Detection of information flow between cortical laminae activities and auditory evoked potentials in rats by means of Granger causality.

We seek to understand the relation between invasive high-resolution data and non-invasive measurement in an animal model in an auditory sensory adaptation experimental setting. In a previous study, we estimated the mutual information between the phase of auditory evoked responses (AER) with the phase of local field potentials (LFP) of auditory cortices at different frequency ranges. The results showed a consistently high level of information sharing between the AER activities as well as the responses from the granular layer, which was known as the main thalamo-recipient layer. However, mutual information was fundamentally an undirected measure of information flow. In this study we investigated how well we could characterize direction of information flow, by using Granger causality (GC), between different cortical laminae and functional projections on to the AER activities. We obtained that based on the GC coefficients, we are able to extract the connectivity between different cortical laminae to some extend and also a strong connection between the AER and granular layer. In our future study, we would like to construct a reliable picture of network connectivity, both functionally and anatomically, between different layers at more specified frequencies and much finer temporal resolutions.

[Guideline "Legal evaluation after closed brain injury in adulthood"]. / Leitlinie "Begutachtung nach gedecktem Schädel-Hirntrauma im Erwachsenenalter".

In 2005 and 2013, the "Deutsche Gesellschaft für Neurowissenschaftliche Begutachtung" (German Society for Neuroscientific Evaluation) together with other societies developed and consented guidelines fort the legal evaluation of patients with closed head injuries and published them trough the National Working Group of Scientific Medical Societies and in this journal. Five years later, a revision was necessary, this was developed on the higher S2 k level of consent through a Delphi conference.

Guidelines for the Treatment of Head Injury in Adults.

The workshop of scientific medical faculties (Arbeitsgemeinschaft wissenschaftlicher medizinischer Fakultäten [AWMF]) of Germany has asked societies of specific medical disciplines to jointly publish guidelines on the treatment of diseases and injuries. On behalf of the Deutsche Gesellschaft für Neurochirurgie, its commission on guidelines initiated an interdisciplinary approach to publish guidelines on the treatment of head injury in adults. These guidelines were published in German by the AWMF in late 2015. Because these guidelines have received widespread attention in Germany and became fundamental for research in head injuries, we have translated the German version into English to make it accessible to the international scientific community.

Indications and Route of Hysterectomy for Benign Diseases. Guideline of the DGGG, OEGGG and SGGG (S3 Level, AWMF Registry No. 015/070, April 2015)

Background: Official guideline "indications and methods of hysterectomy" to assign indications for the different methods published and coordinated by the German Society of Gynecology and Obstetrics (DGGG), the Austrian Society of Gynecology and Obstetrics (OEGGG) and the Swiss Society of Gynecology and Obstetrics (SGGG). Besides vaginal and abdominal hysterectomy, three additional techniques have been implemented due to the introduction of laparoscopy. Organ-sparing alternatives were also integrated. Methods: The guideline group consisted of 26 experts from Germany, Austria and Switzerland. Recommendations were developed using a structured consensus process and independent moderation. A systematic literature search and quality appraisal of benefits and harms of the therapeutic alternatives for symptomatic fibroids, dysfunctional bleeding and adenomyosis was done through MEDLINE up to 6/2014 focusing on systematic reviews and meta-analysis. Results: All types of hysterectomy led in studies to high rates of patient satisfaction. If possible, vaginal instead of abdominal hysterectomy should preferably be done. If a vaginal hysterectomy is not feasible, the possibility of a laparoscopic hysterectomy should be considered. An abdominal hysterectomy should only be done with a special indication. Organ-sparing interventions also led to high patient satisfaction rates, but contain the risk of symptom recurrence. Conclusion: As an aim, patients should be enabled to choose that therapeutic intervention for their benign disease of the uterus that convenes best to them and their personal life situation.

Motion reduction and multidimensional denoising in Voltage-sensitive Dye imaging.

Optical Imaging using Voltage-sensitive Dyes is characterized by low fractional changes in fluorescent light intensity upon the application of a stimulus, which leads to slight value differences between pixels on an in-general noisy image sequence. The application of an anisotropic diffusion filtering scheme, in order to contribute to the denoising of the optical images, is proposed as one option to improve its quality and for a better understanding of the physiological processes they represent. We apply an image registration approach to compensate for motion artifacts, such that we do not need to mount a fixed cranial chamber onto the skull. In this work, electrical stimulation to the tibial nerve in a rat model was used to register evoke potentials, imaging the somatosensory cortex of the animal, which was previously stained with the RH1691 dye.

European Stroke Organisation (ESO) guidelines for the management of spontaneous intracerebral hemorrhage

"BACKGROUND: Intracerebral hemorrhage (ICH) accounted for 9% to 27% of all strokes worldwide in the last decade, with high early case fatality and poor functional outcome. In view of recent randomized controlled trials (RCTs) of the management of ICH, the European Stroke Organisation (ESO) has updated its evidence-based guidelines for the management of ICH. METHOD: A multidisciplinary writing committee of 24 researchers from 11 European countries identified 20 questions relating to ICH management and created recommendations based on the evidence in RCTs using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: We found moderate- to high-quality evidence to support strong recommendations for managing patients with acute ICH on an acute stroke unit, avoiding hemostatic therapy for acute ICH not associated with antithrombotic drug use, avoiding graduated compression stockings, using intermittent pneumatic compression in immobile patients, and using blood pressure lowering for secondary prevention. We found moderate-quality evidence to support weak recommendations for intensive lowering of systolic blood pressure to <140 mmHg within six-hours of ICH onset, early surgery for patients with a Glasgow Coma Scale score 9-12, and avoidance of corticosteroids. CONCLUSION: These guidelines inform the management of ICH based on evidence for the effects of treatments in RCTs. Outcome after ICH remains poor, prioritizing further RCTs of interventions to improve outcome."

[The German guideline "legal evaluation after closed head injury"]. / Die leitlinie "begutachtung nach gedecktem schädel-hirntrauma".

In 2005, the "Deutsche Gesellschaft für Neurowissenschaftliche Begutachtung" (German Society for Neuroscientific Legal Evaluation) together with other Societies published a guideline for the legal evaluation of patients with closed head injuries. Meanwhile, not only scientific progress in imaging techniques but also in other fields such as neuropsychology has necessitated a revision, which is presented here. In the mean time, the handling of guidelines has been systematised in Germany so that a registration with the Cooperation of German Medical Learned Societies is applied for and publication in the German Guideline Registry is expected.

Cubital tunnel syndrome - a review and management guidelines.

Cubital tunnel syndrome (CuTS) is the second most common peripheral nerve compression syndrome. In German-speaking countries, cubital tunnel syndrome is often referred to as sulcus ulnaris syndrome (retrocondylar groove syndrome). This term is anatomically incorrect, since the site of compression comprises not only the retrocondylar groove but the cubital tunnel, which consists of 3 parts: the retrocondylar groove, partially covered by the cubital tunnel retinaculum (lig. arcuatum or Osborne ligament), the humeroulnar arcade, and the deep flexor/pronator aponeurosis. According to Sunderland , cubital tunnel syndrome can be differentiated into a primary form (including anterior subluxation of the ulnar nerve and compression secondary to the presence of an anconeus epitrochlearis muscle) and a secondary form caused by deformation or other processes of the elbow joint. The clinical diagnosis is usually confirmed by nerve conduction studies. Recently, the use of ultrasound and MRI have become useful diagnostic tools by showing morphological changes in the nerve within the cubital tunnel. A differential diagnosis is essential in atypical cases, and should include such conditions as C8 radiculopathy, Pancoast tumor, and pressure palsy. Conservative treatment (avoiding exposure to external noxes and applying of night splints) may be considered in the early stages of cubital tunnel syndrome. When nonoperative treatment fails, or in patients who present with more advanced clinical findings, such as motor weakness, muscle atrophy, or fixed sensory changes, surgical treatment should be recommended. According to actual randomized controlled studies, the treatment of choice in primary cubital tunnel syndrome is simple in situ decompression, which has to be extended at least 5-6 cm distal to the medial epicondyle and can be performed by an open or endoscopic technique, both under local anesthesia. Simple decompression is also the therapy of choice in uncomplicated ulnar luxation and in most post-traumatic cases and other secondary forms. When the luxation is painful, or when the ulnar nerve actually "snaps" back and forth over the medial epicondyle of the humerus, subcutaneous anterior transposition may be performed. In cases of severe bone or tissue changes of the elbow (especially with cubitus valgus), the anterior transposition of the ulnar nerve may again be indicated. In cases of scarring, submuscular transposition may be preferred as it provides a healthy vascular bed for the nerve as well as soft tissue protection. Risks resulting from transposition include compromise in blood flow to the nerve as well as kinking of the nerve caused by insufficient proximal or distal mobilization. In these cases, revision surgery is necessary. Epicondylectomy is not common, at least in Germany. Recurrence of compression on the ulnar nerve at the elbow may occur. This review is based on the German Guideline "Diagnose und Therapie des Kubitaltunnelsyndroms" ( www.leitlinien.net ).

Denoising of single-trial matrix representations using 2D nonlinear diffusion filtering.

In this paper we present a novel application of denoising by means of nonlinear diffusion filters (NDFs). NDFs have been successfully applied for image processing and computer vision areas, particularly in image denoising, smoothing, segmentation, and restoration. We apply two types of NDFs for the denoising of evoked responses in single-trials in a matrix form, the nonlinear isotropic and the anisotropic diffusion filters. We show that by means of NDFs we are able to denoise the evoked potentials resulting in a better extraction of physiologically relevant morphological features over the ongoing experiment. This technique offers the advantage of translation-invariance in comparison to other well-known methods, e.g., wavelet denoising based on maximally decimated filter banks, due to an adaptive diffusion feature. We compare the proposed technique with a wavelet denoising scheme that had been introduced before for evoked responses. It is concluded that NDFs represent a promising and useful approach in the denoising of event related potentials. Novel NDF applications of single-trials of auditory brain responses (ABRs) and the transcranial magnetic stimulation (TMS) evoked electroencephalographic responses denoising are presented in this paper.

[Diagnosis and therapy of cubital tunnel syndrome--state of the art]. / Aktueller Stand der Diagnostik und Therapie des Kubitaltunnelsyndroms.

The cubital tunnel syndrome is one of the most widespread compression syndromes of a peripheral nerve. In German-speaking countries it is known as the sulcus ulnaris syndrome (retrocondylar groove syndrome), which is anatomically incorrect. The cubital tunnel consists of the retrocondylar groove, the cubital tunnel retinaculum (Lig. arcuatum or Osborne band), the humeroulnar arcade and the deep flexor/pronator aponeurosis. According to Sunderland it can be divided into a primary form (including the ulnar luxation and the epitrocheoanconaeus muscle) and a secondary form caused by deformation or other processes of the elbow joint. The diagnosis has to be confirmed by a thorough clinical examination and nerve conduction studies. Neurosonography and MRI are becoming more and more important with improving resolution and enable the direct identification of morphological changes. Differential diagnosis is essential in atypical cases, especially C8 syndrome and pressure palsy. Double crush (double compression syndrome) may occur. Operative treatment is more effective than conservative treatment, which consists primarily of the prevention of exposure to external noxes. According to actual randomised controlled studies the therapy of choice of the primary form in most cases is the simple in situ decompression of the ulnar nerve in the cubital tunnel. This has to be extended at least up to 5-6 cm distally of the medial epicondyle and can be performed in the open or endoscopic technique, both under local anesthesia. Simple decompression is also the therapy of choice in uncomplicated ulnar luxation and in most post-traumatic cases and other secondary forms. In cases of severe bony or tissue changes of the elbow (especially cubitus valgus) the volar transposition of the ulnar nerve may be indicated. This can be performed in a subcutaneous or submuscular technique. Risks of transposition are impairment of perfusion and, above all, kinking caused by insufficient proximal or distal mobilisation of the nerve has to be avoided. In these cases revision surgery is necessary. The epicondylectomy is not common in our country. Recurrences may occur.

[Diagnosis and therapy of carpal tunnel syndrome--guideline of the German Societies of Handsurgery, Neurosurgery, Neurology, Orthopaedics, Clinical Neurophysiology and Functional Imaging, Plastic, Reconstructive and Aesthetic Surgery, and Surgery for Traumatology]. / Diagnostik und Therapie des Karpaltunnelsyndroms--Leitlinie der Deutschen Gesellschaften für Handchirurgie, Neurochirurgie, Neurologie, Orthopädie unter Mitbeteiligung der Gesellschaften für Unfallchirurgie, Klinische Neurophysiologie und Funktionelle Bildgebung sowie Plastiche, Rekonstruktive und Asthetische Chirurgie.

Evidence-based supradisciplinary guideline that deals with the epidemiology, pathogenesis, symptoms, clinical and electrophysiological diagnosis, supplementary imaging investigations, differential diagnosis, conservative and surgical treatments, prognosis and course along with complications and revision surgery. The recommendations on investigation and treatment are based on a comprehensive literature search with critical evaluation and two consensus methods (expert group and Delphi technique) within the participating specialist societies. Besides this long version, a short version and a patient version can be viewed through the AWMF platform. The development of the guideline and the methodological foundations are documented in a method report. MAIN STATEMENTS: Apart from an accurate history and clinical neurological examination (including clinical tests), electrophysiological investigations (distal motor latency and sensory neurography) are particularly important. Radiography, MRI, high-resolution ultrasonography can be regarded as optional supplementary investigations. Among conservative treatment methods, treatment with a nocturnal splint and local infiltration of a corticosteroid preparation are effective. Oral steroids, splinting and ultrasound showed only short-term benefit. Surgical treatment is clearly superior to all other methods. Open and endoscopic procedures (when the endoscopic surgeon has sufficient experience) are equivalent. A routine epineurotomy and interfascicular neurolysis cannot be recommended. Early functional treatment postoperatively is important.

[Development and implementation of the guideline "Diagnosis of and Therapy for Carpal Tunnel Syndrome"]. / Zur Entstehung und Implementierung der Leitlinie "Diagnostik und Therapie des Karpaltunnelsyndroms".

In the period from July 2005 through November 2006, the evidence-based guidelines were developed by a steering committee consisting of three members from each of the societies involved (German Society for Hand Surgery, German Society of Neurosurgery, German Society of Neurology and German Society of Orthopaedics), coordinated by one member each from the DGH and the DGNC, under the methodological guidance of Prof. Selbmann of the German Association of the Scientific Medical Societies (AWMF). Six all-day working sessions and one proceeding to build a consensus (modified Delphi process) were held within the seven specialised societies involved. Degrees of recommendation, based upon the degree of evidence of the underlying literature studies, modified, if necessary, by the expert opinion of the steering committee's members and the external evaluators of the Delphi round, were established for the most important diagnostic and therapeutic methods. In addition to the long version, a short version and a patient information bulletin were prepared as well, and the ways, means, and considerations surrounding their realisation and implementation, and other potential developments were also pursued.

Continuous expression of the homeobox gene Pax6 in the ageing human retina.

PURPOSE: In the past few years, the essential role of the homeobox gene Pax6 for eye development has been demonstrated unambiguously in a variety of species including humans. In humans, Pax6 mutations lead to a variety of ocular malformations of the anterior and posterior segment. However, little is known about PAX6 expression in the adult human retina. We have therefore investigated PAX6 levels and localization in the human retina at various ages. METHODS: Adult human eyes of various ages (17-79 years) were obtained from the Zurich Eye Bank. PAX6 expression levels and patterns were analysed by Western blot analysis of total retinal protein and by immunohistochemistry on paraffin sections, respectively. RESULTS: PAX6 expression in the retina was detected up to 79 years of donor age and was predominantly localized to the ganglion cell layer and the inner part of the inner nuclear layer. CONCLUSIONS: PAX6 remains distinctly expressed throughout the lifespan of the human retina suggesting a role for PAX6 in the retina after completion of eye morphogenesis.

Simple decompression or subcutaneous anterior transposition of the ulnar nerve for cubital tunnel syndrome.

The purpose of this prospective randomised study was to evaluate which operative technique for treatment of cubital tunnel syndrome is preferable: subcutaneous anterior transposition or nerve decompression without transposition. This study included 66 patients suffering from pain and/or neurological deficits with clinically and electromyographically proven cubital tunnel syndrome. Thirty-two patients underwent nerve decompression without transposition and 34 underwent subcutaneous transposition of the nerve. Follow-up examinations evaluating pain, motor and sensory deficits as well as motor nerve conduction velocities, were performed 3 and 9 months postoperatively. There were no significant differences between the outcomes of the two groups at either postoperative follow-up examination. We recommend simple decompression of the nerve in cases without deformity of the elbow, as this is the less invasive operative procedure.

Epidemiology and prevention of fatal head injuries in Germany--trends and the impact of the reunification.

UNLABELLED: A review of the data published on the epidemiology of traumatic brain injuries (TBI) reveals that the data of almost all studies are drawn from local or regional series. Nationwide data are rarely available, or are extrapolated from regional data. In Germany, there has been a nationwide mortality register with ICD-9-coded diagnoses since 1968. In addition, it has been compulsory since 1994 that all hospitals in Germany provide ICD-9 data on all admissions and discharges. Based on data provided by the Federal Bureau of Statistics (Statistisches Bundesamt) in Wiesbaden, all head injuries between 1972 and 1998 were analyzed according to ICD-9 and after 1998 according to the updated ICD-10. The data of hospitalized cases and fatal cases were correlated with population data to calculate incidences and mortality rates. Age-group specific data were also available and analyzed. Head injuries in Germany accounted in 1998 for 19.59% of all injuries. The incidence is 337/100,000. The incidence rate of serious head injury is 33.5/100,000. Mortality decreased continuously from 27.2/100,000 in 1972 to 9.0/100,000 in 2000. The mortality is highest in the group older than 75 years. 68.4% of persons with head injury die before admission to a hospital. After the reunification in 1989/1990, the number of fatal head injuries showed a temporary increase. The number of patients treated in-hospital remained essentially unchanged (276/564 patients in 1998). The majority of hospitalized patients suffered minor head injury. CONCLUSION: Analysis of the admission/discharge data of all German hospitals reveals surprising inside views of age group-related incidence and mortality rates of head injuries in this country. Future research should be focused on patients with minor head injuries who account for nearly 200,000 cases of in-hospital treatment.

[Function of the facial nerve after operative treatment of acoustic neurinomas. Influence of intraoperative monitoring]. / Funktion des N. facialis nach operativer Therapie des Akustikusneurinoms. Bedeutung des intraoperativen Monitorings.

The aim of this study was to evaluate the influence of intraoperative monitoring on the function of the facial nerve after surgical treatment of acoustic neurinomas, classified according to the grading system of Stennert. One hundred thirty patients were divided into two groups. The first group underwent surgery without intraoperative facial monitoring; the second group included intraoperative facial monitoring. Concerning degree of paresis, preoperatively there was no statistically significant difference between the two groups (group 1: 0.77+/-1.5; group 2: 0.4+/-1.2). Despite structural preservation of the facial nerve, postoperative deterioration of its function was observed which consecutively improved postoperatively. Postoperatively, the mean degree of paresis increased to 4.4+/-3.0 in group 1 and 2.4+/-2.3 in group 2. For better understanding of the role of intraoperative monitoring, we investigated the outcome of patients with acoustic neurinomas who underwent surgery over the following 6 months postoperatively. At that time, function improved by 4.1+/-3.2 (group 1) and 2.0+/-2.3 (group 2). We could show that intraoperative monitoring of the facial nerve was a significant factor for better postoperative function in patients undergoing microsurgical excision of neurinomas (P=0.001) .

Brain lesion size and phase shift as an index of cerebral autoregulation in patients with severe head injury.

BACKGROUND: Whether the phase relationship (phase shift) between cerebral blood flow velocity as assessed by transcranial Doppler ultrasound and blood pressure at 0.1 Hz can be used to assess cerebral autoregulation (CA) in patients with severe traumatic brain injury (TBI). METHODS: In 33 healthy volunteers (mean age, SD; 37+/-17 years, range 17-65) middle cerebral artery (MCA) blood velocity (V) was recorded simultaneously with finger blood pressure (BP) over a period of 10 minutes under normocapnic and hypocapnic conditions to generate normative data. In 27 patients with severe TBI (Glasgow Coma scale score < or =8) serial close in time investigations of cranial computed tomography (CT) scanning and phase shift assessment were performed on days 1, 3, 5, and 8 after trauma. Phase shift in the MCA was compared to brain parenchyma lesion size in the MCA territory on CT scanning. Lesion size was classified into 0, normal; 1, presence of a small lesion (diameter <3 cm); 2, presence of a large lesion (>3 cm). FINDINGS: Compared to normocapnia, hypocapnia significantly increased phase shift at 0.1 Hz from 78+/-28 degrees to 101+/-25 degrees (p < 0.001). In the TBI patients, 115 comparisons between CT findings and CA results were possible. Phase shift detected a pathological CA in 31 instances, which were more frequent in CT lesion type 2 (19/42) than in group 0 (7/44) and group 1 (5/29). INTERPRETATION: When CA is intended to be assessed by use of phase shift, the hyperventilation setting needs its own reference values. In MCA territories containing a traumatic lesion greater than 3 cm in diameter phase shift at 0.1 Hz will detect a high frequency (44%) of a disturbed state of CA.

Changes in linear dynamics of cerebrovascular system after severe traumatic brain injury.

BACKGROUND AND PURPOSE: We sought to describe the dynamic changes in the cerebrovascular system after traumatic brain injury by transfer function estimation and coherence. METHODS: In 42 healthy volunteers (mean+/-SD age, 37+/-17 years; range, 17 to 65 years), spontaneous fluctuations of middle cerebral artery blood flow velocity and of finger blood pressure (BP) were simultaneously recorded over a period of 10 minutes under normocapnic and hypocapnic conditions to generate normative spectra of coherence, phase shift, and gain over the frequency range of 0 to 0.25 Hz. Similar recordings were performed in 24 patients with severe traumatic brain injury (Glasgow Coma Scale score 70 mm Hg. Each blood flow velocity/BP recording was related to the presence or absence of middle cerebral artery territory brain parenchyma lesions on cranial CT performed within a close time frame. RESULTS: In controls, hypocapnia decreased coherence (0.0 to 0.20 Hz), increased phase shift (0.0 to 0.17 Hz), and decreased gain in the frequency range of 0.0 to 0.11 Hz but increased gain at frequencies of 0.20 to 0.25 Hz (P<0.01 for all frequency ranges reported). In patients with traumatic brain injury, 102 investigations were possible. Compared with controls, coherence was increased in the frequency range <0.03 Hz and between 0.13 and 0.25 Hz in both normocapnia and hypocapnia, irrespective of the CT findings. Gain was unchanged in normocapnia and in the absence of a CT lesion. Gain was decreased in hypocapnia at frequencies >0.12 Hz irrespective of the presence/absence of a CT lesion. Phase shift decreased rapidly between 0.06 and 0.13 Hz under hypocapnic conditions and under normocapnic conditions in the presence of a CT lesion (P< 0.01). CONCLUSIONS: Use of spontaneous fluctuations of blood flow velocity and BP to assess the cerebrovascular system dynamically requires consideration of the Paco2 level. In different conditions, including severe traumatic brain injury, the cerebrovascular system behaves linearly only in parts of the investigated frequency range.

[Atypical symptoms in carpal tunnel syndrome - treatment and results]. / Atypische Symptome beim Karpaltunnelsyndrom - Therapie und Resultate.

PURPOSE: Additionally to the typical carpal tunnel symptoms, the patients of this study had atypical complaints. Other reasons for these symptoms than those caused by the compression of the median nerve could be excluded using medical examination or imaging techniques. Purpose of this study was to investigate whether decompression of the median nerve may reduce or even abolish the atypical complaints. METHOD: For this prospective study 378 patients with carpal tunnel syndrome were clinically and electroneurographically examined, which was performed before and after (3 months) they underwent surgical decompression of the median nerve. RESULTS: 70 patients (19 % of all patients) with carpal tunnel symptoms suffered from additional atypical symptoms such as cardiac pain, ipsilateral headache as well as neck and shoulder pain. The diagnosis of carpal tunnel syndrome was made using clinical and electroneurographical examination. Carpal tunnel symptoms of all patients disappeared completely after surgery. Respectively, 61 % of those patients with preoperative atypical complaints did also fully recover. CONCLUSION: This study shows that patients with carpal tunnel syndrome may also suffer from atypical complaints. These symptoms have been shown to be associated with the compression of the median nerve. They may be caused by spinal synaptic interaction between sensory and sympathetic/parasympathetic neuronal pathways by somatically-induced reflex responses.

Ultrasound-guided aspiration of brain abscesses through a single burr hole.

Surgical aspiration and/or drainage of brain abscesses is considered to be the first-line treatment for abscesses larger than 25 mm. This is ususally performed with the aid of CT-guided stereotaxy. A method of ultrasound guidance is presented that allows a single burr hole approach with real-time imaging of the whole procedure. A bayonet-like shaped ultrasound probe with tip dimension of 8 x 8 mm only (EUP-NS 32, Hitachi/Ecoscan) with frequencies of 3.5 and 5 MHz is used. After placement of a burr hole the target is identified by transdural insonation, a guideline is adjusted and a mounted puncture-adapter guides the cannula towards the lesion under real-time imaging control. Up to now 12 abscesses in 10 patients were treated. Visualization was always excellent. A second aspiration had to be performed twice. One abscess did not contain enough pus to be cured by aspiration and was removed by open surgery, another could not be tapped by the blunt cannula and was aspirated under stereotactic control using a sharp trocar. Outcome was excellent in 6 patients and fair in 2 patients but this was due to the pre-existing disease. Two patients admitted in deep coma died despite an emergency operation. The presented method has proven to be a very powerful guiding tool in the surgical treatment of brain abscesses through a single burr hole approach.