[Spinal cord vascular diseases]. / Spinale Gefäßmissbildungen.

Spinal vascular malformations include various entities, including spinal dural arteriovenous (AV) fistulas, acquired malformations and cavernous hemangiomas, and spinal arteriovenous malformations. AV fistula refers to a spinal cord vascular malformation in which there is a short-circuit connection between a dural artery and a perimedullary vein superficial to the myelon. The condition is relatively rare, initial clinical symptoms are often misinterpreted, and a definitive diagnosis is often delayed by 12 months or more. However, early diagnosis is important to prevent progression of clinical symptoms, which may include paraplegia. Early magnetic resonance imaging (MRI) is helpful, showing intramedullary edema in the T2-weighted sequences and superficial, markedly dilated veins. Treatment consists of ligation of the AV fistula, either surgically or by embolization. Cavernous hemangiomas, consisting of a large number of closely located immature blood vessels, are also relatively rare and have a low risk of bleeding (approximately 0.2-0.5%). Venous hemorrhage may also occur, resulting in clinical symptoms (including paraplegia).

[Nonaccidental traumatic brain injury in infants and children]. / Nichtakzidentelles Schädel-Hirn-Trauma bei Säuglingen und Kleinkindern.

Violent traumatic brain injury (TBI) can cause brain dysfunction and injury. Accidental and nonaccidental trauma are still the leading cause of childhood death worldwide. It is assumed that about 20% of TBI in children under 2 years of age are nonaccidentally caused. In all cases, nonaccidental TBI is caused by the violent impact on the brain and spinal cord by the massive shaking of the child held by the upper arms or body. This can lead to a rupture of blood vessels, especially bridge veins, as well as axonal shear injuries to the nerve connections and brain swelling. Involvement of the brain stem can lead to initial short-term respiratory arrest. The resulting clinical symptoms include poor drinking, drowsiness, apathy, cerebral seizures, breathing disorders, temperature disorders, and vomiting as a result of increased intracranial pressure. Long-term disorders can include neurological and neuropsychological disorders, hearing disorders, visual disorders up to blindness, and poor school performance. In addition, there are metaphyseal fractures and rib fractures of various forms, also of different ages. Since shaking trauma has a poor prognosis, preventive measures are useful: education!

[COVID-19: neurological manifestations-update : What we know so far]. / COVID-19: neurologische Manifestationen ­ Update : Was wir bisher wissen.

Beyond pulmonary presentation, COVID-19 infection can manifest with a variety of both acute and chronic neurologic and neuropsychiatric (concomitant) symptoms and diseases. Nonspecific symptoms such as headache, fatigue, olfactory and gustatory disturbance have been reported more frequently, and severe disease such as encephalopathy, encephalitis, and cerebrovascular events have been reported relatively rarely. The heterogeneity of neurologic and neuropsychiatric presentations is large, as well as the range of recorded prevalences. Older patients, pre-existing neurologic and non neurologic comorbidities and severe COVID-19 disease were associated with increased risk of severe neurologic complications and higher in-hospital mortality. Probable neurotropic pathomechanisms of SARS-CoV­2 have been discussed, but a multifactorial genesis of neurologic/neuropsychiatric symptoms and disease beyond these is likely.

[New trends in the treatment of bifurcation aneurysms]. / Neue Trends zur Behandlung von Bifurkationsaneurysmen.

CLINICAL ISSUE: Intracranial aneurysms most commonly occur at bifurcation sites. In case of dealing with broad based aneurysms, the risk of accidental vessel occlusion during embolization should not be underestimated. Therefore, several devices are available, e.g. WEB device and barrelsStent. Besides that, a special technique gives the opportunity to place two stents into each other or next to each other into both branches of a bifurcation. Over 300 patients included in 18 studies were treated with Y­stenting (e.g., Medline/Embase) showing a good clinical outcome in 92%. A complete occlusion was achieved in 91%. The rate of neurologic deficits was 4%, the procedure-caused mortality was 2%. Furthermore, 12% of the patients sustained a stroke during the intervention. Ruptured aneurysm was found in 19%. CONCLUSION: All in all, a high occlusion rate and a low rate of mortality and stroke were shown by using Y­stenting.

[Importance of Virchow-Robin spaces]. / Bedeutung der Virchow-Robin-Räume.

Virchow-Robin spaces are perivascular fluid-filled cavities that surround perforating arteries and veins in the brain parenchyma. As a rule in healthy people they are approximately 5 mm in diameter. Typical localizations are brainstem ganglia, mesencephalon and the white matter of the brain. Morphological imaging characteristics of Virchow-Robin spaces are round or tubular, smoothly bordered areas which are hyperintense in T2-weighted sequences. Virchow-Robin spaces represent a physiological structure in normal brain parenchyma. It is assumed that they contain interstitial fluid filled with macrophages and play an important role in the drainage of interstitial fluid in the direction of the cervical lymph system. In many diseases, such as Alzheimer's disease, cerebrovascular diseases and traumatic brain injuries, an association with Virchow-Robin spaces is assumed. In the differential diagnostics lacunar infarcts, cystic space-occupying lesions, low-grade malignant tumors and arachnoid cysts must be considered. In individual studies an association with frequently occurring expanded perivascular spaces in patients with arterial hypertension and patients with CADASIL disease was established. Rarely, Virchow-Robin spaces are so expanded that they lead to compression of the aqueduct or the foramina of Monro with subsequent hydrocephalus.

[Dandy-Walker malformation]. / Dandy-Walker-Malformation.

The Dandy-Walker malformation is the most frequent cerebral malformation. It is defined by hypoplasia and upward rotation of the vermis cerebelli, a cystic enlargement of the fourth ventricle and in total an enlarged posterior fossa with cranially shifted position of the lateral sinus, tentorium and torcula herophili. This malformation was first described by Dandy and Blackfan in 1914 then supplemented again by Taggart and Walker in 1942. The current description as Dandy-Walker malformation was introduced in 1954 by Bender. In addition to these classical findings, the Dandy-Walker malformation is characterized by other abnormalities and malformations of the central nervous system (CNS) including agenesis of the corpus callosum, heterotopia, occipital meningocele, visual deficits and epilepsy. Neurogenetic and imaging examinations have led to a better understanding of this malformation.

[Toxic changes of the central nervous system]. / Toxische Veränderungen des zentralen Nervensystems.

CLINICAL ISSUES: Various toxic agents can cause changes to the white matter of the brain leading to leukoencephalopathies. These changes often lead to signal alterations of the white matter with or without a diffusion restriction signal. White matter lesions can be reversible or irreversible. There are many differential diagnoses of toxic leukoencephalopathies. PRACTICAL RECOMMENDATIONS: For the radiologist it is necessary to be familiar with the causes, the clinical and the imaging presentation of toxic leukoencephalopathies because early treatment often leads to improved prognosis.

[Fetal magnetic resonance imaging]. / Fetale Magnetresonanztomographie.

CLINICAL ISSUE: The most important prenatal screening method for the detailed assessment of the fetus is ultrasound, which is often combined with colour-coded Doppler sonography. In case of sonographically diagnosed fetal pathologies or technical limitations of the ultrasound, supplementary diagnostics may be necessary. STANDARD RADIOLOGICAL METHODS: With fast MRI sequences, fetal MRI screening provides important additional information especially with regard to the most common congenital pathologies-central nervous system (CNS) pathologies (agenesis of the corpus callosum, ventriculomegaly, arachnoid cyst, pathologies of the posterior cranial fossa, dysfunction of the gyrification). Knowledge of the developmental stages of the CNS is very important for accurate clinical assessment and interpretation.

[Metabolic induced changes of the central nervous system]. / Metabolisch verursachte Veränderungen des Zentralnervensystems.

CLINICAL ISSUE: The diagnosis of metabolic disorders of the central nervous system (CNS) can be very challenging for radiologists because of the nonspecific white matter lesions of the brain, the rarity of these diseases, and the variety of possible differential diagnoses. RADIOLOGICAL STANDARD METHODS: Standard for the evaluation of the metabolic disorders is cranial MRI. The MRI spectroscopy can additionally help to reduce the possible differential diagnoses.

[Orbit : Part 2: Diseases of the globe and retrobulbar space]. / Orbita : Teil 2: Retrobulbäre und bulbäre Erkrankungen.

After the first part of the article focused on the anatomy of the orbit and the anatomical relations of the orbital cavity, the second part provides an overview of common diseases of the globe and the retrobulbar space. The main focus is to describe and analyze current imaging procedures and their respective advantages. In addition to inflammatory lesions, traumatic, neoplastic, and congenital entities are also described.

[Pediatric brain tumors]. / Kindliche Hirntumoren.

Brain tumors differ between children and adults both in histology and localization. Malignant gliomas and meningiomas predominate in adults while medulloblastomas and low-grade astrocytomas are the most frequent brain tumors in children. More than one half (50-70%) of pediatric brain tumors have an infratentorial location but only approximately 30% in adults. Brain tumors can be recognized in sonography, cranial computed tomography (CCT) and magnetic resonance imaging (MRI) by their space-consuming character and by their divergent density and intensity in comparison to normal brain parenchyma. They can grow extrusively, even infiltrate the parenchyma or originate from it. Besides clinical symptoms and diagnostics this article describes the most common pediatric brain tumors, i.e. astrocytoma, medulloblastoma, brainstem glioma, craniopharyngioma, neurofibromatosis and ganglioglioma. The most important imaging criteria are outlined.

[Trauma of the lumbar spine and the thoracolumbar junction]. / Trauma der Lendenwirbelsäule und des thorakolumbalen Übergangs.

CLINICAL/METHODICAL ISSUE: Patients who have experienced high energy trauma have a particularly high risk of suffering from fractures of the thoracic and lumbar spine. The detection of spinal injuries and the correct classification of fractures before surgery are not only absolute requirements for the implementation of appropriate surgical treatment but they are also decisive for the choice of surgical procedure. STANDARD RADIOLOGICAL METHODS: By the application of spiral computed tomography (CT) crucial additional information on the morphology of the fracture can be gained in order to estimate the fracture type and possibly the indications for specific surgical treatment options. Magnetic resonance imaging (MRI) is ideally suited to provide valuable additional information regarding injuries to the discoligamentous structures of the spine. PERFORMANCE: Magerl et al. developed a comprehensive classification especially for injuries of the thoracic and lumbar spine, which was adopted by the working group for osteosynthesis (AO). This is based on a 2­pillar model of the spinal column. The classification is based on the pathomorphological characteristics of fractures recognizable by imaging. The injury pattern is of particular importance. ACHIEVEMENTS: In spinal trauma a distinction is made between stable and unstable fractures. The treatment of spinal injuries depends on the severity of the overall injury pattern. PRACTICAL RECOMMENDATIONS: Besides adequate initial treatment at the scene, a trauma CT should be immediately carried out in order that no injuries are overlooked and to ensure a rapid decision on the treatment procedure.

[Neurosarcoidosis]. / Neurosarkoidose.

CLINICAL/METHODICAL ISSUE: Neurosarcoidosis is a relatively rare complication of sarcoidosis that occurs in approximately 5-15 % of patients. The clinical picture is variable. Clinically, neurosarcoidosis is mostly manifested as lesions of the cranial nerves (50-70 %) and several cranial nerves are typically affected. This is the result of aseptic granulomatous basal meningitis. Intraparenchymal granulomas also occur, frequently affecting basal near-midline structures, such as the hypothalamus and pituitary glands and can lead to encephalopathy. STANDARD RADIOLOGICAL METHODS: Diagnostics are essentially performed using magnetic resonance imaging (MRI) as it can demonstrate the thickened meninges, which have a high affinity for contrast media but the results are not specific. Particularly in the absence of systemic sarcoidosis, diagnosis can be difficult. Laboratory tests are not very sensitive and specific, which makes neurosarcoidosis a diagnostic challenge. ACHIEVEMENTS: Due to the substantial morbidity of the disease, early and consistent treatment should be initiated. This is usually carried out with corticosteroids supported by immunosuppressant drugs, such as azathioprine and methotrexate.

[Shaken baby syndrome]. / Shaken-Baby-Syndrom.

The shaken baby syndrome (SBS) or shaking trauma describes the occurrence of subdural hematoma, retinal hemorrhage and diffuse injury to the brain by vigorous shaking of an infant that has a poor prognosis. Rapid cranial acceleration and deceleration leads to tearing of bridging veins, retinal hemorrhages and diffuse brain injuries. In addition to clinical symptoms, such as irritability, feeding difficulties, somnolence, apathy, seizures, apnea and temperature regulation disorders, vomiting also occurs due to increased intracranial pressure. Milder forms of SBS often go undiagnosed and the number of unreported cases (grey area) is probably much higher. Up to 20 % of patients die within days or weeks due to SBS and survivors often show cognitive deficits and clinical symptoms, such as physical disabilities, impaired hearing, impaired vision up to blindness, epilepsy and mental retardation as well as a combination of these conditions; therefore, prevention is very important.

[Clinical aspects and diagnostics of cerebral vasculitis]. / Klinik und Diagnostik zerebraler Vaskulitiden.

CLINICAL/METHODICAL ISSUE: Vasculitis is a rare cause of diseases of the central nervous system (CNS). Vasculitis can be divided into primary and secondary forms, of which the vast majority can be manifested in various organ systems, including the CNS. Isolated vasculitis of the CNS is limited to the CNS and clinical neurological symptoms as with the other forms of vasculitis, are headaches, encephalopathy, focal deficits and seizures. A criterion of isolated CNS vasculitis is the clinical and laboratory diagnostic exclusion of other forms of vasculitis and the involvement of other organ systems. STANDARD RADIOLOGICAL METHODS: Multiple leaps in the caliber of intracranial arteries in cerebral angiography and multiple, small contrast medium-enhanced lesions in magnetic resonance imaging (MRI) of the brain are typical findings, which, however, can also be found in other forms of vasculitis. PERFORMANCE: The only way of proving meningitis is by a biopsy of the brain meninges and parenchyma. It is necessary to make as accurate a diagnosis as possible, especially in the context of therapeutic options of immunosuppression with steroids and cyclophosphamide. ACHIEVEMENTS: Cerebral vasculitis is a rare entity but it is an important diagnosis to consider when the appropriate clinical symptoms are present. Thorough laboratory diagnostics and subsequent brain biopsy are necessary to confirm the diagnosis in order to then be able to initiate a specific treatment.

[Degenerative cerebellar diseases and differential diagnoses]. / Degenerative Kleinhirnerkrankungen und Differenzialdiagnosen.

CLINICAL/METHODICAL ISSUE: Cerebellar syndromes result in distinct clinical symptoms, such as ataxia, dysarthria, dysmetria, intention tremor and eye movement disorders. STANDARD RADIOLOGICAL METHODS: In addition to the medical history and clinical examination, imaging is particularly important to differentiate other diseases, such as hydrocephalus and multi-infarct dementia from degenerative cerebellar diseases. Degenerative diseases with cerebellar involvement include Parkinson's disease, multiple system atrophy as well as other diseases including spinocerebellar ataxia. ACHIEVEMENTS: In addition to magnetic resonance imaging (MRI), nuclear medicine imaging investigations are also helpful for the differentiation. PRACTICAL RECOMMENDATIONS: Axial fluid-attenuated inversion recovery (FLAIR) and T2-weighted sequences can sometimes show a signal increase in the pons as a sign of degeneration of pontine neurons and transverse fibers in the basilar part of the pons. The imaging is particularly necessary to exclude other diseases, such as normal pressure hydrocephalus (NPH), multi-infarct dementia and cerebellar lesions.

[Postoperative spinal column]. / Postoperative Wirbelsäule.

STANDARD PROCEDURE: As a rule, postoperative imaging is carried out after spinal interventions to document the exact position of the implant material. INFORMATION: Imaging is absolutely necessary when new clinical symptoms occur postoperatively. In this case a rebleeding or an incorrect implant position abutting a root or the spinal cord must be proven. In addition to these immediately occurring postoperative clinical symptoms, there are a number of complications that can occur several days, weeks or even months later. These include the failed back surgery syndrome, implant loosening or breakage of the material and relapse of a disc herniation and spondylodiscitis. REVIEW: In addition to knowledge of the original clinical symptoms, it is also important to know the operation details, such as the access route and the material used. RECOMMENDATION: In almost all postoperative cases, imaging with contrast medium administration and corresponding correction of artefacts by the implant material, such as the dual energy technique, correction algorithms and the use of special magnetic resonance (MR) sequences are necessary. RECOMMENDATION: In order to correctly assess the postoperative imaging, knowledge of the surgical procedure and the previous clinical symptoms are mandatory besides special computed tomography (CT) techniques and MR sequences.

[Mechanical thrombectomy - technique]. / Mechanische Thrombektomie - Technik.

Mechanical thrombectomy with stent retrievers in acute stroke has emerged as the technique with the highest recanalization rate of therapeutic procedures available so far. Recently it was demonstrated that compared to intravenous rTPA alone, mechanical thrombectomy improves outcomes of patients with acute occlusions of intracranial arteries of the anterior circulation in several randomized clinical trials. In this article we will give an overview of the steps required for the thrombectomy procedure.

Influence of DGKH variants on amygdala volume in patients with bipolar affective disorder and schizophrenia.

The diacylglycerol kinase eta (DGKH) gene, first identified in a genome-wide association study, is one of the few replicated risk genes of bipolar affective disorder (BD). Following initial positive studies, it not only was found to be associated with BD but also implicated in the etiology of other psychiatric disorders featuring affective symptoms, rendering DGKH a cross-disorder risk gene. However, the (patho-)physiological role of the encoded enzyme is still elusive. In the present study, we investigated primarily the influence of a risk haplotype on amygdala volume in patients suffering from schizophrenia or BD as well as healthy controls and four single nucleotide polymorphisms conveying risk. There was a significant association of the DGKH risk haplotype with increased amygdala volume in BD, but not in schizophrenia or healthy controls. These findings add to the notion of a role of DGKH in the pathogenesis of BD.

[Diffusion-weighted imaging and diffusion tensor imaging in preoperative diagnostics]. / Diffusionsgewichtete Bildgebung und "diffusion tensor imaging" in der präoperativen Diagnostik.

The extent of anisotropy and the direction of diffusion of H protons characterize the tissue structure and qualitative and quantitative evaluation of the appropriate parameters provide inferences for the membrane permeability, axon thickness, integrity and connectivity. The technique of fiber tracking is implemented in the presurgical diagnostics for lesions in the brain to show the relationship of the lesion to the fiber system. The benefit of this technique for preoperative and intraoperative localization of the pyramidal tracts, the primary motor areas, the optic radiation and the speech regions could be confirmed. In focal gliomas the fibers are often displaced to the edge of the tumor; however, in diffusely growing tumors the fiber system is infiltrated by tumor cells. In high-grade gliomas destruction of the fibers often occurs. Limitations are always present in brain regions where several fiber systems cross in different directions, such as the centrum semiovale. Appropriate neuroanatomical knowledge must be present in order to be able to immediately recognize such possible deviant pathways of the fiber tracking.