Joachim K Krauss

Publications of Joachim K Krauss

• Erratum to: Subacute steroid-induced paraparesis: surgical treatment of a devastating "invisible" side effect.

  Authors: M Javad Mirzayan, Thomas Goessling, Tobias Huefner, Joachim K Krauss

  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 05/2012;

• Multiple Microsurgical Resections for Repeated Recurrence of Glioblastoma Multiforme.

  Authors: Bujung Hong, Bettina Wiese, Michael Bremer, Hans E Heissler, Fedor Heidenreich, Joachim K Krauss, Makoto Nakamura

  American journal of clinical oncology. 04/2012;

  OBJECTIVES:: There has been little evidence so far supporting further surgical intervention in case of repeated recurrence of glioblastoma multiforme (GBM). Thus, the efficacy and utility of repeatedOBJECTIVES:: There has been little evidence so far supporting further surgical intervention in case of repeated recurrence of glioblastoma multiforme (GBM). Thus, the efficacy and utility of repeated resection remains unclear but worthy of consideration. The aim of this study was to review the efficacy of multiple repeated resections in patients with recurrent GBM. METHODS:: Forty-two patients underwent repeated surgical resections for recurrent GBM. All patients who underwent >2 surgical interventions were clustered in group A. Group B were patients treated nonsurgically after resection of the first recurrence. Patients' treatment history, including surgical interventions, radiotherapy, chemotherapy regimens, postoperative complications, Karnofsky Performance Score, and survival rate were reviewed. RESULTS:: Group A consisted of 10 patients (median age, 60.5 y) and group B of 32 patients (median age, 56.5 y). Histopathologic findings revealed typical GBM in 8 patients of group A and in 23 patients of group B. An oligodendroglial component was detected in 2 patients of group A and in 7 patients of group B. The median Karnofsky Performance Score after the first surgery for tumor recurrence was 80 in both groups (P=0.084). The median overall survival time was 26 months in patients of group A and 16 months in patients of group B (P=0.052). The 2-year survival rate of group A was 58.3% and significantly higher than in group B (29.0%; P=0.036). The 3-year survival rate of group A was 31.1% and 12.4% of group B (P=0.038). CONCLUSIONS:: Microsurgical resection of repeatedly recurring GBM is likely to prolong survival. Repeated surgical resection may be considered as an effective treatment option in addition to radiochemotherapy in repeated GBM recurrence.

• Deep brain stimulation of the entopeduncular nucleus in rats prevents apomorphine-induced deficient sensorimotor gating.

  Authors: Dominic K Posch, Kerstin Schwabe, Joachim K Krauss, Götz Lütjens

  Behavioural brain research. 03/2012;

  Pharmacologically induced stereotypies and deficient sensorimotor gating, measured as prepulse inhibition (PPI) of the acoustic startle response (ASR), are used as endophenotypes for certain symptomsPharmacologically induced stereotypies and deficient sensorimotor gating, measured as prepulse inhibition (PPI) of the acoustic startle response (ASR), are used as endophenotypes for certain symptoms common to neuropsychiatric disorders, such as schizophrenia and Tourette's syndrome (TS) among others. We here investigated whether high frequency deep brain stimulation (DBS) of the rat entopeduncular nucleus (EPN), the equivalent to the human globus pallidus internus (GPi), would improve PPI-deficits and stereotypies induced by the dopamine receptor agonist apomorphine. Electrodes were stereotactically implanted bilaterally in the EPN of 13 Sprague-Dawley rats. After one week of recovery the rats were stimulated with an amplitude 20% below their individual threshold for side effects (130Hz, 80μs pulse width) or sham-stimulated for epochs of five days. At the end of each epoch the effect of ongoing stimulation or sham-stimulation on apomorphine-induced stereotypies (vehicle and 0.5mg/kg) and deficient PPI (vehicle and 1.0mg/kg) were tested. In nine rats, in which the full protocol could be applied and in which the electrode position was histologically confirmed in the target, EPN DBS did not affect baseline PPI but counteracted the apomorphine-induced PPI-deficit, while apomorphine-induced stereotypies were not affected by DBS. This work indicates an important role of the EPN in the modulation of apomorphine-induced deficient prepulse inhibition. This model may be useful to further investigate the pathophysiological of deficient sensorimotor gating and mechanisms of action of DBS in certain neuropsychiatric disorders.

• Subacute steroid-induced paraparesis: surgical treatment of a devastating "invisible" side effect.

  Authors: M Javad Mirzayan, Thomas Goessling, Tobias Huefner, Joachim K Krauss

  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 02/2012;

  PURPOSE: To emphasize an underestimated side effect following long-term use of steroids. METHODS: We report on surgical treatment of two patients with serious neurologic deficits caused by epiduralPURPOSE: To emphasize an underestimated side effect following long-term use of steroids. METHODS: We report on surgical treatment of two patients with serious neurologic deficits caused by epidural spinal lipoma following long-term intake of cortisone. RESULTS: Early decompression of the spinal cord by removal of epidural lipoma was the most effective treatment in these patients with progressive symptoms. CONCLUSION: Diagnostic work-up of such patients should include early spinal MRI resulting in surgical intervention, if indicated. Decompression of the spinal cord eventually combined with fusion is necessary.

• MRI safety of a programmable shunt assistant at 3 and 7 Tesla*

  Authors: M Javad Mirzayan, Petra M Klinge, Madjid Samii, Friedrich Goetz, Joachim K Krauss

  British journal of neurosurgery. 02/2012;

  Objective. Several new shunt technologies have been developed to optimize hydrocephalus treatment within the past few years. Overdrainage, however, still remains an unresolved problem. One newObjective. Several new shunt technologies have been developed to optimize hydrocephalus treatment within the past few years. Overdrainage, however, still remains an unresolved problem. One new technology which may reduce the frequency of this complication is the use of a programmable shunt assistant (proSA). Inactive in a horizontal position, it impedes CSF flow in a vertical position according to a prescribed pressure level ranging from 0 to 40 cm H(2)O. Methods. We exposed the proSA valve in an ex vivo protocol to MR systems operating at 3 and 7 Tesla to investigate its MRI safety. Results. Following 3 Tesla exposure, no changes in valve settings were noted. Adjustment to any pressure level was possible thereafter. The mean deflection angle was 23 ± 3°. After exposure to 7 Tesla, however, there were unintended pressure changes, and the mechanism for further adjustment of the valves even disintegrated. Conclusion. According to the results of this study, proSA is safe with heteropolar vertical magnet alignment at 3 Tesla. Following 7 Tesla exposure, the valves lost their functional capability.

• Deep brain stimulation of the subthalamic nucleus in the 6-hydroxydopamine rat model of Parkinson's disease: Effects on sensorimotor gating.

  Authors: Christoph Lindemann, Joachim K Krauss, Kerstin Schwabe

  Behavioural brain research. 02/2012; 230(1):243-50.

  Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is effectively used to treat motor symptoms in Parkinson's disease (PD). Recently more attention has been paid to behavioral disturbancesDeep brain stimulation (DBS) of the subthalamic nucleus (STN) is effectively used to treat motor symptoms in Parkinson's disease (PD). Recently more attention has been paid to behavioral disturbances caused by PD itself and by STN DBS. In the 6-hydroxydopamine (6-OHDA) PD rat model we investigated the effect of STN DBS on deficient prepulse inhibition (PPI) induced by the dopamine (DA) receptor agonist apomorphine, which is an operative measure for disturbed sensorimotor gating seen in certain neuropsychiatric disturbances. Male Sprague Dawley rats with bilateral lesions of the nigrostriatal DA system (striatal injection of 6-OHDA or vehicle for sham-lesion) were bilaterally implanted with electrodes for DBS into the STN. After determination of individual thresholds rats were stimulated (130Hz, 80μs pulse width) or sham-stimulated for epochs of six days. On the sixth day of each epoch rats were tested for PPI of the acoustic startle response after apomorphine or vehicle injection in a within randomized cross-over design. Stimulation of the STN improved PPI in vehicle-treated (control) rats, but deteriorated PPI after apomorphine treatment. This effect was more pronounced in sham-lesioned rats. Furthermore, in lesioned rats the startle reaction was marginally enhanced without effect of stimulation or apomorphine treatment. These data suggest that STN DBS interacts with dopaminergic action. With respect to functional neurosurgery, STN DBS alone may improve certain aspects of psychiatric disturbances, but may have a different impact when combined with dopaminergic medication.

• Scaling of movement is related to pallidal γ oscillations in patients with dystonia.

  Authors: Christof Brücke, Julius Huebl, Thomas Schönecker, Wolf-Julian Neumann, Kielan Yarrow, Andreas Kupsch, Christian Blahak, Goetz Lütjens, Peter Brown, Joachim K Krauss, Gerd-Helge Schneider, Andrea A Kühn

  The Journal of neuroscience : the official journal of the Society for Neuroscience. 01/2012; 32(3):1008-19.

  Neuronal synchronization in the gamma (γ) band is considered important for information processing through functional integration of neuronal assemblies across different brain areas. Movement-relatedNeuronal synchronization in the gamma (γ) band is considered important for information processing through functional integration of neuronal assemblies across different brain areas. Movement-related γ synchronization occurs in the human basal ganglia where it is centered at ~70 Hz and more pronounced contralateral to the moved hand. However, its functional significance in motor performance is not yet well understood. Here, we assessed whether event-related γ synchronization (ERS) recorded from the globus pallidus internus in patients undergoing deep brain stimulation for medically intractable primary focal and segmental dystonia might code specific motor parameters. Pallidal local field potentials were recorded in 22 patients during performance of a choice-reaction-time task. Movement amplitude of the forearm pronation-supination movements was parametrically modulated with an angular degree of 30°, 60°, and 90°. Only patients with limbs not affected by dystonia were tested. A broad contralateral γ band (35-105 Hz) ERS occurred at movement onset with a maximum reached at peak velocity of the movement. The pallidal oscillatory γ activity correlated with movement parameters: the larger and faster the movement, the stronger was the synchronization in the γ band. In contrast, the event-related decrease in beta band activity was similar for all movements. Gamma band activity did not change with movement direction and did not occur during passive movements. The stepwise increase of γ activity with movement size and velocity suggests a role of neuronal synchronization in this frequency range in basal ganglia control of the scaling of ongoing movements.

• Changes of Blood Endocannabinoids during Anaesthesia: a Special Case for Fatty Acid Amide Hydrolase Inhibition by Propofol?

  Authors: Carina Jarzimski, Matthias Karst, Alexander A Zoerner, Christin Rakers, Marcus May, Maria T Suchy, Dimitrios Tsikas, Joachim K Krauss, Dirk Scheinichen, Jens Jordan, Stefan Engeli

  British journal of clinical pharmacology. 01/2012;

  Aims:  Endocannabinoids are lipid mediators with numerous physiological actions. A previous study reported that blood concentrations of anandamide, one of the principle endocannabinoids, decreasedAims:  Endocannabinoids are lipid mediators with numerous physiological actions. A previous study reported that blood concentrations of anandamide, one of the principle endocannabinoids, decreased during isoflurane anaesthesia but not during propofol anaesthesia. Animal data suggested that propofol inhibits the anandamide degrading enzyme fatty acid amide hydrolase (FAAH). The aim of our study was to describe the time course of endocannabinoids during different anaesthesia protocols in more detail, and to challenge the hypothesis that propofol acts as a FAAH inhibitor. Methods:  Endocannabinoids were measured during the first hour of anaesthesia in 14 women and 14 men undergoing general anaesthesia with propofol, and in 14 women and 14 men receiving thiopental/sevoflurane. We also incubated whole human blood samples ex vivo with propofol and the known FAAH inhibitor oloxa, and determined FAAH enzyme kinetics. Results:  Plasma anandamide decreased similarly with propofol and thiopental/sevoflurane anaesthesia, and reached a nadir after 10 minutes. Areas under the curve for anandamide were 53.3 [47.4-59.2] nmol/l*60min with propofol, and 48.5 [43.1-53.8] nmol/l*60min with thiopental/sevoflurane (p = ns). Anandamide and propofol plasma concentrations were not correlated at any time point. Ex vivo FAAH activity was not inhibited by propofol. Enzyme kinetics of recombinant human FAAH were K(M) = 16.9 ± 8.8 µmol/l and V(max) = 44.6 ± 15.8 nmol/min*mg FAAH without, and K(M) = 16.6 ± 4.0 µmol/l and V(max) = 44.0 ± 7.6 nmol/min*mg FAAH with 50 µmol/l propofol (p = ns for both). Conclusions:  Our findings challenge the idea that propofol anaesthesia and also propofol addiction are directly mediated by FAAH inhibition, but we cannot exclude other indirect actions on cannabinoid receptors. © 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

• Stationarity in neuromonitoring data.

  Authors: Hans E Heissler, Kathrin König, Joachim K Krauss, Eckhard Rickels

  Acta neurochirurgica. Supplement. 01/2012; 114:93-5.

  Signals reflecting the metabolic and circulatory status of an injured central nervous system are normally corrupted systematically. The patient is part of a therapeutic control-loop and the signalsSignals reflecting the metabolic and circulatory status of an injured central nervous system are normally corrupted systematically. The patient is part of a therapeutic control-loop and the signals acquired are rather determined by the quality of control (stationarity of signals) than by the underlying pathological process. To verify the control-loop hypothesis, neuromonitoring data from 12 randomly selected severely head injured patients (initial GCS ≤ 8, 7 men, 5 women) were analysed for circulatory (blood pressure, intracranial pressure [ICP], cerebral perfusion pressure [CPP]) and metabolic (arterial blood gases, jugular bulb oxygenation [SjvO(2)], brain tissue oxygen partial pressure [ptiO(2)]) variables (n = 10). A total of 120 time series of generally not equidistant sample intervals were assessed for stationarity by Wallis & Moore's runs test. Non-stationarity could only be proven in 23 time series, i.e. the control-loop hypothesis was violated. Trends were mainly found in CPP (n = 5) and ICP (n = 4). The remaining cases spread out on all but one (temperature) signal. Nine patients showed at least one time series with a trend. One patient had clear trends in five out of ten variables that focused on SjvO(2), ptiO(2), ICP and CPP. Absence of stationarity in about 20% of time series is credited to an effective therapeutic control-loop. For analytical purposes, however, the benefit seems to be overestimated. Consequently, neuromonitoring should be considered the analysis of short-term disturbances that are intentionally compensated for by a short response time. Information content is thus reduced even if the number of sensor devices increases.

• Analysis of intracranial pressure time series using wavelets (Haar basis functions).

  Authors: Hans E Heissler, Kathrin König, Joachim K Krauss, Eckhard Rickels

  Acta neurochirurgica. Supplement. 01/2012; 114:87-91.

  Transforming intracranial pressure (ICP) into frequency domain commenced in the early 1980s, arriving at the conclusion that cerebrospinal dynamics were mapped by ICP spectral composition. ClassicalTransforming intracranial pressure (ICP) into frequency domain commenced in the early 1980s, arriving at the conclusion that cerebrospinal dynamics were mapped by ICP spectral composition. Classical analysis tools were not suitable for handling intrinsic signal non-stationarity. To overcome inherent obstacles we introduce a novel approach based upon wavelets. During routine diagnostic volume pressure testing epidural ICP was acquired in 118 patients with suspected cerebrospinal fluid circulatory disorders. Pressure was digitised and conditioned to separate low frequent signal components (<heart rate). ICP fluctuations were computed by subtraction of original and low frequent ICP constituents. Subsequently, multiresolution analysis was performed on fluctuations by discrete Haar wavelet transform and coefficients displayed in dyadic fashion (scalogram). Decomposition of ICP fluctuations led to typical patterns in the scalogram. Episodes of pathological wave activity and artificial ICP changes were topographically detectable in the time frequency plane. The wavelet approach is a simple yet powerful signal processing method to estimate both static and dynamic properties of ICP in various clinical scenarios. It therefore outclasses classical spectral transforms that are limited to analysing real-world data. Haar wavelets are fast and robust. Their disadvantages seem not to counterbalance the advantages in this biomedical application.

• Stereotactic drainage of empyema of the cavum septi pellucidi et vergae.

  Authors: Assel Saryyeva, Makoto Nakamura, Hans-Holger Capelle, Joachim K Krauss

  Stereotactic and functional neurosurgery. 01/2012; 90(1):59-62.

  Background: Persistent midline ventricular cavae may only rarely cause clinical symptoms. Exceptionally, empyemas may develop in these cavae. Optimal treatment has been defined only poorly so far.Background: Persistent midline ventricular cavae may only rarely cause clinical symptoms. Exceptionally, empyemas may develop in these cavae. Optimal treatment has been defined only poorly so far. Methods: Here, we report successful treatment of a bacterial empyema in the cavum septi pellucidi et vergae due to sphenoid sinus sinusitis in a 36-year-old woman by stereotactic puncture and drainage of the empyema and long-term administration of antibiotics. Results and Conclusions: Stereotactic puncture and drainage accompanied by antibiotic therapy result in beneficial outcome in the long term. Transcallosal interhemispheric approaches and free-hand techniques should be discouraged since, according to previously published reports, they may result in severe morbidity or mortality in this condition.

• Deep brain stimulation of the pedunculopontine tegmental nucleus modulates neuronal hyperactivity and enhanced beta oscillatory activity of the subthalamic nucleus in the rat 6-hydroxydopamine model.

  Authors: Mesbah Alam, Hans E Heissler, Kerstin Schwabe, Joachim K Krauss

  Experimental neurology. 01/2012; 233(1):233-42.

  Deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) area has been introduced as a novel surgical therapy for dopamine refractory gait problems, freezing and postural instability in theDeep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) area has been introduced as a novel surgical therapy for dopamine refractory gait problems, freezing and postural instability in the late stage of Parkinson's disease (PD). Lesions of the pedunculopontine tegmental (PPTg) nucleus, the equivalent of the PPN in rodents, were shown to reduce the elevated discharge rate of the subthalamic nucleus (STN) in the 6-hydroxydopamine (6-OHDA) rat model of PD. In order to further elucidate the modulatory effect of the PPTg on the STN we examined the effect of 25 Hz low frequency PPTg stimulation on neuronal single unit activity and oscillatory local field potentials (LFPs) of the STN, and on the electrocorticogram (ECoG) of the primary motor cortex region in rats with unilateral 6-OHDA induced nigrostriatal lesions. Stimulation of the PPTg reduced the enhanced firing rate in the STN, without affecting the firing pattern or approximate entropy (ApEn). It also reduced the activity in the beta band (15-30 Hz) of the STN, which is elevated in 6-OHDA lesioned rats, without affecting beta activity in the motor cortex. We showed a modulatory effect of PPTg stimulation on altered neuronal STN activity in the PD 6-OHDA rat model, indicating that PPTg DBS may alter activity of the basal ganglia circuitry at least partially. It remains unclear, however, how these changes are exactly mediated and whether they are relevant with regard to the descending PPTg projections in the lower brainstem.

• Comparative morphological and immunohistochemical study of human meningioma after intracranial transplantation into nude mice.

  Authors: Sabrina Friedrich, Kerstin Schwabe, Rüdiger Klein, Claudia A Krusche, Joachim K Krauss, Makoto Nakamura

  Journal of neuroscience methods. 12/2011; 205(1):1-9.

  Although surgical resection of benign human meningiomas is the primary goal, in case of relapse or when they are not fully resectable, other strategies including chemotherapeutical treatment would beAlthough surgical resection of benign human meningiomas is the primary goal, in case of relapse or when they are not fully resectable, other strategies including chemotherapeutical treatment would be appropriate. The initial evaluation of chemotherapeutical agents requires an appropriate tumor model, where the natural characteristics of the original benign tumor is reflected. We here tested, whether primary cell cultures of benign human meningiomas would reliably grow after intracranial transplantation into mice, and whether they would show histomorphological and immunohistochemical characteristics of the original human tumor. Cells of 11 benign human meningiomas were transplanted into the prefrontal cortex of nude mice. After 3 months, the mice were sacrificed and their brains were histologically processed for morphological characterization and measurement of tumor volume. Additionally, the proliferation index (PI), the microvessel density, and epithelial membrane antigen (EMA) were compared between human meningiomas and tumors grown in mice by using immunohistochemical methods. Further, cyclooxygenase-2 (COX-2) expression, a possible target for pharmacological manipulation, was examined. The results showed in almost all mice (93%) a tumor formation with meningothelial histomorphology comparable to the original human tumors. The PI, vascular density and COX-2 expression were similar between human and mice meningiomas, but EMA expression was reduced in mice (P<0.01). In conclusion an implantation of benign human meningioma primary cell cultures in mice reliably results in tumor formation with morphological and immunohistological features comparable to the original human tumor. This model may therefore be suitable to test novel therapeutic agents.

• Bilateral deep brain stimulation for cervical dystonia in patients with previous peripheral surgery.

  Authors: Hans-Holger Capelle, Christian Blahak, Christoph Schrader, Hansjörg Baezner, Marwan I Hariz, Tommy Bergenheim, Joachim K Krauss

  Movement disorders : official journal of the Movement Disorder Society. 12/2011; 27(2):301-4.

  There are no data available concerning whether patients with cervical dystonia who have recurrent or new symptoms after peripheral denervation surgery benefit similarly from pallidal deep brainThere are no data available concerning whether patients with cervical dystonia who have recurrent or new symptoms after peripheral denervation surgery benefit similarly from pallidal deep brain stimulation compared with patients who receive primarily pallidal stimulation. Data on 7 cervical dystonia patients with recurrent or progressive dystonia after peripheral denervation who underwent pallidal stimulation were prospectively collected. Deep brain stimulation was performed in Mannheim/Hannover, Germany, or in Umea, Sweden. To the subgroup from Mannheim/Hannover, a second group of patients without previous peripheral surgery was matched. Assessments included the Toronto Western Spasmodic Torticollis Rating Scale and the Burke-Fahn-Marsden dystonia rating scale, as well as the Tsui scale in the Swedish patients. The 4 patients from Mannheim/Hannover experienced sustained improvement from pallidal stimulation by a mean of 57.5% according to the Toronto Western Spasmodic Torticollis Rating Scale (P < .05) and by a mean of 69.5% according to the Burke-Fahn-Marsden dystonia rating scale (P < .05) at long-term follow-up of 40.5 months. The patients from Umea had a mean Tsui score of 7 prior to surgery and a mean score of 3 at the mean follow-up of 8 months (62.5%). In the matched group the Toronto Western Spasmodic Torticollis Rating Scale improved by 58.8% and the Burke-Fahn-Marsden dystonia rating scale by 67% (P < .05) at long-term follow-up (mean, 41.5 months). Patients who had prior peripheral surgery for cervical dystonia experience improvement from subsequent pallidal stimulation that is comparable to that of de novo patients. © 2011 Movement Disorder Society.

• Lesions of the rat entopeduncular nucleus further deteriorate N-methyl-D-aspartate receptor antagonist-induced deficient prepulse inhibition.

  Authors: Götz Lütjens, Joachim K Krauss, Kerstin Schwabe

  Neuroscience letters. 12/2011; 508(1):27-30.

  Lesions of the rat entopeduncular nucleus (EPN), the equivalent to the human globus pallidus internus (GPi), have been shown to improve deficient prepulse inhibition (PPI) induced by the dopamineLesions of the rat entopeduncular nucleus (EPN), the equivalent to the human globus pallidus internus (GPi), have been shown to improve deficient prepulse inhibition (PPI) induced by the dopamine agonist apomorphine. We here tested the effect of EPN lesions on the PPI-disruptive effect of the non-competitive NMDA receptor antagonist dizocilpine in rats. Neurotoxic bilateral lesions of the EPN were induced by ibotenic acid (4 μg in 0.4 μl). Rats were tested for PPI and locomotor activity after systemic injection of dizocilpine (vehicle and 0.15 mg/kg). Bilateral EPN lesions further deteriorated the PPI deficit induced by dizocilpine, while locomotion was not affected. This work indicates that the EPN is an important brain region within the neuronal circuit responsible for NMDA receptor antagonist-induced PPI deficits.

• Complex wound-healing problems in neurosurgical patients: risk factors, grading and treatment strategy.

  Authors: Kartik G Krishnan, Adolf Müller, Bujung Hong, Alexander A Potapov, Gabriele Schackert, Volker Seifert, Joachim K Krauss

  Acta neurochirurgica. 11/2011; 154(3):541-54.

  Wound-healing problems in the neurosurgical patient can be particularly bothersome, owing to various specific risk factors involved. These may vary from simple wound dehiscence to complex multi-layerWound-healing problems in the neurosurgical patient can be particularly bothersome, owing to various specific risk factors involved. These may vary from simple wound dehiscence to complex multi-layer defects with cerebrospinal fluid (CSF) leakage and contamination. The latter is quite rare in practice and requires an individually titrated reconstruction strategy. The objective is to retrospectively analyze neurosurgical patients with complex, recalcitrant wound-healing problems we had treated in our department, attempt to develop a grading system based on the risk factors specific to our specialty and adapt a surgical reconstruction algorithm. During an 11-year period, 49 patients were identified to have had complex, recalcitrant wound-healing problems involving the cranial vault (n = 43) and the skull base (n = 6) that required an adapted surgical wound-management strategy. The etiologies of wound healing problems were aftermaths of surgical treatment of: (1) brain tumors (nine cases), (2) aneurysm clipping (ten cases), (3) trauma (27 patients), and (4) congenital malformations (three patients). Local rotational advancement flaps were performed in 18 patients and free microvascular tissue transfer was performed in 37 cases. Major risk factors leading to recalcitrant wound healing problems in the presented group were: prolonged angiographic interventions (20%), ongoing chemotherapy or radiotherapy (47%), prolonged cortisone application (51%), CSF leak (76%) and, above all, multiple failed attempts at wound closure (94%). Stable long-term wound healing was achieved in all patients using vascularized tissue coverage. A ternary grading system was developed based on various risk factors in the presented cohort. Accordingly, the algorithm for reconstruction in neurosurgical patients was adapted. Primary disease, treatment history, and distorted anatomical structures are major concerns in the management of complex wound-healing problems in neurosurgical patients. The higher the risk factors involved, the more complex is the surgical strategy. Free microvascular tissue transfer offers stable long-term results in recalcitrant cases. However, this may be indicated only in patients with a good prognosis of the underlying disease.

• Fatal outcome despite bilateral decompressive craniectomy for refractory intracranial pressure increase in butane intoxication.

  Authors: Morad Peyravi, M Javad Mirzayan, Joachim K Krauss

  Clinical neurology and neurosurgery. 11/2011;

• Combined pallidal and subthalamic nucleus stimulation in sporadic dystonia-parkinsonism.

  Authors: Johannes C Wöhrle, Christian Blahak, Hans-Holger Capelle, Wolfgang Fogel, Hansjoerg Bäzner, Joachim K Krauss

  Journal of neurosurgery. 09/2011; 116(1):95-8.

  Multifocal deep brain stimulation (DBS) is a new technique that has been introduced recently. A 39-year-old man with dystonia-parkinsonism underwent the simultaneous implantation of subthalamicMultifocal deep brain stimulation (DBS) is a new technique that has been introduced recently. A 39-year-old man with dystonia-parkinsonism underwent the simultaneous implantation of subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS electrodes. While bilateral STN DBS controlled the parkinsonian symptoms well and allowed for a reduction in levodopa, the improvement of dystonia was only temporary. Additional GPi DBS also alleviated dystonic symptoms. Formal assessment at the 1-year follow-up showed that both the parkinsonian symptoms and the dystonia were markedly improved via continuous bilateral combined STN and GPi stimulation. Sustained benefit was achieved at 3 years postoperatively.

• Progressive osteolytic calvarial lesions in children after minor head injury.

  Authors: Elvis J Hermann, Bujung Hong, Almuth Brandis, Joachim K Krauss

  Pediatric neurosurgery. 09/2011; 47(2):133-7.

  Osteolytic lesions of the skull in children have a broad differential diagnosis including congenital, inflammatory and neoplastic lesions. Progressive osteolysis of the skull secondary to head traumaOsteolytic lesions of the skull in children have a broad differential diagnosis including congenital, inflammatory and neoplastic lesions. Progressive osteolysis of the skull secondary to head trauma is rare and has been poorly characterized. The pediatric database at our hospital was screened for children with osteolytic lesions who had a previous mild head injury without fracture or dural tears. We identified 2 children with circumscribed progressive cranial osteolysis after minor head trauma detected by CT and MRI scans. Three additional cases were found in a review of the published literature. Ten children with an osteolytic skull lesion treated between January 1998 and February 2008 were identified in our pediatric database. In 2 children there was evidence of previous mild head injury without a skull fracture. Trauma had occurred 7 and 2 months prior to presentation, respectively. The inner table of the skull was intact in both cases. In 1 case, surgery was performed, and in the other case, a wait-and-see strategy was adopted. Pathological examination in case 1 revealed an organized hemorrhage with focal papillary endothelial hyperplasia. Progressive osteolytic calvarial lesions may occur in both infants and adolescents after mild head injury. They involve either only the diploe and outer table of the skull or both the inner and outer tables. These lesions might be due to intradiploic or subgaleal hematomas triggering an inflammatory process. While surgical resection can be considered to confirm a histopathological diagnosis and to exclude other diagnoses, spontaneous reossification is possible.

• c-Fos expression after deep brain stimulation of the pedunculopontine tegmental nucleus in the rat 6-hydroxydopamine Parkinson model.

  Authors: Assel Saryyeva, Makoto Nakamura, Joachim K Krauss, Kerstin Schwabe

  Journal of chemical neuroanatomy. 08/2011; 42(3):210-7.

  Deep brain stimulation (DBS) is used to alleviate motor dysfunction in Parkinson's disease (PD). The pedunculopontine nucleus (PPN) may be a potential target for severe freezing and posturalDeep brain stimulation (DBS) is used to alleviate motor dysfunction in Parkinson's disease (PD). The pedunculopontine nucleus (PPN) may be a potential target for severe freezing and postural instability with 25 Hz stimulation being considered more effective than 130 Hz stimulation. Here we evaluated the expression of c-Fos after 25 Hz and 130 Hz DBS of the pedunculopontine tegmental nucleus (PPTg, i.e., the rodent equivalent to the human PPN) in the rat 6-hydroxydopamine (6-OHDA) PD model. Anaesthetized male Sprague Dawley rats with unilateral 6-OHDA-induced nigrostriatal lesions were stimulated with 25 Hz, 130 Hz, or 0 Hz sham-stimulation for 4h by electrodes implanted into the ipsilateral PPTg. Thereafter the distribution and number of neurons expressing the immediate early gene c-Fos, a marker for acute neuronal activity, was assessed. DBS of the PPTg induced strong ipsilateral c-Fos expression at the stimulation site, with 25 Hz having a more marked impact than 130 Hz. Additionally, c-Fos was strongly expressed in the central gray. In the dorsal part expression was stronger after 25 Hz stimulation, while in the medial and ventral part there was no difference between 25 Hz and 130 Hz stimulation. Expression in the basal ganglia was negligible. In the rat 6-OHDA PD model stimulation of the PPTg did not affect c-Fos expression in the basal ganglia, but had a strong impact on other functional circuitries. PPN stimulation in humans might therefore also have an impact on other systems than the motor system.