Utility of Magnetic Resonance Imaging for Ligamentous Injury in Cervical Spine Trauma: A 2-Year Consecutive Case Cohort.

BACKGROUND: Magnetic resonance imaging (MRI) is increasingly used as an adjunct to spinal soft tissue evaluation in cervical spine (C-spine) trauma; however, the utility of this information remains controversial. In this consecutive observational study, we reviewed the utility of MRI in patients with C-spine trauma. METHODS: We identified patients in real time over a 2-year period as they presented to our level 1 trauma center for C-spine computed tomography (CT) scan followed by MRI. MRI was obtained by the trauma team prior to the spine service consultation if (1) they were unable to clear the C-spine according to protocol or (2) if the on-call radiologist reported a concern for ligamentous integrity from the CT findings. RESULTS: Thirty-three patients, including 19 males (58%) and 14 females, with a mean age of 54 years, were referred to the spine service for concerns of ligamentous instability. The most common mechanisms of injury were motor vehicle accidents (n = 13) and falls (n = 11). MRI demonstrated ligamentous signal change identified by the radiologist as potentially unstable in all patients. Fifteen patients (45%) had multiple C-spine ligaments affected. The interspinous ligament was involved most frequently (28%), followed by the ligamentum flavum (21%) and supraspinous ligament (15%). All patients underwent dynamic upright C-spine X-rays that were interpreted by both the ordering surgeon and radiologist. There was no evidence of instability in any patient; concurrence between X-ray interpretation was 100%. The cervical collar was successfully removed in all cases. No patients required late surgical intervention, and there were no return visits to the emergency department of a spinal nature. CONCLUSIONS: MRI signal change within the ligaments of the C-spine should be interpreted with caution in the setting of trauma. To physicians less familiar with spinal biomechanics, MRI findings may be perceived in an inadvertently alarming manner. Bony alignment and, when indicated, dynamic upright X-rays remain the gold standard for evaluating the ligamentous integrity of the C-spine.

Early Intervention of Cold-Water Swimming on Functional Recovery and Spinal Pain Modulation Following Brachial Plexus Avulsion in Rats.

Brachial plexus avulsion (BPA) causes peripheral nerve injury complications with motor and sensory dysfunction of the upper limb. Growing evidence has shown an active role played by cold-water swimming (CWS) in alleviating peripheral neuropathic pain and functional recovery. This study examined whether CWS could promote functional recovery and pain modulation through the reduction of neuroinflammation and microglial overactivation in dorsal horn neurons at the early-stage of BPA. After BPA surgery was performed on rats, they were assigned to CWS or sham training for 5 min twice a day for two weeks. Functional behavioral responses were tested before and after BPA surgery, and each week during training. Results after the two-week training program showed significant improvements in BPA-induced motor and sensory loss (p < 0.05), lower inflammatory cell infiltration, and vacuole formation in injured nerves among the BPA-CWS group. Moreover, BPA significantly increased the expression of SP and IBA1 in dorsal horn neurons (p < 0.05), whereas CWS prevented their overexpression in the BPA-CWS group. The present findings evidenced beneficial rehabilitative effects of CWS on functional recovery and pain modulation at early-stage BPA. The beneficial effects are partially related to inflammatory suppression and spinal modulation. The synergistic role of CWS combined with other management approaches merits further investigation.

Non missile penetrating spinal injury.

Non-missile penetrating spinal injury (NMPSI) is a rare form of traumatic spinal injury. Cases with neurological deficit on presentation are treated surgically. In the extremely rare circumstance of NMPSI presenting with no neurological deficit the management is contentious. We report a case of a 43-year-old male presenting with a penetrating stab injury through the thoracolumbar spinal canal. On presentation he had no neurological deficits and subsequently the knife was removed in theatre without deep surgical exploration. In this report we review the literature of non-missile penetrating spinal injuries as well as their management and conclude that exploratory surgery for NMPSI without neurological deficit may not be necessary as previously thought.

Ultrashortwave radiation promotes the recovery of spinal cord injury by inhibiting inflammation via suppression of the MK2/TNF­α pathway.

Mitogen­activated protein kinase­activated protein kinase 2 (MK2) and its mediated inflammation are involved in various diseases, including spinal cord injury (SCI). Ultrashortwave (USW) radiation has previously been reported to exert a protective effect on SCI. In the present study, through a series of reverse transcription­quantitative polymerase chain reaction (RT­qPCR), western blot and immunofluorescence assay, it was found that MK2 and tumor necrosis factor (TNF)­α/interleukin (IL)­1ß were elevated in patients with SCI and in H2O2­treated C8­D1A cells. Through gene level and protein level detection by using of RT­qPCR, western blot, immunofluorescence assay and terminal deoxynucleotidyl transferase (TdT) dUTP nick­end labeling assay, it was demonstrated that USW radiation inhibited the expression of MK2/TNF­α/IL­1ß and suppressed the apoptosis of H2O2­treated C8­D1A cells. Furthermore, it was confirmed that the overexpression of MK2 reversed the protective effect of USW on C8­D1A cells, which indicated that USW achieved its function via regulation of the MK2/TNF­α/IL­1ß pathway. Finally, using a constructed in vivo model and a series of RT­qPCR, western blot and IHC detection, it was confirmed that USW suppressed the expression of MK2 to promote functional recovery following SCI.

A preliminary study into injuries due to non-perforating ballistic impacts into soft body armour over the spine.

The UK Home Office test method for ballistic protective police body armours considers anterior torso impacts to be the worst-case scenario and tests rear armour panels to the same standards as front panels. The aim of this paper was to examine the injuries from spinal behind armour blunt trauma (BABT) impacts. This study used a cadaveric 65 kg, female pig barrel and 9 mm Luger ammunition (9 × 19 mm, FMJ Nammo Lapur Oy) into HG1/A + KR1 soft armour panels over the spine. Injuries were inspected and sections removed for x-radiography and micro-CT assessment. All shots over the spine resulted in deep soft tissue injuries from pencilling of the armour and the shirt worn under the armour. The wounds had embedded fabric debris which would require surgery to remove resulting in increased recovery time over injuries usually seen in anterior torso BABT impacts, which are typically haematoma and fractured ribs. The shot with the deepest soft tissue wound (41 mm) also resulted in a fractured spinous process. Shots were also fired at the posterior and anterior rib area of the pig barrel, for comparison to the spine. Similar wounds were seen on the shots to the posterior rib area while shallower, smaller wounds were seen on the anterior and one anterior rib shot resulted in a single, un-displaced rib fracture. The anatomical differences between pigs and humans would most likely mean that injury to a human from these impacts would be more serious.

Instability in Thoracolumbar Trauma: Is a New Definition Warranted?

STUDY DESIGN: Review of the articles. OBJECTIVE: The objective of this study was to review all articles related to spinal instability to determine a consensus statement for a contemporary, practical definition applicable to thoracolumbar injuries. SUMMARY OF BACKGROUND DATA: Traumatic fractures of the thoracolumbar spine are common. These injuries can result in neurological deficits, disability, deformity, pain, and represent a great economic burden to society. The determination of spinal instability is an important task for spine surgeons, as treatment strategies rely heavily on this assessment. However, a clinically applicable definition of spinal stability remains elusive. MATERIALS AND METHODS: A review of the Medline database between 1930 and 2014 was performed limited to papers in English. Spinal instability, thoracolumbar, and spinal stability were used as search terms. Case reports were excluded. We reviewed listed references from pertinent search results and located relevant manuscripts from these lists as well. RESULTS: The search produced a total of 694 published articles. Twenty-five articles were eligible after abstract screening and underwent full review. A definition for spinal instability was described in only 4 of them. Definitions were primarily based on biomechanical and classification studies. No definitive parameters were outlined to define stability. CONCLUSIONS: Thirty-six years after White and Panjabi's original definition of instability, and many classification schemes later, there remains no practical and meaningful definition for spinal instability in thoracolumbar trauma. Surgeon expertise and experience remains an important factor in stability determination. We propose that, at an initial assessment, a distinction should be made between immediate and delayed instability. This designation should better guide surgeons in decision making and patient counseling.

Percutaneous Spinal Ablation in a Sheep Model: Protective Capacity of an Intact Cortex, Correlation of Ablation Parameters with Ablation Zone Size, and Correlation of Postablation MRI and Pathologic Findings.

BACKGROUND AND PURPOSE: Despite the growing use of percutaneous ablation therapy for the treatment of metastatic spine disease, several issues have yet to be fully addressed. Our aims were to determine whether the vertebral body cortex protects against ablation-induced spinal cord injury; correlate radiofrequency, cryo-, and microwave ablation parameters with resulting spinal ablation zone dimensions and describe normal spinal marrow postablation changes on MR imaging. MATERIALS AND METHODS: Ten thoracolumbar vertebrae in 3 sheep were treated with radiofrequency ablation, cryoablation, or microwave ablation under fluoroscopic guidance. Technique parameters were chosen to produce ablation zones that exceeded the volume of the vertebral bodies in sheep 1 and were confined to the vertebrae in sheep 2 and 3. Expected ablation zone dimensions were based on data provided by the device manufacturers. Postablation MR imaging was performed at 48 hours (sheep 1) or 7 days (sheep 2 and 3). RESULTS: In sheep 1, cryoablation and microwave ablations extended into the spinal canal and caused histologically confirmed neurologic injury, but radiofrequency ablation did not. The mean difference between the lengths of the radiofrequency ablation zone dimensions measured on gross pathology compared with those expected was 9.6 ± 4.1 mm. The gross pathologic cryo- and microwave ablation zone dimensions were within 1 mm of those expected. All modalities produced a nonenhancing ablation zone with a rim of enhancement, corresponding histologically to marrow necrosis and hemorrhagic congestion. CONCLUSIONS: An intact cortex appears to protect against radiofrequency ablation-induced spinal cord injury, but not against non-impedance-based modalities. Ablation dimensions produced by microwave and cryoablation are similar to those expected, while radiofrequency ablation dimensions are smaller. Ablation of normal marrow produces a rim of enhancement at the margin of the ablation zone on MR imaging.

Controversies in Spinal Trauma and Evolution of Care.

Management of spinal trauma is a complex and rapidly evolving field. To optimize patient treatment algorithms, an understanding of and appreciation for current controversies and advancing technologies in the field of spinal trauma is necessary. Therefore, members of the AOSpine Knowledge Forum Trauma initiative used a modified Delphi method to compile a list of controversial issues and emerging technologies in the field of spinal trauma, and a list of the 14 most relevant topics was generated. A total of 45 440 manuscripts covering the breadth of spine and spinal trauma were initially identified. This broad search was then refined using the 14 categories felt to be most relevant to the current field of spinal trauma. The results were further pared down using inclusion criteria to select for the most relevant topics. The 8 remaining topics were classification schemes, treatment of vertebral compression fractures, treatment of burst fractures, timing of surgery in spinal trauma, hypothermia, the importance of global sagittal balance, lumbar subarachnoid drainage, and diffusion magnetic resonance imaging. These 8 topics were felt to be the most relevant, controversial, rapidly evolving, and most deserving of inclusion in this summary. In summary, despite recent advances, the field of spinal trauma has many ongoing points of controversy. We must continue to refine our ability to care for this patient population through education, research, and development. It is anticipated that the new AOSpine fracture classification system will assist with prospective research efforts.

Relationship of biological factors to survival in spinal gunshot injuries.

BACKGROUND: Gunshot injuries are the third leading cause of spinal injuries, after falls from a significant height and traffic accidents. Severity of spinal damage from gunshot injury depends upon certain mechanical and biological factors. The aim of the present study was to investigate the effect of biological factors on survival in cases of spinal gunshot injury. METHODS: A total of 110 cases of spinal gunshot injury admitted multiple times to emergency services between 2012 and 2014 were included. Age, sex, region of trauma, additional organ or systemic involvement, treatment modalities (conservative, surgical), and mortality rates were analyzed. Effects of biological factors on survival were evaluated. RESULTS: Mean age of the study population was 25.51±11.74 years (min: 4; max: 55) and 95.5% of the population was male. Regions of trauma were thoracic in 50 (45.4%) subjects, cervical in 42 (38.2%), and lumbar in 18 (16.4%). Most common American Spinal Injury Association (ASIA) score was category A, as was found in 77 (70%) cases. No significant correlation was found among age, sex, ASIA score, treatment modality (conservative or surgical), and survival (p>0.05). Additional organ or systemic injury was present in 66 (60%) patients. Additional organ or systemic injury significantly affected survival, independent of the spinal region of trauma (p<0.01). CONCLUSION: Spinal gunshot injuries are complex, with unclear treatment protocol. Irrespective of the indications of spinal surgery, additional organ injuries unfavorably affect survival in cases of spinal gunshot injury. Appropriate management of all biological factors directly affects mortality rate in cases of spinal gunshot injury.

Bone Marrow Mesenchymal Stem Cells Expressing Baculovirus-Engineered Bone Morphogenetic Protein-7 Enhance Rabbit Posterolateral Fusion.

Previous studies have suggested that bone marrow-derived mesenchymal stem cells (BMDMSCs) genetically modified with baculoviral bone morphogenetic protein-2 (Bac-BMP-2) vectors could achieve successful fusion in a femur defect model or in a spinal fusion model. In this study, BMDMSCs expressing BMP-7 (Bac-BMP-7-BMDMSCs) were generated. We hypothesized that Bac-BMP-7-BMDMSCs could secrete more BMP-7 than untransduced BMDMSCs in vitro and achieve spinal posterolateral fusion in a rabbit model. Eighteen rabbits underwent posterolateral fusion at L4-5. Group I (n = 6) was implanted with collagen-ß-tricalcium phosphate (TCP)-hydroxyapatite (HA), Group II (n = 6) was implanted with collagen-ß-TCP-HA plus BMDMSCs, and Group III (n = 6) was implanted with collagen-ß-TCP-HA plus Bac-BMP-7-BMDMSCs. In vitro production of BMP-7 was quantified with an enzyme-linked immunosorbent assay (ELISA). Spinal fusion was examined using computed tomography (CT), manual palpation, and histological analysis. ELISA demonstrated that Bac-BMP-7-BMDMSCs produced four-fold to five-fold more BMP-7 than did BMDMSCs. In the CT results, 6 fused segments were observed in Group I (50%, 6/12), 8 in Group II (67%, 8/12), and 12 in Group III (100%, 12/12). The fusion rate, determined by manual palpation, was 0% (0/6) in Group I, 0% (0/6) in Group II, and 83% (5/6) in Group III. Histology showed that Group III had more new bone and matured marrow formation. In conclusion, BMDMSCs genetically transduced with the Bac-BMP-7 vector could express more BMP-7 than untransduced BMDMSCs. These Bac-BMP-7-BMDMSCs on collagen-ß-TCP-HA scaffolds were able to induce successful spinal fusion in rabbits.

Cervical spine immobilization following blunt trauma: a systematic review of recent literature and proposed treatment algorithm.

BACKGROUND: Management of the cervical spine following blunt trauma is commonplace. In 2013, the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) published practice guidelines drawn from evidence dating to 2011. Since then, further publications have emerged that are reviewed, and a simple management algorithm produced to assist practitioners in Australian trauma centres. These publications attempt to shed light on two controversial scenarios, those being the management of symptomatic patients with negative computed tomography (CT) and management of the obtunded patient. METHODS: The search strategy mirrored that of the AANS/CNS guidelines. A search of the National Library of Medicine (PubMed) database for manuscripts published between January 2011 and October 2014 was conducted. One reviewer extracted data from studies assessing the performance of various imaging modalities in identifying traumatic cervical spine injuries. In clinical scenarios where little evidence has emerged since the AANS/CNS guidelines, key manuscripts published prior to 2011 were identified from bibliographies. RESULTS: Awake, asymptomatic patients may be 'cleared' without further imaging. Awake, symptomatic patients without pathology on CT and without neurological deficit can safely be 'cleared' without magnetic resonance imaging. There is no longer a role for flexion-extension films. In the obtunded patient, findings remain conflicting. CONCLUSION: Several of these findings represent a departure from previous practices, including clearance of patients with non-neurological symptoms on the basis of CT and the exclusion of flexion-extension film in detecting injury. Management of the obtunded patient remains controversial.

Validation of the Calgary Spine Severity Score.

BACKGROUND CONTEXT: The Calgary Spine Severity Score (CSSS) is a published triage score reported in the Spine Journal in 2010. It separates spine referrals into four time categories of urgency. It stratifies patients according to clinical, radiologic, and pathologic findings. The CSSS however still requires external validation at another institution and in an unselected sample of patients. PURPOSE: The aim was to validate the CSSS. STUDY DESIGN/SETTING: This was a validation study. PATIENT SAMPLE: The sample included a total of 316 consecutive patients undergoing spinal surgery between April 2014 and September 2014 at a tertiary care hospital in Canada. OUTCOME MEASURES: The outcome was validity of the CSSS via its predicted time to operating room (OR) to predict actual time to OR. METHODS: We applied the CSSS to an unselected sample of consecutive patients from a tertiary care hospital between April 2014 and September 2014. Demographic and clinical data were collected. The CSSS was determined. We compared the time with OR predicted by the CSSS in one of four categories (routine>6 months=CSSS 3-5, priority<6 months=CSSS 6-8, urgent<1 month=CSSS 9-11, and emergent<1 week=CSSS 12-15) with the actual time to OR. We used Kaplan-Meier survival analysis to assess the CSSS predictive ability. Cox proportional hazard models were built and compared via analysis of variance to determine whether the models differed in their ability to fit the data. RESULTS: Three hundred sixteen patients were eligible. Two hundred eighty-nine had sufficient data. One hundred eighteen were a mismatch with the actual time to OR yielding an accuracy of 63%. The CSSS overestimated the urgency in 68 cases and underestimated it in 50 cases. Notably, seven cauda equina syndrome cases were classified as priority (<6 months) instead of emergent. The concordance was 0.70 and the R-square 0.33. We proposed several adjustments to the CSSS to increase its accuracy. The modified CSSS had an accuracy of 96%, overestimating nine cases and underestimating one case. The concordance was 0.77, and the R-square 0.70. CONCLUSIONS: The modified CSSS is an easy-to-use triage score, which represents a substantial improvement as compared with the original CSSS. It now requires further external validation.

The roads to mitochondrial dysfunction in a rat model of posttraumatic syringomyelia.

The pathophysiology of posttraumatic syringomyelia is incompletely understood. We examined whether local ischemia occurs after spinal cord injury. If so, whether it causes neuronal mitochondrial dysfunction and depletion, and subsequent energy metabolism impairment results in cell starvation of energy and even cell death, contributing to the enlargement of the cavity. Local blood flow was measured in a rat model of posttraumatic syringomyelia that had received injections of quisqualic acid and kaolin. We found an 86 ± 11% reduction of local blood flow at C8 where a cyst formed at 6 weeks after syrinx induction procedure (P < 0.05), and no difference in blood flow rate between the laminectomy and intact controls. Electron microscopy confirmed irreversible neuronal mitochondrion depletion surrounding the cyst, but recoverable mitochondrial loses in laminectomy rats. Profound energy loss quantified in the spinal cord of syrinx animals, and less ATP and ADP decline observed in laminectomy rats. Our findings demonstrate that an excitotoxic injury induces local ischemia in the spinal cord and results in neuronal mitochondrial depletion, and profound ATP loss, contributing to syrinx enlargement. Ischemia did not occur following laminectomy induced trauma in which mitochondrial loss and decline in ATP were reversible. This confirms excitotoxic injury contributing to the pathology of posttraumatic syringomyelia.

Biocompatibility of a coacervate-based controlled release system for protein delivery to the injured spinal cord.

The efficacy of protein-based therapies for treating injured nervous tissue is limited by the short half-life of free proteins in the body. Affinity-based biomaterial delivery systems provide sustained release of proteins, thereby extending the efficacy of such therapies. Here, we investigated the biocompatibility of a novel coacervate delivery system based on poly(ethylene argininylaspartate diglyceride) (PEAD) and heparin in the damaged spinal cord. We found that the presence of the [PEAD:heparin] coacervate did not affect the macrophage response, glial scarring or nervous tissue loss, which are hallmarks of spinal cord injury. Moreover, the density of axons, including serotonergic axons, at the injury site and the recovery of motor and sensorimotor function were comparable in rats with and without the coacervate. These results revealed the biocompatibility of our delivery system and supported its potential to deliver therapeutic proteins to the injured nervous system.

Cytoprotective and anti-inflammatory effects of PAL31 overexpression in glial cells.

BACKGROUND: Acute spinal cord injury (SCI) leads to a series of reactive changes and causes severe neurological deficits. A pronounced inflammation contributes to secondary pathology after SCI. Astroglia respond to SCI by proliferating, migrating, and altering phenotype. The impact of reactive gliosis on the pathogenesis of SCI is not fully understood. Our previous study has identified an inflammatory modulating protein, proliferation related acidic leucine-rich protein (PAL31) which is upregulated in the microglia/macrophage of injured cords. Because PAL31 participates in cell cycle progression and reactive astroglia often appears in the injured cord, we aim to examine whether PAL31 is involved in glial modulation after injury. RESULTS: Enhanced PAL31 expression was shown not only in microglia/macrophages but also in spinal astroglia after SCI. Cell culture study reveal that overexpression of PAL31 in mixed glial cells or in C6 astroglia significantly reduced LPS/IFNγ stimulation. Further, enhanced PAL31 expression in C6 astroglia protected cells from H2O2 toxicity; however, this did not affect its proliferative activity. The inhibiting effect of PAL31 on LPS/IFNγ stimulation was observed in glia or C6 after co-culture with neuronal cells. The results demonstrated that the overexpressed PAL31 in glial cells protected neuronal damages through inhibiting NF-kB signaling and iNOS. CONCLUSIONS: Our data suggest that PAL31upregulation might be beneficial after spinal cord injury. Reactive gliosis might become a good target for future therapeutic interventions.

Minimally invasive spine surgery in the treatment of thoracolumbar and lumbar spine trauma.

Thoracolumbar and lumbar trauma account for the majority of traumatic spinal injuries. The mainstay of current treatments is still nonoperative therapy with bracing. Classic treatment algorithms reserved absolute surgical intervention for spinal trauma patients with neurological compromise or instability. Relative indications included incapacitating pain and obesity/body habitus making brace therapy ineffective. In the past decade, minimally invasive surgical (MIS) techniques for spine surgery have been increasingly used for degenerative conditions. These same minimally invasive techniques have seen increased use in trauma patients. The goal of minimally invasive surgery is to decrease surgical morbidity through decreased soft-tissue dissection while providing the same structural stability afforded by classic open techniques. These minimally invasive techniques involve percutaneous posterior pedicle fixation, vertebral body augmentation, and utilization of endoscopic and thoracoscopic techniques. While MIS techniques are somewhat in their infancy, an increasing number of studies are reporting good clinical and radiographic outcomes with these MIS techniques. However, the literature is still lacking high-quality evidence comparing these newer techniques to classic open treatments. This article reviews the relevant literature regarding minimally invasive spine surgery in the treatment of thoracolumbar and lumbar trauma.

Torticollis following tympanoplasty: an index case with lessons in encountering the unexpected.

The term torticollis is derived from the Latin words 'tortis' for twisted and 'collum' for neck. Typical features include sudden onset of severe unilateral pain, with restriction of movements and deviation of the neck to that side. Although torticollis is a well recognised abnormality, there is minimal literature identifying it as a sole long-standing complication in otological surgery. We present the case of a 15-year-old boy who developed permanent torticollis following a routine tympanoplasty. A CT of the neck revealed an atlantoaxial rotatory fixation with cross fusion between C1 and C2. This case highlights a rare cause of torticollis resulting from a routine otological procedure. It also differentiates between Grisel's syndrome, which is characterised by atlantoaxial subluxation as opposed to fusion. The role of the multidisciplinary team is imperative and in particular the need for urgent discussion with the neurosurgical team to ensure prompt assessment and management of the patient takes place.

Relación de la aterosclerosis carotídea con la osteoporosis de columna lumbar y caderas en el infarto agudo de miocardio / Relationship between carotid atherosclerosis and lumbar spine and hip osteoporosis in acute myocardial infarction

OBJETIVO: determinar en pacientes con infarto agudo del miocardio, la existencia de asociación entre la aterosclerosis carotídea y la osteoporosis de la columna lumbar y caderas. MÉTODOS: se exploraron 104 pacientes con diagnóstico clínico y de laboratorio de infarto agudo del miocardio. A cada paciente se les realizó ultrasonido doppler carotídeo, en el que se describió grosor íntima-media, localización y tipo de placas ateromatosas, grado de estenosis e índice aterogénico; seguido de densitometría de columna lumbar y caderas. Se clasificaron los niveles de densidad mineral ósea en normal, osteopenia y osteoporosis, según T score. RESULTADOS: no se encontró correlación entre el valor de la densidad mineral ósea y la magnitud del daño aterosclerótico del sector carotídeo. La mayoría de los factores de riesgo se asociaron con valores normales de grosor íntima-media, índice aterogénico aumentado y baja prevalencia de estenosis significativa, así como de osteopenia densitométrica; el envejecimiento y la hipertensión resultaron los predominantes. CONCLUSIONES: más allá de la existencia de factores de riesgo en común, no hubo asociación entre la osteoporosis y la aterosclerosis carotídea en los pacientes con infarto agudo del miocardio.

OBJECTIVE: determine the relationship between carotid atherosclerosis and lumbar spine and hip osteoporosis in patients with acute myocardial infarction. METHODS: a study was conducted of 104 patients with a clinical and laboratory diagnosis of acute myocardial infarction. All patients underwent carotid Doppler ultrasonography for intima media thickness, location and type of atheromatous plaques, stenosis degree and atherogenic index, followed by lumbar spine and hip densitometry. Bone mineral density levels were classified as normal, osteopenia or osteoporosis, according to the T-score. RESULTS: no correlation was found between bone mineral density values and the extent of atherosclerotic damage to the carotid sector. Most risk factors were associated with normal intima media thickness values, an increased atherogenic index, a low prevalence of significant stenosis, and densitometric osteopenia. Aging and hypertension were the predominant risk factors. CONCLUSIONS: except for the existence of common risk factors, no association was found between osteoporosis and carotid atherosclerosis in patients with acute myocardial infarction.

Nucleotide signaling in astrogliosis.

Acute and chronic damage to the central nervous system (CNS) releases large quantities of ATP. Whereas the ATP concentration in the extracellular space is normally in the micromolar range, under these conditions it increases to millimolar levels. A number of ligand-gated cationic channels termed P2X receptors (7 mammalian subtypes), and G protein-coupled P2Y receptors (8 mammalian subtypes) are located at astrocytes, as confirmed by the measurement of the respective mRNA and protein. Activation of both the P2X7 and P2Y1,2 subtypes identified at astrocytes initiates astrogliosis isolating damaged brain areas from surrounding healthy cells and synthesizing neurotrophins and pleotrophins that participate in neuronal recovery. Astrocytes are considered as cells of high plasticity which may alter their properties in a culture medium. Therefore, recent work concentrates on investigating nucleotide effects at in situ (acute brain slices) and in vivo astrocytes. A wealth of data relates to the involvement of purinergic mechanisms in astrogliosis induced by acute CNS injury such as mechanical trauma and hypoxia/ischemia. The released ATP may act within minutes as an excitotoxic molecule; at a longer time-scale within days it causes neuroinflammation. These effects sum up as necrosis/apoptosis on the one hand and proliferation on the other. Although the role of nucleotides in chronic neurodegenerative illnesses is not quite clear, it appears that they aggravate the consequences of the primary disease. Epilepsy and neuropathic pain are also associated with the release of ATP and a pathologic glia-neuron interaction leading to astrogliosis and cell death. In view of these considerations, P2 receptor antagonists may open new therapeutic vistas in all forms of acute and chronic CNS damage.