Muscular atrophy in severe cases of cubital tunnel syndrome: prognostic factors and outcome after surgical treatment.

BACKGROUND: Cubital tunnel syndrome (CuTS) is a frequent neuropathy, leading to sensor-motoric dysfunction. Many patients even present with muscular atrophy as a sign for severe and long-lasting nerve impairment, usually suggesting unfavourable outcome. We analysed if those patients benefit from surgical treatment on a long-term basis. METHODS: Between January 2010 and March 2015, 42 consecutive cases of CuTS with atrophy of the intrinsic hand muscles were surgically treated in our department. Clinical data of the treatment course and postoperative results were collected. Follow-up was prospectively assessed according to McGowen grading and Bishop outcome score. Mean follow-up time was 39.8 (±17.0) months. RESULTS: All patients were treated with in situ decompression; in 33%, submuscular transposition was performed. Forty-five percent showed improvement of sensory deficits and 57% showed improvement of motor deficits 6 months after the operation. Atrophy improved in 76%. At the time of follow-up, 79% were satisfied with the postoperative result and 77% of patients reached good or excellent outcome according to modified Bishop rating scale. Patients with improvement of atrophy had significantly shorter symptom duration period (7 ± 10 months vs 26 ± 33 months; p < 0.05). In the case of intraoperative pseudoneuroma observation, atrophy improvement was less likely (p < 0.05). CONCLUSIONS: In severe cases of CuTS with atrophy of the intrinsic hand muscles, surgical treatment enables improvement of sensory function, motor function and atrophy even in cases with muscular atrophy. Atrophy improvement was more likely in cases of short symptom duration and less likely in cases with pseudoneuroma.

Brain surface reformatted imaging (BSRI) for intraoperative neuronavigation in brain tumor surgery.

BACKGROUND: For safe resection of lesions situated in or near eloquent brain regions, determination of their spatial and functional relationship is crucial. Since functional magnetic resonance imaging and intraoperative neurophysiological mapping are not available in all neurosurgical departments, we aimed to evaluate brain surface reformatted imaging (BSRI) as an additional display mode for neuronavigation. METHODS: Eight patients suffering from perirolandic tumors were preoperatively studied with MRI and navigated transcranial magnetic stimulation (nTMS). Afterwards, the MRI was automatically transformed into BSR images in neuronavigation software (Brainlab, Brainlab AG, Feldkirchen, Germany). One experienced neuroradiologist, one experienced neurosurgeon, and two residents determined hand representation areas ipsilateral to each tumor on two-dimensional (2D) MR images and on BSR images. All results were compared to results from intraoperative direct cortical mapping of the hand motor cortex and to preoperative nTMS results. RESULTS: Findings from nTMS and intraoperative direct cortical mapping of the hand motor cortex were congruent in all cases. Hand representation areas were correctly determined on BSR images in 81.3 % and on 2D-MR images in 93.75 % (p = 0.26). In a subgroup analysis, experienced observers showed more familiarity with BSRI than residents (96.9 vs. 84.4 % correct results, p = 0.19), with an equal error rate for 2D-MRI. The time required to define hand representation areas was significantly shorter using BSRI than using standard MRI (mean 27.4 vs. 40.4 s, p = 0.04). CONCLUSIONS: With BSRI, a new method for neuronavigation is now available, allowing fast and easy intraoperative localization of distinct brain regions.

Benefit of tumor resection for recurrent glioblastoma.

In the treatment of glioblastoma (GBM) the impact of radical tumor resection as first line therapy is beyond controversy. The significance of a second resection in case of tumor-recurrence remains unclear and is an issue of debate. Since GBMs always recur, it is important to determine whether or not patients will benefit from repeat surgery. We performed a retrospective analysis of our prospectively collected database and evaluated all re-resected patients with primary GBM who underwent second surgery during a 3 years period. All patients underwent early postoperative magnetic resonance imaging. We determined survival after re-resection with regard to possible prognostic factors using Kaplan-Meier estimates and Cox regression analyses. Forty patients were included in this study. Median age was 58 years and median KPS score was 80. Average tumor volume was 5.5 cm(3). A radiologically confirmed complete resection was achieved in 29 patients (72.5 %). Median follow-up was 18.8 months, and median survival after re-resection was 13.5 months. Only complete removal of contrast enhancing tumor was significantly correlated with survival after re-resection according to multivariate analysis. There was a statistical trend for KPS score influencing survival. In contrast, time between first diagnosis and tumor-recurrence, tumor volume at recurrence, MGMT status and MSM score were not significantly correlated with survival after second surgery. In the event of tumor recurrence, patients in good clinical condition with recurrent GBM amenable to complete resection should thus not be withheld second surgery as a treatment option.

Risk of ischemia in glioma surgery: comparison of first and repeat procedures.

The role of repeat resection in the multimodal treatment of gliomas is unclear. Repeat surgery theoretically carries a higher risk of inducing neurological deficits, which might even out any advantage of cytoreduction. We sought to determine whether the occurrence of perioperative infarction is higher for repeat surgery than for first surgery, and sought to identify factors associated with the occurrence of postoperative infarction. Therefore, we searched our database to identify patients who were operated for primary or recurrent glial tumors between October 2007 and October 2010. We analyzed 177 procedures, of which 130 (73.4%) were first surgeries and 47 (26.5%) were repeat. Initial WHO grades, KPS scores, and age were evenly distributed between the groups. Forty-six (26.0%) patients had new DWI lesions on their postoperative MRI scan. Eighteen (10.2%) patients had new lesions greater than 4 cm(3). Among these were 11 (6.2%) patients, for whom the new lesion caused neurologic deficit. There was no difference between first and repeat surgery with regard to the occurrence of new DWI lesions (27.7 vs. 21.3%, P = 0.77) or neurological deficits (10.0 vs. 10.6%, P = 1.0). Tumor location in the insula, operculum, and temporal lobe was found to be significantly associated with the occurrence of new DWI lesions. We conclude that repeat surgery should not be withheld as a treatment option for patients with recurrent gliomas for fear of a higher risk of postoperative infarction or new neurologic deficit than the first surgery.

Resection of gliomas in the cingulate gyrus: functional outcome and survival.

Functional outcome after resection of tumors arising from the gyrus cinguli (GC), part of the limbic system, is not well analyzed. The purpose of this study was to evaluate the feasibility and functional outcome of surgical treatment for a series of 65 patients with gliomas involving the GC. Preoperative data, extent of resection, functional outcome (Karnofsky performance index, KPI, and the National Institute of Health Stroke Scale, NIHSS), and survival of 65 patients with gliomas arising from the GC were analyzed on the basis of a prospectively conducted database of gliomas between 06/1999 and 07/2010. Extent of resection (complete, subtotal, or partial) was based on early postoperative MRI. Eighty-six percent of the gliomas were located in the anterior part of the GC and 14 % in the posterior part. Fifty-five percent of the patients presented with seizures and 17 % with hemiparesis (mean preoperative KPI = 86 ± 17, NIHSS = 1.4 ± 1.7). Histologically, the tumors were WHO Grade II in 25 %, Grade III in 26 %, and Grade IV in 49 %. Complete resection was achieved for 59 %, subtotal resection for 32%, and partial resection for 9 %. Postoperative transient deficits included SMA lesion (14 %) and new or worsened hemiparesis (8 %), which resolved within 30 days (NIHSS early postoperatively 1.7 ± 1.4, late postoperatively 0.8 ± 1.4, and after 6 months 0.6 ± 1.4). According to histopathological grading, median survival was 67 months (WHO°II), 87 months (WHO°III), and 16.5 months (WHO°IV), and overall survival was 34 months. Microsurgical resection of gliomas arising from the GC is feasible; gross total resection can be achieved for 90 % of gliomas arising from the GC with 5 % long-term morbidity.

1H MR spectroscopic imaging with short and long echo time to discriminate glycine in glial tumours.

OBJECT: To investigate glycine (Gly) concentrations in low- and high-grade gliomas based on (1)H MR spectroscopic imaging (MRSI) with short and long echo time (TE). Myoinositol (MI) and Gly appear at the same resonance frequency of 3.56 ppm, but due to strong coupling the MI signal dephases more rapidly. Therefore, their contribution to the 3.56 ppm signal should be distinguishable comparing MRSI data acquired at short and long TE. MATERIALS AND METHODS: (1)H MRSI (TE = 30 and 144 ms) was performed at 3 T in 29 patients with histopathological confirmed World Health Organization (WHO) grade II-IV gliomas and in FIVE healthy subjects. All spectra from the gliomas revealed increase of the 3.56 ppm resonance in the short TE spectra. Signal intensities of Gly and MI were differentiated either by analysing the short to long TE ratio of the resonance or by performing a weighted difference. Gly concentrations were compared between high-grade (WHO III-IV) and low-grade gliomas. RESULTS: High-grade gliomas showed significantly higher Gly concentrations compared to low-grade gliomas. CONCLUSION: Appropriate data processing of short and long TE (1)H MRSI provides a tool to distinguish and to quantify Gly and MI concentrations in gliomas. As Gly seems to be a marker of malignancy, more dedicated spectroscopic methods to differentiate these metabolites are justified.

Does navigated transcranial stimulation increase the accuracy of tractography? A prospective clinical trial based on intraoperative motor evoked potential monitoring during deep brain stimulation.

BACKGROUND: Tractography based on diffusion tensor imaging has become a popular tool for delineating white matter tracts for neurosurgical procedures. OBJECTIVE: To explore whether navigated transcranial magnetic stimulation (nTMS) might increase the accuracy of fiber tracking. METHODS: Tractography was performed according to both anatomic delineation of the motor cortex (n = 14) and nTMS results (n = 9). After implantation of the definitive electrode, stimulation via the electrode was performed, defining a stimulation threshold for eliciting motor evoked potentials recorded during deep brain stimulation surgery. Others have shown that of arm and leg muscles. This threshold was correlated with the shortest distance between the active electrode contact and both fiber tracks. Results were evaluated by correlation to motor evoked potential monitoring during deep brain stimulation, a surgical procedure causing hardly any brain shift. RESULTS: Distances to fiber tracks clearly correlated with motor evoked potential thresholds. Tracks based on nTMS had a higher predictive value than tracks based on anatomic motor cortex definition (P < .001 and P = .005, respectively). However, target site, hemisphere, and active electrode contact did not influence this correlation. CONCLUSION: The implementation of tractography based on nTMS increases the accuracy of fiber tracking. Moreover, this combination of methods has the potential to become a supplemental tool for guiding electrode implantation.

Is postoperative imaging mandatory after meningioma removal? Results of a prospective study.

BACKGROUND: Routine postoperative imaging (PI) following surgery for intracranial meningiomas is common practice in most neurosurgical departments. The purpose of this study was to determine the role of routine PI and its impact on clinical decision making after resection of meningioma. METHODS: Patient and tumor characteristics, details of radiographic scans, symptoms and alteration of treatment courses were prospectively collected for patients undergoing removal of a supratentorial meningioma of the convexity, falx, tentorium, or lateral sphenoid wing at the authors' institution between January 1st, 2010 and March 31st, 2012. Patients with infratentorial manifestations or meningiomas of the skull base known to be surgically difficult (e.g. olfactory groove, petroclival, medial sphenoid wing) were not included. Maximum tumor diameter was divided into groups of < 3 cm (small), 3 to 6 cm (medium), and > 6 cm (large). RESULTS: 206 patients with meningiomas were operated between January 2010 and March 2012. Of these, 113 patients met the inclusion criteria and were analyzed in this study. 83 patients (73.5%) did not present new neurological deficits, whereas 30 patients (26.5%) became clinically symptomatic. Symptomatic patients had a change in treatment after PI in 21 cases (70%), while PI was without consequence in 9 patients (30%). PI did not result in a change of treatment in all asymptomatic patients (p<0.001) irrespective of tumor size (p<0.001) or localization (p<0.001). CONCLUSIONS: PI is mandatory for clinically symptomatic patients but it is safe to waive it in clinically asymptomatic patients, even if the meningioma was large in size.