Experimental and clinical studies indicate that waves of cortical spreading depolarization (CSD) appearing in the ischemic penumbra contribute to secondary lesion growth. We used an embolic stroke model that enabled us to investigate inverse coupling of blood flow by laser speckle imaging (CBF LSF ) to CSD as a contributing factor to lesion growth already in the early phase after arterial occlusion. Embolization by macrospheres injected into the left carotid artery of anesthetized rats reduced CBF LSF in the territories of the middle cerebral artery (MCA) (8/14 animals), the posterior cerebral artery (PCA) (2/14) or in less clearly defined regions (4/14). Analysis of MCA occlusions (MCAOs) revealed a first CSD wave starting off during ischemic decline at the emerging core region, propagating concentrically over large portions of left cortex. Subsequent recurrent waves of CSD did not propagate concentrically but preferentially circled around the ischemic core. In the vicinity of the core region, CSDs were coupled to waves of predominantly vasoconstrictive CBF LSF responses, resulting in further decline of CBF in the entire inner penumbra and in expansion of the ischemic core. We conclude that CSDs and corresponding CBF responses follow a defined spatiotemporal order, and contribute to early evolution of ischemic territories.

BackgroundMany radiological signs are known for the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). However, there is little information about these signs in the pre-symptomatic phase. For pathophysiological investigative purposes we conducted a descriptive image analysis study on pre-symptomatic patients.MethodsPatients that had contact with either the neurological or neurosurgical department of the university hospital Tuebingen from 2010 through 2016 with magnetic resonance images > 3 years before onset of symptoms, were included. The date of onset and severity of symptoms, date of first imaging and birth date were recorded. Evan’s index (EI), width of the third ventricle (3VW), tight high convexity (THC), Sylvian fissure, extent of white matter hyperintensities and aqueductal flow were assessed in images before and around symptom onset.ResultsTen patients were included. In all ten patients the first symptom was gait disturbance. Nine of ten pre-symptomatic images showed classic signs for iNPH. EI showed a significant increase between the pre-symptomatic and symptomatic phase. 3VW showed a trend for increase without significance. THC changed back and forth over time within some patients.ConclusionsIn accordance with the scarce literature available, radiological changes are present at least 3 years before onset of iNPH-symptoms. EI seems to be a robust measure for pre-symptomatic radiological changes. Extrapolating the data, the development of iNPH typical changes might be an insidious process and the development of THC might be a variable and non-linear process. Further studies with larger sample sizes are necessary to put these findings into the pathophysiological perspective for the development of iNPH.

Background: Differences in the postgraduate training programs of neurosurgical residents are suspected throughout Europe. The influence of working hour restrictions by the European Working Time Directive (WTD) 2003/88/EC on the number of surgical procedures remains unclear. We designed a survey to collect information on the number of surgical procedures, performed by European neurosurgical trainees during residency. This article reports preliminary data. Methods: An electronic survey was distributed among the European Association of Neurosurgical Societies (EANS) member countries by national delegates of the training committee, as well as by members of the young neurosurgeons committee. The EANS mailing list of individual members was also used for distribution. All responses received between 04/2018 and 12/2018 were considered. Results: From n=180 responses received, 42 were omitted as responders were still in residency and for 58 relevant information was missing. The final sample was n=80, with a mean responder's age of 43.0 years (SD 8.6) and 88.8% being male. Responses came from 16 European countries; board certification was received between the years of 1976-2018. The numbers of surgical procedures performed independently were 511 (mean, 95% confidence interval (CI) 413-610), supervised were 514 (95%CI 360-668) and assisted were 752 (95%CI 485-1019) throughout residency. More detailed numbers for specific procedure types are reported in the article. Independently performed cranial procedures outnumbered spinal procedures (p<0.006) and adult procedures outnumbered pediatric procedures (p<0.001). There was a strong decrease in case-load between 1976-2018, with trainees performing on average 65 cases less throughout residency for each calendar year increase in board-certification (95% CI-116-15, p=0.012). Trainees graduating residency before introduction of the European WTD 2003/88/EC participated in more procedures than those graduating afterwards (mean 2797 vs. 1418, p=0.005). Conclusions: The preliminary analysis of the first 80 responses now provides a first reference frame for case-load that can be used by current and future European residents to critically compare their own operative numbers to. There was a strong decline in surgical cases over time, and trainees graduating after introduction of the European WTD 2003/88/EC had less surgical exposure. The survey remains open and we invite further European neurosurgeons to provide their data in order to get even more robust estimates.

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Introduction: The mini-supraorbital (MSO) and pterional (PT) approaches have been compared in a number of studies focusing on the treatment of aneurysms, craniopharyngiomas, and meningiomas. The goal of this study was to analyze the surgical exposure to different artificial lesions through interoptic (IO), trans-lamina terminalis (TLT), opticocarotid triangle (OCT), and caroticosylvian (CS) windows from the MSO, frontomedial (FM), and PT perspectives. Methods: The MSO, PT, and FM approaches were performed sequentially in two fixed cadaver heads. Three colored spheres were placed around the optic chiasm: (1) between the optic nerves; (2) between the optic nerve and the internal carotid artery; and (3) between the internal carotid artery and the oculomotor nerve. The surgical exposures to these structures by using the IO, TLT, OCT, and CS windows were compared. Results: (1) IO window: from the MSO and PT approaches, the total surgical exposure mainly allows visualization of contralateral lesions. The FM approach was superior for exploration of both sides of the area between the optic nerves. (2) TLT pathway: the MSO and PT approaches mainly expose the contralateral third ventricle wall. (3) OCT window: the PT approach allows exposure of a larger part of the sphere between the optic nerve and the internal carotid artery than the MSO approach. (4) CS window: the PT approach allows a better exposure of lateral structures such as the oculomotor nerve and of the medial prepontine area in comparison to the MSO approach. Conclusion: Simulation of the surgical situation with artificial lesions is a good model for comparing surgical perspectives and for analyzing feasibility of lesion exposure and resection.

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Choroid plexus papillomas (CPPs) are primary neuroectodermal neoplasms that usually arise in the fourth ventricle in adults. In this study, we present 12 patients with CPP arising from the cerebellopontine angle (CPP-CPA) and/or of the cerebellomedullary angle (CPP-CMA) that were treated in our department. Patients who underwent surgery for the treatment for CPP-CPA/CMA from January 2004 to March 2020 were identified by a computer search of their files from the Department of Neurosurgery, Tübingen. CPPs were classified according to their location into type 1 (tumor portion only in the CPA,), type 2 (tumor portions only in the CMA), and type 3 (tumor portions both in the CPA and CMA). Patients were evaluated for initial symptoms, previous therapies in other hospitals, extent of tumor resection, recurrence rate, and complications by reviewing patient documents. Of approximately 1500 CPA lesions, which were surgically treated in our department in the last 16 years, 12 patients (mean age 42 ± 19 years) were found to have CPP-CPA/CMA. Five were male, and seven were female patients. Gross total resection was achieved in nine cases, and a subtotal resection was attained in three cases. Tumor recurrence in the same location after the first surgery in our hospital was observed in 2 patients after 15 and 40 months of follow-up, and in another patient, distant metastases (C3/4 and L3 levels) were observed. Surgical removal of CPP is the treatment of choice, but additional therapeutic options may be necessary in case of remnant tumor portions, recurrence, or malignant transformation.