Deep brain stimulation in Bassen-Kornzweig syndrome: Still effective after 22 years.

Introduction: Bassen-Kornzweig syndrome or abetalipoproteinemia is a rare autosomal recessive disorder characterized by a malabsorption of dietary fat and fat-soluble vitamins. This deficiency can lead to a variety of symptoms, including hematological (acanthocytosis, bleeding tendency), neurological (tremor, spinocerebellar ataxia), neuromuscular (myopathy), ophthalmological symptoms (retinitis pigmentosa). The thalamic ventral intermediate nucleus (VIM) is a well-established target for deep brain stimulation (DBS) in the treatment of refractory tremor. Research question: We evaluated the clinical long-term follow-up (22 years) after VIM-DBS for refractory tremor in abetalipoproteinemia. We also evaluated the adjustments of stimulation settings and medication balance after DBS procedure. Material and methods: We report a 53-year-old male who suffers from abetalipoproteinemia since the age of 17. He underwent bilateral VIM-DBS to treat his disabling refractory intentional tremor at the age of 31. He still has a very good response to his tremor with limited stimulation adaptations over 22 years. For more than two decades follow-up, the treatment significantly improved his ADL functions and therefore also the QoL. Discussion and conclusion: The VIM target for DBS in the treatment of refractory tremor has been extensively reported in the literature. Thalamic VIM-DBS is a safe and effective treatment for a severe, refractory tremor as a neurological symptom caused by abetalipoproteinemia. It also highlights the importance of a multidisciplinary follow-up, to adjust and optimize the stimulation/medication balance after VIM-DBS surgery.

Subventricular zone contacting glioblastoma: tumor size, molecular biological factors and patient survival.

BACKGROUND: Several studies show that subventricular zone (SVZ) contact of glioblastoma at diagnosis is a negative prognosticator of survival. In this report, we study glioblastoma patient survival, molecular biological and MRI-based volumetric findings according to SVZ contact. PATIENTS AND METHODS: We conducted a retrospective study of adult patients diagnosed with supratentorial glioblastoma and uniformly treated with temozolomide-based chemoradiotherapy after surgery. The patient cohort was dichotomized according to tumor contact with the SVZ at diagnosis as determined on preoperative MR imaging. Tumor volume was measured using semi-automated segmentation technique. MGMT-gene promoter methylation and IDH mutation status were determined on stored tumor tissue. Kaplan-Meier survival curves were constructed. Cox regression analysis was used to adjust for known confounding factors of glioblastoma patient survival. RESULTS: A total of 214 patients were included in the study of whom 68% belonged to the SVZpos group. Median tumor volume was significantly larger in the SVZpos group (33,8 mL vs 15,6 mL; p < .001). MGMT-unmethylated glioblastoma was more frequent in the SVZpos group (61.4% vs 44.9%; p = .028). The overall survival and progression-free survival were 12.2 months and 5.9 months for the SVZpos patient group but 16.9 months and 10.3 months for the SVZneg group (log-rank p = .016 and .007 respectively). In multivariate Cox survival analysis, SVZ contact proved a negative prognostic parameter, independent from age, KPS, extent of resection, MGMT-methylation and IDH mutation status. CONCLUSIONS: This study confirms SVZ contact at diagnosis as an independent negative prognostic factor for glioblastoma patient survival. SVZpos glioblastoma had larger tumor size and a larger proportion of unmethylated tumors than SVZneg glioblastoma. Further research is needed to establish whether the observed differences are solely explained by a different molecular profile of SVZpos glioblastoma or by interaction of glioblastoma with the unique SVZ microenvironment.

Weak MGMT gene promoter methylation confers a clinically significant survival benefit in patients with newly diagnosed glioblastoma: a retrospective cohort study.

INTRODUCTION: Quantitative methylation specific PCR (qMSP) is a frequently used technique to assess MGMT gene promoter methylation in glioblastoma patients. The optimal technical cut-off value to distinguish methylated from unmethylated samples is nevertheless still undetermined. In literature, a "grey zone" of diagnostic uncertainty has been described. METHODS: We performed a retrospective analysis of newly diagnosed glioblastoma patients treated according to the Stupp protocol. Epidemiological data were gathered from the individual patient files. MGMT gene promoter methylation status was determined on stored tumour samples using qMSP. A strong, weak or absent promoter methylation was determined based on Cq values (quantification value) of the MGMT and ACTB primers as well as a positive control sample. RESULTS: In total, 181 patient files were reviewed and included for statistical analysis. MGMT promoter hypermethylation was detected in 38.7% of glioblastoma patients. The median overall survival of unmethylated and strongly methylated patients was 10.1 months and 19.7 months respectively. Furthermore, 11% of the total patient cohort had a weak MGMT gene promoter methylation. The median OS in this subgroup was 15.4 months, significantly better compared to the unmethylated cohort (P < 0.001). Multivariate Cox regression analysis showed weak MGMT promoter methylation as an independent prognostic parameter for overall survival. CONCLUSION: Glioblastoma patients with weak promoter methylation show a statistically significant longer overall survival when compared to clearly unmethylated patients. Patients with grey zone qMSP test results should receive additional molecular analysis in future to further direct individual therapy strategies.

Chordoid glioma of the third ventricle.

BACKGROUND: Chordoid glioma is a rare tumour (World Health Organisation grade II) originating from the third ventricle with both glial and chordoid features. It was first described by Brat in 1998. Since there is no detailed information available on the outcome after surgery and adjuvant treatment, we reviewed the literature. METHODS: A literature search through PUBMED revealed 50 cases of chordoid glioma. Most reports were found in pathology journals. Information on the postoperative course was sometimes very limited. We reviewed the available literature and studied in detail the presenting symptoms, mortality and postoperative complications in relation to the extent of resective surgery, as well as the importance of adjuvant treatment. CONCLUSIONS: Mortality in the immediate postoperative period is 32% and is higher after gross total resection as compared to subtotal resection. Non-fatal postoperative complications are hypothalamic disorders and mental alterations. Gross total resection is the treatment of choice since no recurrence has been reported after macroscopically complete resection, but this is often difficult because of the location and adherence to the hypothalamus. The role of postoperative radiotherapy is uncertain. There is some indication that radiosurgery with or without conventional irradiation is superior to conventional radiation alone. Planned subtotal resection followed by stereotactic radiosurgery can be a safe and effective alternative in a patient in whom gross total resection is considered to be too risky. There is no report on the use of chemotherapy in the treatment of chordoid gliomas. More information about the optimal treatment strategy is needed, and more reports are also needed.

Frameless neuronavigation-guided endoscopic total en-bloc removal of a third ventricular colloid cyst: a case report on surgical technique.

A 26-year-old man was referred to our department with recurrent episodes of loss of consciousness. The radiological evaluation of the patient's cranium showed a third ventricular colloid cyst with only a slight degree of obstructive hydrocephalus. The complete, en-bloc removal of the cyst was achieved by a frameless neuronavigation-guided endoscopic resection technique. The patient had an uneventful post-operative period and was discharged home on the fourth post-operative day without any neurological or psychological deficit. The surgical technique and pertinent literature are discussed with emphasis on factors that contribute to our successful total en-bloc removal of the third ventricular colloid cyst.