In Vitro Biomechanical Study of Epidural Pressure during the Z-shape Elevating-Pulling Reduction Technique for Cervical Unilateral Locked Facets

Objective: To analyze the mechanism of the halo vest-assisted Z-shape elevating-pulling reduction technique for cervical unilateral locked facets, and confirm the safety of the spinal cord under the epidural pressure that occurs during the reduction process. Methods: Eleven osteoligamentous whole coronal and cervical spine specimens were established as skull-neck-thorax models of cervical unilateral locked facets at the C5/6 level. The halo vest-assisted Z-shape elevating-pulling reduction technique was then applied to reduce the locked facets. The changes in the epidural pressure in five cervical positions (cervical physiological curvature, cervical lateral bending, cervical unilateral locked facets, cervical unilateral perched facets, and reduction) were measured by a pressure sensor during the reduction procedure. The models simultaneously underwent multi-angle radiographic examination and CT scanning. Results: Successful closed reduction was achieved via the halo vest-assisted Z-shape elevating-pulling reduction technique in all 11 models. The epidural pressure in the cervical unilateral locked facets position was significantly higher than that in the other four cervical positions (P < 0.005). There was no significant difference in the epidural pressures measured during cervical lateral bending, cervical unilateral perched facets, and reduction. Conclusions: Maximum epidural pressures were measured in the position of cervical unilateral locked facets. The halo vest-assisted Z-shape elevating-pulling reduction technique achieved spinal decompression without causing secondary spinal cord injury. The halo vest-assisted Z-shape elevating-pulling reduction technique is safe and effective, and has a high success rate of reduction.

Motor Control After Human SCI Through Activation of Muscle Synergies Under Spinal Cord Stimulation

Spinal cord stimulation (SCS) has enabled motor recovery in paraplegics with motor complete spinal cord injury (SCI). However, the physiological mechanisms underlying this recovery are unknown. This paper analyzes muscle synergies in two motor complete SCI patients under SCS during standing and compares them with muscle synergies in healthy subjects, in order to help elucidate the mechanisms that enable motor control through SCS. One challenge is that standard muscle synergy extraction algorithms, such as non-negative matrix factorization (NMF), fail when applied to SCI patients under SCS. We develop a new algorithm-rShiftNMF-to extract muscle synergies in these cases. We find muscle synergies extracted by rShiftNMF are significantly better at interpreting electromyography (EMG) activity, and resulting synergy features are more physiologically meaningful. By analyzing muscle synergies from SCI patients and healthy subjects, we find that: 1) SCI patients rely significantly on muscle synergy activation to generate motor activity; 2) interleaving SCS can selectively activate an additional muscle synergy that is critical to SCI standing; and 3) muscle synergies extracted from SCI patients under SCS differ substantially from those extracted from healthy subjects. We provide evidence that after spinal cord injury, SCS influences motor function through muscle synergy activation.

Abdominal girth has a strong correlation with ultrasound-estimated epidural depth in parturients: a prospective observational study

BACKGROUND

Preprocedural ultrasound examination of vertebral column guides to locate desired intervertebral space and provides a prevision of needle trajectory and estimated needle depth in parturients. The objective of this study was to assess the correlation between ultrasound-estimated epidural depth (ED) with abdominal girth (AG), body mass index (BMI), weight, height, and age.

METHODS

In this prospective, observational study, ultrasound imaging was done at L3-4 interspace in transverse median plane (TP) and paramedian sagittal oblique plane (PSO) to obtain ultrasound estimates of skin to epidural space depth. Combined spinal epidural anesthesia was performed at L3-4 interspace. AG, BMI, age, height, and weight were recorded for every parturient.

RESULTS

Data from 130 parturients were analyzed. Estimated ED was 56.5 ± 9.5 mm in TP, 57.5 ± 9.3 mm in PSO, and actual epidural depth was 57.9 ± 9.4 mm. Correlation coefficients between ED and AG were 0.797 in TP (95% CI 0.727-0.854, p < 0.001) and 0.803 in PSO (95% CI 0.733-0.857, p < 0.001). Correlation coefficients between ED and BMI were 0.543 in TP (95% CI 0.405-0.661, p < 0.001) and 0.566 in PSO (95% CI 0.428-0.680, p < 0.001). Correlation coefficients between ED and weight were 0.593 in TP (CI = 0.466-0.695, p < 0.001) and 0.615 in PSO (CI = 0.500-0.716, p < 0.001). Height and age had no significant correlation with ED.

CONCLUSIONS

Abdominal girth has a strong correlation with ultrasound-estimated epidural depth in parturients.

Optically Guided Epidural Needle Placement Using 405-nm Wavelength for Accurate Puncture

Several approaches of locating the epidural space have been proposed. However, loss of Resistance method (LOR) remains the most common method for epidural anesthesia. Different optical signals were received from the ligamentum flavum and the epidural space allows operator to pinpoint position of the needle and determine whether the needle tip has entered the epidural space. Optical signals throughout the penetration process was recorded and position of needle tip was confirmed with a C-arm fluoroscopy. 60 lumbar punctures were performed in 20 vivo porcine models, and success rate of locating the epidural space with the optical auxiliary is calculated statistically. The data are expressed in mean ± SD. During all the lumber puncture processes, the strength of optical signals received decreased significantly while the needle tip penetrates the ligamentum flavum and entered the epidural space. The strength of optical signal received when needle tip was in the ligamentum flavum was 1.38 ± 0.57. The signal strength at epidural space was 0.46 ± 0.35. Strength of signal decreased by 67% when entered epidural space, and there is no significant differences in decrease of strength from data obtained from thevertebrae (lumbar segments)L2-L3, L3-L4, and L4-L5. Finally, we calculated with assistance of the proposed optical auxiliary, the success rate for guiding the needle tip to the epidural space using was as high as 87%. It is evidently believed that the optical auxiliary equipped is visualized to assist operators inserting needle accurately and efficiently into epidural space during epidural anesthesia operation.

Epidural electrical stimulation test versus local anesthetic test dose for thoracic epidural catheter placement: a prospective observational study

PURPOSE

This study examined the concordance between epidural electrical stimulation test (EEST) and local anesthetic (LA) test dose to indicate correct thoracic epidural catheter position. The relationship between the test results and epidural postoperative analgesia was also assessed.

METHODS

This prospective observational cohort study was done in patients receiving thoracic epidural analgesia for abdominal surgery. After insertion, the epidural catheter was tested using a nerve stimulator to elicit a motor response. The LA test dose was then administered, and sensory block to ice and pinprick was assessed. The primary outcome was the presence/absence of motor response to EEST and sensory block to test dose. Concordance of responses was assessed using kappa statistics, and their predictive power of postoperative epidural analgesia was evaluated.

RESULTS

Sixty-eight thoracic epidural catheters were inserted, of which 62 were used perioperatively. The kappa agreement between EEST and LA test dose responses was moderate at 0.42 (95% confidence interval [CI], 0.18 to 0.67). Positive responses to EEST and LA test dose were observed in 62 (100%) and 50 (81%) patients, respectively, while 52 patients (84%) showed adequate analgesia postoperatively. The sensitivity (95% CI) of EEST and LA test dose to predict adequate postoperative epidural analgesia was 1 (0.93 to 1) and 0.79 (0.65 to 0.89), respectively, and the positive predictive values (95% CI) of EEST and LA test dose were 0.84 (0.75 to 0.93) and 0.82 (0.71 to 0.92), respectively.

CONCLUSION

Following thoracic epidural catheter insertion, the responses to the EEST and LA test dose showed "moderate" agreement. The EEST has a higher sensitivity than the LA test dose to predict adequate epidural analgesia following abdominal surgery, however, both tests have a comparable positive predictive value.

Inadvertent epidural anesthesia associated with catheterization following continuous psoas compartment block in a patient with scoliosis: A Case report

RATIONALE

Psoas compartment block (PCB) is typically performed using surface anatomical landmarks and neurostimulation for guidance. However, anatomical anomalies, such as scoliosis, make this technique unreliable, posing a challenge for the anesthesiologist when inducing regional anesthesia.

PATIENT CONCERNS

A 69-year-old woman with lumbar scoliosis scheduled for total hip arthroplasty underwent PCB with catheterization.

DIAGNOSES

Inadvertent epidural anesthesia with catheterization following PCB was diagnosed using a lumbar radiograph.

INTERVENTIONS

Due to hypotension induced by local anesthetic (LA) epidural diffusion, the patient received intravenous hydration and vasopressor. Since bilateral sensory block was noted at the T3 level, with an incomplete motor blockade in both legs, the surgery was performed under epidural anesthesia.

OUTCOMES

The patient remained hemodynamically stable throughout the duration of the surgical procedure. The surgery was uneventful and without further complications.

LESSONS

Patients with lumbar scoliosis are highly at risk of LA epidural diffusion, following PCB using traditional landmark-based approach. Other nerve-localizing technique can minimize the risk of this complication.

Long-term recording reliability of liquid crystal polymer µECoG arrays

OBJECTIVE

The clinical use of microsignals recorded over broad cortical regions is largely limited by the chronic reliability of the implanted interfaces.

APPROACH

We evaluated the chronic reliability of novel 61-channel micro-electrocorticographic (µECoG) arrays in rats chronically implanted for over one year and using accelerated aging. Devices were encapsulated with polyimide (PI) or liquid crystal polymer (LCP), and fabricated using commercial manufacturing processes. In vitro failure modes and predicted lifetimes were determined from accelerated soak testing. Successful designs were implanted epidurally over the rodent auditory cortex. Trends in baseline signal level, evoked responses and decoding performance were reported for over one year of implantation.

MAIN RESULTS

Devices fabricated with LCP consistently had longer in vitro lifetimes than PI encapsulation. Our accelerated aging results predicted device integrity beyond 3.4 years. Five implanted arrays showed stable performance over the entire implantation period (247-435 d). Our regression analysis showed that impedance predicted signal quality and information content only in the first 31 d of recordings and had little predictive value in the chronic phase (>31 d). In the chronic phase, site impedances slightly decreased yet decoding performance became statistically uncorrelated with impedance. We also employed an improved statistical model of spatial variation to measure sensitivity to locally varying fields, which is typically concealed in standard signal power calculations.

SIGNIFICANCE

These findings show that µECoG arrays can reliably perform in chronic applications in vivo for over one year, which facilitates the development of a high-density, clinically viable interface.

Recovery of Over-Ground Walking after Chronic Motor Complete Spinal Cord Injury

Persons with motor complete spinal cord injury, signifying no voluntary movement or sphincter function below the level of injury but including retention of some sensation, do not recover independent walking. We tested intense locomotor treadmill training with weight support and simultaneous spinal cord epidural stimulation in four patients 2.5 to 3.3 years after traumatic spinal injury and after failure to improve with locomotor training alone. Two patients, one with damage to the mid-cervical region and one with damage to the high-thoracic region, achieved over-ground walking (not on a treadmill) after 278 sessions of epidural stimulation and gait training over a period of 85 weeks and 81 sessions over a period of 15 weeks, respectively, and all four achieved independent standing and trunk stability. One patient had a hip fracture during training. (Funded by the Leona M. and Harry B. Helmsley Charitable Trust and others; ClinicalTrials.gov number, NCT02339233 .).

A Case of Epidural Lipomatosis in Pregnancy: Management during Labour and Caesarean Section

BACKGROUND

Spinal epidural lipomatosis (SEL) is a rare condition of adipose tissue accumulation in the epidural space. As a result of excess adipose tissue, neuraxial anaesthesia has been reported to behave unpredictably in patients with this condition.

CASE

A 36-year-old woman had worsening postural headaches during pregnancy. MRI revealed SEL involving the thecal sac between L3/L4 and L5/S1. She had induction of labour but ultimately required a CS for delivery. Her anaesthesia was managed with an epidural inserted at L3/4. She developed a high block with relative sacral sparing.

CONCLUSION

Although neuraxial anaesthesia was thought to be contraindicated in patients with SEL, it can be done safely. Care must be taken to provide slow epidural titration to avoid high sensory block in patients with this condition.

Epidural Electrotherapy for Epilepsy

Penetrating electronics have been used for treating epilepsy, yet their therapeutic effects are debated largely due to the lack of a large-scale, real-time, and safe recording/stimulation. Here, the proposed technology integrates ultrathin epidural electronics into an electrocorticography array, therein simultaneously sampling brain signals in a large area for diagnostic purposes and delivering electrical pulses for treatment. The system is empirically tested to record the ictal-like activities of the thalamocortical network in vitro and in vivo using the epidural electronics. Also, it is newly demonstrated that the electronics selectively diminish epileptiform activities, but not normal signal transduction, in live animals. It is proposed that this technology heralds a new generation of diagnostic and therapeutic brain-machine interfaces. Such an electronic system can be applicable for several brain diseases such as tinnitus, Parkinson's disease, Huntington's disease, depression, and schizophrenia.

Smart Optical Catheters for Epidurals

Placing the needle inside the epidural space for locoregional anesthesia is a challenging procedure, which even today is left to the expertise of the operator. Recently, we have demonstrated that the use of optically sensorized needles significantly improves the effectiveness of this procedure. Here, we propose an optimized configuration, where the optical fiber strain sensor is directly integrated inside the epidural catheter. The new design allows the solving of the biocompatibility issues and increases the versatility of the former configuration. Through an in vivo study carried out on a porcine model, we confirm the reliability of our approach, which also opens the way to catheter monitoring during insertion inside biological spaces.

Ex vivo animal-model assessment of a non-invasive system for loss of resistance detection during epidural blockade

During recent decades epidural analgesia has gained widespread recognition in many applications. In this complex procedure, anaesthetist uses a specific needle to inject anesthetic into the epidural space. It is crucial the appropriate insertion of the needle through inhomogeneous tissues placed between the skin and the epidural space to minimize anesthetic-related complications (e.g., nausea, headache, and dural puncture). Usually, anaesthetists perform the procedure without any supporting tools, and stop pushing the syringe when they sense a loss of resistance (LOR). This phenomenon is caused by the physical properties of the epidural space: the needle breaks the ligamentum flavum and reaches the epidural space, in this stage the anaesthetist perceives a LOR because the epidural space is much softer than the ligamentum flavum. To support the clinician in this maneuver we designed a non-invasive system able to detect the LOR by measuring the pressure exerted on the syringe plunger to push the needle up to the epidural space. In a previous work we described the system and its assessment during in vitro tests. This work aims at assessing the feasibility of the system for LOR detection on a more realistic model (ex vivo pig model). The system was assessed by analyzing: its ability to hold a constant value (saturation condition) during the insertion of the needle, and its ability to detect the entrance within the epidural space by a decrease of the system's output. Lastly, the anaesthetist was asked to assess how the ex vivo procedure mimics a clinical scenario. The system reached the saturation condition during the needle insertion; this feature is critical to avoid false positive during the procedure. However, it was not easy to detect the entrance within the epidural space due to its small volume in the animal model. Lastly, the practitioner found real the model, and performed the procedures in a conventional manner because the system did not influence his actions.

A hybrid, low-cost tissue-like epidural needle insertion simulator

Epidural and spinal anesthesia are mostly performed "blind" without any medical imaging. Currently, training of these procedures is performed on human specimens, virtual reality systems, manikins and mostly in clinical practice supervised by a professional. In this study a novel hybrid, low-cost patient simulator for the training of needle insertion into the epidural space was designed. The patient phantom provides a realistic force feedback comparable with biological tissue and enables sensing of the needle tip position during insertion. A display delivers the trainee a real-time feedback of the needle tip position.

A screening method to distinguish syndromic from sporadic spinal extradural arachnoid cyst

BACKGROUND

Spinal extradural arachnoid cyst (SEDAC) is a cystic lesion that protrudes into the epidural space from a small dural defect. Early diagnosis of SEDAC is important because its expansion causes neurological damage. Two types of SEDAC, syndromic and sporadic, are present. Syndromic SEDAC is inherited as a part of lymphedema-distichiasis syndrome caused by mutations in the FOXC2 gene; however, it is often mistaken as sporadic because of low penetrance. It is not reasonable to conduct a genetic testing for all SEDAC patients and their family members. The aim of this study is to establish an effective screening method to distinguish syndromic SEDAC from sporadic SEDAC.

METHODS

We performed a retrospective review of medical records and imaging studies of 29 subjects who were diagnosed with SEDAC. Clinical features, family history and magnetic resonance imaging (MRI) were analyzed. Mutations in FOXC2 were examined by Sanger-sequencing of the entire coding region of the genes. SEDAC having a mutation in FOXC2 gene was defined with syndromic SEDAC.

RESULTS

Eleven subjects had a heterozygous mutation in FOXC2. They were all familial and hence syndromic SEDAC. Only one proband had known family history of SEDAC at diagnosis. MRI findings and physical examinations, especially eye and leg examinations, were quite useful to screen syndromic SEDAC. Physical examination often showed accompanying lymphedema and distichiasis in syndromic SEDAC. Syndromic SEDAC tended to have multiple cysts out of the thoracolumbar area.

CONCLUSIONS

We established an effective screening method based on physical examinations and MRI findings.

The Effect of Caudal Epidural Pulsed Radiofrequency Stimulation in Patients with Refractory Chronic Idiopathic Axonal Polyneuropathy

BACKGROUND

Many patients with chronic idiopathic axonal polyneuropathy (CIAP) suffer from neuropathic pain, which is managed using several oral medications and modalities. However, despite these treatments, pain persists in some patients.

OBJECTIVE

In the clinical field, clinicians frequently meet patients with neuropathic pain caused by CIAP. The authors investigated the effect of caudal epidural pulsed radiofrequency (PRF) for the management of CIAP-induced refractory neuropathic pain.

STUDY DESIGN

This is a prospective study.

SETTING

The outpatient clinic of a single academic medical center in KoreaMETHODS: Twenty patients with neuropathic pain and a diagnosis of refractory CIAP were recruited. For PRF stimulation, a 22-gauge cannula was inserted into the epidural space through the sacral hiatus under fluoroscopic guidance. PRF stimulation was administered once at 5 Hz with a 5-ms pulse width for 600 seconds at 55 V. The effect of stimulation was evaluated using a numeric rating scale (NRS) at 2 weeks and 1, 2, and 3 months after the procedure. Successful pain relief was defined as a reduction in the NRS score of>/= 50% as compared with the score prior to treatment. In addition, at 3 months after treatment, patient satisfaction levels were examined; patients that reported "very good" (score = 7) or "good" (score = 6) results were considered to be satisfied with the procedure.

RESULTS

Neuropathic pain was significantly reduced at 2 weeks and at 1, 2, and 3 months follow-up after PRF (P < 0.001, repeated measures one-factor analysis). In addition, at 3 months post-PRF, half of the patients achieved a successful response (>/= 50% pain reduction) and were satisfied with treatment results.

LIMITATIONS

A small number of patients were recruited, and we did not perform long-term follow-up.

CONCLUSION

Caudal epidural PRF may be a good treatment option for managing neuropathic pain induced by CIAP, especially when pain is unresponsive to oral medications.

KEY WORDS

Pulsed radiofrequency, chronic idiopathic axonal neuropathy, caudal epidural stimulation, neuropathic pain chronic pain, refractory pain.

Epidural catheter anchored in the posterior lateral epidural space: How to manage it

We describe a case of an epidural catheter entrapment without knotting, kinking, shearing or breakage confirmed by CT scan and how to manage it. A patient was admitted for tibial fracture repair under general anesthesia with an epidural. At discharge day, multiple attempts to retrieve the catheter were made. Contrast CT scan showed the catheter anchored in the left posterior-lateral epidural space. Despite the absence of guidelines regarding epidural catheter entrapment, all the methods described in the literature were used. This is a rare complication and it may be associated with neurological and infectious complications. Radiologic imaging should be obtained to better characterize the catheters' position and plan removal. In this case, tension in the paraspinal muscles or in the supraspinous and intraspinous ligaments could explain the entrapment. General anesthesia with the non-depolarising muscle relaxant allowed muscles and ligaments to relax and we were able to retrieve the catheter intact.

Comparison of Electrical and Ultrasound Neurostimulation in Rat Motor Cortex

Ultrasound (US) is known to non-invasively stimulate and modulate brain function; however, the mechanism of action is poorly understood. This study tested US stimulation of rat motor cortex (100 W/cm², 200 kHz) in combination with epidural cortical stimulation. US directly evoked hindlimb movement. This response occurred even with short US bursts (3 ms) and had short latency (10 ms) and long refractory (3 s) periods. Unexpectedly, the epidural cortical stimulation hindlimb response was not altered during the 3-s refractory period of the US hindlimb response. This finding suggests that the US refractory period is not a general suppression of motor cortex, but rather the recovery time of a US-specific mechanism.

Clinical Course of Cervical Percutaneous Epidural Neuroplasty in Single-Level Cervical Disc Disease with 12-Month Follow-up

BACKGROUND

Cervical disc disease is a common and occasionally disabling condition, occurring as a natural consequence of aging in the vast majority of the adult population. Percutaneous epidural neuroplasty (PEN) has been used to deliver highly concentrated drugs for chronic neck pain and to prevent scarring in cases refractory to conventional epidural blocks. However, the clinical course after PEN in cervical disc disease is not well-documented.

OBJECTIVE

The purpose of this study was to evaluate the efficacy of cervical PEN for single-level cervical disc disease.

STUDY DESIGN

A retrospective observational study.

METHODS

A consecutive series of 100 patients who underwent cervical PEN for single-level disc disease (bulging or protrusion) were included in this study. Preoperatively, all patients underwent magnetic resonance imaging (MRI), and visual analog scale (VAS) scores as well as Odom's criteria were measured preoperatively and at post-operative follow-up visits (one, 3, 6, and 12 months).

LIMITATIONS

The results of this study are limited by the lack of a control group that did not undergo treatment with PEN.

RESULTS

Additional block therapy was performed in 58 patients (58.0%). Subsequent surgery was performed in 10 patients (10.0%, excluded from data of clinical follow-up). Mean neck pain and VAS arm pain scores for all follow-up patients decreased from 6.82 and 4.74 preoperatively to 2.18 and 1.87 at 12 months after PEN (P < 0.001). More than 80% and 40% of all patients with and without additional block therapy after cervical PEN, respectively, showed good and excellent outcomes according to Odom's Criteria during 12 months of follow-up. During this follow-up period, no severe complications related to the procedure were observed.

CONCLUSION

Cervical PEN was shown to be a safe and effective treatment for neck and arm pain in single-level disc disease during 12 months of follow-up. Key words: Neck pain, cervical disc disease, pain management, percutaneous epidural neuroplasty, adhesiolysis, clinical course.

A Coaxial Dual-element Focused Ultrasound Probe for Guidance of Epidural Catheterization: An Experimental Study

Ultrasound guidance for epidural block has improved clinical blind-trial problems but the design of present ultrasonic probes poses operating difficulty of ultrasound-guided catheterization, increasing the failure rate. The purpose of this study was to develop a novel ultrasonic probe to avoid needle contact with vertebral bone during epidural catheterization. The probe has a central circular passage for needle insertion. Two focused annular transducers are deployed around the passage for on-axis guidance. A 17-gauge insulated Tuohy needle containing the self-developed fiber-optic-modified stylet was inserted into the back of the anesthetized pig, in the lumbar region under the guidance of our ultrasonic probe. The inner transducer of the probe detected the shallow echo signals of the peak-peak amplitude of 2.8 V over L3 at the depth of 2.4 cm, and the amplitude was decreased to 0.8 V directly over the L3 to L4 interspace. The outer transducer could detect the echoes from the deeper bone at the depth of 4.5 cm, which did not appear for the inner transducer. The operator tilted the probe slightly in left-right and cranial-caudal directions until the echoes at the depth of 4.5 cm disappeared, and the epidural needle was inserted through the central passage of the probe. The needle was advanced and stopped when the epidural space was identified by optical technique. The needle passed without bone contact. Designs of the hollow probe for needle pass and dual transducers with different focal lengths for detection of shallow and deep vertebrae may benefit operation, bone/nonbone identification, and cost.

Development of a real-time lumbar ultrasound image processing system for epidural needle entry site localization

A fully-automatic ultrasound image processing system that can determine the needle entry site for epidural anesthesia (EA) in real time is presented in this paper. Neither the knowledge of anesthetists nor additional hardware is required to operate the system, which firstly directs the anesthetists to reach the desired insertion region in the longitudinal view, i.e., lumbar level L3-L4, and then locates the ideal puncture site by instructing the anesthetists to rotate and slightly adjust the position of ultrasound probe. In order to implement these functions, modules including image processing, panorama stitching, feature extraction/selection, template matching and support vector machine (SVM) classification are incorporated in this system. Additionally, a user-friendly graphical user interface (GUI), which displays the processing results and guides anesthetists intuitively, is further designed to conceal the intricacy of algorithms. Feasibility and effectiveness of the proposed system has been evaluated through a set of realtime tests on 53 volunteers from a local hospital.

Eyes on the needle: Identification and confirmation of the epidural space

Epidural catheters are used to provide effective intraoperative and postoperative analgesia. Standard epidural catheterization techniques rely on palpation of surface anatomy and the experience of the anesthesiologist. Failure to correctly place an epidural catheter can lead to inadequate analgesia and serious complications, such as dural puncture headache. Exciting new devices and techniques are being developed for identification of the epidural space and confirmation of catheter entry. This article reviews and describes the recent research findings. The devices and techniques are categorized into three sections: devices that modify the loss of resistance technique; visual confirmation using the epidural needle; and confirmation of placement of the epidural catheter.

Primary acquired spondylodiscitis shows a more severe course than spondylodiscitis following spine surgery: a single-center retrospective study of 159 cases

Spondylodiscitis may arise primarily via hematogenous spread or direct inoculation of virulent organisms during spine surgery. To date, no comparative data investigating the differences between primary and postoperative spondylodiscitis is available. Thus, the purpose of this retrospective study was to investigate differences between these two etiologies. One hundred fifty-nine patients that were treated at our department were included in the retrospective analysis. The patients were categorized into two groups based on the etiology of spondylodiscitis: group NS, primary spondylodiscitis without prior spinal surgery; group S, spondylodiscitis following spinal surgery. Evaluation included magnetic resonance imaging (MRI), laboratory values, clinical outcome, and operative or conservative management. Preoperative MRI showed higher rates of epidural and paraspinal abscess in patients with primary spondylodiscitis (p < 0.005). Vertebral bone destruction was more severe in group NS (p < 0.05). Survival rate in group S (98.2%) was higher than in group NS (87.5%, p = 0.024). The extent of the operative procedure in patients who were surgically treated (n = 116) differed between the two groups (p < 0.005). In conclusion, spondylodiscitis is a life-threatening and serious disease and requires long-term treatment. Primary spondylodiscitis is frequently associated with epidural and paraspinal abscess, vertebral bone destruction and has a higher mortality rate than postoperative spondylodiscitis. Therefore, primary spondylodiscitis shows a more severe course than spondylodiscitis following spine surgery.

Pneumocephalus Following Unidentified Dural Puncture: A Case Report with an Unusual Neurological Presentation

Pneumocephalus is a rare consequence of epidural anesthesia, which may occur following inadvertent or unidentified dural puncture when the loss of resistance to air technique is applied to identify the epidural space. Headache is the most common symptom presented in this condition, usually with sudden onset. This case report describes an unusual presentation of diffuse pneumocephalus after an unidentified dural puncture. The patient (male, 67 years old) was submitted to epidural catheter placement for the treatment of acute exacerbation of ischemic chronic pain using loss of resistance to air technique. No cerebrospinal fluid or blood flashback was observed after needle withdrawal. Shortly after the intervention, the patient presented symptoms of lethargy, apathy, and hypophonia, which are not commonly associated with pneumocephalus. No motor or sensory deficits were detected. Cranial computed tomography showed air in the frontal horn of the left ventricle, subarachnoid space at interhemispheric fissure and basal cisterns, confirming the diagnosis of diffuse pneumocephalus. The patient remained under vigilance with oxygen therapy and the epidural catheter left in place. After 24 hours, cranial computed tomography showed air in the temporal and frontal horns of the left ventricle, with no air in the subarachnoid space. The patient presented no neurological signs or symptoms at this time. Although headache is the most common symptom presented in reported cases of pneumocephalus, this case shows the need for the clinician to be aware of other signs and symptoms that may be indicative of this condition, in order to properly diagnose and treat these patients.Key words: Pneumocephalus, continuous epidural analgesia, ischemic chronic pain, loss-of-resistance to air technique, dural puncture, headache, unusual presentation.

Use of colour Doppler and M-mode ultrasonography to confirm the location of an epidural catheter - a retrospective case series

PURPOSE

Epidural anesthesia and analgesia has a reported failure rate ranging from 13% to 32%. We describe a technique using colour Doppler and M-mode ultrasonography to determine the position of the epidural catheter after placement in adults.

METHODS

This retrospective review included 37 adult patients who received postoperative epidural analgesia and underwent technically difficult epidural catheter placement. The demographic characteristics, type of surgery, use of ultrasonography, method of insertion, intervertebral level, and success of epidural localization using colour Doppler were noted for each patient. Pain scores on postoperative day 1 and the presence of a patchy block were also reviewed.

RESULTS

Colour Doppler study helped to indicate the catheter's path from the skin to the epidural space during saline injection in 33 patients (89%). Saline flow within the epidural space (catheter tip confirmation) was successfully detected with colour Doppler in 25 patients (67.5%) and with M-mode ultrasonography in 28 patients (75%). Appropriate dermatomal analgesia was noted in 35 patients (94.5%) during local anesthetic infusion.

CONCLUSION

Our preliminary data suggest the feasibility of using colour Doppler and M-mode ultrasonography to confirm proper epidural catheter placement.

Optimal Angle of Contralateral Oblique View in Cervical Interlaminar Epidural Injection Depending on the Needle Tip Position

BACKGROUND

Chronic neck and upper extremity pain associated with cervical origin is common, and cervical interlaminar epidural steroid injections (CILESIs) are frequently used to manage the symptoms of cervical spinal disorders. However, CILESIs are associated with risks such as dural puncture and cord injury.

OBJECTIVES

We aimed to determine the optimal needle tip visualization, in order to minimize CILESIs-induced complications.

STUDY DESIGN

Retrospective observational study.

SETTING

The single center study in Seoul, Republic of Korea.

METHODS

Participants were 312 adults with neck or upper extremity pain caused by cervical lesion such as cervical herniated nucleus pulposus (HNPs). They underwent magnetic resonance imaging (MRI). Patients with severe cervical spinal stenosis, prior posterior cervical spine surgery, or other anatomical abnormalities of the vertebral laminae were excluded from the study. By using axial T2-weighted spin-echo MRI, we defined the area between the spinous processes as the anterior posterior zone 1 (APZ1), and the area lateral to the spinous processes as the anterior posterior zone 2 (APZ2). Line 1 was drawn along the ventral margin of lamina that confined APZ1, and line 2 was similarly drawn in order to define APZ2. The angles between the midsagittal line and lines 1 and 2 were defined as angle 1 and angle 2, respectively. Angles were measured at the C5-6, C6-7, and C7-T1 levels, on both right and left sides at each level.

RESULTS

Angle 1 values (in degrees) at right C5-6, left C5-6, right C6-7, left C6-7, right C7-T1, and left C7-T1 were 62.54 ± 10.52, 64.34 ± 9.86, 62.03 ± 10.27, 62.87 ± 10.64, 61.64 ± 11.0, and 62.58 ± 10.83, respectively. Angle 2 values at right C5-6, left C5-6, right C6-7, left C6-7, right C7-T1, and left C7-T1 were 50.44 ± 6.84, 50.77 ± 7.00, 49.15 ± 6.07, 49.89 ± 6.45, 50.84 ± 6.68, and 50.24 ± 6.60, respectively. There were significant differences between angles 1 and 2 at each level.

LIMITATIONS

This study is a retrospective review and did not employ controls, blinding, or randomization. Additionally, the optimal CLO angles for CILESIs and cervicothoracic interlaminar epidural steroid injections (CTILESIs) have not been assessed in clinical studies. Another limitation is that we divided lamina into only APZ1 and APZ2.

CONCLUSIONS

During CILESIs, a contralateral oblique (CLO) view at 60 degrees is superior to other angles for visualizing the epidural space when the needle tip is placed in the interlaminar space and within the spinous processes margin. When the needle tip is placed in the interlaminar space and lateral to the spinous processes, a CLO view at 50 degrees is most appropriate.Institutional Review Board (IRB) approval number: S2016-0390-0001Key words: Chronic neck pain, chronic upper extremity pain, cervical epidural injections, cervical interlaminar steroid injections, steroid, needle tip position, needle tip visualization, fluoroscopy, complication, contralateral oblique view.

The influence of patient position on withdrawal force of lumbar epidural catheters after total knee arthroplasty: A randomized trial

STUDY OBJECTIVE

Elderly patients with degenerative knee disease may have accompanying degenerative spine conditions. There are no studies on lumbar epidural catheter withdrawal forces in these patients. The aim of this study was to investigate withdrawal forces and possible associated risk factors in patients undergoing total knee arthroplasty (TKA).

DESIGN

Prospective randomized trial.

SETTING

Operating room and ward in a university hospital.

PATIENTS

Seventy-eight patients aged 65 to 80years who were undergoing TKA and combined spinal epidural anesthesia were enrolled.

INTERVENTIONS

Lumbar epidural catheterization was performed in a lateral position before surgery and the patients were randomly allocated to one of 3 positions for removal: flexed lateral (L), prone (P), and sitting (S). On the third postoperative day, the lumbar epidural catheters were removed by a single investigator with the patient in the assigned position.

MEASUREMENTS

We measured the peak tension during catheter withdrawal and evaluated the factors affecting peak tension.

MAIN RESULTS

The forces required to remove the catheters were considerably greater in the sitting and prone than in the flexed lateral position: group P (3.9N [0.28-10.36]), group S (4.1N [0.04-11.57]), and group L (1.3N [0.07-3.65]) (P<.001). There was a positive correlation between the length of catheter in the epidural space and peak tension (P=.0026, β coefficient=.223).

CONCLUSIONS

For ease of removal of catheters from the lumbar epidural space, the flexed lateral position is recommended for elderly patients undergoing TKA. When placing the epidural catheter, the physician should be careful not to insert a catheter that is excessively long.

Contrast Runoff Correlates with the Clinical Outcome of Cervical Epidural Neuroplasty Using a Racz Catheter

BACKGROUND

Epidural neuroplasty using a Racz catheter has a therapeutic effect. Studies have found no correlation between foraminal stenosis and the outcome of epidural neuroplasty, which is thought to depend on contrast runoff.

OBJECTIVE

To examine the correlation between the contrast spread pattern and pain reduction in cervical epidural neuroplasty using a Racz catheter.

STUDY DESIGN

Retrospective study.

SETTING

An interventional pain-management practice in a university hospital.

METHODS

Fluoroscopic images were reviewed retrospectively. The spread of contrast from the neural foramen to a nerve root was called contrast runoff. If the contrast did not spread in this manner, then there was no contrast runoff. We defined successful epidural neuroplasty as a 50% or greater reduction from the pre-procedure numeric rating scale (NRS) score for total pain, and an at least 40% reduction in the neck pain and disability scale (NPDS) score.

RESULTS

This study reviewed 169 patients. Among the patients who had a contrast runoff pattern, the epidural neuroplasty was rated as successful in 96 (74.4%), 97 (75.2%), 86 (66.7%), and 79 (61.2%) cases one, 3, 6, and 12 months after the procedure, respectively. When there was no contrast runoff, the epidural neuroplasty was successful in 12 (30%), 12 (30%), 10 (25%), and 10 (25%) cases at one, 3, 6, and 12 months after the procedure (P < 0.001). Logistic regression of the contrast spread pattern and predicting successful epidural neuroplasty gave similar results. Patients with a contrast runoff pattern had odds ratios of 6.788, 7.073, 6.000, and 4.740 at one, 3, 6, and 12 months, respectively (P < 0.001).

LIMITATIONS

This study lacked a control group, and the patients were not classified by their diagnosed disease, such as spinal stenosis, herniated nucleus pulposus, and post-spinal surgery syndrome.

CONCLUSIONS

Cervical epidural neuroplasty with a contrast runoff pattern had a higher success rate. Contrast runoff should be observed during neuroplasty, even in the presence of foraminal stenosis.

KEY WORDS

Cervical spinal pain, contrast, contrast runoff, epidural neuroplasty, percutaneous adhesiolysis, Racz catheter.

Fluoroscopically Guided Thoracic Interlaminar Epidural Injection: A Comparative Epidurography Study Using 2.5 mL and 5 mL of Contrast Dye

BACKGROUND

Thoracic epidural anesthesia (TEA) is frequently used to maintain intraoperative analgesia. After injecting the initial bolus dose of epidural local anesthetics (LA), intermittent injection of LA through an epidural catheter is required to maintain the intraoperative analgesia. For intermittent epidural administration, usually 2 - 5 mL of LA has been used. However, no studies have suggested an optimal volume of LA of TEA for intermittent epidural administration of TEA.

OBJECTIVE

We focused on identifying an optimal volume of LA of TEA using epidurography of the thoracic level with 2 different volumes of contrast dye.

STUDY DESIGN

Prospective, randomized study.

SETTING

An interventional pain management practice in South Korea.

METHODS

After Institutional Review Board approval, 70 patients undergoing thoracic epidural catheterization for upper abdominal and thoracic surgery were randomly assigned to one of the 2 contrast dye volume groups of 35 patients each (A, 2.5 mL and B, 5.0 mL). Epidurography was evaluated to confirm how many spinal segments were covered by contrast dye. The spreads in the cephalad and caudad directions were also evaluated.

RESULTS

The total number of vertebral segments evaluated by contrast dye were 7.5 ± 2.0, and 8.4 ± 2.6, respectively in groups A and B. The number of patients who showed contrast dye spread of more than 5 vertebral segments was 34/35 (97%) in both groups. Group B resulted in higher contrast dye distribution in the cephalad direction compared to group A (T2.6 vs. T3.6 ).

LIMITATIONS

We used a test dose of contrast dye to confirm the contrast was in epidural space, not intrathecal or vascular, before injection of the main dose of contrast dye. The present study did not include the volume of test dose.

CONCLUSION

The volume of 2.5 mL for intermittent epidural administration would be enough for the analgesic effect of upper abdominal and thoracic surgery while avoiding excessive upper thoracic and cervical spread.

KEY WORDS

Thoracic epidural anesthesia, intermittent epidural administration, optimal volume, epidurography, cephalad, caudad, analgesic effect.

Design and evaluation of a low cost intracranial pressure monitoring system

One of the most life-threatening neural conditions is elevated intracranial pressure (ICP); it is associated with ischemia and poor short- and long-term outcomes. Currently, monitoring systems that accurately measure ICP are either highly invasive or inaccurate. This work explores the design and evaluation of an epidural intracranial pressure monitoring system for low-cost, minimally invasive detection. Our goal is to develop a monitoring system that could also be integrated with an electrocorticography (ECoG) system. To this end we created a minimally invasive epidural ICP monitor for use with a 2 mm burr hole craniotomy. A MEMS piezoresistive sensors is used in the system, and its performance is evaluated for intracranial pressure measurements. Our system is calibrated and tested on the benchtop and demonstrated in vivo using an animal model.

[Complications Associated with Spinal Cord Stimulation, Radiofrequency and Pulsed Radiofrequency]

Intraoperative complications regarding spinal cord stimulation (SCS) are dural or arachnoidal puncture, spinal or radicular injury and bleeding. Most common complications after SCS are malposition of epidural lead and unexpected device trouble. Other severe complica- tions are infection, hematoma and post dural puncture headache. Complications associated with radiofre- quency and pulsed radiofrequency are bleeding, infec- tion, tissue damage, sensory or motor disturbance and burn injury. And there is known spinal cord infarction as a severe complication. We should explain about the therapeutic procedure and associated complications to patients. Moreover, the immediate assessing of complications and appropriate treatments are necessary.

[Spinal cord stimulation for the management of chronic pain]

Neuromodulation techniques modify the activity of the central or peripheral nervous system. Spinal cord stimulation is a reversible and minimally invasive treatment whose efficacy and cost effectiveness are recognized for the treatment of chronic neuropathic pain or ischemic pain. Spinal cord stimulation is not the option of last resort and should be considered among other options before prescribing long-term opioids or considering reoperation. The selection and regular follow-up of patients are crucial to the success of the therapy.

Idiopathic Lumbar Epidural Lipomatosis Mimicking Disc Herniation: A Case Report

Spinal epidural lipomatosis is a rare condition which is described as the accumulation of fat in the extradural territory and often causes dural impingement. Spinal epidural lipomatosis has been implicated in causing a variety of neurologic impairments ranging from back pain, radiculopathy, claudication, myelopathy or even cauda equina syndrome. We report a 46-year-old female with obesity and a history of chronic back pain and radiculopathy who developed idiopathic Spinal epidural lipomatosis diagnosed by magnetic resonance imaging. The purpose of this report is to present a case of spinal epidural lipomatosis presenting with symptomatic cord compression and also remind this rare condition as a the differential diagnosis of epidural lesions in patients with risk factors.

Successful steroid treatment of coma induced by severe spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) is a syndrome characterized by low cerebrospinal fluid (CSF) pressure and postural headaches. It is a rare condition which may sometimes present with severe symptoms such as stupor or coma. The standard treatment protocol includes conservative measures such as bed rest, hydration, and steroids. However, severe cases may require invasive measures such as epidural blood patch (EBP), continuous epidural saline infusion, epidural fibrin glue, or surgical repair of the dural defect. In this report, we describe a case of severe SIH resulting in coma that exhibited dramatic improvement on intravenous administration of steroids. This is the first report of severe SIH causing coma that was treated non-invasively by steroids only.

Unintentional epidural placement of a thoracic paravertebral catheter inserted using an ultrasound-guided technique: a case report

This is the first case report describing the epidural misplacement of an infusion catheter, which was intended to be located in the thoracic paravertebral space using an ultrasound-guided technique. The patient was a 57-year-old female undergoing a laparoscopy-assisted left partial nephrectomy. Before surgery, a Tuohy needle was inserted into the paravertebral space at the left ninth intercostal space using an in-plane transverse ultrasound-guided approach in the lateral-to-medial direction. A catheter was then threaded into the paravertebral space through the needle. Subsequently, the catheter position was secured, although ultrasound-guided confirmation of air injected through the catheter into the paravertebral space was not obtained. Twenty milliliters of 0.5 % levobupivacaine was administered through the catheter at both the initiation and conclusion of surgery. A neurologic examination following surgery revealed paraplegia, along with sensory deficits in the bilateral T3-S5 dermatome. The motor dysfunction in the lower extremities lasted 7 h, and the sensory block lasted 13.5 h. Postoperative radiologic confirmation of the catheter position concomitant with the spread of radiopaque dye revealed that the tip of the catheter was lying in the epidural space. Unless precise attention is paid to detection of the catheter tip location, a thoracic paravertebral catheter can enter into the epidural space even under ultrasound guidance.

Concomitant epidural and subdural spinal abscess: a case report

BACKGROUND CONTEXT

Spinal subdural abscess (SSA) is a rare occurrence for which the management typically involves open surgical removal and washout.

PURPOSE

This case report aims to review the literature and discuss the management of patients with SSA.

STUDY DESIGN

We present a case of a 33-year-old female who presented with a spinal epidural abscess and concurrent SSA. She presented in the context of intravenous (IV) drug use, back pain, and generalized lower extremity weakness.

METHODS

The literature was reviewed with a focus on modern treatment options for SSA. Our patient was managed with IV antibiotics, and separate laminectomies and washouts for both lesions.

RESULTS

The patient recovered well with return of neurologic function and normalization of infection markers. The review of the literature resulted in a management flowchart that will help direct treatment of SSA.

CONCLUSIONS

The literature suggests that in a patient with a definitive diagnosis of SSA, limited surgical management and IV antibiotics are the mainstay of treatment in a patient with a decline in neurologic function. There may be a role for expectant management in the absence of diagnostic imaging or the neurologically stable patient.

Percutaneous and Endoscopic Adhesiolysis in Managing Low Back and Lower Extremity Pain: A Systematic Review and Meta-analysis

BACKGROUND

Chronic refractory low back and lower extremity pain is frustrating to treat. Percutaneous adhesiolysis and spinal endoscopy are techniques which can treat chronic refractory low back and lower extremity pain.Percutaneous adhesiolysis is performed by placing the catheter into the tissue plane at the ventrolateral aspect of the foramen so that medications can be injected. Adhesiolysis is used both for pain caused by scarring which is not resistant to catheter placement and other sources of pain, including inflammation in the absence of scarring.Mechanical lysis of scars with a catheter may or may not be necessary for percutaneous adhesiolysis to be effective. Spinal endoscopy allows direct visualization of the epidural space and has the possibility to use laser energy to treat pathology.

STUDY DESIGN

A systematic review of the effectiveness of percutaneous adhesiolysis and spinal endoscopic adhesiolysis to treat chronic refractory low back and lower extremity pain.

OBJECTIVE

To evaluate and update the effectiveness of percutaneous adhesiolysis and spinal endoscopic adhesiolysis to treat chronic refractory low back and lower extremity pain.

METHODS

The available literature on percutaneous adhesiolysis and spinal endoscopic adhesiolysis in treating persistent low back and leg pain was reviewed. The quality of each article used in this analysis was assessed. The level of evidence was classified on a 5-point scale from strong, based upon multiple randomized controlled trials to weak, based upon consensus, as developed by the U.S. Preventive Services Task Force (USPSTF) and modified by ASIPP. Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to September 2015, and manual searches of the bibliographies of known primary and review articles.

OUTCOME MEASURES

Pain relief of at least 50% and functional improvement of at least 40% were the primary outcome measures. Short-term efficacy was defined as improvement of 6 months or less; whereas, long-term efficacy was defined more than 6 months.

RESULTS

For this systematic review, 45 studies were identified. Of these, for percutaneous adhesiolysis there were 7 randomized controlled trials and 3 observational studies which met the inclusion criteria. For spinal endoscopy, there was one randomized controlled trial and 3 observational studies. Based upon 7 randomized controlled trials showing efficacy, with no negative trials, there is Level I or strong evidence of the efficacy of percutaneous adhesiolysis in the treatment of chronic refractory low back and lower extremity pain. Based upon one high-quality randomized controlled trial, there is Level II to III evidence supporting the use of spinal endoscopy in treating chronic refractory low back and lower extremity pain.

CONCLUSION

The evidence is Level I or strong that percutaneous adhesiolysis is efficacious in the treatment of chronic refractory low back and lower extremity pain. Percutaneous adhesiolysis may be considered as a first-line treatment for chronic refractory low back and lower extremity pain. The evidence is Level II to III that spinal endoscopy is effective in the treatment of chronic refractory low back and lower extremity pain.

KEY WORDS

Spinal pain, chronic low back pain, post lumbar surgery syndrome, epidural scarring, adhesiolysis, endoscopy, radicular pain.

A model of evoked potentials in spinal cord stimulation

Electrical stimulation of the spinal cord is used for pain relief, and is in use for hundreds of thousands of cases of chronic neuropathic pain. In spinal cord stimulation (SCS), an array of electrodes is implanted in the epidural space of the cord, and electrical currents are used to stimulate nearby nerve fibers, believed to be in the dorsal columns of the cord. Despite the long history of SCS for pain, stretching over 30 years, its underlying mechanisms are poorly understood, and the therapy has evolved very little in this time. Recent work has resulted in the ability to record complex compound action potential waveforms during therapy. These waveforms reflect the neural activity evoked by the therapeutic stimulation, and reveal information about the underlying physiological processes. We aim to simulate these processes to the point of reproducing these recordings. We establish a hybrid model of SCS, composed of a three dimensional electrical model and a neural model. The 3D model describes the geometry of the spinal regions under consideration, and the electric fields that result from any flow of current within them. The neural model simulates the behaviour of spinal nerve fibers, which are the target tissues of the therapy. The combination of these two models is used to predict which fibers may be recruited by a given stimulus, as well as to predict the ensuing recorded waveforms. The model is shown to reproduce major features of spinal compound action potentials, such as threshold and propagation behaviour, which have been observed in experiments. The model's coverage of processes from stimulation to recording allows it to be compared side-by-side with actual experimental data, and will permit its refinement to a substantial level of accuracy.

Immediate and acute adverse effects following transforaminal epidural steroid injections with dexamethasone

BACKGROUND

Transforaminal epidural steroid injections (TFESI) are widely used for the conservative treatment of radicular pain. The use of dexamethasone in TFESIs is relatively new; therefore, immediate and acute adverse effects that it may cause are not fully updated.

OBJECTIVE

To evaluate immediate and acute adverse effects following TFESI with dexamethasone.

STUDY DESIGN

Prospective, observational study.

SETTING

A spine center affiliated with a rehabilitation hospital.

METHODS

One hundred fifty consecutive patients receiving TFESI for the management of radicular and axial spinal pain at the cervical, lumbar, and sacral levels with dexamethasone using fluoroscopic guidance with digital subtraction technology were enrolled. The occurrence of adverse effects in patients in the 2-week time period following interventions was monitored through a set of questionnaires followed up by phone calls scheduled for 1 day, day 3, and day 14. Intensity and duration of side effects were recorded.

RESULTS

Of the 150 patients enrolled, 31 patients (19.5%) experienced adverse effects within the first 30 minutes following the intervention. The most common adverse effects were numbness and tingling in the limb, which developed in 19 patients (11.95%) followed by perineal pruritus that occurred in 7 cases (4.4%). Patients also reported experiencing adverse effects within the 3 days following intervention; most complained of headaches, insomnia, hiccups, flushing, and increased radicular pain. No major complications were noted.

LIMITATIONS

The sample size enrolled might be too small to perceive possible rare side effects related to the procedure. The 2-week follow-up period is a limitation for evaluating late side effects.

CONCLUSIONS

This study offers provision to interventionalists that TFESI with dexamethasone when performed by experienced hands and with proper technique has minor self-limited transient adverse effects that can be easily managed. Patients should be made aware of these adverse effects and their management. Further larger studies are needed to validate the safe use of dexamethasone and the safety of transforaminal epidural injections.

A randomised controlled trial using the Epidrum for labour epidurals

The aim of our study was to determine if using the Epidrum to site epidurals improves success and reduces morbidity. Three hundred parturients requesting epidural analgesia for labour were enrolled. 150 subjects had their epidural sited using Epidrum and 150 using standard technique. We recorded subject demographics, operator experience, number of attempts, Accidental Dural Puncture rate, rate of failure to site epidural catheter, rate of failure of analgesia, Post Dural Puncture Headache and Epidural Blood Patch rates. Failure rate in Epidrum group was 9/150 (6%) vs 0 (0%) in the Control group (P = 0.003). There were four (2.66%) accidental dural punctures in the Epidrum group and none in the Control group (P = 0.060), and 2 epidurals out of 150 (1.33%) in Epidrum group were re-sited, versus 3/150 (2%) in the control group (P = 1.000). The results of our study do not suggest that using Epidrum improves success or reduces morbidity.

[Pure spinal epidural cavernous hemangioma: report of one case]

A 55-year-old man presented with progressive numbness and weakness of both lower limbs is reported. MRI demonstrated a pure epidural lesion at T3-6 space appearing as isointense on T1-weighted images with enhancement by contrast medium and hyperintense on T2-weighted images. The lesion was totally removed microsurgically. Histological examination revealed cavernous hemangioma. The patient made a good recovery after surgery.

Dural tear of unusual cause

Epidural analgesia is highly recommended in cancer anorectal surgery. In addition to the fight against pain it provides some benefit in allowing early rehabilitation of patients. One of the risks of this practice is the dural tear creating a cerebrospinal fluid leak (CSF) in the epidural space (EPD). Clinical features the typical positional headache, a procession of various more or less severe symptoms: nausea, vomiting, dizziness, visual or hearing impairment or radicular pain. We report a dural of unusual cause secondary of the obstruction of tuohy catheter by vertebral cartilage.