Does sagittal position of the CTDR-related centre of rotation influence functional outcome? Prospective 2-year follow-up analysis

PURPOSE

Recent studies describe significant rates of heterotopic ossification (HO) after cervical total disc replacement (CTDR). Little is known about the reasons, and one aspect that requires further in vivo investigation is the biomechanical alteration after CTDR and the role of the implant-related centre of rotation (CORi) in particular. The role of the sagittal position of the CORi on functional outcome in two versions of a semi-constrained disc prosthesis with sagittally different CORi is the topic of this study.

METHODS

Patients were candidates for single-level CTDR between C3 and C7 who suffered from CDDD and received a standard or flat version of activ C™ (Aesculap AG, Tuttlingen). Clinical and radiographic assessments were determined preoperatively, intraoperatively, at discharge and again at 6 weeks, 6 months, 1 and 2 years. Radiographic examinations were performed independently using specialized quantitative motion analysis software.

RESULTS

Clinical outcome improved significantly regarding NDI as well as VAS on neck and arm pain with no differences in mean improvement by study group. Segmental angle measures show a significantly better lordotic alignment for both groups after surgery, but the degree of correction achieved is higher in the flat group. Correlation analysis proves that the more anterior the CORi is positioned, the higher the lordotic correction is achieved (Pearson rho -0.385). Segmental ROM decreased in the standard group but was maintained for flat implants. At present, our data do not demonstrate a correlation between CORi and ROM at 2 years. Two years after surgery, severe HO grade III-IV was present in 31.6 % standard and 13.1 % flat cases with significant differences. Grouping according to HO severity showed comparable sagittal positions of CORi for flat implants but a more posterior position in the severe HO group for standard implants.

CONCLUSIONS

Our results confirm the influence of CORi location on segmental alignment, kinematics and HO for a semi-constrained CTDR, but it also indicates a multifactorial process.

Effect of degeneration on gene expression of chondrogenic and inflammatory marker genes of intervertebral disc cells: a preliminary study

AIM

New techniques for biological repair in the treatment of degenerative disc disease (DDD) have been developed recently. The question arises whether it is possible to find a predictive marker to identify a patient population which could benefit from this new treatment option. Standard magnetic resonance imaging (MRI) fails to differentiate between pathologic painful and asymptomatic aging discs. Neurological symptoms contribute to identifying the pathological level. In this preliminary translational research study we analysed the gene expression of structure proteins and inflammatory mediators as well as histological features of lumbar intervertebral discs in symptomatic patients with various signs of degeneration in the MRI.

METHODS

Specimens of intervertebral disc tissue were obtained from 20 patients undergoing lumbar nucleotomy. Preoperatively, a group selection based on four pre-defined MRI-criteria was performed: Group 1 (mild signs of degeneration), group 2 (moderate), group 3 (moderate-severe), group 4 (severe).

RESULTS

An increase of the expression of structural proteins and inflammatory markers could be observed in MRI-groups 2 and 3. Gene expression of collagen type I and II and aggrecan went along with levels of cyclooxygenase-2 (COX-2) and (fibroblast growth factor-2) FGF-2 expression. Histological examination showed signs of granulation tissue in only 35% of cases, but no differences between the groups.

CONCLUSION

Our findings implicate that the gene expression of structural proteins might correlate with the appearance of inflammatory mediators in symptomatic patients with moderate disc changes in the MRI in this preliminary clinical subset. The assessment of cell activity and protein expression in a larger number of patients could be next step to support and supplement the present data.

Murine Pre-Eclampsia Induced by Unspecific Activation of the Immune System Correlates with Alterations in the eNOS and AT1 Receptor Expression in the Kidneys and Placenta

It remains arguable if an animal model can be of use in pre-eclampsia (PE) studies, as it is clearly a human disease not observed spontaneously in other species. The aim of this study was to investigate whether PE-like signs in mice inoculated with activated Th1 cells were accompanied by abnormal expression of molecules related to the regulation of blood pressure, viz. nitric oxide synthase enzymes (eNOS and iNOS) and angiotensin (Ang) II receptors (AT1R and AT2R), in order to analyse the relevance of this model for human disease. In this model, C57/BL6-mated BALB/c females received lymphocytes crosslined with anti-CD3 and cultured with interleukin (IL)-2 and IL-12 to mimic PE pathology. Control mice received PBS. eNOS, iNOS and AT1R but not AT2R expression was augmented in the kidneys of PE-mice compared with control pregnant mice. The expression of eNOS but not of iNOS was augmented at the fetal-maternal interface of PE-mice as compared with the controls. NOSs regulate the synthesis of NO, a blood pressure and parturition mediator. As its expression is increased in PE patients, our data suggest that the Th1 cells-induced signs in this model are due to similar mechanisms as in humans. AT1R and AT2R mediate the effect of Ang II, and particularly the AT1R appears to be involved in the pathogenesis of human PE. The increased AT1R expression in the kidneys of PE-mice reinforces the theory that Th1 cells elicit a pathological situation closely resembling the human PE. All together, our data support the use of this animal model to study mechanisms underlying clinically overt PE.

[Brain metastases of lung cancer]

Cerebral metastases are a frequent complication of lung cancer. They often determine patients' prognosis and need urgent therapeutic intervention. Based on histologic type, former therapies, age and performance of the patient, the number of cerebral lesions and the extracerebral tumour activity, individualized treatments are applied. For patients who suffer from non-small cell lung cancer and a single CNS lesion the best results can be achieved if they are surgically resected or receive radiosurgery. Their survival time can be markedly increased in comparison to patients who undergo whole brain irradiation. If multiple metastases are seen in CT or MRI, whole brain irradiation is the therapy to choose. Furthermore it should be initiated if small cell lung cancer metastasizes to the brain. More aggressive local treatment options appear promising, but a clear role for them has not yet been defined. Systemic chemotherapy gains more attention in the treatment of small and non-small cell lung cancer with brain metastases. How to increase the efficacy through simultaneous application of chemo- and radiotherapy is tested in current trials. This article gives an overview on clinical presentation and diagnosis of cerebral metastases in lung cancer and reviews current treatment options.

Upregulation of Bcl-2 at the foetal-maternal interface from mice undergoing abortion

Several burning questions remain unanswered in pregnancy-related research. Pro- and anti-inflammatory cytokines orchestrate an intriguing interaction leading either to the development of a normal individual or to its rejection. Augmented Th1 cytokines' production is involved in immunological rejection of the foetus. Excessive production of Th1 cytokines, particularly of tumour necrosis factor (TNF)-alpha, also triggers apoptosis. Thus, in the present work we investigated the incidence of apoptosis in a well-known experimental model of Th1-induced abortion, characterized by increased local TNF-alpha levels. Apoptosis of lymphocytes as well as their Th1 and Th2 cytokine production were analysed by flow cytometry. TNF-alpha mRNA levels were additionally analysed by real time reverse transcription-polymerase chain reaction (RT-PCR) in placental and decidual samples. Total placental apoptosis activity was investigated by measuring caspase-3 activity and by TdT-mediated dUTP nick end label staining. Immunohistochemistry, Western blot and real time RT-PCR were used to localize and quantify several anti- and pro-apoptotic molecules at the foetal-maternal interface. Despite elevated Th1 levels at the foetal-maternal interface, mice undergoing abortion presented comparable apoptotic rates. Interestingly, we found a significant upregulation of the anti-apoptotic Bcl-2 protein at the foetal-maternal interface from abortion-prone mice, while no changes could be observed for pro-apoptotic molecules. In the light of our results, we conclude that there is no evidence of increased apoptosis in mice undergoing immunological abortion in spite of elevated TNF-alpha levels. This is probably due to a selective upregulation of anti-apoptotic pathways (i.e. Bcl-2) at the foetal-maternal interface as a compensatory and/or protective mechanism.

Increased intracranial pressure induces a rapid systemic interleukin-10 release through activation of the sympathetic nervous system

There is a bi-directional communication between the immune and central nervous system. In this context, it is known that patients with traumatic brain injury suffered from systemic immunodepression and an increased risk to develop infectious complications. We investigated the role of an increased intracranial pressure (ICP) and sympathetic activation on systemic immune changes. A sustained increase in ICP was achieved by inflation of a subdural balloon. At different time points, plasma levels of the anti-inflammatory cytokine, interleukin (IL)-10, were measured. Furthermore, the effect of a sympathetic blockade by co-administration of the beta2-adreoreceptor antagonist, propranolol, was evaluated. Finally, we examined the impact of epinephrine infusion on blood IL-10 levels. We showed that an increase in ICP with activation of the sympathetic nervous system was able to induce systemic release of IL-10. This effect was blocked by administration of the beta2-adreoreceptor antagonist. Furthermore, epinephrine infusion directly induced systemic release of IL-10. Our data suggested that sympathetic activation with release of epinephrine may induce systemic immunodepression with risk of infectious complications in brain-injured patients.

Differences in immune cell invasion into the cerebrospinal fluid and brain parenchyma during cerebral infusion of interleukin-1beta

Cytokine-mediated inflammatory cell recruitment into the brain is a critical step in the response to diverse insults, including infection, trauma, and stroke. Hence, continous intra-cerebroventricular infusion of interleukin (IL)-1beta leads to an impressive cell invasion into the cerebrospinal fluid, as well as the brain parenchyma. Neither tumor necrosis factor-alpha nor IL-6 induced any significant cell invasion at all. However, the diverse immune cells (granulocytes, monocytes/macrophages) showed a different time course of invasion. Moreover, there was an association between the number of infiltrating immune cells and the infused IL-1 concentration. By analyzing intra-brain immune events, we demonstrated a time- and dose-dependent induction of intercellular adhesion molecule (ICAM)-1, whereas there were no differences for P-selectin, vascular cell adhesion molecule (VCAM)-1, and monocyte-chemotractant protein (MCP)-1, comparing vehicle and IL-1-infused animals. In conclusion, we assume IL-1beta to be a key cytokine for the granulocyte and monocyte recruitment into the central nervous system after various insults. However, granulocytes anticipate monocyte invasion.

Late neurological deterioration 30 years following conservative treatment of a lower cervical spine fracture--a case report

A today 44 years old man suffered from a compression and subluxation fracture of C 4 and C 5 vertebral body during a swimming accident in 1971. The primary therapy was conservative and the patient was rehabilitated. Since 1997 the patient showed a slowly progressive right hemiparesis with signs of cervical myelopathy. The diagnostic procedures revealed a severe deformity of the cervical spine with myelon compression. We performed an operation with replacement of C4 and C5 and dorsal stabilization at the same time. This very impressive case shows the risk of a late and slowly onset of myelopathic deterioration while latent bony instability persist post traumatic. The authors think in agreement with the actual literature that the early operative stabilization of instable fractures of the lower cervical spine is inevitable. According to the grade of neurological and bony damage the operation should not be performed later than 8-12 hours after injury.

Effects of tacrolimus on hemispheric water content and cerebrospinal fluid levels of glutamate, hypoxanthine, interleukin-6, and tumor necrosis factor-α following controlled cortical impact injury in rats

Object. Disturbance of calcium homeostasis contributes to evolving tissue damage and energetic impairment following traumatic brain injury (TBI). Calcium-mediated activation of calcineurin results in production of tissue-damaging nitric oxide and free oxygen radicals. Inhibition of calcineurin induced by the immunosuppressant tacrolimus (FK506) has been shown to reduce structural and functional damage after ischemia. The aims of the present study were to investigate time- and dose-dependent short-term antiedematous effects of tacrolimus following TBI.

Methods. A left temporoparietal contusion (controlled cortical impact injury [CCII]) was induced in 51 male Sprague—Dawley rats. Tacrolimus (1 or 3 mg/kg body weight) was administered by a single intraperitoneal injection at 5 minutes, 30 minutes, or 4 hours after CCII occurred. Control rats received physiological saline. Water contents of traumatized and nontraumatized hemispheres, as well as cerebrospinal fluid (CSF) levels of mediators reflecting tissue damage (the proinflammatory cytokines interleukin [IL]-6 and tumor necrosis factor [TNF]—α, the excitotoxin glutamate, and the adenosine triphosphate—degradation product hypoxanthine), were determined 24 hours after trauma.

Although CSF levels of IL-6 and TNFα were completely suppressed by tacrolimus at all time points and at both concentrations, CSF levels of glutamate and hypoxanthine, as well as edema formation, were only marginally influenced. Significant reduction of cerebral water content was confined to nontraumatized hemispheres. In addition, the higher dose of tacrolimus failed to exert significant antiedematous effects on traumatized hemispheres.

Conclusions. Under the present study design, the potency of tacrolimus in reducing edema formation following CCII seems limited. However, its immunosuppressive effects could be of value in influencing the posttraumatic inflammatory response known to aggravate tissue damage.

Temporal profile of cerebrospinal fluid glutamate, interleukin-6, and tumor necrosis factor-alpha in relation to brain edema and contusion following controlled cortical impact injury in rats

Traumatic brain injury is associated with release of the excitotoxin glutamate and production of pro-inflammatory cytokines IL-6 and tumor necrosis factor-alpha (TNF-alpha). Following controlled cortical impact injury, cerebrospinal fluid (CSF) glutamate, IL-6, and TNF-alpha concentrations were measured to investigate their relationship to evolving tissue damage. Compared to non-traumatized rats CSF glutamate, IL-6 and TNF-alpha levels were significantly increased by 8 h after trauma (P<0.005). Parallel to increasing brain swelling and contusion CSF glutamate was significantly elevated over time, reaching highest levels by 48 h (33+/-4 microM) while IL-6 and TNF-alpha showed maximum values at 24 h after trauma (42+/-7 and 4.7+/-1 pg/ml) (P<0.005). The observed different temporal profile of CSF glutamate, IL-6, and TNF-alpha following focal traumatic brain injury could be of therapeutic importance.

Helper virus-free herpes simplex virus type 1 amplicon vectors for granulocyte-macrophage colony-stimulating factor-enhanced vaccination therapy for experimental glioma

Subcutaneous vaccination therapy with glioma cells, which are retrovirally transduced to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF), has previously proven effective in C57BL/6 mice harboring intracerebral GL261 gliomas. However, clinical ex vivo gene therapy for human gliomas would be difficult, as transgene delivery via retroviral vectors occurs only in dividing cells and ex vivo glioma cells have a low growth fraction. To circumvent this problem, a helper virus-free herpes simplex virus type 1 (HSV-1) amplicon vector was used. When primary cultures of human glioblastoma cells were infected with HSV-1 amplicon vectors at an MOI of 1, more than 90% of both dividing and nondividing cells were transduced. When cells were infected with an amplicon vector, HSVGM, bearing the GM-CSF cDNA in the presence of Polybrene, GM-CSF secretion into the medium during the first 24 hr after infection was 1026 ng/10(6) cells, whereas mock-infected cells did not secrete detectable GM-CSF. Subcutaneous vaccination of C57BL/6 mice with 5 x 10(5) irradiated HSVGM-transduced GL261 cells 7 days prior to intracerebral implantation of 10(6) wild-type GL261 cells yielded 60% long-term survivors (>80 days), similar to the 50% long-term survivors obtained by vaccination with retrovirally GM-CSF-transduced GL261 cells. In contrast, animals vaccinated with the same number of nontranduced GL261 cells or with GL261 cells infected with helper virus-free packaged HSV-1 amplicon vectors carrying no transgene showed only 10% long-term survivors. In conclusion, helper virus-free HSV-1 amplicon vectors appear to be effective for cytokine-enhanced vaccination therapy of glioma, with the advantages that both dividing and nondividing tumor cells can be infected, no viral proteins are expressed, and these vectors are safe and compatible with clinical use.

Mechanisms of brain-mediated systemic anti-inflammatory syndrome causing immunodepression

Overwhelming inflammatory immune response can result in systemic inflammation and septic shock. To prevent excessive and deleterious action of proinflammatory cytokines after they have produced their initial beneficial effects, the immune system can release several anti-inflammatory mediators, including interleukin-10, interleukin-1 receptor antagonist, and soluble tumor necrosis factor receptors, thus initiating a compensatory anti-inflammatory response syndrome. However, in vivo the delicate balance between pro- and anti-inflammatory responses is additionally controlled by the central nervous system. Therefore, proinflammatory cytokines stimulate the hypothalamic-pituitary-adrenal axis and enhance sympathetic nerve system activity. The mediators of these neuroimmune pathways can again suppress immune cell functions to control systemic inflammation. The question is, however, what happens if the immunoinhibitory CNS pathways are activated without systemic inflammation? This can result from production of cytokines in the brain following infection, injury, or ischemia or in response to various stressors (e.g., life events, depression, anxiety) or directly from brainstem irritation. The answer is that this may generate a brain-mediated immunodepression. Many animal and clinical studies have demonstrated a stress and brain cytokine mediated decrease in the cellular immune response at the lymphocyte level. More recently, the importance of monocytes in systemic immunocapacity has been shown. Monocytic inactivation with decreased capability of antigen presentation and depressed secretion of proinflammatory cytokines increases the risk of infectious complications. Interestingly, cytokines in the brain and other stressors can also generate systemic immunodepression at the monocyte level. In this scenario the catecholamine-induced release of the potent anti-inflammatory cytokine interleukin-10 is a newly discovered mechanism of the brain-mediated monocyte deactivation in addition to the "well known" immunosuppressive action of glucocorticoids. Furthermore, other neuropeptides such as alpha-melanocyte-stimulating hormone and beta-endorphin which can be released in stressful situations have also inhibitory effects on immune cells. Thus mediators of the CNS are implicated in the regulation of immune functions and may play a role in both conditioning the host's response to endogenous or exogenous stimuli and generating a "brain-mediated" immunodepression.

Continuous infusion of proinflammatory cytokines into the brain to study brain cytokine induced local and systemic immune effects

Proinflammatory cytokines are produced in the brain after various kinds of insult (ischemia, trauma, infection). In this process interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha are most important. These cytokines are key mediators of inflammation. Furthermore, these cytokines can act as neurotransmitters and develop direct effects on the central nervous system (CNS) including fever, sleep and stimulation of the neuroendocrine as well as sympathetic nervous system. Moreover, IL-1beta and TNF-alpha may also be involved in brain repair and regenerating processes. However, most of the data about the role of cytokines in the brain have been obtained from either in vitro studies or bolus injections into the brain parenchyma or cerebroventricular system. On the other hand, it is known that cytokines are released continuously into the brain after a cerebral insult over a period of 24 to 48 h. In order to further complete the knowledge about the interactions between neural and immune cells to overcome the primary insult and initiate repair and regeneration in the CNS, a new animal model of local inflammation reaction was established using chronic intracerebral infusion of rat recombinant cytokines.

Brain IL-1beta increases neutrophil and decreases lymphocyte counts through stimulation of neuroimmune pathways

Leukocytosis after cerebral injury is well described and may participate in the generation of cerebral damage. However, the mechanisms of brain-induced leukocytosis are still speculative. Since it is known that proinflammatory cytokines are involved in neuroimmunomodulation and since others and we have demonstrated high cytokine levels in the cerebrospinal fluid following injury, we supposed that brain cytokines may also influence leukocyte counts. In order to evaluate this hypothesis, we established an animal model using continuous intracerebroventricular (i.c.v.), intrahypothalamic (i.h.), or intravenous infusion of the proinflammatory cytokines tumor necrosis factor (TNF)-alpha and IL-1beta. Controls received vehicle solution. With this experimental paradigm we could show that i.c.v. and i.h. infusion of IL-1beta but not TNF-alpha dramatically increased neutrophil counts, whereas lymphocytes dropped. Blocking the hypothalamic-pituitary-adrenal (HPA) axis by hypophysectomy abolished the neutrophilia, whereas the lymphopenia remained unchanged. Furthermore, application of the beta2-adrenoreceptor antagonist propranolol prevented the decrease of lymphocytes and diminished the neutrophilia. All parameters normalized within 48 h after termination of infusion. So, our results demonstrate that brain IL-1beta can modify blood leukocyte counts through stimulation of both the sympathetic nervous system (SNS) and the HPA axis.

Brain-IL-1beta induces local inflammation but systemic anti-inflammatory response through stimulation of both hypothalamic-pituitary-adrenal axis and sympathetic nervous system

It is well established that systemic inflammation induces a counter-regulatory anti-inflammatory response particularly resulting in deactivation of monocytes/macrophages. However, recently we demonstrated a systemic anti-inflammatory response without preceding signs of systemic inflammation in patients with brain injury/surgery and release of cytokines into the cerebrospinal fluid (CSF). In order to analyze the mechanisms and pathways of systemic immunodepression resulting from sterile cerebral inflammation we established an animal model using continuous intra-cerebroventricular (i.c.v.) or intra-hypothalamic (i.h.) infusion of rat recombinant (rr) tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta for 48 h. Controls received intra-venous (i.v.) cytokine administration. Interestingly, i.c.v. and i.h. infusion of IL-1beta but not TNF-alpha produced distinct signs of central nervous system (CNS) inflammation. Correspondingly, i.c.v. infusion of IL-1beta particularly diminished the TNF-alpha but increased the IL-10 concentration in whole blood cultures after endotoxin stimulation. All parameters normalized within 48 h after termination of the infusion. Blocking the hypothalamic-pituitary-adrenal (HPA) axis by hypophysectomy (HPX) led to complete recovery of the diminished TNF-alpha concentration and temporarily inhibited the IL-10 increase. Blocking the sympathetic nervous system (SNS) transmission by application of the beta2-adrenoreceptor antagonist propranolol not only inhibited the increase but further downregulated the endotoxin induced IL-10 concentration in the media of whole blood cell cultures, whereas the TNF-alpha decrease was only partially prevented. Interestingly, HPX and propranolol also diminished the cell invasion into the CSF. In summary, activation of both the HPA axis and the SNS plays an important role in systemic anti-inflammatory response resulting from cytokines in brain and cerebral inflammation.

Sympathetic activation triggers systemic interleukin-10 release in immunodepression induced by brain injury

The mechanism of immunodepression after brain injury is not yet clear. Here we demonstrate rapid systemic release of the immunoinhibitory cytokine interleukin-10, monocytic deactivation and a high incidence of infection in patients with 'sympathetic storm' due to acute accidental or iatrogenic brain trauma. In vitro studies showed that within minutes catecholamines trigger the secretion of interleukin-10 from unstimulated monocytes through a beta-adrenoreceptor-mediated, cAMP/protein kinase A-dependent pathway. We found that in a rat model of acute brain injury, the beta-receptor antagonist propranolol prevented the increase of interleukin-10 plasma levels. Rapid monocytic interleukin-10 release after sympathetic activation may represent a common pathway for immunodepression induced by stress and injury.

Callosal and corticospinal tract function in patients with hydrocephalus: a morphometric and transcranial magnetic stimulation study

In 15 patients with symptomatic hydrocephalus, pressure-induced morphological changes of the brain and the function of callosal and corticospinal fibres were studied. Morphometry of the corpus callosum (CC) was performed on midsagittal MR images. Focal transcranial magnetic stimulation of the motor cortex was used to assess simultaneously excitatory motor responses in contralateral hand muscle (corticospinally mediated effect) and inhibition of tonic EMG activity in ipsilateral hand muscles (transcallosal inhibition (TI) of the contralateral motor cortex). Before a shunt operation, the midsagittal area of the CC was reduced by 34% on average. The height and, to a lesser degree the length, of the CC were increased before the shunt operation. Thresholds and central motor latencies of corticospinally mediated responses were normal, response amplitudes were smaller than in normal subjects. Motor thresholds increased from 38, SD 5 to 52, SD 8% (P < 0.01) within 7 days after ventricular drainage, reflecting the increase in the distance between stimulation coil and brain. The threshold increase paralleled a restoration of normal anatomical conditions within 7 days after shunt operation and the improvement of motor symptoms and might be a predictor of successful decompression. Transcallosal inhibition could be elicited in all patients. The measurements of TI lay within the normal range except the duration, which was prolonged in 73% of 15 patients before shunt operation as a probable indicator of an increased dispersion of callosal conduction. The normalization of the area and shape of the CC after shunt operation and the normal corticospinal and callosal conduction times exclude degeneration, demyelination or functional block of a large proportion of callosal or corticospinal tract fibres or a substantial loss of nerve cells in motor cortex.

Diminished monocytic HLA-DR expression and ex vivo cytokine secretion capacity in patients with glioblastoma: effect of tumor extirpation

Severe immunodysregulation on lymphocyte level has been described in patients with glioblastoma and is likely involved into its unfavorable prognosis. Although the major importance of monocytic cells for immunoregulation is well established, only very limited data exist regarding the monocyte status in glioblastoma patients. Here we demonstrate a markedly diminished monocytic HLA-DR expression and ex vivo cytokine secretion capacity (TNF-alpha, IL-1beta, IL-10) as signs for monocyte deactivation in glioblastoma patients but not in patients with astrocytoma. As known in immunocompromised patients from other reasons, monocyte deactivation indicate global immunodepression associated with an enhanced risk of infectious complications. Interestingly, tumor resection resulted in partial recovery from the monocytic deactivation. This suggests that the glioblastoma itself contributed to this phenomenon. However, IL-10 and the active forms of transforming growth factor-beta2 and -beta1, which are produced by glioblastoma cells and known to inhibit monocyte function, were not detectable in plasma in our patients. Moreover, low levels of the adrenocorticotropic hormone and cortisol excluded hypothalamo-pituitary-adrenal axis involvement. So, further investigations are necessary to clarify the mechanism. The demonstrated severe glioblastoma-associated monocytic deactivation may contribute to its unfavorable prognosis. Therefore, monocytes may represent target cells for new adjuvant immunotherapies in glioblastoma.

Topography of fibers in the human corpus callosum mediating interhemispheric inhibition between the motor cortices

In 1 split-brain patient and 13 patients with circumscript surgical lesions within different parts of the corpus callosum (CC), the topography of fibers within the CC mediating an interhemispheric inhibition between the motor cortices was investigated in the phase of a stable disconnection syndrome. The aim of the study was to characterize the system of callosal fibers activated by transcranial magnetic brain stimulation in more detail as a basis for a diagnostic application of this technique. The locations and areas of the lesions were measured on sagittal magnetic resonance (MR) slices and attributed to five segments of the CC, because the borders of the anatomic subdivisions of the CC are not clearly defined. Transcallosal inhibition (TI) of tonic electromyographical hand muscle activity was elicited by focal transcranial magnetic stimulation over the primary motor cortex. In a reference group of normal subjects, TI started after 35.8+/-3.6 msec had a duration of 24.8+/-2.7 msec and an estimated transcallosal conduction time of 15.5+/-3.0 msec (range, 10.2-20.0 msec, n = 24 hands). No significant differences were found for the TI originating from the right and left motor cortices. From the absence and presence of TI in patients with lesions in different parts of the CC it can be concluded that most of the fibers mediating TI pass through the posterior third and anterior fourth segment of the CC, that is, through the posterior half of the trunk of the CC. The clinical findings suggest a role for TI in the performance of fast and complex hand motor tasks.

Neuropsychological and neurophysiological consequences of partial callosotomy

Sixty-five patients with lesions affecting the third ventricle (54 patients) or the corpus callosum itself (11 patients) underwent partial callosotomy or a circumscribed callosal resection. Before the surgery 20 patients were studied using the battery of cognitive, affective and behavioural tests which was repeated 10 and 100 days after surgery. No disconnection syndrome was over observed after the partial commissurotomy. Transcranial magnetic stimulation over the sensorimotor cortex was performed in 10 patients to determine conduction time of callosal fibres by measuring inhibition of tonic voluntary electromyographic activity in muscle's ipsilateral to the activated hemisphere. It was found that this inhibition was absent in patients with lesions of the trunk of the corpus callosum and present in patients with lesions of the genu or splenium. In addition magnetic resonance imaging measurements of the corpus callosum were performed in 40 normal subjects to establish a classification system for corpus callosal area. The results showed a wide variability of the cross-sectional area of the corpus callosum. The comparison of the shape of the corpus callosum lead to a categorisation according to the presence and location of depressions on its surface.

Different release of cytokines into the cerebrospinal fluid following surgery for intra- and extra-axial brain tumours

To elucidate the role of cytokines in brain repair processes and in local inflammation after neurosurgical procedures, cerebrospinal fluid (CSF) samples from 8 patients with intra-axial tumours and 8 patients with extra-axial tumours were analysed for interleukin (IL)-1 beta, IL-1 receptor antagonist (IL-1 ra), IL-6, IL-8, IL-10, and tumour necrosis factor (TNF)-alpha at the beginning and after surgery. Levels of IL-6 and IL-8 increased dramatically in all patients just hours after surgery and fell during subsequent days. IL-1 beta was found only in low amounts in the CSF of both patient groups. Other cytokines demonstrated different courses. In patients with intra-axial tumours IL-1 ra peaked two to four hours after surgery with a subsequent decrease. In patients with extra-axial tumours there was a continuous low-level IL-1 ra release into the CSF without a peak. TNF-alpha was not present in detectable levels in the CSF after surgery for extra-axial tumours but was found to peak two to four hours after surgery for intra-axial tumours. IL-10 was detected in the CSF of both patient groups, but a higher peak was seen after surgery for extra-axial tumours. These results suggest different requirements for the cytokine response and an involvement of different cell types in cytokine release. However, the analysis of the CSF from both patient groups showed no differences in cell counts and populations, with a mild pleocytosis being present in both patient groups after surgery. Therefore, we conclude that after surgery for extra-axial tumours cytokines were predominately produced by non-immune cells stimulated through hypoxia or mechanical irritation. After surgery for intra-axial tumours with a significant brain injury immune cells-activated by necrotic material-seen to be involved in the process of cytokine synthesis. In these cases an additional IL-1ra and TNF-alpha peak was found and these cytokines may be markers for cerebral injury.

Very low monocytic HLA-DR expression indicates high risk of infection--immunomonitoring for patients after neurosurgery and patients during high dose steroid therapy

In patients with disturbed immunoreactivity caused by trauma or immunosuppressive therapy infections are still a severe problem. To determine whether measurement of monocytic HLA-DR expression is useful for identifying patients with a high risk of infection after elective neurosurgery, blood was obtained from 57 patients during the first 3 days after surgery. HLA-DR expression was lower in 14 patients who developed infection, compared with patients with an uncomplicated postoperative course (p < 0.0001). Out of ten patients with less than 30% HLA-DR positive monocytes, nine developed infection. In 11 neurosurgical patients additional investigations were performed. Measurements in these patients show that HLA-DR expression decreased temporarily within hours after surgery, coinciding with a considerable increase of inflammatory cytokines in CSF, but, surprisingly, not in plasma. High plasma concentrations of ACTH and cortisol hours after surgery indicated a hypothalamus-pituitary axis response, probably involved in the downregulation of monocytic HLA-DR expression. Likewise, monitoring of dermatological patients (n = 10) who received high dose systemic steroids revealed a very low HLA-DR expression in those patients who later developed infection. Our studies show that very low HLA-DR expression indicates high risk of infection. We recommend the measurement of this parameter for immunomonitoring.

Immunodepression following neurosurgical procedures

OBJECTIVE

To determine the influence of a selective, sterile central nervous system surgery on immune reactivity, particularly whether a decrease of monocytic human leukocyte antigen-DR expression, indicating immunodepression, occurs after neurosurgery and if this measurement is useful for identification of patients with a high risk of infection.

DESIGN

Prospective study.

SETTING

Department of neurosurgery and intensive care unit in a university hospital.

PATIENTS AND INTERVENTIONS

Blood samples were obtained from 46 patients at least once during the first 3 days after undergoing sterile central nervous system surgery. Fourteen of these patients developed infectious complications as defined by clinical and microbiological criteria. In ten of 46 patients, paired samples of blood and cerebrospinal fluid were collected from a ventricle drain at the following times: 1 day before surgery; several times on the day of surgery; and every day after surgery for at least 6 days.

MEASUREMENTS AND MAIN RESULTS

Monocytic human leukocyte antigen-DR expression, as measured by flow cytometry on days 1 through 3 after surgery in 46 patients, was lower in 14 patients who developed infection after neurosurgery (p < .0001). In all ten closely monitored patients, monocytic human leukocyte antigen-DR expression decreased temporarily after surgery. Of these patients, only one patient showed a persistent and considerably decreased monocytic human leukocyte antigen-DR expression. This patient was the only patient in this subgroup who developed sepsis syndrome. In order to assess whether the monocytic human leukocyte antigen-DR decrease was associated with a preceding inflammatory response, local and systemic concentrations of interleukin (IL)-1 beta, IL-6, IL-8, tumor necrosis factor-alpha, and interferon-gamma were measured in this subgroup. These cytokines were not detectable in plasma during the first days after surgery. In contrast, considerable increases of IL-6 and IL-8 concentrations were detectable in cerebrospinal fluid within hours after surgery.

CONCLUSIONS

A decrease of monocytic human leukocyte antigen-DR expression occurs after neurosurgery and is associated with a preceding, strong, intracranial (but not systemic) inflammatory response. A very low monocytic human leukocyte antigen-DR expression (< 30% positive monocytes) suggests the possibility of infection. Measurement of monocytic human leukocyte antigen-DR expression could help to detect patients with a high risk of infection after neurosurgery. Our results suggest that even sterile central nervous system surgery may contribute to general immunodepression. The local intracranial inflammatory response may be involved in this process.

Magnetic resonance imaging of a glioblastoma of the optic chiasm. Case report

Malignant optic glioma causing blindness was difficult to diagnose prior to the introduction of computerized tomography (CT) and magnetic resonance (MR) imaging, because earlier neuroradiological procedures often gave negative results and the clinical symptoms for this entity are not specific. In such cases only a craniotomy or postmortem examination revealed the tumor. The authors found no precise description in the literature of a malignant optic glioma diagnosed with modern imaging methods. They present a patient in whom biopsy results confirmed the CT and MR findings of glioblastoma multiforme of the optic chiasm.

Intrastriatal dopamine infusion reverses compensatory increases in D2-dopamine receptors in the 6-OHDA lesioned rat

Direct infusion of dopamine into the corpus striatum has been proposed as a potential approach for the treatment of Parkinson's disease. The present study examined the effect of intrastriatal dopamine infusion on D2-dopamine receptors in the 6-hydroxydopamine (6-OHDA) lesioned rat brain. The completeness of the 6-OHDA-induced nigrostriatal injury was confirmed using [3H]-mazindol autoradiography and apomorphine-induced behaviour. Intrastriatal infusion of three different dopamine doses significantly reduced the apomorphine-induced behaviour. [3H]-spiperone autoradiography performed one day after the termination of dopamine infusion into the striatum revealed a dramatic reduction of D2-dopamine receptor binding. The mean +/- SEM percent reduction of D2 receptor binding in the affected areas of the striatum was 28.8 +/- 1.0% for 4.74 micrograms dopamine/h infusion rate, 35.0 +/- 1.6% for 9.48 micrograms dopamine/h infusion rate and 33.3 +/- 5.0% for 14.22 micrograms dopamine/h infusion rate when compared to the unlesioned side. Infusion of vehicle alone did not have any effect. The present results support the concept that intrastriatal dopamine infusion may be a useful therapeutic approach for the treatment of Parkinson's disease.

Transcallosal removal of lesions affecting the third ventricle: an anatomic and clinical study

A series of 54 patients with lesions affecting the third ventricle with a wide range of pathology were operated on by the transcallosal approach. Hydrocephalus was present in 68.5% of all patients, and preoperative shunting was performed in 73.0% of them. Before the partial callosotomy, 16 patients were studied by the use of a cognitive, affective, and behavioral battery, which was repeated 10 and 100 days after the operation. No physiological consequences were ever observed after the partial commissurotomy. The postoperative callosal defect was verified by magnetic resonance imaging. Furthermore, 40 formalin-fixed brains were sectioned to study the variations of the anterior cerebral arteries. On the other hand, magnetic resonance imaging measurements of the corpus callosum in 40 normal subjects were performed to establish a classification system for the corpus callosal area. The results showed a wide variability of the cross-sectional area of the corpus callosum. The differences in the thickness of the truncus were responsible for this variability; the length of the corpus callosum was uniform. This may suggest that subjects with a large corpus callosum may have more interhemispheric connections with higher specialization of each hemisphere and that a smaller number of callosal connections may correlate with more ipsilateral pathways and more independent hemispheres. The results and the clinical as well as anatomical material indicate that the anterior transcallosal route is a safe and feasible alternative in the management of a wide spectrum of pathological lesions within the third ventricle and deserves preference over the transcortical technique.

[Tuberculosis of the CNS--once again a current neurosurgical disease]

Tuberculosis is relative uncommon in developed countries. The incidence is still considerable in India, in the Middle East and South America. Neurosurgically important manifestations of tuberculosis are intracranial tuberculomas, tuberculous meningitis with hydrocephalus and tuberculous spondylitis. Therefore experiences in the management of these three kinds of neurotuberculosis are described and an overview of the literature is given. The diagnosis of intracranial tuberculomas is difficult because the symptoms are similar to those of many other types of intracranial tumor and the CT-findings are unspecific. Clinical recognition of neurotuberculosis rests mainly on the evidence of the general disease. A positive skin test supports the diagnosis. The management of tuberculomas enclosed stereotactic biopsy to confirm the diagnosis, medical treatment and surgery. But surgery is only indicated for larger symptomatic mass lesions producing midline shift and severe intracranial hypertension. With antituberculous drugs treated tuberculomas begin to decrease in size within the first two months of therapy. Hydrocephalus is a common complication of tuberculous meningitis. Due to the low incidence the first diagnosis in industrialized countries is a hydrocephalus of unknown origin. The diagnosis of tuberculous meningitis is suspected in any case of subacute meningitis with a CSF profile demonstrating a predominance of lymphocytes, elevated protein value, hypoglycaemia and negative stains for bacterial or fungal organisms, because positive smears for acid-fast bacilli are seldom. Without treatment, tuberculous meningitis is invariably fatal within 4 to 6 weeks. Therefore, when ever tuberculous meningitis is suspected, antituberculous therapy must be started.(ABSTRACT TRUNCATED AT 250 WORDS)