Joachim Klisch

Hyperglycemia in Patients with Focal Cerebral Ischemia after Intravenous Thrombolysis: Influence on Clinical Outcome and Infarct Size

The aim of the present prospective study was to investigate whether hyperglycemia influences the clinical outcome or the infarct size after intravenous thrombolysis of focal cerebral ischemia. A consecutive series of hyperglycemic (n = 14) and normoglycemic patients (n = 17) with acute focal cerebral ischemia (<3 h) in the middle cerebral artery (MCA) territory received rtPA (0.9 mg/kg body weight) intravenously. Clinical outcome was measured using the NIH Stroke Score on admission and was followed up until day 28. Infarct volume was measured by diffusion-weighted MR imaging on admission, on days 3 and 7. There was a significantly better neurological outcome on day 28 in the normoglycemic patients than in the hyperglycemic group (NIH SS 4.0 versus 7.4; p < 0.05). The infarction volume increased significantly in the hyperglycemic patients Δ = 39.9 ± 17.4% compared to normoglycemic patients Δ = 27.1 ± 14.1% (p < 0.05). The present study suggests that hyperglycemia in patients with a focal MCA ischemia can cause a worse clinical outcome despite recanalization of the occluded vessel by thrombolysis therapy. This correlates with a markedly larger increase of the infarction volume in the hyperglycemic group. These results may be explained by an accentuated lactate accumulation and pH decrease by elevated energy levels which cannot be compensated by restoration of blood flow alone.

Safety and Therapeutical Benefit of Hemicraniectomy Combined with Mild Hypothermia in Comparison with Hemicraniectomy Alone in Patients with Malignant Ischemic Stroke

Introduction: Both for hemicraniectomy and for hypothermia, several reports describe a beneficial effect in patients with malignant supratentorial cerebral ischemia. We compared the safety and the clinical outcome in patients with a malignant supratentorial infarction who were treated with hemicraniectomy alone (HA) or received a combination therapy with hemicraniectomy and hypothermia of 35°C (HH), respectively. Methods: In a prospective and randomized study, 25 consecutive patients were treated after an ischemic infarction of more than two thirds of one hemisphere by HA (n = 13 patients) or the HH combination therapy (n = 12 patients). Safety parameters were compared between both treatment groups, the clinical outcome was assessed during treatment and after 6 months. Results: Age, cranial CT or MRI findings, initial National institutes of Health Stroke Scale Score (NIHSSS) and level of consciousness were not significantly different between both groups. Hemicraniectomy was performed within 15 ± 6 h after the ischemic event. Hypothermia was induced immediately after surgery. Overall mortality was 12% (2/13 vs. 1/12 in the two groups), but none of these 3 patients died due to treatment-related complications. There were no severe side effects of hypothermia. Duration of need for intensive care or for mechanical ventilation and infectious status did not differ significantly between both groups, but the need for catecholamine application was increased in the HH group. The clinical outcome showed a tendency for a better outcome in the HH compared with the HA group with respect to status after 6 months, as assessed by the NIHSSS (10 ± 1 vs. 11 ± 3, p < 0.08). Discussion: The present study suggests that a combined therapy of mild hypothermia and hemicraniectomy in malignant brain infarction does not imply additional risks by side effects and improves functional outcome as compared with hemicraniectomy alone.

Determination of hemisphere dominance for language: comparison of frontal and temporal fMRI activation with intracarotid amytal testing

The reliability of frontal and temporal fMRI activations for the determination of hemisphere language dominance was evaluated in comparison with intracarotid amytal testing (IAT). Twenty-two patients were studied by IAT (bilateral in 13, unilateral in 9 patients) and fMRI using a paradigm requiring semantic decisions. Global and regional (frontal and temporoparietal) lateralisation indices (LI) were calculated from the number of activated (r>0.4) voxels in both hemispheres. Frontolateral activations associated with the language task were seen in all patients, temporoparietal activations in 20 of 22. Regional LI corresponded better with IAT results than global LI. Frontolateral LI were consistent with IAT in all patients with bilateral IAT (including three patients with right dominant and one patient with bilateral language representation) and were not conflicting in any of the patients with unilateral IAT. Temporoparietal LI were discordant with IAT in two patients with atypical language representation. In the determination of hemisphere dominance for language, regional analysis of fMRI activation is superior to global analysis. In cases with clear-cut fMRI lateralisation, i.e. consistent lateralised activation of frontal and temporoparietal language zones, IAT may be unnecessary. FMRI should be performed prior to IAT in all patients going to be operated in brain regions potentially involved in language.

Diffusion‐weighted MRI during early global cerebral hypoxia: a predictor for clinical outcome?

Objectives– As prognostic assessment of prolonged cerebral hypoxia is often difficult on clinical grounds, a tool for an early prognosis of clinical outcome is desirable.

Intrasaccular Flow-Disruption Treatment of Intracranial Aneurysms: Preliminary Results of a Multicenter Clinical Study

BACKGROUND AND PURPOSE: The endovascular treatment of intracranial aneurysms with unfavorable anatomy (large aneurysms, wide-neck) is frequently challenging and is also associated with a high incidence of significant recurrences. The WEB, an intrasaccular flow disrupter, was designed for use in this type of aneurysm. We report our early experience with this device in this multicenter study. MATERIALS AND METHODS: Twenty patients with 21 aneurysms were treated by using the WEB in 3 European centers. The ability to successfully deploy the WEB, immediate posttreatment angiographic results, adverse events, clinical outcome, and angiographic follow-up results were recorded. RESULTS: Aneurysm location was the ICA (4/21, 19.1%), MCA (8/21, 38.1%), AcomA (5/21, 23.8%), and BA (4/21, 19.1%). No treatment failures were reported. Treatment was performed exclusively with the WEB in 16/21 (76.2%) patients. Additional treatment (coiling and/or stent placement) was used in 5/21 (23.8%) patients. One patient (4.8%) experienced transient clinical worsening (mRS 1 at 1 month, mRS 0 at 3 months) related to a thromboembolic event. Inadvertent detachment of the WEB was observed, and the WEB was retrieved in 1 patient, without adverse effects. In the short-term follow-up (2–8 months), adequate occlusion (total occlusion or neck remnant) was observed in 80.0% of aneurysms. CONCLUSIONS: Intrasaccular flow disruption is a new endovascular approach for aneurysm treatment. In our preliminary experience, this treatment was feasible and mostly used in bifurcation aneurysms (MCA, BA, ICA) with unfavorable anatomy. Further studies are needed to precisely evaluate the indications, safety, and efficacy of this new technique.

Endovascular WEB flow disruption in middle cerebral artery aneurysms: preliminary feasibility, clinical, and anatomical results in a multicenter study.

BACKGROUND The endovascular treatment of middle cerebral artery (MCA) aneurysms with unfavorable anatomy (wide neck, unfavorable morphology) is frequently challenging. Flow disruption with the WEB is a potentially interesting endovascular treatment for this type of aneurysm. OBJECTIVE To report in a multicenter series the preliminary treatment experience of MCA aneurysms with flow disruption by the WEB. METHODS Thirty-three patients with 34 MCA aneurysms were treated with the WEB in 5 European centers. The ability to successfully deploy the WEB, procedure- and device-related adverse events, morbidity and mortality of the treatment, and short-term angiographic follow-up results were analyzed. RESULTS Most treated aneurysms were unruptured (85.3%) and were between 5 and 10 mm (85.3%) with a neck size ≥  4 mm (88.2%). The treatment failed in 1 of the 34 aneurysms (2.9%) owing to a lack of appropriate device size. Treatment was performed exclusively with the WEB in 29 of 33 aneurysms (87.9%). Additional treatment (coiling and/or stenting) was used in 4 of 33 aneurysms (12.1%). Mortality of the treatment was 0.0% and morbidity was 3.1% (intraoperative rupture with modified Rankin Scale score of 3 at the 1-month follow-up). In short-term follow-up (range, 2-12 months), adequate occlusion (total occlusion or neck remnant) was observed in 83.3% of aneurysms. CONCLUSION WEB flow disruption seems to be a promising technique for the treatment of complex MCA aneurysms, particularly those with a wide neck or unfavorable dome-to-neck ratio.

WEB-DL Endovascular Treatment of Wide-Neck Bifurcation Aneurysms: Short- and Midterm Results in a European Study

Short- and midterm results of endovascular aneurysm treatment with the new WEB-DL device were assessed in 45 patients from 12 European centers. Of these, 42 aneurysms were unruptured and most were located either in the MCA bifurcation or the posterior circulation. Adequate occlusion was observed in 81% and 90% of aneurysms at 6 and 13 months, respectively. Results suggest that WEB endovascular treatment of wide-neck bifurcation aneurysms offers stable occlusion in a class of aneurysms that are historically unstable. BACKGROUND AND PURPOSE: Flow disruption with the WEB-DL device has been used safely for the treatment of wide-neck bifurcation aneurysms, but the stability of aneurysm occlusion after this treatment is unknown. This retrospective multicenter European study analyzed short- and midterm data in patients treated with WEB-DL. MATERIALS AND METHODS: Twelve European neurointerventional centers participated in the study. Clinical data and pre- and postoperative short- and midterm images were collected. An experienced interventional neuroradiologist independently analyzed the images. Aneurysm occlusion was classified into 4 grades: complete occlusion, opacification of the proximal recess of the device, neck remnant, and aneurysm remnant. RESULTS: Forty-five patients (34 women and 11 men) 35–74 years of age (mean, 56.3 ± 9.6 years) with 45 aneurysms treated with the WEB device were included. Aneurysm locations were the middle cerebral artery in 26 patients, the posterior circulation in 13 patients, the anterior communicating artery in 5 patients, and the internal carotid artery terminus in 1 patient. Forty-two aneurysms were unruptured. Good clinical outcome (mRS < 2) was observed in 93.3% of patients at the last follow-up. Adequate occlusion (complete occlusion, opacification of the proximal recess, or neck remnant) was observed in 30/37 patients (81.1%) in short-term follow-up (median, 6 months) and in 26/29 patients (89.7%) in midterm follow-up (median, 13 months). Worsening of the aneurysm occlusion was observed in 2/28 patients (7.1%) at midterm follow-up. CONCLUSIONS: The results suggest that the WEB endovascular treatment of wide-neck bifurcation aneurysms offers stable occlusion in a class of aneurysms that are historically unstable. Additionally, our data show that opacification of the WEB recess can be delineated from true neck or aneurysm remnants.

Treatment of intramedullary hemangioblastomas, with special attention to von Hippel-Lindau disease.

OBJECTIVEHemangioblastomas of the central nervous system are rare vascular tumors that can occur as sporadic lesions or as component tumors of autosomal dominant von Hippel-Lindau disease. With the availability of magnetic resonance imaging, asymptomatic tumors are detected more frequently, especially among patients with von Hippel-Lindau disease, and the questions of whether and when these lesions should be treated arise. To identify surgical outcomes and the timing of surgery for intramedullary hemangioblastomas, we retrospectively analyzed data for a series of 28 consecutive patients whom we surgically treated for intramedullary hemangioblastomas in the past 10 years. METHODSAll tumors were completely removed. Functional grades, according to the McCormick scale, were determined before and after surgery and in follow-up assessments. Several clinical characteristics were correlated with changes in functional grades in follow-up assessments, compared with preoperative grades. RESULTSFunctional grades in follow-up assessments improved for 28.6% of the patients and remained unchanged for 71.4%. No patient was in worse condition, compared with preoperative status. Peritumoral edema on preoperative magnetic resonance imaging scans was correlated with significantly higher surgical morbidity rates. Four asymptomatic patients were surgically treated because of tumor or pseudocyst progression on serial magnetic resonance imaging scans. All of those patients remained asymptomatic postoperatively. CONCLUSIONIntramedullary hemangioblastomas can be removed with low surgical morbidity rates and excellent long-term prognoses. The timing of surgery for patients with von Hippel-Lindau disease and multiple lesions remains a matter of debate. On the basis of our data, we established the strategy of operating also on asymptomatic lesions that exhibit radiological progression, before significant neurological deficits occur, which are often not reversible.

Time-resolved projection MRA : clinical application in intracranial vascular malformations

Abstract We report preliminary results of imaging intracranial vascular malformations with time-resolved projection MRA after a bolus injection of contrast median before and after endovascular treatment. Projection angiograms are acquired with a slice-selective snapshot FLASH sequence with a time resolution of two images per second, 40–60 images being acquired consecutively after bolus injection of 15 ml Gd-DTPA. Postprocessing of images in 2D projection MRA by correlation analysis offers several advantages with significant improvement of signal-to-noise, leading to adequate anatomical resolution. Subsecond projection MRA is a reliable technique for imaging intracranial vessels and gives information about the haemodynamics of vascular malformations.

Localization of Interictal Delta and Epileptiform EEG Activity Associated with Focal Epileptogenic Brain Lesions

The present study was aimed at investigating the accuracy of electric source reconstruction in the presurgical evaluation of epilepsy patients. Spontaneous EEG activity of 14 patients with focal intracerebral epileptogenic lesions was analyzed by source reconstruction based on high-resolution EEG (64-channel system) and a boundary element method head model accounting for the individual head anatomy. Equivalent dipole modeling was applied to focal delta and interictal epileptiform activity. The localization results were validated quantitatively by comparison with the sites of the structural lesions. In 6 of 9 patients with focal delta activity, the maximum of dipole concentration was closer than 10 mm to the nearest lesion margin and mostly at the border or within pathologically altered cortical tissue. In all 11 patients showing interictal epileptiform activity, the localization results were found in the same lobe as the lesion. In almost half of them, they were closer than 10 mm to the lesion margin. Patients with larger distances (22-36 mm) mostly had hippocampal atrophy or sclerosis. Their dipole locations did not appear in the affected hippocampus, but in the adjacent temporal neocortex. In conclusion, electric source reconstruction applied to both abnormal slow and interictal epileptiform EEG activity seems to be a valuable additional noninvasive component in the multimodal presurgical evaluation of epilepsy patients.