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The therapy of acute ischemic stroke aims at fast recanalization of the occluded brain vessel. In contrast to intravenous thrombolysis (IVT), endovascular approaches yield higher recanalization rates especially in large vessel occlusions. Mechanical thrombectomy with the Merci Retriever received FDA approval in 2004 as an adjunct to IVT or in the case of failed recanalization after IVT. The time window for treatment is 8 h from stroke onset. However, the recanalization rate was 55 %, still leaving space for further improvement. In addition to the Merci Retriever, the Penumbra System received FDA approval in 2008. The newest endovascular approach comprising retrievable intracranial stents results in an increased recanalization rate exceeding 90 % and has markedly reduced the time to recanalization. On the other hand, the complication rate has not increased yet. These promising results suggest a combined therapy for acute ischemic stroke. In a first step IVT can be started independently of the size of the treating hospital and in a next step the patient is transferred to a neuroradiological center. If vessel occlusion persists, additional endovascular recanalization is performed (bridging concept). Patients who don't qualify for IVT are candidates for mechanical thrombectomy up to 8 h after stroke onset.

This article provides an overview on the actual state of the interventional neuroradiological management of carotid cavernous fistulas depending on their anatomy and pathophysiology. The results are based on our experience gained during the treatment of patients with complex CCF during the last 15 years. Indications, procedures, and results of transarterial, transvenous and combined arteriovenous approaches for balloon occlusion, embolization, coiling and stenting of these lesions are discussed. Progress in this field is constant so that new technical advances are expected to improve the safety and to expand the indications for these procedures in the future.

Description of special techniques for retrograde angioplasty of cerebral arteries with protection of the brain.During the last 3 years, 51 dilatations of cerebral vessels were carried out in 45 patients; in 8, special techniques were required. In cases with particular operative risks, angioplasty of cerebral vessels can be performed using various techniques (double catheter [8 cases], retrograde PTA [8 cases], kissing balloon technique [3 cases]).All stenoses were successfully dilated, using a local anaesthetic. One patient with a double stenosis of the common carotid artery developed severe headache and visual disturbances in the ipsilateral eye following dilatation of a tight stenosis with total remission of all symptoms within 24 hours.Stenoses of cerebral arteries where surgery would be difficult and associated with a high risk can be dilated by retrograde PTA using a double catheter technique with a low complication rate.

5 unusual cases of cerebral tuberculosis are reported. Three of the cases initially showed the typical history and aspect of herpes simplex encephalitis, and two of a cerebral tumour. Both CT and MRI, and also the clinical neurological symptoms, were confusing. Microbiological culture in three and histological preparation in two cases confirmed the diagnosis of cerebral tuberculosis. Three cases showed the development of tuberculomas under therapy. The study of the literature suggests that this is not rare, which is explained by pathogenetic reflexions concerning the allergic genesis of the tuberculomas.

The results of magnetic resonance imaging, using a 0.5 Tesla superconductive magnet in 6 patients with clinical (6), angiographic (6) and histologic (4) diagnosis of posterior fossa tumors were reviewed and compared with x-ray computed tomography. Optimal visualization of normal and abnormal anatomic relationships and the possibility and value of calculated T1- and T2-pictures with the aid of spin-echo-technique are discussed.

The influence of MR on the EEG and neuropsychological functions was investigated. An EEG was done in 8 of 20 patients before and after 0.5 Tesla MRI. Computerized EEG analysis showed no significant differences in respect of the dominant frequency and the power spectrum. The memory functions of 12 patients were investigated by clinically proven neuropsychological tests before and after MRI (0.5 and 1.5 tesla). The results demonstrated no measurable influence of MRI on cognitive functions.

CT follow-up studies were done in 65 alcoholics before an inpatient treatment and after a period with confirmed abstinence of 5 weeks duration. The scans were rated "blind" by linear measurement of well defined distances. An improvement (significant reduction of brain "atrophy") was found in 33 patients (50.8%), 5 patients (7,7%) showed a trend towards progression of brain "atrophy". The possibility of recovery tends to be significantly greater in younger subjects. These findings and the results of recent MR follow-up studies are consistent with decreased free water during alcohol intoxication and an increase in brain water during alcohol withdrawal.

A comparison between clinical and MRI findings in 20 patients with syringomyelia produced the following results: 1. The position and extent of the syrinx do not correspond with the clinical findings. 2. Successfully operated syringomyelia cavities collapse in their sagittal diameters. The resulting oval shape of the syrinx can be used to evaluate shunt insufficiency. 3. In almost half of the patients, the diameter of the spinal cord is within the 95th percentile of normal controls and would therefore not have been diagnosed by myelography. 4. Anomalies of the cranio-cervical junction were present in only one-third of the patients. This finding does not support the hypothesis that syringomyelia is caused by hydrodynamic factors only.

Angiographic control of ultrasonographic findings (continuous-wave (CW) Doppler sonography) at the subclavian artery was performed in 149 patients, altogether 254 subclavian arteries, 89 with and 165 without stenosis or occlusion at Doppler examination. Additionally, in 70 of these persons the vertebral haemodynamic situation was investigated by means of angiography. CW Doppler sonography proved a highly reliable method for the diagnosis of subclavian lesions and subclavian steal syndrome. If properly performed, CW Doppler sonography does not fail to reveal stenoses amounting to more than 50%, occlusions, and retrograde vertebral blood flow. Regarding tight stenosis or occlusion of the subclavian artery and retrograde blood flow in the vertebral artery, Doppler sonography yielded no false positive findings, but false positive results may be possible in mild stenoses.

The resolution of NMR and CT was compared using axial sections of the normal anatomic structures of the facial skeleton. It was shown that NMR was superior in differentiating muscles, tonsils, mucosa, lymph nodes and blood vessels. The demonstration of bone and its differentiation from air-containing spaces is often difficult. Metallic, non-ferromagnetic dental fillings, which cause serious artefacts on CT, do not affect NMR.