Long-term outcomes five years after selective dorsal rhizotomy

BACKGROUND

Selective dorsal rhizotomy (SDR) is a well accepted neurosurgical procedure performed for the relief of spasticity interfering with motor function in children with spastic cerebral palsy (CP). The goal is to improve function, but long-term outcome studies are rare. The aims of this study were to evaluate long-term functional outcomes, safety and side effects during five postoperative years in all children with diplegia undergoing SDR combined with physiotherapy.

METHODS

This study group consisted of 35 children, consecutively operated, with spastic diplegia, of which 26 were Gross Motor Function Classification System (GMFCS) levels III-V. Mean age was 4.5 years (range 2.5-6.6). They were all assessed by the same multidisciplinary team at pre- and at 6, 12, 18 months, 3 and 5 years postoperatively. Clinical and demographic data, complications and number of rootlets cut were prospectively registered. Deep tendon reflexes and muscle tone were examined, the latter graded with the modified Ashworth scale. Passive range of motion (PROM) was measured with a goniometer. Motor function was classified according to the GMFCS and measured with the Gross Motor Function Measure (GMFM-88) and derived into GMFM-66. Parent's opinions about the children's performance of skills and activities and the amount of caregiver assistance were measured with Pediatric Evaluation Disability Inventory (PEDI).

RESULTS

The mean proportion of rootlets cut in S2-L2 was 40%. Muscle tone was immediately reduced in adductors, hamstrings and dorsiflexors (p < 0.001) with no recurrence of spasticity over the 5 years. For GMFCS-subgroups I-II, III and IV-V significant improvements during the five years were seen in PROM for hip abduction, popliteal angle and ankle dorsiflexion (p = 0.001), capacity of gross motor function (GMFM) (p = 0.001), performance of functional skills and independence in self-care and mobility (PEDI) (p = 0.001).

CONCLUSION

SDR is a safe and effective method for reducing spasticity permanently without major negative side effects. In combination with physiotherapy, in a group of carefully selected and systematically followed young children with spastic diplegia, it provides lasting functional benefits over a period of at least five years postoperatively.

Spinal cord injury-induced attenuation of GABAergic inhibition in spinal dorsal horn circuits is associated with down-regulation of the chloride transporter KCC2 in rat

Most spinal cord injury (SCI) patients suffer from chronic pain. Effective therapy for this pain is lacking, and the underlying mechanisms are poorly understood. The spinal superficial dorsal horn (SDH) contains neuronal circuits capable of modulating primary afferent information involved in pain processing. KCC2 is an isoform of the K(+)-Cl(-) cotransporter that contributes to the regulation of transmembrane anion gradient which plays a key role in shaping GABA(A) receptor-mediated signalling in the CNS. We tested the hypothesis that SCI causes down-regulation of KCC2 distal to the injury and contributes to the neuronal hyperresponsiveness and pain-related behaviours. SCI was a hemisection at T(13) level of adult Sprague-Dawley rats. Spinal sagittal slices with attached dorsal roots (DR) were prepared from L(4) to L(6) level. The reversal potentials of GABA responses (E(GABA)) and DR-evoked IPSPs and EPSPs of L(4-6) SDH neurones in sham-operated and SCI rats were compared using gramicidin-perforated patch-clamp recordings. Here we report that thoracic SCI-induced down-regulation of KCC2 in the lumbar SDH parallels the development of allodynia. The subsequent changes of E(GABA) in SDH neurones attenuate the GABA(A) receptor-mediated inhibitory synaptic transmission. These changes cause certain normally subthreshold primary A and C fibre inputs to evoke action potential output in SDH neurones. We conclude that SCI induces KCC2 down-regulation and subsequent changes of E(GABA) in the SDH below the injury site. The resulting disinhibition unmasks normally ineffective SDH neuronal circuits and may contribute to the below-level central pain-related behaviours after incomplete SCI.

Contrast flow selectivity during transforaminal lumbosacral epidural steroid injections

BACKGROUND

Lumbosacral transforaminal epidural steroid injections (LS-TFESIs) are an accepted procedure used in the comprehensive, conservative care for lumbar disc pathology and/or spinal stenosis induced low back pain with a radicular component. Historically, the terminology used to describe the transforaminal technique of instilling medications into the epidural space and/or exiting structures has varied. These procedures have also been referred to as either diagnostic or therapeutic selective nerve root blocks (SNRBs). Although this procedure is typically used to "selectively" treat isolated pathology, the "SNRB" terminology suggests that one can selectively diagnose or treat a specific nerve root as a pain generator by anesthetizing or blocking it. It has been recently demonstrated that L4 and L5 SNRBs are often non-"selective" by investigating the extent of epidural contrast flow patterns after injecting 1.0 mL of contrast. Our study attempts to identify the minimum injectate volume at which LS-TFESIs may still be considered "selective" with no injectate extending to either the adjacent (superior and/or inferior) levels or to the contralateral side.

OBJECTIVE

Quantitatively evaluate contrast flow level selectivity noted during fluoroscopically guided lumbosacral transforaminal epidural steroid injections (LS-TFESIs).

STUDY DESIGN

Prospective, nonrandomized, observational human study.

METHODS

Thirty patients (female = 10, male = 20) undergoing LS-TFESIs were investigated. After confirming appropriate spinal needle position with biplanar imaging, 4.0 mL of nonionic contrast was slowly injected. Fluoroscopic images were recorded at 0.5 mL increments. These biplanar contrast flow images were evaluated to determine which 0.5 mL volume increment was no longer specific for the injected level. In particular, we documented when contrast extended either to a superior or inferior spinal segment or crossed the midline spine to the contralateral side.

RESULTS

After injecting 0.5 mL of contrast, 30% of LS-TFESIs performed in this study were no longer "selective" for the specified root level. After injecting 1.0 mL of contrast, 67% of LS-TFESIs performed in this study were no longer "selective" for the specified root level. After injecting 1.5 mL of contrast, 87% of LS-TFESIs performed in this study were no longer "selective" for the specified root level. After injecting 2.5 mL of contrast, 90% of LS-TFESIs performed in this study were no longer "selective" for the specified root level.

CONCLUSIONS

Diagnostic LS-TFESI or SNRB blocks limiting injectate to a single, ipsilateral segmental level cannot reliably be considered diagnostically selective with volumes exceeding 0.5mL. Injectate volumes greater than 0.5mL are consistently non-selective and cannot be used reliably for diagnostic block procedures in the epidural space.

The co-inhibitory molecule PD-1 modulates disease severity in a model for an inherited, demyelinating neuropathy

We have previously shown that mice heterozygously deficient for P0 are characterized by a late onset myelin disorder implicating CD8+ T-lymphocytes and macrophages. We now investigated the impact of the co-inhibitory molecule "programmed death" (PD)-1 (CD279), a CD28-related receptor expressed on activated T- and B-lymphocytes on the pathogenic phenotype of CD8+ T-lymphocytes in the P0 myelin mutants. PD-1 deficiency in P0+/- mice leads to a stronger increase of CD8+ T-lymphocytes and a substantially aggravated histological phenotype in the PNS compared to P0+/- mice expressing PD-1. Correspondingly, functional down-stream features, such as electrophysiological parameters, walking coordination and mechano-sensation are more affected than in PD-1-expressing myelin mutants. Our study demonstrates that a monogenic nerve disorder can be substantially modified by immune-controlling mechanisms. Thus, understanding the implication of disease-modifiers in inherited demyelination could be of pivotal interest for limiting the detrimental impact of primarily genetically-mediated myelin disorders by fostering immuno-regulatory pathways.

Sectioning of filum terminale externum using a rigid endoscope through the sacral hiatus. Cadaver study

AIM

Tethered cord syndrome (TCS) is a stretch-induced functional disorder of the spinal cord, which is directly related to filum fixation. Classic surgical approaches to the filum involve open surgery and include varying amounts of spinal bone removal. In an effort to reduce the morbidity and mortality of these procedures, the authors explored a less invasive method. They evaluated the ability, safety and feasibility for endoscopic sectioning of the filum terminale externum by performing upward orientated navigation in the extradural sacral spinal canal through the sacral hiatus using a rigid endoscope.

METHODS

Four adult, phenol-formalin embalmed cadavers were used for endoscopic section of the filum terminale externum at the tip of thecal sac. After preparing the anatomical area of sacral hiatus, a rigid endoscope (Storz, of 3.8 mm external diameter with two working channels, of 1 mm each, one for suction-irrigation and one as working) was inserted into the extradural sacral spinal canal and the filum terminale externum was identified and cut easily at the distal end of thecal sac at the level of S2. In all cases, it was possible to manipulate the rigid endoscope and inspect the full length of the extradural sacral spinal canal, especially at the S1-S2 level.

RESULTS

The results indicate that the tested transhiatal approach for upward orientated extradural endoscopy represents a minimally invasive procedure that provides an appropriate and feasible route to the extradural sacral spinal canal.

CONCLUSION

Such approach is an attractive alternative for filum terminale externum sectioning in cases where tethered cord syndrome is not accompanied by any other pathology. Moreover if filum terminale internum sectiong is indicated, it can be performed in second stage.

Quantitative changes in the cervical neural foramen resulting from axial traction: in vivo imaging study

BACKGROUND CONTEXT

Cervical traction has a long history as a method of conservative treatment for cervical spine diseases. However, information on quantitative changes in the cervical neural foramen resulting from axial traction in vivo is lacking.

PURPOSE

To quantitatively evaluate the changes in the neural foramen of the cervical spine during axial traction in vivo.

STUDY DESIGN

A prospective radiographic analysis of the cervical neural foramen of adult volunteers.

PATIENT SAMPLE

Fifteen healthy volunteers (10 men, 5 women) without any history of cervical spine disease.

OUTCOME MEASURES

The changes in cervical cross-sectional foraminal areas and heights were measured.

METHODS

Cervical magnetic resonance (MR) images of the volunteers were taken at the neutral position and were reconstructed in the oblique plane perpendicular to the long axis of each neural foramen from the C2-3 to the C6-7 level. The changes in the neural foraminal dimensions at incremental axial traction forces (0, 5, 10, and 15 kg) were analyzed.

RESULTS

After each 5-kg incremental increase in traction weight, there was a significant (p value less than .05) increase in area and height of the intervertebral foramen compared with the position in which no weight was applied. There was an average increase of 5.81%, 16.56%, and 18.9% in the foraminal area and an average increase of 3.75%, 8.67%, and 10.43% in foraminal height compared with the position with no weight at traction of 5, 10, and 15 kg, respectively. There was no statistically significant difference for the increase in foraminal area and height from 10 to 15 kg of traction (p value greater than .05).

CONCLUSIONS

There was a significant increase in intervertebral foraminal area and height after each 5-kg increment in traction weight compared with the position in which no weight was applied. From 10 to 15 kg of traction, there was no significant change in the foraminal area and height.

[The measurement of nerve root tensile stress]

In the majority of the cases sciatica is caused by an intervertebral disc herniation compressing the nerve root. The compression determines an increased tension in the nerve root. We believe that the magnitude of this stress offers more information about the root impairment that the disc displacement measured on MRI images.

MATERIAL AND METHODS

We present in this paper an original device which allows for intraoperative root stress analysis. The device consists of a force transducer composed of an elastic element and a displacement limitation.

RESULTS

The initial measurements were performed on silicon catheters and human cadavers in two different situations: 1. free nerve root; 2. blocked nerve root. Next step was intraoperative nerve roots tensile stress recording during lumbar disc surgery. Different force values were obtained for the same displacement (3 mm perpendicular on nervous root): F1 = 0.21 N; F2 = 0.78 N. Considering experimental values, the tensile stress inside of a nervous root is determined by using specific mechanical calculations presented in this paper. This is a simple and useful device for rapid intraoperative recording of nerve root mechanical stress.

Root repair review: basic science background and clinical outcome

Spinal nerve root injuries have a profound effect on the different parts (PNS and CNS) of the root itself as well as the pertinent spinal cord segment. A root avulsion from the spinal cord is a longitudinal spinal cord injury. There is degeneration of sensory and motor axons, loss of synapses, deterioration of local segmental connections, nerve cell death and reactions among non neuronal cells with scar formation, i.e. a cascade of events similar to those known to occur in any injury to the spinal cord. For function to be restored, nerve cells must survive and there must be regrowth of new nerve fibres along a trajectory consisting of CNS growth-inhibitory tissue in the spinal cord as well as PNS growth-promoting tissue in nerves. Problems in PNS regeneration such as non directional growths and unspecific reinnervation of target organs lead to unpredictable sensorimotor activity and conspires against a useful recovery of function. From the results of basic science experiments, a surgical strategy to treat root avulsion with spinal cord injury has been developed. In humans this technique is currently the most promising treatment of any spinal cord injury, with return of useful function together with pain alleviation in cases where all nerves to the extremity have been avulsed from the spinal cord. At present the shortcomings of this technique are proportionate to the delay before surgery, which leads to death of nerve cells and incomplete and unpredictable recovery. In order to improve this situation and achieve further recovery of useful function including sensory perceptions and to fully alleviate pain it is necessary to pursue research and development of both basic and clinical science.

Differential galanin upregulation in dorsal root ganglia and spinal cord after graded single ligature nerve constriction of the rat sciatic nerve

Single ligature nerve constriction (SLNC) is a newly developed animal model for the study of neuropathic pain. SLNC of the rat sciatic nerve induces pain-related behaviors, as well as changes in the expression of neuropeptide tyrosine and the Y(1) receptor in lumbar dorsal root ganglia (DRGs) and spinal cord. In the present study, we have analyzed the expression of another neuropeptide, galanin, in lumbar DRGs and spinal cord after different degrees of constriction of the rat sciatic nerve. The nerve was ligated and reduced to 10-30, 40-80 or 90% of its original diameter (light, medium or strong SLNCs). At different times after injury (7, 14, 30, 60 days), lumbar 4 and 5 DRGs and the corresponding levels of the spinal cord were dissected out and processed for galanin-immunohistochemistry. In DRGs, SLNC induced a gradual increase in the number of galanin-immunoreactive (IR) neurons, in direct correlation with the degree of constriction. Thus, after light SLNC, a modest upregulation of galanin was observed, mainly in small-sized neurons. However, following medium or strong SLNCs, there was a more drastic increase in the number of galanin-IR neurons, involving also medium and large-sized cells. The highest numbers of galanin-IR neurons were detected 14 days after injury. In the dorsal horn of the spinal cord, medium and strong SLNCs induced a marked ipsilateral increase in galanin-like immunoreactivity in laminae I-II. These results show that galanin expression in DRGs and spinal cord is differentially regulated by different degrees of nerve constriction and further support its modulatory role on neuropathic pain.

Pressure changes under the ischial tuberosities of seated individuals during sacral nerve root stimulation

Neuromuscular stimulation via the sacral nerve roots is proposed for prevention of ischial pressure ulcers following a spinal cord injury (SCI). Acute effects of sacral functional magnetic stimulation (FMS) on seat interface pressure changes were investigated in five nondisabled volunteers. Similar effects were demonstrated with functional electrical stimulation in people with SCI who used a sacral anterior root stimulator implant. The results indicated that sacral nerve root stimulation, either by FMS or implanted electrical stimulation, induced gluteus maximus contraction and mild pelvic tilt sufficient for clinically significant reductions in ischial pressures during sitting.

[Ziconotide: an innovative alternative for intense chronic neuropathic pain]

INTRODUCTION

Intense chronic pain is a very important health problem, as it has a high prevalence (5-10%), a multifactorial aetiology and its management is very often a very complex affair. Treatment of severe cases sometimes requires interventional approaches, such as continuous intrathecal infusion of opioids.

CASE REPORT

We report the case of a 38-year-old female with intense neuropathic pain in the lower back and the lower limbs secondary to three operations on the L5-S1 lumbar segment. After implementing several different pharmacological regimes involving both oral and implanted systems (spinal cord stimulation and subarachnoid infusion pump with different pharmacological combinations) with no clinical improvement, intrathecal infusion with ziconotide was included in the protocol.

CONCLUSIONS

Ziconotide is the first specific neuronal blocker that acts on the calcium channel by blocking the N-type voltage-dependent calcium channels. It is a new non-opioid analgesic with approved indication in the treatment of intense chronic pain, in patients who require intrathecal analgesics and are refractory to other analgesic treatments. Therefore, we shall have to consider this drug as a therapeutic alternative in patients do not experience sufficient relief with the pharmacological agents and means currently available to treat them.

The effectiveness of motorised lumbar traction in the management of LBP with lumbo sacral nerve root involvement: a feasibility study

BACKGROUND

Traction is commonly used for the treatment of low back pain (LBP), predominately with nerve root involvement; however its benefits remain to be established. The aim of this study was to test the feasibility of a pragmatic randomized controlled trial to compare the difference between two treatment protocols (manual therapy, exercise and advice, with or without traction) in the management of acute/sub acute LBP with 'nerve root' involvement.

METHODS

30 LBP patients with nerve root pain were recruited and randomly assigned to one of two treatment groups. Primary outcome measures were the: McGill pain questionnaire, Roland Morris disability questionnaire, and the SF36 Questionnaire; recorded at baseline, discharge, 3 and 6 months post-discharge.

RESULTS

27 patients completed treatment with a loss of another four patients at follow up. Intention to treat analysis demonstrated an improvement in all outcomes at follow up points but there appeared to be little difference between the groups.

CONCLUSION

This study has shown that a trial recruiting patients with 'nerve root' problems is feasible. Further research based upon a fully powered trial is required to ascertain if the addition of traction has any benefit in the management of these patients.

TRIAL REGISTRATION

REGISTRATION NUMBER

ISRCTN78417198.

Neurophysiological monitoring of lumbosacral spinal roots during spinal surgery: continuous intraoperative electromyography (EMG)

INTRODUCTION

Neurophysiological monitoring during spinal surgery reduces the associated neurological complications. Continuous EMG recording has developed an useful technique for spinal root monitoring

PATIENTS AND METHODS

Fifty four patients who underwent surgery for several lumbosacral spinal lesions (low and high degree spondylolisthesis, spinal stenosis, degenerated or herniated lumbar discs) were studied to evaluate the effectiveness of continuous EMG recording in monitoring spinal root function during surgery. Electrical root or screw stimulation was also performed in nine of them. To correlate surgical spinal root lesion with a precise EMG injury activity an animal study with 5 pigs was performed; lesion was produced by prolonged spinal root traction.

RESULTS

In the porcine group EMG discharges lasting longer than one minute after cessation of root traction was noted in 74% of spinal root levels (neurotonic discharges or pseudo-rhythmic activity in 70% of the cases). Spinal root lesion was demonstrated through EMG three weeks after surgery. In the patient group pathological-significant EMG activity was not recorded in any case during monitoring. Mechanical or chemical root stimulation during surgery produced brief lasting EMG bursts of no pathological significance. Only a patient developed a mild acute L5-S1 radiculopathy after surgery (1 false negative) and post-operative deficit was not observed in the rest. Electrical stimulation of spinal roots and screws allowed to identify root level and prove the adequate placement of screws.

CONCLUSION

Spontaneous and evoked EMG recordings are simple techniques that provide continuous information about lumbosacral spinal roots function throughout surgery.

[Paresthesia in various spinal anesthesia techniques for cesarean section]

OBJECTIVE

To determine the incidence of paresthesia with different spinal puncture techniques using a 27-gauge Whitacre needle.

MATERIAL AND METHODS

Spinal puncture was performed in 224 elective cesarean sections using different techniques in this single-blind, prospective trial. Patients were randomized to 4 groups: group 1, combined epidural and subarachnoid puncture using an introducer needle; group 2, combined epidural and subarachnoid puncture without an introducer; group 3, subarachnoid puncture with an introducer; and group 4, subarachnoid puncture with an introducer to within a few millimeters of the dural sac, at which point the introducer was withdrawn.

RESULTS

Paresthesia developed in 23, 11, 16 and 5 patients in groups 1, 2, 3 and 4, respectively. Various nerve roots were affected. In 2 and 11 cases the fourth and fifth lumbar nerve roots were affected; in 29 and 13 cases, the first and second sacral nerve roots were involved. In comparison with group 4, the risk of paresthesia was 7, 2.5 and 4 times greater in groups 1, 2 and 3, respectively.

CONCLUSIONS

Combined epidural-subarachnoid puncture leads to a higher incidence of paresthesia in comparison with simple spinal puncture, probably because the lumbar puncture is performed on a dural sac that has been previously deformed due to the "tent effect" caused by the epidural needle. Fewer cases of paresthesia occur when the subarachnoid puncture is slow and steady and the introducer needle is withdrawn millimeters before it reaches the dural sac.

Percutaneous endoscopic discectomy for far lateral lumbar disc herniations: prospective study and outcome of 66 patients

BACKGROUND

Extraforaminal disc herniations represent up to 11% of all lumbar herniated discs. Numerous surgical approaches have been described. Percutaneous endoscopic discectomy (PED) is one of the minimally invasive techniques; after mastering this procedure it is a practical method that is used for treatment of foraminal or extraforaminal disc herniation. The outcome of PED for treatment of foraminal or extraforaminal disc herniation has been studied.

METHOD

A total of 66 patients with foraminal or extraforaminal lumbar disc herniation was treated by applying the PED technique between January 1998 and June 2005. The positions of the herniated disc levels were L2-3 (n=5, 8%), L3-4 (n=19, 28%) and L4-5 (n=42; 64%). The selected patients had no previous surgery, appropriate conservative therapies were done before the operations, and MRI was the main diagnostic method with the clinical findings. Evaluation of the patients with clinical examinations, visual analogue pain scale (VAS) and Oswestry scale was performed preoperatively, on postoperative day 7 and in the postoperative 6-12 months period.

RESULTS

In two patients (n=1, L4-5 and n=1, L3-4) disc material could not be removed with PED, so discectomy was performed with microscopic visualization during the same session. Three patients (n=3, L4-5) were reoperated on three to six months after primary surgery due to recurring disc problems with microscope visualization. In two patients (n=2, L4-5) root nerves were partially damaged, and in two patients (n=2, L4-5) root nerves were impinged by the working channel. These 4 patients had dysesthesias from just after surgery to a mean of 45 days after surgery. One of recurrent cases was among these patients. Neurological examinations showed minimal muscle weakness of the quadriceps femoris and diminished sensation of the L4 dermatomal area in patients with partial nerve root damage. This patient improved and the neurologic examination became normal with disappearance of the dysesthesia. There was no sign of reflex sympathetic dystrophy (RDS). With these two patients VAS and Oswestry scales scores decreased significantly early in the postoperative follow-up. The postoperative 6-month average scores are favourable in comparison with the average score at postoperative day 7. The postoperative 12-month scores showed no significant differences to those of postoperative month 1.

CONCLUSION

Percutaneous endoscopic discectomy is a minimally invasive method and offers many benefits to the patient, but extensive surgical practice is needed to become a capable surgeon. Consequently this technique can only be a treatment option on appropriate patients. This study reconfirmed that the removal of fragmented disc material is achieved and offers a pain-free status.

Retroperitoneal mesenchymal chondrosarcoma mimicking a large retroperitoneal sacral schwannoma

We report a case of retroperitoneal chondrosarcoma in which preoperative radiological study induced to a possible diagnosis of sacral schwannoma. A 25-year-old woman was admitted to our neurosurgical institute for a progressive sciatic pain with gait difficulties with a sudden radicular deficit with right positive Lasegue's sign at 30 degrees, loss of Achilles reflex, sensory deficit on right S1 dermatome, and complete motor deficit of right plantar flexion. We performed an en bloc removal of the lesion via an anterior retroperitoneal approach. We believe that the treatment of choice is radical surgical excision of the tumor with complete en-bloc removal of the lesion; postoperative radiotherapy and chemotherapy should be valuated case by case.

Novel biomechanical quantification methodology for lumbar intraforaminal spinal nerve adhesion in a laminectomy and disc injury rat model

Spinal nerve fibrosis following injury or surgical intervention may play an important role in the pathophysiology of chronic back pain. In this current study, we demonstrate the role of biomechanical quantification of lumbar intraforaminal spinal nerve adhesion and tethering in the analysis of the post-laminectomy condition and describe a direct methodology to make this measurement. Twenty age-matched Sprague-Dawley male rats were divided into operative and non-operative (control) groups. Operative animals underwent a bilateral L5-L6 laminectomy with right-side L5-6 disc injury, a post-laminectomy pain model previously published by this lab. At eight weeks, animals were sacrificed and the strength of adhesion of the L5 intraforaminal spinal nerve to surrounding structures was quantified using a novel biomechanical methodology. Operative animals were found to have a significantly greater load to displace the intact right L5 spinal nerve through the intervertebral foramen when compared to control animals. The findings show that the post-laminectomy condition creates quantifiable fibrosis of the spinal nerve to surrounding structures and supports the conclusion that this fibrosis may play a role in the post-laminectomy pain syndrome.

Lumbar radiculopathy in ankylosing spondylitis with dural ectasia

We present a 57-year-old man with ankylosing spondylitis (AS) and significant dorsal lumbar dural ectasia (diverticulum). An L5 nerve root monoradiculopathy associated with AS has not been previously reported. The quantity and extent of such ectasia is variable but may be related to cauda equina syndrome. Long-term follow-up of these cases may reveal whether or not solitary nerve lesions gradually lead to cauda equina syndrome. We recommend that asymptomatic or symptomatic patients with dural ectasia should be closely observed without need for immediate surgical intervention.

B-cell neurolymphomatosis confined to the peripheral nervous system

Patients with neurolymphomatosis show lymphoma cells within the peripheral nerves, nerve root/plexus, or cranial nerves. However, most neurolymphomatosis patients show lymphomatous infiltration not only in the peripheral nervous system (PNS), but also in the meninges, Virchow-Robin space, and brain parenchyma. Here, we report a 74-year-old woman with diffuse large B-cell lymphoma presenting with motor-sensory-autonomic polyneuropathy and multiple cranial neuropathies. A diagnosis of neurolymphomatosis was made by sural nerve biopsy. Postmortem examination indicated that lymphoma cell infiltration in the nervous system was confined to the PNS with no involvement of the central nervous system, including the meninges. This was a very rare case of B-cell neurolymphomatosis with lymphomatous infiltration confined to the PNS, suggesting specific affinity of the lymphoma cells for the PNS in this patient.

Functional posterior rhizotomy: the Tokyo experience

PURPOSE

The author describes the history of functional posterior rhizotomy (FPR), the surgical procedure currently used, and the results together with its future perspective in Japan. The modern form of FPR was introduced to Japan in 1995, and the first surgery was carried out in 1996. Despite initial resistance from orthopedic surgeons, the procedure has eventually gained wide recognition in the country.

MATERIALS AND METHODS

The author has operated on 98 patients (60 boys and 38 girls, aged from 2 to 19 years old) by the end of 2006. Most patients were mild to severely disabled children with spastic hypertonia because of cerebral palsy and other diseases. The surgical procedure used is based on the Peacock's procedure with some modification for the mildly disabled children whose spasticity was predominantly the muscles of the ankle joint. Intraoperative neurophysiology was an indispensable tool for preserving urogenital function and for judging which root/rootlet to be cut.

RESULTS

Seventeen to 83% of the root/rootlets were found to be abnormal and were cut, clearly correlating with the degree of disability. However, there was a wide difference in the cutting rate, even in children with the same degree of disability. The result of surgery in this group of patients was the same as in previously published data. Twenty out of 51 patients (39%) followed for more than a year at the current institute showed improved locomotion after FPR. Thirty patients (59%) demonstrated suprasegmental effects after FPR.

CONCLUSION

The role of FPR will grow in importance as a treatment for spasticity in Japan in the future.

"Migration" of traumatic subarachnoid hematoma? A case report

BACKGROUND

Traumatic spinal SAH with neurologic deficits is rare and easily misdiagnosed, especially after traumatic intracranial hemorrhage.

CASE DESCRIPTION

We report a case of spinal SAH with root compression occurring after a scooter accident.

CONCLUSIONS

Physicians should be aware of descending migration of intracranial SAH as a possible cause of spinal cord or root compression, especially in the patient with late onset spinal symptoms.

Atypical cervical astrocytoma manifesting as occipitalgia

A 23-year-old female presented with chronic occipitalgia without signs of increased intracranial pressure followed by worsening headache and slight gait unsteadiness. Cerebral magnetic resonance (MR) imaging showed no corresponding lesions. Cervical MR imaging revealed a cervical intramedullary tumor. Intraoperatively the subpial tumor was found to stretch the 3rd-5th dorsal nerve roots posteriorly, which was thought to cause the intolerable headache. Total tumor resection was achieved without requiring myelotomy using electrophysiological monitoring with somatosensory and motor evoked potentials. Histological examination identified diffuse astrocytoma. Postoperatively the headache had completely resolved. Cervical astrocytoma of subpial location is a very rare cause of headache in adults. The subpial location enables surgical extirpation because minimal or no myelotomy is needed.

[A case of delayed cervical epidural hematoma with C5 nerve root palsy after posterior cervical laminoplasty]

Delayed postoperative spinal epidural hematoma (DPSEH) is a rare and potentially devastating complication of laminoplasty, and cervical nerve root palsy occurs more frequently than DPSEH, especially with C5 nerve root palsy. The authors describe a case of DPSEH with C5 nerve root palsy that developed in a patient 3 days after he underwent laminoplasty. In this case, a 78-year-old man with a history that having taken Aspirin without the doctor's instruction for 5-6 years, he underwent cervical laminoplasty for mild myelopathy. On the 3rd postoperative day, he complained of weakness of his left upper extremity and could not raise his left arm. The symptom aggravated in the next few days. On the 9th postoperative day, there was an obvious motor deficit of both upper and lower extremities. Magnetic resonance imaging demonstrated abnormal signal characteristics consistent with a hematoma at levels C3-C4, compressing spinal cord. The clot was evacuated during emergency revision surgery, and the postoperative course after the operation was uneventful and the muscle strength was improved five days later. Therefore, the symptoms of DPSEH are not so typical that its possibility should be kept in mind. Sometimes a differential diagnosis should be made with C5 nerve root palsy which may only represent weakness of upper extremities. The authors recommend that magnetic resonance imaging is helpful for the diagnosis of DPSEH and a revision surgery should be taken as soon as possible once the hematoma causing the neurologic deterioration was confirmed.

A ligamentum flavum hematoma presenting as an L5 radiculopathy

This study reports two patients with ligamentum flavum hematoma, of which only seven cases have been reported in the literature. Two elderly male patients (74 and 80 years) presented with a history of chronic lumbar strain and effort. They had low back pain radiating to both legs. Their neurologic examination findings were consistent with left L5 root compression. Magnetic resonance imaging showed an epidural mass lesion at L4-L5 that was continuous with the ligamentum flavum. After removal of the hematoma, the symptoms completely resolved. The most common cystic lesion in the lumbar spine is synovial cyst associated with the facet joints, but ligamentum flavum hematoma should be included in the differential diagnosis. The clinical, radiological and surgical features are described. Surgery should be the treatment of choice to resolve symptoms in ligamentum flavum hematoma.

Intraoperative mapping of sacral nervous system (S2-4)

Electrophysiological mapping of the sacral nervous system was used during operations on 80 patients with conus and cauda equina lesions. At surgery, under controlled muscle relaxation, the sacral neural elements (S2-4) were mapped using direct mono-polar stimulation and recording of compound muscle action potentials (CMAPs) from the external anal sphincter (EAS). Responses were obtained in 86.25% (69/80) of the patients. In 33 (82.5%) out of 40 patients with preoperative deficits involving the S2-4 segments, CMAPs could be elicited. Identification of nerve roots was useful in dissection of lipomyelomeningocoeles, tumour excisions and untethering of filum terminale. In three patients, stimulation of the filum terminale elicited motor responses and, hence, it was not sectioned. Intraoperative mapping of the S2-4 nerve roots under controlled muscle relaxation is feasible in a majority of patients, including those with deficits involving S2-4. This method was useful in sparing viable nerve roots during surgery in conus and cauda equina regions, and identification of 'functional' filum terminale.

Efficacy and safety of percutaneous sacroplasty for painful osteoporotic sacral insufficiency fractures: a prospective, multicenter trial

STUDY DESIGN

A prospective observational cohort study of consecutive osteoporotic patients with sacral insufficiency fractures (SIFs).

OBJECTIVE

Assess the safety and efficacy of sacroplasty in treating osteoporotic SIFs.

SUMMARY OF BACKGROUND DATA

SIFs can cause low back pain in osteoporotic patients. Symptomatic improvement may require up to 12 months. Treatment includes limited weight-bearing and bed rest, oral analgesics, and sacral corsets. Significant mortality and morbidity are associated with pelvic insufficiency fractures. Percutaneous sacroplasty is an alternative treatment for SIF patients, and initial reports have documented its safe and effective performance. Yet, follow-up intervals have been short, and study cohorts small precluding definitive assessment of sacroplasty's safety and efficacy.

METHODS

Baseline Visual Analogue Scale (VAS), analgesic usage, and duration of symptoms were recorded. Subsequent VAS ratings were assessed at 30 minutes and at 2, 4, 12, 24, and 52 weeks postprocedure. Analgesic usage and patient satisfaction were assessed at final follow-up. Each procedure was performed under intravenous conscious sedation using fluoroscopy. Two bone trochars were inserted between the sacral foramen and sacroiliac joint through which 2 to 3 mL of polymethylmethacrylate was injected.

RESULTS

Thirty-seven patients, 27 females, were treated. Mean age was 76.6 years, and mean symptom duration was 34.4 days. All patients were available at each follow-up interval except 1 patient who died due to unrelated pulmonary disease before the 4-week follow-up. The mean VAS score at baseline was 7.7 and 3.2 within 30 minutes, and 2.1 at 2, 1.7 at 4, 1.3 at 12, 1.0 at 24, and 0.7 at 52 weeks postprocedure. Improvement at each interval and overall was statistically significant using the Wilcoxon Rank Sum Test. One case of transient S1 radiculitis was encountered.

CONCLUSIONS

Sacroplasty appears to be a safe and effective treatment for painful SIF. The rate of improvement is rapid and sustained through 1 year.

[Sacral nerve stimulation, an effective treatment for fecal incontinence]

Sacral nerve stimulation (SNS) became recently an essential therapeutic modality in the treatment of anal incontinence. Indications range from anorectal functional disorders to limited sphincteric lesions. An electrode is inserted through a sacral foramen, generally S3, to stimulate the corresponding nerve root. Patient's selection needs a meticulous multidisciplinary approach. Improved continence of more than 50% is frequently encountered and quality of life is significantly improved after implantation. SNS is a minimal-invasive technique, with very few risks of complications.

[Posterior extrusion of Biocompatible Orthopaedic Polymer (BOP) graft mimicking a calcified lumbar disc herniation: case report]

OBJECTIVE AND IMPORTANCE

We present a case of intracanalar extrusion of a L5S1 Biocompatible Orthopaedic Polymer (BOP) graft associated with a L4L5 disc herniation 19 years after a lumbar intersomatic fusion for a L5S1 disc herniation. Radiological aspect of this complication should be recognized by neurosurgeons.

CLINICAL PRESENTATION

A 55-year old man presented with a right L5 sciatic pain. Neurological examination found a severe weakness in dorsal flexion of the foot. A lumbar CT scanner disclosed aspects consistent with right L4L5 and huge calcified L5S1 lumbar disc herniation.

INTERVENTION

The patient was operated via a bilateral paravertebral approach and a L5 laminectomy. A dense and extensive epidural scarring was seen. The right L4L5 herniated disc was excised. At the left L5S1 level, fibres from a BOP graft had separated into large fragments extruded into the vertebral canal through the dura. The fibres could only be removed partially because of nerve roots adherence. The patient developed postoperative cerebrospinal fluid (CSF) leakage that required a second operation for dural closure. The postoperative course was uneventful and the patient recovered the right L5 root deficit.

CONCLUSION

Neurosurgeons should be aware of the radiological aspect of this complication. If it is recognized on CT scan and asymptomatic, conservative management should be proposed because of the risk of nerve roots injury or postoperative CSF leakage.

Pigmented villonodular synovitis originating from the lumbar facet joint: a case report

The authors successfully treated a rare case of pigmented villonodular synovitis (PVNS) that originated from the lumbar facet joint (L4-5). A 43-year-old man presented with a complaint of left severe sciatica causing difficulty in walking. Magnetic resonance imaging (MRI) demonstrated an extradural mass on the left side at L4 and the mass compressed the dural tube and was continuous with the left L4-5 facet joint. A computed tomography myelogram revealed an extradural defect of contrast medium at the L4 level and an erosion of the L4 lamina. A total synovectomy with unilateral osteoplastic laminectomy was performed. The histological findings were a diagnosis of PVNS. The patient's symptoms resolved completely and the MRI at postoperative 3 years demonstrated no recurrence of PVNS. It is important to totally remove the synovium, which is the origin of PVNS in order to prevent the recurrence. We think that our procedure is reasonable and adequate for lumbar PVNS.

Harms titanium mesh cage fracture

Interbody fusion has become a mainstay of surgical management for lumbar fractures, tumors, spondylosis, spondylolisthesis and deformities. Over the years, it has undergone a number of metamorphoses, as novel instrumentation and approaches have arisen to reduce complications and enhance outcomes. Interbody fusion procedures are common and successful, complications are rare and most often do not involve the interbody device itself. We present here a patient who underwent an anterior L4 corpectomy with Harms cage placement and who later developed a fracture of the lumbar titanium mesh cage (TMC). This report details the presentation and management of this rare complication, as well as discusses the biomechanics underlying this rare instrumentation failure.

Contralateral radiculopathy after transforaminal lumbar interbody fusion

Transforaminal lumbar interbody fusion (TLIF) is an effective treatment for patients with degenerative spondylolisthesis and degenerative disc disease. Opposite side radiculopathy after the TLIF procedure has been recognized in this institution but has not been addressed in the literature. We present a case of opposite side radiculopathy after the TLIF procedure. We believe that this complication is related to asymptomatic stenosis on the contralateral side that is unmasked by the increased lordosis of the TLIF. The authors recommend increasing both disc height and foraminal height when choosing an interbody graft, and possibly decompressing the opposite foramen when preoperative MRI demonstrates foraminal stenosis.

Cervical Radiculopathy

Cervical radiculopathy is a condition encountered commonly in the evaluation of neck pain that may result in significant discomfort and functional deficits. Although the long-term prognosis of this condition is favorable, a standardized approach to therapy is important to minimize unnecessary tests and identify patients who require more urgent intervention. Patient education, pain control, and physical therapy are the first line of therapy. Patients who have protracted pain or significant functional deficits may require a more thorough evaluation, including imaging, electrodiagnostic testing, and, possibly, surgical referral. This article outlines the basic clinical, diagnostic, and therapy considerations in the evaluation of cervical radiculopathy.

Spread of contrast during L4 and L5 nerve root infiltration under fluoroscopic guidance

BACKGROUND

Lumbar selective nerve root blocks have been performed to establish the origin of lumbar radiculopathy in clinically difficult cases. The diagnostic ability of selective nerve root blocks remains controversial because of concern over potential spread of an injectate onto adjacent structures.

OBJECTIVE

To investigate the spread of different volumes of water-soluble contrast during L4 and L5 selective nerve root blocks.

DESIGN

Retrospective, observational case series.

METHODS

Analysis of medical records and X-ray images obtained during L4 and L5 selective nerve root blocks.

RESULTS

During L4 selective nerve root block 1 ml of contrast spread onto L5 nerve roots in 46.1% of subjects and during L5 nerve root block 1 ml of contrast spread onto S1 nerve root in 57.7%. There was statistically significant difference (p<0.0001) between spread of contrast onto the medially located nerve root in the same lumbar segment and nerve roots in the lumbar segment above.

CONCLUSIONS

Injection of 1 ml of contrast under fluoroscopic guidance does not guarantee selective spread of the contrast around L4 or L5 nerve roots only. There is also spread toward the more medial nerve root in the same spinal segment during L4 and L5 nerve root infiltration. These findings suggest that it is possible to differentiate between L4 and L5 nerve root pathology using a sequential nerve root blocks under fluoroscopic guidance.

Neurophysiological detection of iatrogenic C-5 nerve deficit during anterior cervical spinal surgery

Object

The incidence of postoperative C-5 spinal nerve root palsy following decompressive cervical spinal surgery has been reported to be as high as 12% for anterior procedures and 30% for posterior procedures. The present study was conducted to document the prevalence of iatrogenic C-5 nerve root deficit during anterior cervical spinal surgery, as well as to evaluate the sensitivity and specificity of intraoperative transcranial electrical stimulation (TES)–induced motor evoked potentials (MEPs) and spontaneous electromyographic (EMG) activity for identifying evolving C-5 nerve root impairment.

Methods

The authors conducted a retrospective study of 238 consecutive anterior cervical spinal procedures performed by a single surgeon at Christiana Care Hospital within a 48-month period. Techniques used to monitor spinal nerve root function included TES-induced MEPs and spontaneous EMG activity from deltoid, biceps, triceps, wrist extensor, and hand intrinsic muscles innervated by the C5–T1 spinal nerve roots. Spinal cord function was monitored by recording TES-induced MEPs from upper- and lower-extremity muscles as well as somatosensory evoked potentials from stimulation of the ulnar and posterior tibial nerves.

Conclusions

Transcranial electrical stimulation–induced MEPs and spontaneous EMG activity offer complementary information about evolving iatrogenic C-5 spinal nerve root impairment during anterior cervical spinal surgery. The TES-induced MEPs provide prognostic information and show increased sensitivity to C-5 deficit compared with spontaneous EMG activity alone. Monitoring of spinal nerve root function using only EMG activity carries a risk of false-negative findings; without timely warning of impending neurological impairment, timely intervention to prevent permanent deficit cannot occur.

Is spinal cord isolation a good model of muscle disuse?

The patterns of normal daily activity that are required to maintain normal skeletal muscle properties remain unknown. The present study was designed to determine whether spinal cord isolation can be used as a reliable experimental model of neuromuscular inactivity, that is, as a baseline for the absence of activity. Electromyograms (EMGs) were recorded from selected hindlimb muscles of unanesthetized rats over 24-hour periods before and 7, 30, 60, and 90 days after surgical isolation of the lumbar spinal cord. Our data indicate that some rat slow muscle fibers pre-surgery were activated for less than 3 hours per day. Spinal cord isolation (SI) reduced the mean daily integrated EMG (IEMG) and daily EMG duration in the primary slow extensor muscle (soleus) to <1% of control, and in the primary fast extensor muscles [medial gastrocnemius (MG) and vastus lateralis (VL)] to <2% of control. These parameters were decreased to <8% and 3% of control, respectively, in a primary fast flexor muscle, the tibialis anterior (TA). From 30 to 90 days post-SI, the mean amplitudes of the spontaneous EMG bursts were relatively normal in the soleus, increased approximately 2-fold in the MG and VL, and increased approximately 4-fold in the TA. Some evidence of the normal antagonistic flexor-extensor relationship was apparent in the brief periods of recorded activity post-SI. These results indicate that SI eliminates nearly all of the normal EMG activity in the hindlimb muscles in the presence of relatively normal muscle innervation and functional intraspinal neural circuitry.

Laparoscopic endopelvic sacral implantation of a Brindley controller for recovery of bladder function in a paralyzed patient

BACKGROUND

A number of techniques are being investigated to accomplish bladder control recovery in paralyzed patients using the neurostimulation, but currently, all techniques are based on the dorsal implantation of the electrodes using a laminectomy.

METHODS

On 27 April 2006 we performed a laparoscopic implantation of a Finetech-Brindley bladder controller on the endopelvic sacral roots in a Th8 completely paralyzed woman who had previously undergone the removal of a Brindley controller due to an arachnoiditis after extrathecal implantation with intradural sacral deafferentation.

RESULTS

We required about 3.5 h for the entire surgical procedure; no complications occurred and the patients went home on 5th postoperative day. The patient is now able to void empty her bladder and her rectum using the controller without further need for self-catheterisation.

CONCLUSIONS

The presented new technique of laparoscopic implantation of electrodes on the endopelvic portion of the sacral nerve roots is an option to be considered in all paralyzed patients with further wish for electrical induced miction/defecation after previous deafferentation.

Cervical radiculopathy: pathophysiology, presentation, and clinical evaluation

Cervical radiculopathy is a common condition that usually results from compression and inflammation of the cervical nerve root or roots in the region of the neural foramen. It is frequently caused by cervical disc herniation and cervical spondylosis. The diagnosis can be established by history and physical examination, but care should be taken, as diagnoses can mimic or coexist with cervical radiculopathy, such as entrapment neuropathies. The pathophysiology, presentation, and clinical evaluation of cervical radiculopathy are discussed.

Neuromodulation of the cervical spinal cord in the treatment of chronic intractable neck and upper extremity pain: a case series and review of the literature

Electrical spinal neuromodulation in the form of spinal cord stimulation is currently used for treating chronic painful conditions such as complex regional pain syndrome, diabetic neuropathy, postherpetic neuralgia, peripheral ischemia, low back pain, and other conditions refractory to more conservative treatments. To date, there are very few published reports documenting the use of spinal cord stimulation in the treatment of head/neck and upper limb pain. This paper reports a case series of 5 consecutive patients outlining the use of spinal cord stimulation to treat upper extremity pain. All subjects had previously undergone cervical fusion surgery to treat chronic neck and upper limb pain. Patients were referred following failure of the surgery to manage their painful conditions. Spinal cord stimulators were placed in the cervical epidural space through a thoracic needle placement. Stimulation parameters were adjusted to capture as much of the painful area(s) as possible. In total, 4 out of 5 patients moved to implantation. In all cases, patients reported significant (70-90%) reductions in pain, including axial neck pain and upper extremity pain. Interestingly, 2 patients with associated headache and lower extremity pain obtained relief after paresthesia-steering reportedly covered those areas. Moreover, 2 patients reported that cervical spinal cord stimulation significantly improved axial low back pain. Patients continue to report excellent pain relief up to 9 months following implantation. This case series documents the successful treatment of neck and upper extremity pain following unsuccessful cervical spine fusion surgery. Given this initial success, prospective, controlled studies are warranted to more adequately assess the long term utility and cost effectiveness of electrical neuromodulation treatment of chronic neck and upper extremity pain.

Intraoperative electrophysiologic studies on the functions of nerve roots involved in cervical dumbbell-shaped schwannoma and their clinical utility

BACKGROUND

It is difficult to expect the degree of neurologic deficits after resection of involved nerve roots before and during the surgery for cervical dumbbell-shaped schwannoma. We present the results of studies for cervical nerve root functions in patients with cervical schwannoma using intraoperative electrophysiologic assessment and the potential of their clinical relevance is also discussed.

OBJECTIVE

To present the utility of intraoperative electrophysiologic studies to detect the functions of the nerve roots involved in cervical schwannoma and adjacent nerve roots.

METHODS

Five patients with dumbbell-shaped cervical schwannoma arising from the cervical nerve roots composing the brachial plexus were studied. Compound muscle action potentials (CMAPs) after stimulation of nerve roots involved in the schwannoma were recorded from upper limb muscles anatomically correspond to their myotome. Adjacent nerve roots were also stimulated. Motor-evoked potentials (MEPs) after transcranial electric stimulation were also recorded during surgery. In 3 patients, sensory nerve action potentials (SNAPs) after digital nerve stimulation were also recorded from cervical nerve roots.

RESULTS

In 4 patients, CMAPs after stimulation of cervical nerve roots involved with the schwannoma were not obtained or were very small compared with those obtained after stimulation of adjacent nerve roots. In 2 of 4 patients, SNAPs after digital nerve stimulation were recorded with small amplitude from the nerve roots involved in schwannoma. Minimal (n=2, within 80% attenuation of amplitude) or no changes (n=2) were observed after total resection of the schwannoma and no apparent motor weakness occurred in these 4 patients. In a patient with cervical schwannoma involved in C8 nerve root, CMAPs with large amplitude were recorded after stimulation of the C8 nerve root. SNAPs after stimulation of digit V were recorded with larger amplitude from the T1 root compared with those recorded from the C8 nerve root. Intradural parts of the tumor arising from C8 posterior rootlets were completely removed after transaction of posterior rootlets. During removal of intraforaminal parts of the tumor, motor evoked potentials were decreased over 50% of controls. Incomplete removal was chosen to avoid deterioration of motor function. Transient dysesthesia of digit V and slight weakness occurred after surgery.

CONCLUSIONS

The residual function of motor and sensory nerve roots involved with cervical schwannoma differed between individuals and could be detected using intraoperative electrophysiologic assessment.

Minimally Invasive 2-Level Posterior Cervical Foraminotomy

INTRODUCTION

The management of cervical radiculopathy has undergone significant evolution, and the most recent advancement is the integration of minimally invasive surgical techniques. There have been relatively few reports in the medical literature describing the clinical results of minimally invasive cervical spine surgery. The authors describe the surgical indications, technique, and preliminary clinical outcomes in a series of patients who underwent the 2-level minimally invasive posterior cervical foraminotomy procedure.

METHODS

This report is composed of 21 consecutive patients with cervical radiculopathy who underwent a minimally invasive 2-level posterior cervical foraminotomy at our institution between 2003 and 2005. Magnetic resonance imaging demonstrated foraminal or posterolateral pathology at 2 ipsilateral adjacent spinal levels in each patient. Radicular arm pain was the most common presenting symptom, and was encountered in all 21 patients.

RESULTS

The mean follow up for the patients was 23 months (range 12 to 36). Complete resolution of preoperative symptoms was achieved in 19 out of 21 patients (90%). Sixteen patients were discharged home the same day of surgery, and the mean estimated blood loss was 35 mL (range 10 to 100 mL). There were no perioperative complications.

CONCLUSIONS

Minimally invasive 2-level posterior cervical foraminotomy can be safely performed on an outpatient basis with results comparable to that of conventional foraminotomy. This procedure should be considered as a potential alternative to 2-level anterior cervical discectomy and fusion or open foraminotomy in selected patients.

Intraoperative electromyography monitoring in minimally invasive transforaminal lumbar interbody fusion

Object

Minimally invasive transforaminal lumbar interbody fusion (TLIF) is an increasingly popular method for achieving lumbar decompression and fusion. The procedure is technically more demanding than open fusion, with correspondingly more theoretical risk of complication. The authors describe the use of intraoperative electromyography (EMG) as an adjunct to surgery to reduce the risk of complications.

Methods

Between August 2005 and April 2006, 25 consecutive patients underwent minimally invasive TLIF in which a total of 105 pedicle screws were placed. Intraoperative EMG was performed and included passive recordings during decompression and interbody graft placement, as well as active recording during the placement of the pedicle access needle and testing of the pedicle tap. A uniform protocol for active monitoring was used, with the pedicle access needle set at 7 mA. To assess hardware placement, all patients underwent postoperative radiography and 20 underwent postoperative computed tomography (CT) scanning.

In no patient did the authors observe significant EMG activation during decompression. In five cases, intermittent nerve root firing was noted after the interbody graft was placed, but this did not correlate with any postoperative deficits. Using the active stimulation protocol, 76.2% of screw placements required one or more changes to the trajectory of the pedicle access needle. With successful placement of the pedicle access needle, in all 105 screws, the pedicle tap nerve root stimulation threshold was greater than 15 mA. Postoperative radiography was performed in all patients and CT scanning was performed in 20 patients (with 85 screws being placed). Postoperative imaging revealed only three cases of pedicle breach. In all cases, the breach was at the lateral wall of the pedicle and not thought to be clinically relevant.

Conclusions

A continuous stimulation pedicle access needle alerts the surgeon to incorrect medial trajectories and may lead to safer pedicle cannulation. As a result of electrophysiological feedback, the pedicle access needle trajectory was altered in 76.2% of the reported cases. The use of the authors’ protocol resulted in a 0% incidence of clinically relevant malpositioned hardware and a low overall neurological complication rate. Intraoperative nerve root monitoring is a useful adjunct to minimally invasive TLIF.

Anterior decompression via a wide transvertebral approach and a ceramic insert in a patient with cervical degenerative disease

BACKGROUND

The transvertebral approach is useful for decompression in patients with cervical radiculopathy; because the intervertebral disk is preserved, moveability is retained. We performed wide deletion of the vertebral body to increase the patient population eligible for treatment with this approach and include patients with compression of the cervical spinal cord.

METHODS

In patients undergoing anterior decompression, we performed vertebrotomy (13 x 8 mm) at the midline of the cervical vertebral body at the upper level using a surgical saw. The resulting hole facilitates decompression of the cervical cord and nerve root; a ceramic insert is introduced in the area of deletion. To prevent graft extrusion, the bilateral wings of the bone graft are fastened with bioabsorbable screws.

RESULTS

We used this approach in 163 patients with several cervical diseases. Collapse of the vertebral body and fusion of the operated intervertebral disk were encountered in only 1 patient (0.61%). There was no significant difference between pre- and postoperative alignment. Reoperation was required in 7 patients whose symptoms did not improve, in 1 with disk hernia, in 5 with severe spondylosis, and in 1 with combined-type OPLL.

CONCLUSIONS

Although this approach is appropriate in patients undergoing cervical anterior decompression, the narrowness of the visual field may result in insufficient decompression, and its indication is restricted to patients with cervical disk hernia, mild cervical spondylosis, and segmental OPLL. In patients with segmental instability, continuous or combined OPLL, severe cervical spondylosis, and kyphosis, this approach should not be used.

Posttraumatic intratumoural haemorrhage: an unusual presentation of spinal ependymoma

Ependymomas presenting with intratumoural and/or subarachnoid haemorrhages are seen rarely. These haemorrhages are mostly due to anticoagulation, epidural analgesia or pregnancy. A 62-year-old male farmer with cauda equina syndrome after a work-related trauma is presented. He was admitted to our hospital with paraparesis, faecal incontinence and sensory loss below the level of the lumbar-2 dermatome. Magnetic resonance imaging of the spine displayed an intradural mass lesion at the level of the first lumbar vertebrae. The lesion was excised totally via dorsal midline approach. Histopathologic examination revealed grade-3 ependymoma with intratumoural haemorrhage. The patient's symptoms were relieved completely on postoperative day 7. The patient was given information about periodical examination for recurrence and discharged on the third postoperative week. Asymptomatic spinal lesions should be considered for operation whenever detected because of unpredicted complications.

Percutaneous endoscopic discectomy for extraforaminal lumbar disc herniations: extraforaminal targeted fragmentectomy technique using working channel endoscope

STUDY DESIGN

A retrospective analysis of 41 patients operated for excision of soft lumbar extraforaminal disc herniation (EFDH) by percutaneous endoscopic extraforaminal approach under local anesthesia by a new technique.

OBJECTIVES

To describe a new and safer percutaneous endoscopic technique for the removal of soft EFDH and report the results on the basis of a new objective criterion modified from Oswestry Disability Index (ODI).

SUMMARY OF BACKGROUND DATA

EFDHs usually occur in older patients and present with atypical symptoms. Their diagnosis and treatment are still controversial, with various authors describing open midline or paraspinal approaches using the microscope with varying amounts of success. Percutaneous endoscopic techniques have traditionally been considered unsuitable for these herniations.

METHODS

Forty-one patients with a soft EFDH were subjected to percutaneous endoscopic discectomy with the new technique. In our technique, the skin entry point is medial and the angle of approach steeper as compared with the earlier described endoscopic techniques. This might help in avoiding exiting root injury and increasing the efficacy of the procedure. The results were analyzed on the basis of percentage change in ODI as compared with preoperative values.

RESULTS

Mean follow-up was 34.1 month. Mean VAS score for radicular pain improved from 8.6 to 1.9, and mean ODI improved from 66.3 to 11.5. Overall, 92% of patients experienced satisfactory outcome. Two patients had poor outcome due to the need for subsequent open surgery.

CONCLUSION

Percutaneous endoscopic discectomy using the "extraforaminal targeted fragmentectomy" technique is an effective and safe procedure for the select group of patients with a soft EFDH.