Viktor Bartanusz

The blood–spinal cord barrier: Morphology and Clinical Implications

The blood–spinal cord barrier (BSCB) is the functional equivalent of the blood–brain barrier (BBB) in the sense of providing a specialized microenvironment for the cellular constituents of the spinal cord. Even if intuitively the BSCB could be considered as the morphological extension of the BBB into the spinal cord, evidence suggests that this is not so. The BSCB shares the same principal building blocks with the BBB; nevertheless, it seems that morphological and functional differences may exist between them. Dysfunction of the BSCB plays a fundamental role in the etiology or progression of several pathological conditions of the spinal cord, such as spinal cord injury, amyotrophic lateral sclerosis, and radiation‐induced myelopathy. This review summarizes current knowledge of the morphology of the BSCB, the methodology of studying the BSCB, and the potential role of BSCB dysfunction in selected disorders of the spinal cord, and finally summarizes therapeutic approaches to the BSCB. Ann Neurol 2011;

The Influence of Preoperative Back Pain on the Outcome of Lumbar Decompression Surgery

Study Design. Prospective study with 12-month follow-up. Objective. To examine how the relative severity of low back pain (LBP) to leg/buttock pain (LP) influences the outcome of decompression surgery for spinal stenosis. Summary of Background Data. Decompression surgery is a common treatment for lumbar spinal canal stenosis, with generally good outcome. However, concomitant LBP at presentation can make it difficult to decide whether decompression alone will result in a good overall outcome. Methods. The Spine Society of Europe Spine Tango system was used to acquire the data from 221 patients. Inclusion criteria were lumbar degenerative spinal stenosis, first-time surgery, maximum 3 affected levels, and decompression as the only procedure. Before and 12 months after surgery, patients completed the multidimensional Core Outcome Measures Index (COMI; includes 0–10 LP and LBP scales); at 12 months, global outcome was rated on a Likert-scale and dichotomized into “good” and “poor” groups. Results. There was a low but significant positive correlation between baseline LP-minus-LBP scores and both improvement in the multidimensional COMI score after 12 months (r = 0.21, P = 0.003) and the score on the 12-month global outcome scale (r = 0.19, P = 0.007). In the good outcome group, mean baseline LP was 2.3 (±3.7) points higher than LBP; in the poor group, the corresponding value was 0.8 (±3.4) (P = 0.01 between groups). In multivariate regression analyses (controlling for age, gender, comorbidity), baseline LBP intensity was the most significant predictor of the 12-month COMI score, and preoperative LP-minus-LBP score of the global outcome (each P < 0.05). Conclusion. Overall, greater back pain relative to LP at baseline was associated with a significantly worse outcome after decompression. This finding seems intuitive, but has rarely been quantified in the many predictor studies conducted to date. Consideration of relative LBP and LP scores may assist in clinical decision-making and in establishing realistic patient expectations.

Spatial and temporal expression levels of specific microRNAs in a spinal cord injury mouse model and their relationship to the duration of compression

BACKGROUND CONTEXT MicroRNAs, a class of small nonprotein-coding RNAs, are thought to control gene translation into proteins. The latter are the ultimate effectors of the biochemical cascade occurring in any physiological and pathological process. MicroRNAs have been shown to change their expression levels during injury of spinal cord in contusion rodent models. Compression is the most frequent mode of damage of neural elements in spinal cord injury. The cellular and molecular changes occurring in the spinal cord during prolonged compression are not very well elucidated. Understanding the underlying molecular events that occur during sustained compression is paramount in building new therapeutic strategies. PURPOSE The purpose of our study was to probe the relationship between the expression level changes of different miRNAs and the timing of spinal cord decompression in a mouse model. STUDY DESIGN A compression spinal cord injury mouse model was used for the study. METHODS A laminectomy was performed in the thoracic spine of C57BL/6 mice. Then, the thecal sac was compressed to create the injury. Decompression was performed early for one group and it was delayed in the second group. The spinal cord at the epicenter of the injury and one level rostral to it were removed at 3, 6, and 24 hours after trauma, and RNA was extracted. Expression levels of six different microRNAs and the relationship to the duration of compression were analyzed. This work was supported in part by the University Research Council Grants Program at the University of Texas Health Science Center San Antonio (Grant 130267). There are no specific conflicts of interest to be disclosed for this work. RESULTS Expression levels of microRNAs in the prolonged compression of spinal cord model were significantly different compared with the expression levels in the short duration of compression spinal cord injury model. Furthermore, microRNAs show a different expression pattern in different regions of the injured spinal cord. CONCLUSIONS Our findings demonstrate that spinal cord compression causes alterations in the expression of different miRNAs in the acute phase of injury. Their expression is related to the duration of the compression of the spinal cord. These findings suggest that early decompression of the spinal cord may have an important modulating effect on the molecular cascade triggered during secondary injury through the changes in expression levels of specific microRNAs.

Pseudomyogenic hemangioendothelioma (epithelioid sarcoma-like hemangioendothelioma, fibroma-like variant of epithelioid sarcoma) of the thoracic spine.

PurposePseudomyogenic hemangioendothelioma is a soft tissue tumor found in young adults, predominantly males. The tumor has been reported in various locations in the body, including the head, neck, chest wall, abdominal wall, genital region, and extremities. Until now, there has been no indication of occurrence in the spine.MethodsA 25-year-old male presented with spinal cord compression, due to an extradural tumor involving the third and fourth thoracic vertebrae with extension into the right pleural cavity.ResultsHistopathologic examination revealed a pseudomyogenic hemangioendothelioma, also described as epithelioid sarcoma-like hemangioendothelioma, or fibroma-like variant of epithelioid sarcoma.ConclusionWe describe the first occurrence of pseudomyogenic hemangioendothelioma in the thoracic spine. According to previous reports based on other locations, the tumor has an indolent clinical course with a small risk of metastasis, therefore complete macroscopic excision is the treatment of choice. Local recurrence may occur even with complete surgical resection, requiring close follow-up; adjuvant therapy is warranted.

Calcifying pseudoneoplasm of the atlantoaxial joint in a Child: Case report

Calcifying pseudoneoplasm of the spine is a rare nonneoplastic lesion of unknown origin described in adolescents and adults. Its clinical manifestations include axial pain, myelopathy, or radiculopathy. Surgery is the preferred method of treatment. The authors report the occurrence of calcifying pseudoneoplasm at the C1-2 cervical segment in a 22-month-old child who became completely asymptomatic 2 months after open biopsy. A review of the literature is presented, emphasizing the uniqueness of the presented case in comparison with the previously published cases. The 22-month-old healthy girl presented with sudden onset of neck pain. Due to persistence of the symptoms 2 weeks after onset, imaging studies were performed that revealed an inhomogeneous calcified mass extending from the transverse ligament to the C1-2 interlaminar space and facet joint on the left side. Open biopsy of the mass at the C1-2 lamina was performed. The histological features were consistent with calcifying pseudoneoplasm. The childs neck pain progressively improved and she remained asymptomatic at the 1-year follow-up. The postoperative MRI at 8 months did not reveal any progression of the lesion. Contrary to reported cases, calcifying pseudoneoplasm of the spine may occur as early as 2 years of age and should be included in the differential diagnosis of calcified lesions in this age group. Complete resection is not a prerequisite to clinical improvement when there is no compromise of neural structures; conservative management is appropriate.

Spinal instrumentation after complete resection of the last lumbar vertebra: an in vitro biomechanical study after L5 spondylectomy.

Study Design. Human cadaveric ilio-lumbosacral spines were tested in an in vitro biomechanical flexibility experiment to investigate the biomechanical stability provided by four different types of spinal reconstruction techniques after spondylectomy of the L5 vertebral body. Objective. To compare the biomechanical stability provided by four reconstruction methods after L5 spondylectomy. Summary of Background Data. Clinical studies have shown that total spondylectomy of the L5 vertebral body presents a challenging scenario for spinal reconstruction. Biomechanical studies on spinal reconstruction after total spondylectomy have been performed at the thoracolumbar junction. However, there have been no biomechanical studies after L5 spondylectomy. Methods. Seven cadaveric lumbosacral spines (L2-S1) with intact ilium were used. After intact testing, spondylectomy of the L5 vertebra was performed and the spine was reconstructed using an expandable cage for anterior column support. Supplementary fixation was performed as a sequential order of: (1) bilateral pedicle screws at L4-S1 (SP), (2) anterior plate and bilateral pedicle screws at L4-S1 (ASP), (3) bilateral pedicle screws at L3-S1 and iliac screws (MP), and (4) anterior plate at L4-S1, bilateral pedicle screws at L3-S1 and iliac screws (AMP). Range of motion (ROM) for each construct was obtained by applying pure moments in flexion, extension, lateral bending, and axial rotation. Results. In flexion, extension and lateral bending all the instrumented constructs significantly decreased (P < 0.05) the range of motion (ROM) compared to intact. In axial rotation, only the circumferential support constructs (ASP, AMP) provided significantly decreased (P < 0.05) ROM, whereas posterior instrumentations alone (SP, MP) were comparable to intact spines. Conclusion. After L5 spondylectomy, the L4-S1 cage with posterior short segment instrumentation provides stability in lateral bending that is not further increased by adding L3 pedicle-iliac screws and L4-S1 anterior plate. However, an anterior L4-S1 plate provides additional stability in flexion, extension, and axial rotation.

Systematic review of observational studies reveals no association between low back pain and lumbar spondylolysis with or without isthmic spondylolisthesis

PurposeThe hypothesis that spondylolysis (SL) and/or isthmic spondylolisthesis (IS) cause low back pain (LBP) is widely accepted representing surgical indication in symptomatic cases. If SL/IS cause LBP, individuals with these conditions should be more prone to LBP than those without SL/IS. Therefore, the goal of the study was to assess whether the published primary data demonstrate an association between SL/IS and LBP in the general adult population.MethodsSystematic review of published observational studies to identify any association between SL/IS and LBP in adults. The methodological quality of the cohort and case–control studies was evaluated using the Newcastle-Ottawa scale.ResultsFifteen studies met inclusion criteria (one cohort, seven case–control, seven cross-sectional). Neither the cohort study nor the two highest-quality case–control studies detected an association between SL/IS and LBP; the same is true for the remaining studies.ConclusionsThere is no strong or consistent association between SL/IS and LBP in epidemiological studies of the general adult population that would support a hypothesis of causation. It is possible that SL/IS coexist with LBP, and observed effects of surgery and other treatment modalities are primarily due to benign natural history and nonspecific treatment effects. We conclude that traditional surgical practice for the adult general population, in which SL/IS is assumed to be the cause of non-radicular LBP whenever the two coexist, should be reconsidered in light of epidemiological data accumulated in recent decades.

Current strategies in the management of spinal metastatic disease.

The treatment of metastatic spinal cord compression is complex. The three treatment modalities that are currently applied (in a histologically non-specific manner) are surgery, radiotherapy and the administration of steroids. The development of new spinal instrumentations and surgical approaches considerably changed the extent of therapeutic options in this field. These new surgical techniques have made it possible to resect these tumours totally, with subsequent vertebral reconstruction and spinal stabilization. In this respect, it is important to clearly identify those patients who can benefit from such an extensive surgery. We present our management algorithm to help select patients for surgery and at the same time identifying those for whom primary non-surgical therapy would be indicated. The retrospective review of surgically treated patients in our department in the last four years reveals a meagre application of conventional guidelines for the selection of the appropriate operative approach in the surgical management of these patients. The reasons for this discrepancy are discussed.

Diurnal salivary cortisol measurement in the neurosurgical-surgical intensive care unit in critically ill acute trauma patients.

Acute trauma patients represent a specific subgroup of the critically ill population due to sudden and dramatic changes in homeostasis and consequently extreme demands on the activity of the hypothalamic-pituitary-adrenocortical (HPA) axis. Salivary cortisol is an accepted surrogate for serum free cortisol in the assessment of HPA axis function. The purpose of this study was (1) to establish the feasibility of salivary cortisol measurement in acute trauma patients in the neurosurgical-surgical intensive care unit (NSICU), and (2) to determine the diurnal pattern of salivary cortisol in the acute phase after injury. Saliva from 50 acute trauma patients was prospectively collected twice a day at 6AM and 4PM during the first week after injury in the NSICU. Mean PM cortisol concentrations were significantly higher in subjects versus controls (p<0.001). Subjects failed to develop the expected PM versus AM decrease in cortisol concentration seen in controls (p=0.005). Salivary cortisol did not vary significantly with baseline Glasgow Coma Scale (GCS), Injury Severity Score, sex, injury type, ethnicity, or age. When comparing mean AM and PM salivary cortisol by GCS severity category (GCS ⩽8 and GCS >8) the AM salivary cortisol was significantly higher in patients with GCS ⩽8 (p=0.002). The results show a loss of diurnal cortisol variation in acute trauma patient in the NSICU during the first week of hospitalization. Patients with severe brain injury had higher morning cortisol levels than those with mild/moderate brain injury.

Conjugate eye deviation due to traumatic striatal-subthalamic lesion

We report the case of a 22-year-old man after severe cranial trauma, who was noted to have conjugate eye deviation (CED) to the left. A magnetic resonance imaging (MRI) scan demonstrated a lesion in the left (ipsilateral) striatal-subthalamic region. The involvement of supranuclear fibres from the left frontal eye field (FEF) traveling to the right parapontine reticular formation (PPRF) could explain this clinical finding. Alternatively, involvement of deep brain nuclei, such as the striatum and the subthalamic nucleus, could be responsible for this phenomenon. This neurological presentation is unusual after severe cranial trauma.