roots.

The nerve supply of the lumbar intervertebral disc

The anatomical studies, basic to our understanding of lumbar spine innervation through the sinu-vertebral nerves, are reviewed. Research in the 1980s suggested that pain sensation was conducted in part via the sympathetic system. These sensory pathways have now been clarified using sophisticated experimental and histochemical techniques confirming a dual pattern. One route enters the adjacent dorsal root segmentally, whereas the other supply is non-segmental ascending through the paravertebral sympathetic chain with re-entry through the thoracolumbar white rami communicantes. Sensory nerve endings in the degenerative lumbar disc penetrate deep into the disrupted nucleus pulposus, insensitive in the normal lumbar spine. Complex as well as free nerve endings would appear to contribute to pain transmission. The nature and mechanism of discogenic pain is still speculative but there is growing evidence to support a 'visceral pain' hypothesis, unique in the muscloskeletal system. This mechanism is open to 'peripheral sensitisation' and possibly 'central sensitisation' as a potential cause of chronic back pain.

[Effects of linear polarized light irradiation around the lumbar sympathetic ganglion area upon the skin temperature of lower extremities]

BACKGROUND

The effect of linear polarized light irradiation around the lumbar sympathetic ganglion area upon the skin temperature of legs may be similar to that of irradiation of near stellate ganglion area upon arms.

METHODS

Linear polarized light irradiation was induced with SUPER LIZER (Tokyo Iken, Tokyo, Japan). The C probe of SUPER LIZER was placed on the left side of the supine at the level of L2.

RESULTS

Seven-minute irradiation around the lumbar sympathetic ganglion area increased significantly the skin temperature of the irradiated side leg.

CONCLUSIONS

These results suggest that linear polarized light irradiation around the lumbar sympathetic ganglion area might be useful and beneficial for clinical application.

Spinal projection of spindle afferents of the longissimus lumborum muscles of the cat

The connections and monosynaptic projections of muscle spindle afferents of individual heads of the longissimus lumborum have been studied in cats by natural stimulation, by electrical stimulation and by spike-triggered averaging from single identified afferents. The spindle afferents were classified by sensitivity to vibration and by the effect of succinylcholine on their response to ramp-and-hold muscle stretches. Axonal conduction and synaptic effects were recorded as field potentials and focal synaptic potentials during systematic exploration of the spinal cord in segments L1 to L4 with extracellular metal microelectrodes, singly and in linear arrays. Ascending branches of afferent axons within the cord had a significantly higher mean conduction velocity (CV: 56.5 m s(-1)) than descending branches (40.8 m s(-1)). The CV of ascending branches was significantly positively correlated with a measure of the strength of intrafusal bag(2) muscle fibre contacts, but not to a measure of bag(1) contacts. Two sites of monosynaptic excitatory projection in the cord were identified, namely to the intermediate region (laminae V, VI and VII) and to ventral horn region (laminae VIII and IX). In tests of 154 single afferents, signs of central projection were detected for 60, providing 122 regions of maximum negative focal synaptic potentials (FSPs) of mean amplitude 7.51 microV. Their longitudinal spacing indicated that axons gave off descending collaterals at intervals of 1.5-3.5 mm. Based on the amplitude of FSPs, the projection of secondary afferents is stronger than that of primaries in the intermediate region and possibly also in the ventral horn region. Evidence is also presented that spindle afferent input from different heads of the longissimus converges into any given spinal segment and that input in one spinal root projects to adjacent segments. It is concluded that the organization of the longissimus monosynaptic spindle input favours relatively tonic and diffuse stretch reflexes.