[Long-term effects of deep brain stimulation for movement disorders: a literature-based analysis]. / Langzeiteffekte der tiefen Hirnstimulation bei Bewegungsstörungen : Eine literaturbasierte Analyse.

BACKGROUND: Deep brain stimulation has become an established therapy for various movement disorders but questions regarding its long-term effectiveness remain. OBJECTIVES: This study was designed to evaluate the long-term effectiveness of deep brain stimulation for movement disorders refractory to current medical therapy based on published long-term studies. METHODS: A review was carried out of all available studies with a minimum follow-up of 5 years of patients with deep brain stimulation for Parkinson's disease, essential tremor and dystonia. RESULTS: A total of 23 studies of deep brain stimulation for Parkinson's disease, 7 studies for essential tremor and 14 studies for dystonia were included. After a follow-up of at least 5 years, improvement of current motor scores could be observed in Parkinson's disease (subthalamic stimulation) by approximately 40%, by approximately 50% for essential tremor and by 60% for dystonia (mostly generalized forms). In Parkinson's disease, motor improvements tend to diminish over time due to progression of dysarthria, axial symptoms and other motor features less responsive to deep brain stimulation. Non-dopaminergic symptoms tend to progress and lessen the positive effects on the quality of life. There appears to be a subgroup of patients with essential tremor who show decreasing effectiveness of deep brain stimulation, probably related to disease progression. Currently, no single prognostic marker has been established to identify this subgroup. Most forms of secondary dystonia seem to respond more variably than primary generalized dystonia. CONCLUSION: Deep brain stimulation remains a relatively safe and effective therapy in carefully selected patients after long-term follow-up according to published data, although disease progression and other disease-specific factors seem to modify its effectiveness over time.

Intraindividual comparison of histopathological diagnosis obtained by stereotactic serial biopsy to open surgical resection specimen in patients with intracranial tumours.

BACKGROUND: There are concerns in the literature about the accuracy of histopathological diagnosis obtained by stereotactic biopsy in patients with brain tumours. The aim of this study was to analyse intraindividually the histopathological accuracy of stereotactic biopsies of intracerebral lesions in comparison to open surgical resection. MATERIALS AND METHODS: Between 2007 and 2011 a total of 635 patients underwent stereotactic serial biopsy in our department. Among these patients we identified 51 patients, who underwent magnetic resonance (MR) based stereotactic biopsy and subsequent open resection within 30 days. Mortality and morbidity data as well as final histopathological diagnoses of both procedures were compared with regard to tumour grade and tumour cell type. Patients with discrepancies between the histological diagnosis obtained by biopsy and open resection were classified into three subgroups (same cell type but different grading; same grading but different cell type and different grading as well as different cell type). RESULTS: The mean number of tissue samples taken by stereotactic serial biopsy from each patient was 12 (range 7-21). Minor morbidity was 6% and major morbidity was 14% after open surgery compared to no morbidity after stereotactic biopsy. Mortality was 2% after stereotactic biopsy (one patient died after stereotactic biopsy as a result of a fatal bleeding) compared to 0% in the resection group. Silent bleeding rate without any clinical symptoms was 8% in the biopsy group. A complete correlation of histopathological findings between the biopsy group and the resection group was achieved in 76% and was increased to 90% by analyzing clinical and neuroradiological information. In patients with recurrence the correlation was higher (94%) than for patients with primary brain lesions (67%). The discrepancies between the open resection group and biopsy group were analysed. CONCLUSION: Stereotactic MR guided serial biopsy is a minimal invasive procedure with low morbidity and high diagnostic accuracy for diagnosis and grading of brain tumours. Diagnostic accuracy of stereotactic biopsy can be enhanced further by careful interpretation of neuroradiological and clinical information.

Global tracking in human gliomas: a comparison with established tracking methods.

PURPOSE: Global tracking (GT) is a recently published fibre tractography (FT) method that takes simultaneously all fibres into account during their reconstruction. The purpose of this study was to compare this new method with fibre assignment by continuous tracking (FACT) and probabilistic tractography (PT) for the detection of the corticospinal tract (CST) in patients with gliomas. METHODS: Tractography of the CST was performed in 17 patients with eight low grade and nine anaplastic astrocytomas located in the motor cortex or the corticospinal tract. Diffusions metrics as fractional anisotropy (FA), mean (MD), axial (AD) and radial diffusivity (RD) were obtained. The methods were additionally applied on a physical phantom to assess their accuracy. RESULTS: PT was successful in all (100 %), GT in 16 (94 %) and FACT in 15 patients (88 %). The case where GT and FACT, both, missed the CST showed the highest AD and RD, whereas the one where FACT algorithm, alone, was not successfully showed the lowest AD and RD of the group. FA was reduced on the pathologic side (FApath 0.35 ± 0.16 (mean ± SD) versus FAcontralateral 0.51 ± 0.15, pcorr < 0.03). RD was increased on the pathologic side (RDpath 0.67 ± 0.29 × 10(-3) mm(2)/s versus RDcontralateral 0.46 ± 0.08 × 10(-3) mm(2)/s, pcorr < 0.03). In the phantom measurement, only GT did not detect false positive fibres at fibre crossings. CONCLUSION: PT performed well even in areas of increased diffusivities indicating a severe oedema or disintegration of tissue. FACT was also susceptible to a decrease of diffusivities and to a susceptibility artefact, where GT was robust.

Bevacizumab as salvage therapy for progressive brain stem gliomas.

OBJECTIVE: There is no standard of care for patients with progredient brain stem gliomas. Therefore, we report about clinical, radiological and metabolic response to anti-angiogenic treatment with bevacizumab in a series of 3 patients with gliomas involving the brain stem. PATIENTS AND METHODS: Three patients with histologically confirmed gliomas involving the brain stem were treated with bevacizumab for tumor progression. The clinical data, histopathological findings as well as MRI and PET follow up examinations during bevacizumab therapy were retrospectively analyzed. RESULTS: The histopathological diagnosis revealed an anaplastic astrocytoma WHO grade III in two patients and an astrocytoma WHO grade II in 1 patients with clinical and neuroradiological signs of malignization. One patient is still progression-free 97 weeks after initiation of bevacizumab therapy. Mean progression-free survival and overall survival for the other two patients after initiation of bevacizumab therapy was 34.5 weeks and 43.5 weeks. During bevacizumab therapy mean KPS improved from 60 to 80 and mean dosage of daily dexamathasone was reduced from 7.3 mg to 1.3 mg. MRI showed a decrease of T2 weighted hyperintense lesions in all patients and a decrease of contrast enhancement in two patients. (18)F-FET-PET showed a decrease of tracer uptake in all cases (mean maximum decrease: 25%). CONCLUSION: In this series treatment of progressive gliomas involving the brain stem with bevacizumab resulted in an improved clinical condition of the patients as well as a reduction of the T2 weighted lesions and reduced amino acid uptake in the tumor area. It therefore may represent a therapeutic salvage option for this type of tumor.

A comprehensive analysis of vascular complications in 3,889 glioma patients from the German Glioma Network.

Ischemic strokes, intracranial hemorrhages (ICH) and deep venous thromboembolism (DVT) are clinically important events in patients with gliomas. In this multicentre, noninterventional observational study, current data pertaining to frequency, contributing factors and outcomes of vascular events during times of anti-angiogenic therapy with the antibody against vascular endothelial growth factor, bevacizumab (BEV) was collected from the German Glioma Network. Among 3,889 glioma patients, 70 ischemic strokes (1.8 %) and 123 ICH (3.2 %) were recorded. 143 DVT (5.0 %) were recorded in 2,855 patients. Rates of DVT and ICH, but not of ischemic strokes, increased with the World Health Organization (WHO) grade of glioma. In 81 BEV-treated patients, five ischemic strokes (6.2 %), one ICH (1.2 %) and six DVT (7.4 %) were documented. Compared to patients that were not treated with BEV, ischemic stroke rate was significantly higher during treatment with BEV (p < 0.001). The rates of DVT (p = 0.123) or ICH (p = 0.571) in BEV-treated patients did not differ. On cerebral magnetic resonance imaging (MRI), BEV-related ischemic strokes appeared as diffusion-restricted sites next to contrast-enhancing tumor. 67 % of ICH, 61 % of ischemic strokes and 18 % of DVT occurred postoperatively (within 30 days after tumor resection). Outcome after postoperative ICH was significantly worse than after spontaneous ICH (p = 0.008). Ischemic stroke outcomes did not differ between postoperative and spontaneous occurrence (p = 0.401). Rate of pulmonary embolism did not differ significantly between postoperative and spontaneous DVT (p = 0.133). Relatively low rates of ICH and DVT might be partially due to a high proportion of low-grade gliomas in this patient cohort. The finding of a relevant number of symptomatic, therapy-associated intracerebral diffusion restrictions should be controlled in ongoing phase III studies.

Complementary therapy use in patients with glioma: an observational study.

OBJECTIVE: Despite novel multimodal therapeutic approaches, the vast majority of glial tumors are not curable. Patients may search for complementary therapies in order to contribute to the fight against their disease or to relieve symptoms induced by their brain tumor. The extent of the use of complementary or alternative therapies, the patients' rationale behind it, and the cost of complementary therapy for gliomas are not known. We used a questionnaire and the database of the German Glioma Network to evaluate these questions. METHODS: A total of 621 questionnaires were available for evaluation from patients with glial tumors of WHO grades II to grade IV. The patients were recruited from 6 neuro-oncologic centers in Germany. Complementary therapy was defined as methods or compounds not used in routine clinical practice and not scientifically evaluated. RESULTS: Forty percent of the responding patients reported the use of complementary therapies. Significant differences between the group of complementary therapy users and nonusers were seen with respect to age (younger > older), gender (female > male), and education (high education level > low education level). The motivation for complementary therapy use was not driven by unsatisfactory clinical care by the neuro-oncologists, but by the wish to add something beneficial to the standard of care. CONCLUSIONS: In clinical practice, patients' use of complementary therapies may be largely overseen and underestimated. The major motivation is not distrust in conventional therapies. Neuro-oncologists should be aware of this phenomenon and encourage an open but critical dialogue with their patients.

Treatment strategies of space-occupying intradural metastases of the cauda equina of nonneurogenic origin.

BACKGROUND: Compressive intradural metastases of the cauda equina are a rare site of metastatic spread in systemic cancer. So far, only few reports have been published with conflicting statements concerning a surgical versus nonsurgical approach. METHOD: Five patients with symptomatic space-occupying intradural metastases of the cauda equina were analyzed retrospectively, focusing on the influence of surgical intervention on pain relief, neurological outcome and thus the patients' quality of life. FINDINGS: At the time of diagnosis, all patients were in an advanced metastatic state. Surgical resection was the primary treatment in four patients and radiotherapy in one. Despite infiltration of the cauda rootlets, gross total tumour resection could be achieved in two of the four patients treated surgically. Functional outcome was beneficial in these patients with marked and immediate relief of pain and improvement of motor function even following incomplete tumour resection. CONCLUSIONS: Surgical treatment of compressive intradural metastases of the cauda equina seems to be feasible with low operative risk and with the potential benefit of an immediate relief of pain and improvement in motor function and thus an increase in quality of life.

Relevance of ICP and ptiO2 for indication and timing of decompressive craniectomy in patients with malignant brain edema.

BACKGROUND: The exact effects of decompressive craniectomy on intracranial pressure (ICP) and cerebral tissue oxygenation (ptiO2) are still unclear. Therefore, we have monitored ICP and ptiO2 intra-operatively and correlated these values to different operative steps during craniectomy. METHODS: ICP and ptiO2 values have been monitored both, simultaneously and continuously, in 15 patients with cerebral edema due to posttraumatic or postischemic brain swelling. Indications for craniectomy were an increase in ICP above 25 mmHg or a decrease in ptiO2 below 10 mmHg resistant to conservative treatment (e.g. mannitol, hyperventilation, adequate arterial blood oxygenation, etc.). In all cases, we performed a fronto-temporo-parietal craniectomy (15 x 12 cm) and dura enlargement with galea-periosteum. During craniectomy, monitoring of ICP and ptiO2 in the affected hemisphere was continued. Values were recorded and correlated with the different operative steps. FINDINGS: We performed craniectomy according to our treatment protocol in 5 patients. Prior to surgery, mean ICP values were 25.6 mmHg (range: 23-29 mmHg), mean ptiO2 values were 5.9 mmHg (range: 2.4-9.5 mmHg), and mean CPP values were 66 mmHg (range: 60-70 mmHg). After removing the bone flap, ICP values dropped to physiological values (mean: 7.4 mmHg), whereas ptiO2 values increased only slightly (mean: 11 mmHg). Opening of the dura resulted in a further decrease of ICP (mean 4.8 mmHg) and an increase of ptiO2 to normal limits (mean: 18.8 mmHg). After skin closure, mean ICP was 6.8 mmHg and mean ptiO2 was 21.7 mmHg, respectively. We found a significant decrease of ICP after craniectomy (p<0.042) and after dura enlargement (p<0.039) as well as a statistically significant increase in ptiO2 after craniectomy (p<0.043) and after dura enlargement (p<0.041). CONCLUSION: As a large bone flap in decompressive craniectomy is essential for adequate ICP reduction, the results of the presented cases suggest that dura enlargement is the crucial step to restore adequate brain tissue oxygenation and that ptiO2 monitoring could be an important tool for timing craniectomy in the future.

Spinal epidural abscess: prognostic factors and comparison of different surgical treatment strategies.

BACKGROUND: Spinal epidural abscess (SEA) is a rare but potentially devastating disease requiring immediate surgical intervention and appropriate antibiotic treatment. The standard approach to decompress SEA is laminectomy. No report covers comprehensively the indications for the less invasive interlaminar approach, the usefulness of intra-operative ultrasonography and the suspected benefit of inserting a suction-irrigation drainage. METHOD: A retrospective evaluation of the medical and radiological data was undertaken in 27 consecutive patients with SEA operated on during a period of 10 years by a dorsal approach. Factors influencing outcome were evaluated with special regard to different surgical strategies concerning the invasiveness of the operative approach, the use of intra-operative ultrasound and the use of different drainage systems. FINDINGS: Outcome was mainly determined by the pre-operative neurological condition and the localization of the abscess. Recurrence rate was dependent on the longitudinal extent of the mass and the intra-operative finding of granulation tissue, but not on the administration of a postoperative suction-irrigation drainage. An interlaminar approach was equally matched to a decompression by laminectomy in lumbar SEA concerning the incidence of residual/recurrent abscess formation. In concomitant spondylodiscitis, laminectomy bore the risk of the formation of a postoperative kyphotic deformity. The use of intra-operative ultrasound allowed the visualization of hidden inflammatory masses and, thus, reduced the rate of residual abscess formation. CONCLUSION: An interlaminar approach should be considered instead of laminectomy in lumbar SEA and in impending anterior column instability due to spondylitis. Intra-operative ultrasound is a beneficial aid for the determination of the extent of decompression during surgery and is practicable even through a narrow interlaminar bony window. The insertion of postoperative suction-irrigation drainage had no beneficial effect on outcome but bore the risk of epidural fluid congestion.

Neuronavigation combined with electrophysiological monitoring for surgery of lesions in eloquent brain areas in 42 cases: a retrospective comparison of the neurological outcome and the quality of resection with a control group with similar lesions.

The purpose of this study was to achieve a more radical resection of tumors in the area of the motor cortex via minimal craniotomy using a combination of neuronavigation and neurophysiological monitoring with direct electrical cortical stimulation and to compare retrospectively the clinical outcome and postoperative magnetic resonance imaging with a control group that was operated on in our service when the combination of these monitoring techniques was not available. A total of 42 patients with tumors in or near the central region underwent surgery with neuronavigation guidance and neurophysiological monitoring. The primary motor cortex was identified intraoperatively by the somatosensory evoked phase reversal method and direct cortical stimulation. The functional areas were transferred into the neuronavigation system. By stimulating the identified primary motor cortex and displaying the motor area in the operating microscope a permanent control of the motor function was possible during the whole operation. Using these techniques a more radical tumor resection - evaluated by postoperative MRI - was achieved in the study group (p = 0.04) and also a trend toward a better neurological outcome.

Xanthogranuloma of the Erdheim-Chester type within the sellar region: case report.

Manifestations of Erdheim-Chester disease in the central nervous system are very rare. Cases with localization in the retroorbital space, hypothalamic area and posterior pituitary as well as intracerebral lesions are known. In our neurosurgical unit, a 51-year-old male patient with a history of hypophyseal insufficiency and visual deficits underwent surgery for a pituitary lesion. Histological and immunohistochemical examination revealed a xanthogranulomatous lesion composed of very large CD68-positive foam cells with small nuclei and some Touton-like giant cells, histiocytes, as well as loci with small lymphocytes and isolated eosinophilic granuolcytes, embedded in fibrotic tissue. Based on these findings, the histological diagnosis was a xanthogranuloma of the Erdheim-Chester type.

Intracerebral paraganglioma.

Paragangliomas of the CNS are relatively rare. Cases of location in the pineal and pituitary glands, cerebellopontine angle, cauda equina and filum terminale are known. In our neurosurgical unit a 42-year-old male patient with a history of vertigo and a generalized seizure underwent an operation for a fronto-temporal tumour. The histological diagnosis was paraganglioma.