Bevel direction of epidural needles reliably predicts direction of catheter placement and contrast spread in human cadavers: results of a pilot study

STUDY OBJECTIVE

To confirm the relationship between bevel orientation, catheter direction, and radiopaque contrast spread in the lumbar region.

DESIGN

Pilot cadaver study.

SETTING

Anatomy laboratory of a university hospital.

MEASUREMENTS

Cadavers were randomized to two groups of 4 cadavers each. In Group 1, needle bevel direction at epidural entry was cephalad; in Group 2, it was caudad. After placement of each epidural catheter in L4-L5 interspace, 2 mL of radiopaque contrast was injected and a lumbar posterior-anterior radiograph was obtained. Catheter direction and direction of radiopaque contrast spread were collected.

MAIN RESULTS

Due to the inability to access the epidural space secondary to surgical changes in the lumbar spine, one cadaver in the cephalad group was excluded. In 7 of 7 (100%) cadavers, the catheter tip direction according to the radiograph corresponded directly with bevel direction.

CONCLUSIONS

A strong relationship exists between bevel orientation and catheter direction; however, catheter position does not reliably predict the direction in which the injected fluid spreads in all cadavers.

Definition of the to be named ligament and vertebrodural ligament and their possible effects on the circulation of CSF

Few studies have been conducted specifically on the dense connective tissue located in the posterior medial part of the cervical epidural space. This study was undertaken to examine the presence of this connection between the cervical dura mater and the posterior wall of spinal canal at the level of C1–C2. 30 head-neck specimens of Chinese adults were used. Gross dissection was performed on the suboccipital regions of the 20 specimens. Having been treated with the P45 plastination method, 10 specimens were sliced (9 sagittal and 1 horizontal sections). As a result, a dense fibrous band was identified in the nuchal ligament of 29 specimens (except for one horizontal section case). This fascial structure arose from the tissue of the posterior border of the nuchal ligament and then projected anteriorly and superiorly to enter the atlantoaxial interspace. It was termed as to be named ligament (TBNL). In all 30 specimens the existence of a fibrous connection was found between the posterior aspect of the cervical dura mater and the posterior wall of the spinal canal at the level of the atlas to the axis. This fibrous connection was identified as vertebrodural ligament (VDL). The VDL was mainly subdivided into three parts, and five variations of VDL were identified. These two structures, TBNL and VDL, firmly link the posterior aspect of cervical dura mater to the rear of the atlas-axis and the nuchal region. According to these findings, the authors speculated that the movements of the head and neck are likely to affect the shape of the cervical dural sleeve via the TBNL and VDL. It is hypothesized that the muscles directly associated with the cervical dural sleeve, in the suboccipital region, may work as a pump providing an important force required to move the CSF in the spinal canal.

High cervical epidural neurostimulation for post-traumatic headache management

Headache following head injuries has been reported for centuries. The majority of post-traumatic headache (PTH) patients will report resolution of their complaints within a few months from the time of the initial injury. PTHs can contribute to disability, lost productivity, and health care costs. In this article we discuss a 40-year-old male with a history of motor vehicle accident and basal skull fracture. The patient had no headache history prior to the accident. He presented with more than 3 years persistent daily headache. The patient described constant throbbing and stabbing quality headaches predominantly on the left hemicranium with constant facial pain. He denies having aura, nausea, or vomiting, but reported occasional neck tightness. An extensive workup was carried out under the direction of the patient's primary neurologist. Secondary to persistent intractable pain, the patient was referred to the pain clinic for further evaluation. As his headaches were resistant to all trialed strategies, we decided to turn our therapeutic focus toward electrical neuromodulation along with continuing multimodal medications and multidisciplinary approach. During 7 days of high cervical dorsal column electrical nerve stimulation trial, he reported almost 90% pain reduction and significant improvement on his quality of life. On 12 months follow-up after he underwent a permanent implant of high cervical dorsal column electrical nerve stimulation, he reported the same level of pain reduction along with 100% satisfaction rate. To the best of our knowledge, there have been no publications to date concerning the application of high cervical nerve stimulation for PTH.

[Epiduroscopy]

This article introduces the equipment used for epiduroscopy and describes its indications, procedures for use, treatment outcomes, the potential complications and future developments. Epiduroscopy is used in the treatment and diagnosis of intractable low back and leg pain in patients in whom nerve block is not efficacious and when pain recurs after operation. The characteristics of epiduroscopy are that it is: 1) safe and less invasive; 2) used for endoscopic washing of the epidural space and fluoroscopic X-ray; 3) it allows injection of an agent into the lesion; and 4) it results in no change in the normal lumbar structure after operation. Epiduroscopy is expected to provide successful outcomes for many patients with intractable low back and leg pain through further improvements in equipment related to epiduroscopy, advances in technology, the accumulation of data regarding its efficacy and safety, and the coverage of treatment by insurance.

[Racz Spring Guide Catheter epidural lysis of adhesions and percutaneous neuroplasty]

In recent years, failed back neck surgery syndrome (FBNSS) has been increasing as the number of spinal surgeries rises. In particular, the frequencies of surgeries for intervertebral disk herniation and spinal stenosis are high, and FBNSS is commonly attributable to these procedures. FBNSS is a challenging disease for us pain clinicians, and its causes and treatment methods are diverse. FBNSS resulting from epidural adhesive radiculopathy often cannot be resolved by conventional conservative therapies. Treatments using spinal cord stimulation and epiduroscopy are performed in Japan. However, because these are invasive surgical procedures that require hospitalization, they are offered only at certain centers in the country. In contrast, Racz Spring Guide Catheters epidural neuroplasty can be carried out in outpatient settings, is less invasive and achieves excellent pain relief. Because of the superior performance and handiness of the Racz Spring Guide Catheter instruments, it is a technique that can be carried out in many institutions. This report describes the instruments and operative techniques applied for Racz Spring Guide Catheter epidural neuroplasty.

Spontaneous C1-2 cerebrospinal fluid leak treated with a targeted cervical epidural blood patch using a cervical epidural Racz catheter

A 39-year-old woman with no history of trauma or meningitis presented to the neurology department of our hospital with an occipital headache, neck pain, nausea, and dizziness that had worsened during the previous month. The headache worsened when sitting or standing and partially regressed when lying down. She was diagnosed with spontaneous intracranial hypotension (SIH) and received conservative management. After failing to respond to conservative management, she underwent an autologous epidural blood patch (EBP) at the T7-8 level. The headache and associated symptoms did not improve after the procedure. Magnetic resonance (MR) myelography suggested a cerebrospinal fluid leakage at the C1-2 level resulting in intracranial hypotension. An 18-gauge Tuohy needle was inserted at the T1-2 interlaminal level using a paramedian approach under fluoroscopic guidance. The cervical epidural Racz catheter was threaded through the Tuohy needle up to the cervical spine and the catheter tip was confirmed to be at the right cervical 1-2 site on an anteroposterior (AP) view. Five mL of autologous blood was injected into the epidural space through the cervical epidural Racz catheter. Her occipital headache and associated symptoms gradually disappeared after the procedure. Seven days later the headache was largely resolved and she was discharged. Follow-up magnetic resonance imaging (MRI) showed the disappearance of abnormal radiological features associated with intracranial hypotension. She currently remains symptom free for 9 months. Delivery of autologous blood patch via a cervical epidural Racz catheter inserted from the upper thoracic spine can be a safe and effective method for patients with SIH due to cerebrospinal fluid (CSF) leakage in the upper cervical spine.

Spinal epidural lipomatosis in lumbar magnetic resonance imaging scans

The goal of this study was to quantify the frequency of advanced spinal epidural lipomatosis (SEL) detected on lumbar magnetic resonance imaging (MRI) scans performed at the authors' hospital and to compare the frequency, cause, and progression of SEL in these cases with that reported in the literature. The total number of MRI examinations of the lumbar spine performed at this hospital over 45 months was 1498 (705 men and 793 women; mean age, 60.3 years). After the MRI data were reduced (T1- and T2-weighted sagittal and axial images) on the basis of the exclusion criteria, the anterior and posterior diameters of the dural sac and spinal canal were measured, as well as the thickness of the epidural fat. On the basis of these parameters, the severity of SEL was classified as grade 0 to grade III. Five cases of grade III SEL were diagnosed. The frequency of grade III SEL noted in this study was 0.33% (5/1498). Obesity (body mass index greater than 27.5) was noted in 3 cases, and the use of exogenous corticosteroids was noted in 3 cases. Exogenous steroid usage associated with advanced SEL in this study was greater than that reported in the literature. Most symptoms of SEL progress slowly, and early diagnosis allows for a dose reduction of the prescribed steroids. Thus, lumbar MRI examinations should be conducted aggressively in patients with exogenous steroid use and presenting with low back pain or buttock pain.

[Case of spinal epidural abscess after continuous epidural block to manage the pain of herpes zoster]

A woman in her 90's received continuous epidural block for the pain of herpes zoster. Four days after epidural catheterization, she was found with cellutitis. Fourteen days after epidural catheterization, spinal epidural abscess was pointed out on MRI. Since there were no neurological symptoms, we performed conservative medical management with antibiotics. She recovered without sequela When the symptoms of cellutitis appeared after epidural block (even if there are neither neurological symptoms nor infectious signs), there is a possibility of progressing into spinal epidural abscess.

[Spinal anesthesia with low doses of local anesthetic in patients with multiple trauma]

The aim of the study was to compare the safety of low doses of local anesthetic spinal anesthesia with the traditional by frequency of hypotension and bradycardia in patients with polytrauma. We observed 144 patients with multiple injuries, including fractures of the lower limbs: I group patients 7.5-10 mg intrathecal bupivacaine group II--15-20 mg of bupivacaine. The relative risk (RR) of hypotension for the control group compared with the study was 9.3 (95 % CI 2.79-39.3). The relative risk (RR) of insufficient duration of anesthesia when using unilateral technique was not significantly higher--2.56 (95% CI 0.73-11.32). Found that spinal anesthesia with low doses of local anesthetic can significantly reduce the risk of hypotension and bradycardia in patients with multiple injuries, but during prolonged surgical interventions unilateral spinal anesthesia is advisable to combine with catheterization of the epidural space.

The distance from skin to cervical and high thoracic epidural space on chinese adults as read from MRI

BACKGROUND

A few studies on the depth from the skin to the cervical epidural space (DSES) have been reported from the United States, South Korea, Japan, and Taiwan. There are no published reports from mainland China.

OBJECTIVES

The goal of this study was to collect standard data on Chinese adults from mainland China in a large medical center with a wide geographical range of patients.

STUDY DESIGN

A prospective study.

SETTING

Department of Anesthesiology, Pain Medicine, and Critical Care Medicine, Aviation General Hospital of China Medical University.

METHODS

The survey included 410 patients. Measurements were made of DSES, the dural sac, and the spinal cord by automatic measuring ruler on transverse and sagittal images of the cervical spine at the C5-6, C6-7, C7-T1, T1-2, and T2-3 intervertebral space obtained by magnetic resonance imaging (MRI). We also obtained the width of the epidural space by measuring the distance from the (LF) to the dural sac.

RESULTS

DSES at C5-6, C6-7, C7-T1, T1-2, and T2-3, respectively, was 4.69 ± 0.84 cm, 5.14 ± 0.98 cm, 5.56 ± 1.03 cm, 5.81 ± 0.94 cm, and 5.76 ± 0.86 cm on T2W (weighted) MRIs obtained in the sagittal plane (mean ± SD). The distance at C5-6, C6-7, and C7-T1 in transverse images was 4.67 ± 0.86 cm, 5.18 ± 1.02 cm, and 5.55 ± 0.97 cm, respectively. All measured distances from the skin to the epidural space were significantly greater in men than in women. Multivariate regression analysis revealed significant partial correlation between DSES and (BMI).

LIMITATION

Limitations include the absence of healthy individuals as well as the influence of the difference in neck positioning during the MRI examination vs. active epidural puncture.

CONCLUSION

DSES varied with the cervical intervertebral level in those patients studied from the population of mainland China. The greatest DSES was noted at C7-T1 in men and T1-2 in women, and the least was at C5-6 in both men and women. DSES had a significant relationship with neck circumference and BMI in both genders. We suggest that the DSES be measured with MRI before performing epidural puncture. The lower cervical and upper thoracic intervertebral spaces appear to provide a greater margin of safety for epidural puncture.

Large animal model for development of functional restoration paradigms using epidural and intraspinal stimulation

Restoration of movement following spinal cord injury (SCI) has been achieved using electrical stimulation of peripheral nerves and skeletal muscles. However, practical limitations such as the rapid onset of muscle fatigue hinder clinical application of these technologies. Recently, direct stimulation of alpha motor neurons has shown promise for evoking graded, controlled, and sustained muscle contractions in rodent and feline animal models while overcoming some of these limitations. However, small animal models are not optimal for the development of clinical spinal stimulation techniques for functional restoration of movement. Furthermore, variance in surgical procedure, targeting, and electrode implantation techniques can compromise therapeutic outcomes and impede comparison of results across studies. Herein, we present a protocol and large animal model that allow standardized development, testing, and optimization of novel clinical strategies for restoring motor function following spinal cord injury. We tested this protocol using both epidural and intraspinal stimulation in a porcine model of spinal cord injury, but the protocol is suitable for the development of other novel therapeutic strategies. This protocol will help characterize spinal circuits vital for selective activation of motor neuron pools. In turn, this will expedite the development and validation of high-precision therapeutic targeting strategies and stimulation technologies for optimal restoration of motor function in humans.

[Spinal paralysis by extradural hematoma following catheter removal]

A 63-year-man with lung cancer underwent right upper lobectomy under general anesthesia combined with thoracic epidural anesthesia. The surgical course was uneventfully completed. On the second postoperative day, he developed complete paralysis below T4 level 1 hour after removal of the epidural catheter. The magnetic resonance imaging (MRI) showed extradural hematoma compressing the spinal cord from T4 to T6 segments. Surgical removal of hematoma was scheduled. However, his neurological condition improved rapidly within a couple of hours, and the surgery was not carried out. The time course of recovery from complete paralysis suggests that extradural hematoma diffused into the extradural space, resulting in a decrease in the epidural pressure.

Needle position analysis in cases of paralysis from transforaminal epidurals: consider alternative approaches to traditional technique

BACKGROUND

Transforaminal technique for epidural steroid injections, unlike other approaches, is uniquely associated with permanent, bilateral, lower extremity paralysis.

OBJECTIVE

To review the literature and analyze the reported cases of paralysis from lumbar transforaminal epidural steroid injections to possibly establish a cause and to prevent this complication.

STUDY DESIGN

Eighteen cases of paralysis from transforaminal epidural injection have been reported. We could analyze the position of the needle within the neural foramen based on the available images and/or description among 10 of these 18 cases. Five cases were performed with computed tomography guidance and 12 cases were performed with fluoroscopic guidance [unknown in one case]. Additionally, other variables associated with the procedure, including the technique, were also examined.

METHODS

Analysis of the needle position in the neural foramen in cases of paralysis from transforaminal epidural steroid injections. This analysis is based on images and/or description provided in published reports.

RESULTS

Paralysis in these cases seems to be associated with a well performed traditional safe triangle approach with good epidural contrast spreads. Analyzed data shows that 77.7% of the time, the needle was in the superior part of the foramen. In 71.4% of the cases, the needle was in the anterior part of the foramen. This coincides with the location of the radicular artery in the foramen. In 22.2%, the needle was in the midzone (neither in the superior nor inferior zone). No level was spared as this event occurred at every foramen from T12 to S1. Ten of these events happened during a left-sided procedure and 8 during a right-sided procedure. No relation to this complication was noted when other variables like type and size of the needles, side of the injection, local anesthetic, contrast, or volume of injectate were taken into consideration.

LIMITATIONS

Only 18 cases of paralysis from transforaminal epidurals have been reported. Out of these, only 10 cases included images or descriptions which could be evaluated for our study.

CONCLUSION

In light of the anatomical and radiological evidence in the literature that radicular arteries dwell in the superior part of the foramen and along with our needle position analysis, we suggest that the traditional technique of placing the needle in the superior and anterior part of the foramen must be reexamined. Alternative, safer techniques must be considered, one of which is described.

[Continuous infusion of low-dose remifentanil for palliation of pain with epidural catheterization]

BACKGROUND

To prospectively determine the safety and effectiveness of continuous infusion of low-dose remifentanil for the reduction of pain in patients for epidural catheterization.

METHODS

This study was approved by the institutional review board. Written informed consent was obtained. Fifty two patients (27 men, 25 women, age range 16-96 years, mean age 68 years) were given continuous infusion of various rates of application (none, 0.02, 0.05, and 0.07 microg x kg -1 x hr-1) of remifentanil. Blood pressure, heart rate, pulse oximetry oxygen saturation and respiratory rate were recorded during the procedure of epidural catheterization. Pain score was measured with the visual analogue scale (VAS), and complications including muscle stiffness, nausea and vomiting, and depressed level of consciousness were monitored.

RESULTS

Every rate of application, pulse oximetry oxygen saturation and systemic blood pressure were decreased but the reduction was not marked. The muscle stiffness, nausea and vomiting, and depressed level of consciousness were not observed in all the cases. No other serious complications were observed.

CONCLUSIONS

Continuous infusion of low-dose remifentanil is a safe and effective method for palliation of pain in epidural catheterization.

Clinical assessment of a CMC/PEO gel to inhibit postoperative epidural adhesion formation after lumbar discectomy: a randomized, control study

PURPOSE

To evaluate effectiveness of carboxymethylcellulose/polyethylene oxide (CMC/PEO) gel in improving clinical outcomes after the first-time lumbar discectomy.

METHOD

Ninety-three patients with herniated lumbar disc at L4-L5 or L5-S1 were enrolled and randomized into two groups: CMC/PEO gel treatment group and control group. All the patients underwent laminotomy and discectomy by posterior approach. The preoperative and postoperative Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) scores for lower-back pain and leg pain were analyzed and compared between two groups at 30- and 60-day time points.

RESULTS

No patient presented with any clinically measurable adverse event during surgery. There were no significant differences between the treated group and the control group on the preoperative ODI and VAS scores. In general, the ODI and VAS scores decreased in both groups at all the time points. At the 30-day time point, the VAS scores for back pain and leg pain and the ODI scores in treatment group were lower by 9.9 % (P = 0.0302), 27.0 % (P = 0.0002) and 16.3 % (P = 0.0007) than those in control group. And at the 60-day time point, the ODI and VAS scores further decreased in both groups. The VAS scores for leg pain in treatment group were lower by 4.5 % than that in the control group (P = 0.0149). However, no significant difference was detected between two groups on the ODI and VAS scores for back pain.

CONCLUSIONS

The results demonstrated that CMC/PEO gel is effective in reducing posterior dural adhesions in the spine with no apparent safety issues. It can improve patients' postoperative clinical outcome.

Intracranial somatosensory responses with direct spinal cord stimulation in anesthetized sheep

The efficacy of spinal cord stimulators is dependent on the ability of the device to functionally activate targeted structures within the spinal cord, while avoiding activation of near-by non-targeted structures. In theory, these objectives can best be achieved by delivering electrical stimuli directly to the surface of the spinal cord. The current experiments were performed to study the influence of different stimulating electrode positions on patterns of spinal cord electrophysiological activation. A custom-designed spinal cord neurostimulator was used to investigate the effects of lead position and stimulus amplitude on cortical electrophysiological responses to spinal cord stimulation. Brain recordings were obtained from subdural grids placed in four adult sheep. We systematically varied the position of the stimulating lead relative to the spinal cord and the voltage delivered by the device at each position, and then examined how these variables influenced cortical responses. A clear relationship was observed between voltage and electrode position, and the magnitude of high gamma-band oscillations. Direct stimulation of the dorsal column contralateral to the grid required the lowest voltage to evoke brain responses to spinal cord stimulation. Given the lower voltage thresholds associated with direct stimulation of the dorsal column, and its possible impact on the therapeutic window, this intradural modality may have particular clinical advantages over standard epidural techniques now in routine use.

Evidence for using air or fluid when identifying the epidural space

Lumbar epidural analgesia is frequently employed to provide pain relief for women during labor. Anesthesia providers use various methods to identify the epidural space. Some providers use air, some use fluid, and others use a combination of air and fluid during the loss of resistance technique. Loss of resistance to air has been speculated to result in a lesser quality of analgesia compared with loss of resistance to only fluid. A search strategy focusing on preappraised sources was used to locate evidence from interventional and observational studies. Four evidence sources were located, including a systematic review with meta-analysis of 4 older studies. The evidence reviewed was inconclusive in determining whether a difference in analgesia quality results from the use of air or fluid during the loss of resistance technique. Future studies should include an adequate number of subjects and address other problems such as operator experience, observer blinding, equivalence of subject characteristics, outcomes definition and measurement, and composition of epidural solution. Providers should consider other factors when selecting loss of resistance medium, such as the reported complications of large amounts of air injected into the epidural space and surrounding structures.

[Analysis of locomotor activity in decerebrated cats during electromagnetic and epidural electrical spinal cord stimulation]

It was shown that the epidural and the electromagnetic tonic stimulation with frequency 5 Hz applied to the lumbal as well as to the cervical region of the spinal cord enabled stepping on a moving treadmill belt in decerebrated cats. It was found that there were differences in initiation of the stepping movements during epidural and electromagnetic stimulation depending on the region of spinal cord stimulation. Stimulation at frequency of 0.3 Hz induced single reflex responses in the anterior and posterior limbs. On the basis of analysis of the response structure it was concluded that the locomotor ability during epidural and electromagnetic stimulation depended on the degree of polysynaptic pathways activation. The hypothesis about stepping pattern generator activation through the dorsal roots during epidural stimulation and more direct activation of neuronal locomotor networks in the case of electromagnetic spinal cord stimulation is discussed.

[The finding of glucose in the fluid obtained by epidural catheter after its insertion during combined intradural-epidural anaesthesia with hyperbaric bupivacaine is a usual occurrence]

OBJECTIVES

To determine whether the appearance of glucose in the fluid spontaneously obtained by the epidural catheter after its insertion during combined intradural-epidural anaesthesia with hyperbaric bupivacaine is a usual occurrence.

PATIENTS AND METHODS

A prospective, observational study was conducted on 34 patients with combined intradural-epidural anaesthesia in whom an epidural catheter was introduced, after locating the epidural space with a saline solution, inserting a spinal needle and injecting hyperbaric bupivacaine. After observing whether any fluid was spontaneously dripping from it, it was determined if this contained glucose. Withdrawal of the needle and washing its lumen with saline solution, it was checked whether there was glucose in washout. The samples were analysed using a glucose meter. When the motor block disappeared a dose of local anaesthetic was administered through the epidural catheter. The relationship of the demographic parameters with the spontaneous dripping of the epidural catheter was evaluated.

RESULTS

Spontaneous dripping by the epidural catheter after its insertion was observed in 22 patients. All the samples obtained contained glucose. There was glucose in 9 out of 34 epidural needle wash samples. None of the patients suffered from excessive motor-sensory block. There was a statistically significant relationship between patient age (P<.05) and spontaneous dripping by the catheter (the higher the age, more dripping).

CONCLUSION

The finding of glucose in the fluid obtained by the epidural catheter is a frequent occurrence and is of no clinical significance. We propose that it could be due to a leak of cerebrospinal fluid by the dural puncture needle during or after the administering of the hyperbaric bupivacaine and the spillage of this into the epidural space.

[Two cases showing the absence of motor evoked potentials without developing postoperative paraplegia following thoracoabdominal aortic repair--role of epidural cooling, spinal drainage and aorto-iliac side-arm conduit distal perfusion]

We describe two cases which developed loss of motor evoked potentials from bilateral lower limbs following thoracoabdominal aortic repair. Paraplegia was suspected in both cases; however, one case of Crawford type 2 aneurysm showed transient left leg monoplegia with a sensory deficit and the other case of aortic pseudoaneurysm showed no neurologic dysfunction postoperatively. We employed epidural cooling and spinal drainage for spinal protection and distal perfusion was provided through aorto-iliac side-arm conduit. Despite the prolonged spinal ischemia during thoracoabdominal aortic repair, spinal drainage and epidural cooling were very helpful for protecting the spinal cord from ischemia. The interpretation of MEPs seems very difficult especially when the potentials remain absent even after reconstruction or reperfusion of segmental arteries, because variety of intraoperative factors may affect them.

Unsuspected spondylolysis in patients with lumbar disc herniation on MRI: The usefulness of posterior epidural fat

BACKGROUND AND PURPOSE

Lumbar disc herniation (LDH) at the level of non-displaced spondylolysis (isthmic spondylolisthesis) is an uncommon association rarely evaluated in the literature. In this study, authors examine whether the continuous posterior epidural fat between the dura mater and spinous process (continuous double-hump sign) at the level of LDH is a valuable tool to identify patients with non-displaced spondylolysis on MRI.

METHODS

Eighteen patients (group 1) presented at our department (2000-2010) with a LDH associated with an undiagnosed non-displaced spondylolysis on MRI. Spondylolysis was confirmed by direct visualization of the defect on CT-scan, dynamic radiography, MRI or at surgery. To validate this method, we made the same evaluation in 20 surgically treated patients (group 2) with a one-level LDH without spondylolysis.

RESULTS

In all patients of group 1 spondylolysis was unsuspected on the MRI report. However, a positive "continuous double-hump sign" was seen in 16 patients. The spondylolysis was recognized on MRI in six cases, on CT-scan in nine cases and on dynamic radiography in one case. Two cases were diagnosed surgically. In group 2, only one patient had a positive "continuous double-hump sign". This new sign had a specificity of 95%, sensitivity of 88.88%, and accuracy of 92.10% for diagnosis of non-displaced spondylolysis.

CONCLUSIONS

Non-displaced spondylolysis may be associated with adjacent LDH. Although uncommon, it is important for neurosurgeons to be aware of this association because of its implication on the therapeutical management. MRI is not always sufficient to recognize a non-displaced spondylolysis with certainty; however "continuous double-hump sign" may be used as a simple valuable diagnosis tool.

Two cases of spontaneous epidural emphysema during asthmatic attack

Two cases of spontaneous epidural emphysema that occurred during asthmatic attacks in a 13-year-old and a 15-year-old are reported here. Epidural emphysema was diagnosed in both cases by using computed tomography (CT), and in 1 case by using magnetic resonance imaging (MRI). Neither patient had neurological findings. Both patients were discharged with no respiratory difficulties. It is generally believed that a diagnosis of epidural emphysema can only be made on CT. In this report, MRI was used to make the diagnosis of subdural emphysema, and it demonstrated that the air was localized within the epidural fat.

Pathophysiology and management of spontaneous intracranial hypotension--a review

Spontaneous Intracranial Hypotension is a syndrome involving reduced intracranial pressure secondary to a dural tear which occurs mostly due to connective tissue disorders such as Marfans Syndrome, and Ehler Danlos Syndrome. Patients with dural ectasias leading to CSF leakage into the subdural or epidural space classically present with orthostatic headaches and cranial nerve deficits mostly seen in cranial nerves V-VIII. Diagnosis of SIH is confirmed with the aid of neuroimaging modalities of which Cranial MR imaging is most widely used. SIH can be treated conservatively or with epidural blood patches which are now widely being used to repair dural tears, and their effectiveness is being recognized. Recently epidural injection of fibrin glue has also been used which has been found to be effective in certain patients.

Inadvertent epidural injection of drugs for intravenous use. A review

INTRODUCTION

The frequency of inadvertent injection of drugs in the epidural space is probably underestimated and underreported, but it can cause serious morbidity and possibly mortality.

OBJECTIVE

The aim of this review is to collate reported incidents of this type, to describe the potential mechanisms of occurrence and to identify possible therapeutic solutions.

METHODS

We searched into medical databases and reviewed reference lists of papers retrieved.

RESULTS

A list is reported of more than 50 drugs that were inadvertently injected into the epidural space. This list includes drugs which produce no, little or short-lasting neurological deficits, but also includes drugs that may be more etching and can result in temporary or even permanent neurological deficit.

DISCUSSION

Most drugs do not lead to sequelae other than pain during injection or transient neurological complaints. Other drugs may have more deleterious consequences, such as paraplegia. Both the dose of the inadvertent injected drug and the time frame play an important role in the patient's outcome. "Syringe swap", "ampoule error", and epidural/intravenous line confusion due to inaccurate or absent colour coding of epidural catheters were the main sources of error. Preventive strategies, including non Luer-lock epidural injection ports, might increase safety.

Cephalad angulation of epidural needle insertion may be an important factor for safe epidural space approach: a mathematical model

BACKGROUND AND OBJECTIVES

Epidural approach angle is one of the determining factors for needle traveling length to reach the epidural space. Likewise, the margin of safety against accidental dural puncture should be affected by epidural approach angle because the space available for epidural needle tip movement in the epidural space is depending on the inserting angle to the epidural space. The purpose of this study is to conjecture the effect of the angle formed with the skin and an epidural needle on the margin of safety against accidental dural puncture using a mathematical model.

CASE REPORT

Suppose that the width of the epidural space is A mm and that the force advancing the epidural catheter is Ckgf and the diameter of the catheter is D mm. In this situation, assuming that the cephalad angle with the midline approach formed with the skin and an epidural needle is θ, the following parameters can be determined: the available distance for the needle tip in the epidural space = A/sinθmm; cephalad advancing force of catheter = C*cosθkgf; and the pressure at the site of dura matter where the epidural catheter is pushing = 400*C*sinθ.πD(-2)kgf.cm(-2). The longer the distance available for the needle tip, the larger the margin of safety for dura injury by the epidural needle. It is supposed that θ should be set smaller to make the margin of safety larger. Likewise, smaller θ could decrease the pushing pressure and more effectively create a distinct cephalad advancing force.

CONCLUSIONS

Acute cephalad angulation should be considered to increase the margin of safety for epidural approach and catheterization.

[Effect of the continuous epidural saline infusion for patients with postdural puncture headache after pulmonary resection]

The dual puncture is one of the diseaseful complications at the induction of the epidural anesthesia, which causes severe symptoms of intracranial hypotension such as headache and nausea. The clinical courses of 3 patients with the dual puncture symptoms after pulmonary resections were retrospectively reviewed, and the effect of the continuous epidural saline infusion treatment (CESI) for the dual puncture was evaluated. Pneumococcal empyema developed in 1 patient who had been treated with conservative management. In contrast, the symptoms of the others who were treated with the CESI were quickly recovered or were effectively prevented. This report strongly suggested that the CESI was convenient and effective treatment for dual punctune symptoms by suppressing the cerebrospinal fluid leakage by elevation of the fluid pressure in the extradural space.

[Fixation of the epidural catheter using Tegaderm]

BACKGROUND

Effect of epidural anesthesia is affected by catheter tip position. Migration of an epidural catheter is known and several methods were reported to secure fixation of the catheter, but there were no gold standard method to fix it.

METHODS

We compared six different methods to fix the epidural catheter with Tegaderm transparent film dressing. Three groups employed forming circular loop at the skin exit site and other three groups employed directing straight up to the right shoulder. Each group was divided into three subgroups by position and use of record label of Tegaderm transparent film dressing. Epidural catheter migration was recorded for two postoperative days. We compared the magnitude of catheter movement in two days and changes in length of catheter insertion in two days for each group.

RESULTS

The magnitude of catheter movement is smaller in the group without circular loop formed at skin exit but all these three subgroups showed significant outward migration in two days.

CONCLUSIONS

We conclude that fixation of epidural catheter by only Tegaderm can not be a gold standard even if circular loop and record label are used.

Steroid induced spinal epidural lipomatosis--case report and review of the literature

Steroids are one of the most commonly prescribed medications for a variety of medical conditions, often long term. Spinal epidural lipomatosis (SEL) is a state of pathological fatty tissue overgrowth in the vertebral canal. It is a rare and dangerous complication of chronic steroid therapy that may lead to back pain, radiculopathy, or paraparesis. We describe a patient that was taking long term steroids and presented with progressively worsening weakness of the lower extremities. On the MRI scan, a long segment of unusual accumulation of fatty deposits in the posterior aspect of the spinal canal resulting in canal stenosis extending from C7 to the T10 level was observed. Despite an appropriate diagnosis and surgical intervention, his weakness did not resolve. We discuss the implications of this case in the primary care practice.

[Postraumatic epidural arachnoid spinal cyst: case report]

INTRODUCTION

Extradural arachnoid spinal cysts are unfrequent lesions that are associated with spinal trauma, surgery and less frequently with congenital anomalies. The clinical manifestations are similar to those seen with other compressive spinal cord lesions. Magnetic resonance techniques allow to diagnose correctly this pathology and to define its thopographic situation. The pathologic history of the patient is essencial to establish the ethiology. Surgery is the elective treatment in most cases.

CLINICAL CASE

The patient is a 35 years old man who has a medical history of penetrating spinal trauma two years ago. In that instance he suffered an unilateral spinal cord section at D2-D3 level with the corresponding Brown Sequard syndrome. A small wound was detected at the skin dorsal level and it was closed without difficulties. At the beginning, he improved his motor right leg function with rehabilitation and vitamins. After two years of good recovery he came to our hospital suffering a neurological deterioration of six months of evolution. The physical examination revealed an spastic paraparesis. Magnetic resonance was performed demonstrating a cystic extradural collection compressing the spinal cord at D3-D4 level. Surgical decompressive treatment allowed to excise the cyst and it was possible to define a dural tear that was closed successfully. The outcome was good with restoration of the initial motor function that he had after the spinal trauma.

CONCLUSIONS

Surgical management of postraumatic epidural arachnoid spinal cyst allows to detect the meningeal tear and to close it, which is highly effective on these kinds of lesions.

Spontaneous otogenic pneumocephalus

The diagnosis and management of spontaneous otogenic pneumocephalus with literature review is described. A young sportsman experienced headache and fluctuating mass in his occiput during increased physical activity. A large extradural intracranial pneumocephalus with corresponding emphysema was imaged on a CT scan. Transmastoid identification and plugging of temporal bone defect solved the problem with complete pneumocephalus and emphysema resorption.

[Post-operative complications peculiar to lumboperitoneal shunt: possible consequences due to side leakage of CSF from around the inserted spinal tube into the lumbar epidural space]

This is a report on a few possible consequences of occasional side leakage of CSF into the lumbar epidural space. In this report, we refer to such CSF side leakage from around the inserted spinal tube which occurred during the early stages following our lumboperitoneal shunt operations in two of our patients. This leakage can lead to over-drainage of CSF, and such complications as post-operative orthostatic headache, subdural effusion, and/or subdural hematoma can also result. The diagnosis of these complications can be verified if CSF components in the lumbar epidural space are visible in T2 weighted-fat saturation images captured on MRI. Commonly, CSF over-drainage is attributed to improper pressure settings of the shunt valve and/or siphon effects of shunt systems induced by the patients' postural changes. In addition to this, we strongly suggest anticipating the complications peculiar to lumboperitoneal shunt, because these are possible occurrences, although they have never been pointed out. In the surgical treatment of idiopathic normal pressure hydrocephalus, which is found mainly in elderly patients, increasing numbers of surgeons these days prefer lumboperitoneal shunt to ventriculoperitoneal shunt, as the former causes less damage to the brain. Given this trend towards lumboperitoneal shunt operations, we urge that the complications mentioned here be borne in mind as possible consequences.

October 2001: 40-year-old Xhosa male with back pain and leg weakness

A 40-year-old Xhosa male presented with progressive upper lumbar back pain and weakness At examination he was emaciated and had enlarged lymph nodes in the groin and axilla. Both lower limbs were severely atrophic and weak. Sensation to touch and pain was decreased below L3 bilaterally. MR of the spine showed a discrete, contrast-enhancing epidural mass. A T10-T12 laminectomy revealed an soft, vascular extradural tumor dorsal to the cord. The mass was loosely applied to the dura and easy to remove. The operative specimen consisted of a sausage-shaped (3.5 x 2.0 x 1.2 cm), thinly-encapsulated mass of reddish-brown tissue. The cut surface had a mottled, vaguely nodular, yellowish-brown appearance. Microscopic examination revealed sheets of hematopoeitic elements, including myeloid, red cell and megakaryocytic lines, the latter showing Factor 8-related positivity. The final diagnosis was extramedullary hematopoiesis (EMH). A bone marrow biopsy performed as a result of the diagnosis showed a myeloproliferative disease and polycythemia vera. EMH in the spinal epidural space is a rare but treatable cause of progressive paraparesis in patients with a variety of hematological disorders. Since 1956 there have been more than 50 reported cases, most of which occurred in association with thalassaemia. In spinal cord compression secondary to EMH, the lesions are commonly localized to the mid-lower thoracic region.

Migrating radicular pain caused by gas-collection in the lumbar epidural region: case report

Finding gas into the intervertebral disc space is a relatively common occurrence, whereas lumbar disc herniations containing gas or lumbar epidural gas-collections are rarely observed. The Author reports a very rare case of a patient who first suffered from right-side sciatica and then, a few months after being treated, from left-side cruralgy; both symptoms were found to be caused by epidural gas-collection at different levels of the spinal canal.

Sudden transient paraplegia shortly after preoperative thoracic epidural catheterization--a case report

We report a case of sudden onset of paraplegia shortly after thoracic epidural catheterization for postoperative analgesia and discuss the possible causes of this event. A 38-year-old woman was scheduled to receive right lobectomy of liver because of hepatocellular carcinoma. Thoracic epidural catheterization for postoperative analgesia was performed before the induction of anesthesia. After skin disinfection and local anesthetic skin infiltration with lidocaine, epidural catheterization through T(10-11) interspace was performed. Dural puncture without any neurological symptoms was noticed in the attempt and the epidural space was successfully identified through T(9-10) interspace in the second attempt. However, acute motor weakness and sensory impairment were met as the epidural catheter was being threaded into the epidural space. Magnetic resonance imaging (MRI) revealed no abnormal findings and the neurological deficits resolved spontaneously within 2h without any sequela. Finally, it was supposed that the transient neurological deficits were resultant from accidental subarachnoid injection of the local anesthetics used for skin infiltration. Preoperative image studies of the spine revealed a relatively short skin-to-dura distance either from median or paramedian approach, which might be the cause of the inadvertent intrathecal injection of local anesthetic during skin infiltration.

Primary osteolytic intraosseous meningioma of the frontal bone

Almost 1-2% of meningiomas are lesions described as ectopic or extradural meningiomas. Primary intraosseous meningiomas are a rare form of intra-bone tumours that account for approximately 67% of extradural meningiomas. A 41-year-old male patient presented with a headache and a bulge at the right frontal region. Cranial computed tomography displayed a hyperostotic lesion. Magnetic resonance imaging showed enhancement of the bone lesion after injection of gadolinium. A burr hole was drilled at the thickest section of the lesion, and pathological examination of the bone dust extracted from this site was performed. The pathological study indicated the presence of a meningioma. Right frontal craniectomy was performed and the hyperostotic bone was resected. No invasion was observed at the dura. A calvarial defect was reconstructed during the same session with methyl methacrylate cranioplasty.

Epidural cyst with cauda equina syndrome after epidural anesthesia

A 40-year-old woman without remarkable medical history received epidural anesthesia for uterine cervix conization. Six hours after the operation, cauda equina syndrome occurred. Magnetic resonance imaging of the spine revealed epidural fluid accumulation around L5, as well as L4/5 herniated intervertebral disc found incidentally. Surgical decompression was performed with H-reflex monitoring. Epidural injection could result in cystic accumulation complicated with cauda equina syndrome.

[The direction and the position of epidural catheter tips inserted 5 cm or 7 cm cephalad did not differ]

BACKGROUND

Epidural catheter insertion is a common procedure in gynecological surgeries. At a previous study, we investigated the catheter's direction and position, inserted 7cm cephalad from T12-L1, with postoperative plain X-P using picture archiving communication system (PACS). 74% of the catheters advanced in cephalad direction and 71.4% of the catheter tips stayed within one vertebra from the puncture level. We estimated that the catheters were too long to advance straight. Then, we planned another prospective study to compare the catheter advanced 7 cm or 5 cm regarding its direction and tip position.

METHODS

Fifty-one female patients receiving gynecological surgery were enrolled. Epidural catheters were inserted from T12-L1 intervertebral space in cephalad direction for the length of 5 cm confirmed with postoperative plain X-P using PACS. The catheter's direction, the length, and the position were verified and compared with the result of the previous study.

RESULTS

The catheters going cephalad appeared more frequently among 5 cm group than 7 cm group. Those going caudalad appeared more frequently among 7 cm group than 5 cm group. However, the catheter tip final position and the length from the puncture levels were not significantly different between the groups.

CONCLUSIONS

The direction and the position of epidural catheter inserted 5 cm or 7 cm cephalad did not differ.

[The effect of the Sanqi qisodium hyaluronate gel on the collagen of epidural scar after rabbits laminectomy]

OBJECTIVES

To study the effects of Sanqi qisodium hyaluronate gel on collagen-I and collagen-III expression in the process of rabbits' epidural scar formation after operation.

METHODS

Ninety-six white rabbits with 6-month-old, half males and half females, weighted from 2 to 2.5 kg, which were randomly divided into normal saline group (A), Sanqi group (B), qisodium hyaluronate group (C) and Sanqi qisodium hyaluronate gel group (D). The laminectomy of rabbits were performed in group A, B, C, D, the duras were surrounded with normal saline, Sanqi liquid, qisodium hyaluronate and Sanqi qisodium hyaluronate gel respectively. Animals of each group were killed at 1, 2, 4, 8 weeks after operation. Use Masson staining for histological observation of collagen, and in situ hybridization staining for the analysis of collagen-I and collagen-III expression.

RESULTS

In the Masson staining, Sanqi qisodium hyaluronate gel group was more regular than the control group in the shape of collagen texture. As to the expression of collagen-I, and Sanqi qisodium hyaluronate gel group was lower than normal saline group, the Sanqi group and qisodium hyaluronate group at 4 weeks after using medicine (P < 0.01); while the Sanqi qisodium hyaluronate gel group was higher than normal saline group, Sanqi group and qisodium hyaluronate group in the collagen-III expression (P < 0.01).

CONCLUSIONS

Sanqi qisodium hyaluronate gel could improve collagen's arrangement of the rabbit's epidural scar after operation, reduce its rigidity and increase flexibility.

[Epidural use of electrostimulation catheters in a complex of balanced anesthesia in patients with infantile cerebral paralysis]

The paper presents the results of epidural blocks using Arrow electrostimulation catheters in 25 patients with infantile cerebral paralysis for anesthetic provision of reconstructive orthopedic operations. The findings lead to the conclusion that epidural anesthesia with electrostimulation catheters provides a high anesthesia quality and safety.

[Spinal cord stimulation]

Spinal cord stimulation (SCS) is an established treatment for intractable neuropathic pain. SCS is performed using an implantable pulse generator connected to leads with electrodes positioned in the dorsal epidural space, which are then used to stimulate the ascending and descending dorsal column fibres to achieve paresthesia covering the area of pain. It is based on the Gate Control Theory, introduced by Melzack and Wall in 1965, which suggests that stimulation of large afferent fibres can inhibit pain transmission at the level of the dorsal horns. More recent studies indicate that SCS releases substance P serotonin, noradrenaline and GABA in the dorsal horns; activation of the GABAB receptor may be linked to a decrease in the release of glutamate and other excitatory amino acids, resulting in a decrease of neuropathic pain. The clinical indications for SCS are mainly peripheral vascular diseases (PVD), refractory angina, failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS) type 1 and type 2, spinal cord stenosis and neuropathic pain. The new puncture trial method is less invasive and can reduce psychological resistance of the patient for SCS manipulation.

Caudal epidural blood patch

This report describes the use of a single shot, through the needle caudal approach to epidural blood patch (EBP) in a patient with persistent leakage of cerebrospinal fluid following lumbosacral laminectomy. A previous report of caudal EBP in an adult patient with an epidural catheter suggested that the success of the procedure could be comparable without the use of a catheter. This case report documents the success of through the needle caudal EBP in an adult patient.

[Case of transient paralysis and paresthesia after epidural blood patch]

A 47-year-old woman with postdural puncture headache suffered from transient paralysis and paresthesia immediately after the epidural blood patch. After one and a half hour, these symptoms disappeared spontaneously. We suspect that the spinal cord or spinal nerve root was transiently pressed by the viscous blood mass, because blood sampling maneuver took a few minutes. With passing of time, the viscous blood spread through the epidural space, and neurological symptoms improved. Although the risks of epidural blood patch are relatively low, we should closely pay attention to unexpected side effects.

Posterior epidural mass: can a posteriorly migrated lumbar disc fragment mimic tumour, haematoma or abscess?

A 60-year-old woman complained of low back pain radiating to both buttocks and to the anterior aspect of the left thigh. MRI showed a left posterolateral epidural mass at the L1-L2 level. An epidural abscess was suspected, but the biochemistry was normal. Excision yielded complete relief of symptoms. Pathological examination demonstrated that the specimen was a migrated disc fragment. The authors found 29 other cases of disc migration to the posterior epidural space; two of these were at the thoracic level. Eleven of the 27 lumbar cases (40%) were complicated with Cauda Equina Syndrome (CES). MRI is the method of choice to make the diagnosis. The differential diagnosis includes tumour, haematoma and abscess.