Anatomical damages in the spinal nerve roots and the spinal cord after brachial plexus injury: descriptive study from a cohort of consecutive patients who underwent DREZ-lesioning for pain-practical implications.

BACKGROUND: Systematic descriptions of anatomical damage after brachial plexus injury (BPI) at the intradural level have been scarcely reported in detail. However, considering these damages, not only in the spinal nerve roots but also in the spinal cord itself, is crucial in determining the appropriate surgical approach to restore upper limb function and address refractory pain. Therefore, the authors present a descriptive study focusing on intradural findings observed during microsurgical DREZ-lesioning. METHODS: This study enrolled 19 consecutive patients under the same protocol. Microsurgical observation through exposure of C4 to Th1 medullary segments allowed to describe the lesions in spinal nerve roots, meninges, and spinal cord. Electrical stimulation of the ventral roots checked the muscle responses. RESULTS: Extensive damage was observed among the 114 explored roots (six roots per patient), with only 21 (18.4%) ventral (VR) and 17 (14.9%) dorsal (DR) roots retaining all rootlets intact. Damage distribution varied, with the most frequent impairments in C6 VRs (18 patients) and the least in Th1 VRs (14 patients), while in all the 19 patients for the C6 DRs (the most frequently impaired) and in 14 patients for Th1 DRs (the less impaired). C4 roots were found damaged in 12 patients. Total or partial avulsions affected 63.3% and 69.8% of DRs and VRs, respectively, while 15.8% and 14.0% of the 114 DRs and VRs were atrophic, maintaining muscle responses to stimulation in half of those VRs. Pseudomeningoceles were present in 11 patients but absent in 46% of avulsed roots. Adhesive arachnoiditis was noted in 12 patients, and dorsal horn parenchymal alterations in 10. CONCLUSIONS: Knowledge of intradural lesions post-BPI helps in guiding surgical indications for repair and functional neurosurgery for pain control.

Excitability of the radiculo-medullary circuitry in spastic cerebral palsy: An intraoperative neurophysiological study in children undergoing selective dorsal rhizotomy.

AIM: To explore - through intraoperative neurophysiology mapping and recordings - the comparative distribution of the reflexive excitability of the L2 to S2 radiculo-metameric segments of the spinal cord in a series of children with bilateral spastic cerebral palsy (CP) who underwent selective dorsal rhizotomy (SDR). METHOD: Our series included 46 consecutive children (36 males, 10 females; aged 5-16 years, mean 8 years) who underwent SDR, using keyhole interlaminar dorsal rhizotomy. The procedure allowed access to all L2 to S2 roots independently, while preserving the posterior architecture of the lumbar spine. Dorsal roots were stimulated selectively to test reflexive excitability of the corresponding radiculo-metameric levels. Stimulation parameters were identical for all roots for optimal comparison between root levels, with an intensity just above threshold to avoid excessive diffusion. The responses in the main muscular groups in each lower limb were clinically observed and electromyograms recorded. Degrees of excitability were quantified according to Fasano's scale. RESULTS: The difference between root levels was highly significant. Median values of excitability were 1, 2, 3, 3, 3, and 3 for the L2, L3, L4, L5, S1, and S2 levels respectively. Lower root levels exhibited significantly more excitability. INTERPRETATION: In addition to insight into the spasticity of children with CP, the profile of segmental excitability can be useful in establishing surgical planning when programming SDR. WHAT THIS PAPER ADDS: Keyhole interlaminar dorsal rhizotomy modality allowed selective stimulation of all L2-S2 dorsal roots for testing excitability. There were significant differences in reflexive excitability of L2-S2 radiculo-medullary segments. Lower segments of L2-S2 medullary levels have higher excitability. Interindividual variability in excitability of lumbosacral segments justifies intraoperative neurophysiology. This original article is commented on by Young on pages 9-10 of this issue.

Muscle Tone Assessment under General Anesthesia for Sjögren-Larsson Syndrome and Spasticity.

INTRODUCTION: Study of muscle tone in individuals with severe spasticity (Modified Asworth Scale - MAS:3) under general anesthesia can confirm or rule out the eventual necessity of the impending spasticity relieving ablative neurosurgery by observing the hypertonia reduction and passive range of motion expansion. Therefore, what we measure under muscle relaxants is practically a fixed deformity. CASE PRESENTATION: The study was performed on a girl with Sjögren-Larsson syndrome, presenting with icthyosis and spastic diplegia. Proposed intervention was Dorsal Rhizotomy. Under general anesthesia, with and without muscle relaxants, hypertonia was significantly reduced (MAS:1), but the angle of motion did not increase much. CONCLUSION: We decided not to perform such a neurosurgical procedure. In ambiguous situations, the proposed study can help in decision-making for spasticity treatment.

How I do it: Selective dorsal rhizotomy, using interlaminar approaches, for spastic diplegia/quadriplegia in children with cerebral palsy.

BACKGROUND: Dorsal rhizotomy is considered the gold standard for treating spastic diplegia/quadriplegia in children with cerebral palsy, when rehabilitation programs reveal insufficient to control excess of spasticity. METHOD: The Keyhole Interlaminar Dorsal rhizotomy modality has been developed to access-individually-all L2-S2 roots, intradurally at the corresponding dural sheath, and preserve the posterior spine architecture. Intraoperative neuromonitoring consists of stimulating each ventral root, to verify its myotomal innervation, and dorsal roots, to explore their reflexive muscular responses in order to help determination of the proportion of rootlets to be cut. CONCLUSION: This modality, which requires 5 ± 1 h duration, offers tailored accuracy.

Usefulness of external anal sphincter EMG recording for intraoperative neuromonitoring of the sacral roots-a prospective study in dorsal rhizotomy.

BACKGROUND: In conus medullaris and cauda equina surgery, identification of the sacral nerve roots may be uncertain in spite of their anatomical/radiological landmarks. Mapping the sacral roots by recording the muscular responses to their stimulation may benefit from EMG recording of the External Anal sphincter (EAS) in addition to the main muscular groups of the lower limbs. METHOD: In a consecutive series of 27 lumbosacral dorsal rhizotomy (DRh), authors carried out a prospective study on the reliability of the EMG recording of the EAS for identification of the S1 and S2 sacral roots. RESULTS: An EAS-response was recorded in all the 27 (bilaterally) explored individuals, testifying good sensitivity and selectivity of the method. EAS-responses were obtained in 96.3% of the 54 stimulated sides of the S2 root versus in only 16.66% for the S1 root, so that an absence of response would indicate S1 rather than S2 level. Furthermore, comparison between myotomal distribution of the S1 and S2 roots showed a significant difference (p < 0.00001), so that myotomal profile may help to identify root level. CONCLUSIONS: EMG recording of the EAS can be recommended for current intraoperative neuromonitoring. This simple method also provides-indirectly by extrapolation-information on the sacral motor pathways of the external urethral sphincter (EUS), as the later has the same somatic innervation via the pudendal nerve and related S2, S3, and S4 roots. Method can be helpful not only for DRh, of all varieties, but also for spine surgery, correction of dysraphisms, lipomas and/or tethered cord, and tumor resection.

Muscle responses to radicular stimulation during lumbo-sacral dorsal rhizotomy for spastic diplegia: Insights to myotome innervation.

OBJECTIVE: Most of knowledge on muscle radicular innervation was from explorations in root/spinal cord pathologies. Direct and individual access to each of the lumbar-sacral -ventral and dorsal- nerve roots during dorsal rhizotomy for spastic diplegia allows precise study of the corresponding muscle innervation. Authors report the lumbo-sacral segmental myotomal organization obtained from recordings of muscle responses to root stimulation in a 20-children prospective series. METHODS: Seven key-muscles in each lower limb and anal sphincter were Electromyography (EMG)-recorded and clinically observed by physiotherapist during L2-to-S2 dorsal rhizotomy. Ventral roots (VR), for topographical mapping, and dorsal roots (DR), for segmental excitability testing, were stimulated, just above threshold for eliciting muscular response. RESULTS: In 70% of the muscles studied, VR innervation was pluri-radicular, from 2-to-4 roots, with 1 or 2 roots being dominant at each level. Overlapping was important. Muscle responses to DR stimulation were 1.75 times more extended compared to VR stimulation. Inter-individual variability was important. CONCLUSIONS: Accuracy of root identification and stimulation with the used method brings some more precise information to radicular functional anatomy. SIGNIFICANCE: Those neurophysiological findings plead for performing Intra-Operative Neuromonitoring when dealing with surgery in the lumbar-sacral roots.

Dorsal rhizotomy for children with spastic diplegia of cerebral palsy origin: usefulness of intraoperative monitoring.

OBJECTIVE The utility of intraoperative neuromonitoring (ION), namely the study of muscle responses to radicular stimulation, remains controversial. The authors performed a prospective study combining ventral root (VR) stimulation for mapping anatomical levels and dorsal root (DR) stimulation as physiological testing of metameric excitability. The purpose was to evaluate to what extent the intraoperative data led to modifications in the initial decisions for surgical sectioning established by the pediatric multidisciplinary team (i.e., preoperative chart), and thus estimate its practical usefulness. METHODS Thirteen children with spastic diplegia underwent the following surgical protocol. First, a bilateral intradural approach was made to the L2-S2 VRs and DRs at the exit from or entry to their respective dural sheaths, through multilevel interlaminar enlarged openings. Second, stimulation-just above the threshold-of the VR at 2 Hz to establish topography of radicular myotome distribution, and then of the DR at 50 Hz as an excitability test of root circuitry, with independent identification of muscle responses by the physiotherapist and by electromyographic recordings. The study aimed to compare the final amounts of root sectioning-per radicular level, established after intraoperative neuromonitoring guidance-with those determined by the multidisciplinary team in the presurgical chart. RESULTS The use of ION resulted in differences in the final percentage of root sectioning for all root levels. The root levels corresponding to the upper lumbar segments were modestly excitable under DR stimulation, whereas progressively lower root levels displayed higher excitability. The difference between root levels was highly significant, as evaluated by electromyography (p = 0.00004) as well as by the physiotherapist (p = 0.00001). Modifications were decided in 11 of the 13 patients (84%), and the mean absolute difference in the percentage of sectioning quantity per radicular level was 8.4% for L-2 (p = 0.004), 6.4% for L-3 (p = 0.0004), 19.6% for L-4 (p = 0.00003), 16.5% for L-5 (p = 0.00006), and 3.2% for S-1 roots (p = 0.016). Decreases were most frequently decided for roots L-2 and L-3, whereas increases most frequently involved roots L-4 and L-5, with the largest changes in terms of percentage of sectioning. CONCLUSIONS The use of ION during dorsal rhizotomy led to modifications regarding which DRs to section and to what extent. This was especially true for L-4 and L-5 roots, which are known to be involved in antigravity and pelvic stability functions. In this series, ION contributed significantly to further adjust the patient-tailored dorsal rhizotomy procedure to the clinical presentation and the therapeutic goals of each patient.

Primary Ewing sarcoma of the axis-C2: A case report and the review of the literature.

INTRODUCTION: Neck pain and torticollis are common symptoms in the pediatric population that rarely requires further investigation. However, in case symptoms persist, then a more meticulously approach should be considered. Underlying conditions such as infections, neck injury, autoimmune disorders or even cervical spine cancer should be excluded from diagnosis. Cervical spine cancer is a rare neurosurgical entity in the pediatric population and even rarer is atlantoaxial Ewing's sarcoma. In this report, we present a rare case of primary Ewing's sarcoma of the axis. CASE REPORT: A 3.5-year-old female with progressive neck pain and intermittent episodes of torticollis was referred to our outpatient clinic. Imaging studies revealed a malignant tumor located on C2 vertebra. Diagnosis of Ewing's Sarcoma was confirmed via open biopsy and the patient was treated with Euro-EWING 99 chemotherapy. CONCLUSION: Pediatric neck pain and/or torticollis should raise high suspicion for malignancy of cervical spine. Modern diagnostic means and techniques can assist in the screening and diagnosis of these tumors.

Intraoperative Monitoring of Diaphragm Neural Pathways During Cervical Surgery by Electrical Stimulation and Recordings of Ventilator Waveforms: Physiological Bases and Pilot Study.

BACKGROUND: Surgery on the cervical spine entails the risk of damaging the neural structures responsible for diaphragmatic innervation, namely (C3)-C4-(C5) roots. In some "difficult" cases, anatomic identification of these structures may be hard to achieve. Therefore, monitoring of the diaphragm through the ventilation waveforms displayed on the anesthesia machine can be of practical help. According to literature review, very few publications have reported such monitoring. METHODS: The present work aimed at investigating the feasibility and reliability of identifying cervical root(s) responsible for diaphragmatic innervation, by observing the changes on the recorded waveforms, indicating diaphragmatic responses to direct radicular electrical stimulation. In this study, the events not only on the capnography curve but also on pressure-time and flow-time waveforms were analyzed. Eight patients undergoing cervical Microsurgical DREZotomy (MDT) were enrolled in the study, as this surgical modality allows easy access to the C4 root, known to be prominent in diaphragmatic innervation. The technique did not require any harmful additional maneuver to the current anesthesia and surgical protocols. RESULTS: Stimulation resulted in specific patterns of changes in the 3 waveforms in all 8 patients and proved "easy" to interpret, provided that close cooperation exists between the anesthesiologist and the surgeon. CONCLUSION: Intraoperative monitoring of the diaphragmatic responses to stimulation can be advocated in surgery at the cervical spine level, and also more widely in surgery in the supraclavicular region, when neural structures responsible for diaphragmatic function are at risk.

Focal Dystonia in Hemiplegic Upper Limb: Favorable Effect of Cervical Microsurgical DREZotomy Involving the Ventral Horn - A Report of 3 Patients.

BACKGROUND: Focal dystonia in hemiplegic upper limbs is poorly responsive to medications or classical neurosurgical treatments. Only repeated botulinum toxin injections show efficacy, but in most severe cases effects are transient. OBJECTIVES: Cervical DREZ lesioning, which has proven efficacious in hyperspasticity when done deeply (3-5 mm) in the dorsal horn, may have favorable effects on the dystonic component when performed down to, and including, the base of the ventral horn (5-6 mm in depth). METHODS: Three patients underwent deep cervical microsurgical DREZotomy (MDT) for focal dystonia in the upper limb. RESULTS: Hypertonia was reduced, and sustained dystonic postures were suppressed. Residual motor function (hidden behind hypertonia) came to the surface. CONCLUSIONS: Cervical MDT may be a useful armamentarium for treating refractory focal dystonia in the upper limb.

Ventilator waveforms on anesthesia machine: a simple tool for intraoperative mapping of phrenic nerve and mid-cervical roots.

BACKGROUND: A crucial aspect of surgery on the supraclavicular region, lateral neck, and mid-cervical vertebral region is the identification and sparing of the phrenic nerve and cervical (C4) root that are responsible for diaphragmatic innervation. Therefore intraoperative mapping of these nerve structures can be useful for difficult cases. Electrical stimulation with simultaneous observation of the ventilator waveforms of the anesthesia machine provides an effective method for the precise intraoperative mapping of these structures. In the literature, there is only one publication reporting the use of one of the waveforms (capnography) for this purpose. METHODS: Capnography and pressure-time waveforms, two mandatory curves in anesthesiological monitoring, were studied under electrical stimulation of the phrenic nerve (one patient) and the C4 root (eight patients). The aim was to detect changes that would verify diaphragmatic contraction. No modifications in anesthesia or surgery and no additional maneuvers were required. RESULTS: In all patients, stimulation was followed by identifiable changes in the two waveforms, compatible with diaphragmatic contraction: acute reduction in amplitude on capnography and repetitive saw-like elevations on pressure-time curve. Frequency of patterns on pressure-time curve coincided with the frequency of stimulation; therefore the two recordings were complementary. CONCLUSIONS: This simple method proved effective in identifying the neural structures responsible for diaphragmatic function. We therefore suggest that it should be employed in the various types of surgery where these structures are at risk.

Keyhole interlaminar dorsal rhizotomy for spastic diplegia in cerebral palsy.

BACKGROUND: The efficiency and safety of dorsal rhizotomies for cerebral palsy lie in the accuracy of radicular identification together with selectivity of root sectioning. Two different exposures are currently in use. The first is extended laminotomy/laminectomy from the upper lumbar level to the sacrum, which allows accurate identification of all L2-S2 roots/rootlets. The second is limited laminotomy exposing the conus/cauda equina at the thoracolumbar junction; this less invasive method limits accessibility to the roots. To optimize the accuracy and selectivity while minimizing invasiveness, the authors developed a tailored interlaminar procedure targeting the radicular levels involved in the harmful components of spasticity directly and individually. METHODS: Six patients with spastic diplegia at different levels of the Gross Motor Functional Classification System were selected. In each patient, two to three interlaminar spaces, preselected according to planning, were enlarged in the "keyhole" fashion, respecting the spinous processes and interspinous ligaments. Ventral root stimulation identified the radicular level. Dorsal root stimulation evaluated its implication in the hyperactive segmental circuits, helping quantify the percentage of rootlets to be cut. RESULTS: There were neither wound-related nor general complications. At 1 year of follow-up, X-ray examination did not reveal kyphosis or instability. In all children, the excess of spasticity was reduced. The Ashworth score decreased from 3.2 on average to 0.6 postoperatively (range: 2-4 to 0-2). Regarding the functional status at 1 year of follow-up for the three ambulatory children, the Gillette ability-to-walk score increased from 3/10 on average to 7.3/10 postoperatively (range: 2-4 to 7-8). For the three non-ambulatory children, abnormal postures, painful contractures and ease of care were much improved. CONCLUSION: Keyhole interlaminar dorsal rhizotomy (KIDr) offers direct intradural access to each of the ventral/dorsal roots, thus maximizing the reliability of anatomical mapping and allowing individual physiological testing of all targeted roots. The interlaminar approach minimizes invasiveness by respecting the posterior spine structures.

Achondroplasia with synostosis of multiple sutures.

We report for the second time on a case of achondroplasia with synostosis of multiple sutures. The most common mutation for achondroplasia (FGFR3 Gly380Arg, resulting in 1138G>A) was identified. Imaging studies disclosed complex craniosynostosis and neurosurgical intervention was carried out, particularly for posterior plagiocephaly.

Cerebral abnormalities in infants with myelomeningocele.

BACKGROUND AND PURPOSE: We evaluated brain abnormalities associated with myelomeningocele in infants. MATERIAL AND METHODS: Between June 1995 and June 2008, 42 patients with myelomeningocele were treated in our hospital. Only 24 patients (13 males, 11 females, mean age 1.5 months, range 1 day - 11 months) were evaluated by both spinal and brain magnetic resonance imaging (MRI) and were enrolled in the study. RESULTS: Brain MRI revealed: hydrocephalus in 21 (87.5%) patients, all of whom required immediate shunting. Total agenesis of the corpus callosum was observed in 2 (8.3%) patients, partial agenesis was seen in 4 (17%) patients and 8 (34%) patients had dysplasia of the corpus callosum. Absence of the septum pellucidum was observed in 2 (8%) patients. Widening of the interhemispheric fissure and colpocephaly were noted in 10 (41%) and in 3 (12%) patients, respectively. Abnormal white matter maturation was observed in 2 (8%) patients. Small posterior fossa was observed in 18 (74%) patients, Chiari malformation in 16 (67%) patients, cerebellar and brain stem hypoplasia in 3 (12%) and 7 (30%) patients, respectively. CONCLUSIONS: MRI examination of the myelomeningocele site is not sufficient. Clinicians should consider obtaining imaging studies of the entire neuraxis in patients with myelomeningocele.

Anaplastic oligodendrogliomas after treatment of acute lymphoblastic leukemia in children: report of 2 cases.

Radiation-induced brain tumors are suggested to be the late complication of acute lymphoblastic leukemia (ALL) treatment. High-grade gliomas, meningiomas, and sarcomas are the most frequent neoplasms. Secondary anaplastic oligodendrogliomas are exceedingly rare. Five cases of pure anaplastic oligodendroglioma have been reported in the literature, and only 1 case was in a child after ALL treatment. The authors present 2 cases of pediatric anaplastic oligodendroglioma after treatment of ALL. Furthermore, they performed a molecular cytogenetic study and found loss of 1p in both cases. The authors provide a review of the previous cases and discuss their findings.

Extragastrointestinal stromal tumors of the omentum: review apropos of a case with a novel gain-of-function KIT mutation.

INTRODUCTION: We describe a case of extragastrointestinal stromal tumor (EGIST) of the omentum harboring a novel KIT mutation and review the literature on omental EGISTs, emphasizing on molecular genetic data. CASE PRESENTATION: A large EGIST arising from the lesser omentum was incidentally diagnosed in a 68-year-old man during emergency laparotomy for intra-abdominal hemorrhage following a car accident. The tumor was composed of CD117+/CD34+ spindle-shaped cells with low mitotic activity. Analysis of tumor DNA revealed a heterozygous duplication of 30 bp in exon 11 of KIT. Nine months after R0 resection, positron emission tomography showed abnormal uptake in the upper abdomen. The patient was treated with imatinib mesylate and is alive and well 2 years after the operation. DISCUSSION: Omental EGISTs remain silent despite a large tumor size. They are diagnosed at a median age of 65 years and show low proliferative activity in the majority (about 80%) of cases. Although the median follow-up period of published cases is only 20 months, mortality appears to be low after R0 resection and is expected to decrease further following the recent introduction of imatinib therapy for high-risk tumors. Accumulating molecular genetic data may lead to improved prognostic classification and patient management.