Recurrent reversible in-stent-stenosis after flow diverter treatment.

Flow diverter stents (FDS) are well established in the treatment of intracranial aneurysms which are difficult to treat with conventional endovascular techniques. However, they carry a relatively high risk of specific complications compared to conventional stents. A minor but frequent finding is the occurrence of reversible in-stent-stenosis (ISS) that tend to resolve spontaneously over time. Here, we report the case of a patient in their 30s who was treated with FDS for bilateral paraophthalmic internal carotid artery (ICA) aneurysms. ISS were found at the respective early follow-up examinations on both sides and had resolved at the 1-year follow-up examinations. Surprisingly ISS reoccurred at both sides in later follow-up examinations and again resolved spontaneously. The recurrence of ISS after resolution is a finding that has not been described previously. Its incidence and further development should be investigated systematically. This might contribute to our understanding of the mechanisms underlying the effect of FDS.

Endovascular Treatment Strategies for Aneurysms of the Origin of the Posterior Inferior Cerebellar Artery.

BACKGROUND: Treatment of aneurysms at the origin of the posterior inferior cerebellar artery (PICA) is challenging. Surgery is difficult due to the deep location and proximity to cranial nerves and endovascular treatment is complicated due to the often tortuous anatomy of the PICA and its small diameter. The purpose of this study is to report our experience with the endovascular treatment of aneurysms at the origin of the PICA. METHODS: Consecutive patients with aneurysms at the origin of the PICA who were endovascularly treated at our department were identified from our registry of neuro-angiographies. Clinical, angiographic, and treatment data were analyzed. Endpoints included successful occlusion and recurrence. RESULTS: Twenty-nine patients were included. 79.3% of the aneurysms were wide-neck with a dome-to-neck ratio <2.65.5% of all endovascular procedures were performed by coiling alone. The procedural rupture rate was 18.75% for endovascularly treated aneurysms presenting with subarachnoid hemorrhage (SAH). Successful embolization was achieved non-significantly more often in the coiling-only group (94.7% vs. 70%, P = 0.066). Aneurysm recurrence after successful occlusion was observed in one case. CONCLUSIONS: Though aneurysm and parent vessel characteristics were challenging successful occlusion was achieved in a high rate of treatments, often with standalone coiling. Adjunctive techniques like retrograde stenting seem promising to further enhance endovascular results. Interestingly aneurysms arising solely from the origin of the PICA without the V4-segment involved presented with SAH significantly more often and wide-neck aneurysms presenting with SAH had a significantly higher periinterventional rupture rate.

[Capillary telangiectasia]. / Kapilläre Teleangiektasie.

Brain capillary telangiectasia is usually a small collection of dilated capillary-like vessels. In most cases it is a harmless incidental finding with no clinical significance. They are most commonly located in the pons. In terms of image morphology, they show brush-like signal extinction in T2*/SWI (susceptibility-weighted imaging) sequences and contrast enhancement in T1-weighted images. Other sequences are usually unremarkable unless they involve unusually large capillary telangiectasias. Angiographically they usually remain silent. Sometimes they are associated with venous abnormalities and/or cavernomas. Their distinctive radiographic features usually allow for a reliable diagnosis. Differential diagnostic considerations, such as differentiation from a tumorous or inflammatory process, are sometimes necessary.

[Middle meningeal artery embolization for chronic subdural hematomas]. / Embolisation der A. meningea media bei chronischen subduralen Hämatomen.

The treatment of chronic subdural hematoma (cSDH) represents a challenge due to high recurrence rates (2-37%). One possible treatment option is middle meningeal artery (MMA) embolization as an alternative to surgery. In contrast to acute SDH, which is caused by a rupture of the bridging veins, cSDH has a different pathomechanism. Injury to the so-called dural boundary cell layer results in an intermittent or continuous cycle of cell proliferation, angiogenesis, secretion, and bleeding due to rupture of newly formed vessels within the SDH membrane. This membrane is supplied by the MMA. Embolization of the MMA leads to resorption of the cSDH. The results published so far regarding MMA embolization as sole therapy or in combination with surgical treatment are encouraging with a long-term success rate of up to 90%.

Comparison of the maximum possible lengths of insertable screws in the Subaxial Cervical Spine.

BACKGROUND: Lateral mass screws are the most commonly used fixation technique in the Subaxial Cervical Spine (SCS), their main advantages being that they are easy to insert and safe in their application. Pedicle screws are significantly longer, are quite challenging to insert in most settings and are accompanied by the risk of serious complications such as vascular and neural injuries. We have therefore developed a new technique, which permits safe insertion of long screws in the SCS. METHODS: A radiological evaluation was carried out to determine the maximum possible insertable screw length in the SCS when using the following techniques: pedicle, lateral mass (Magerl's) and "Attallah" screws. Scans of 66 cervical spines were analyzed to determine the maximum possible screw lengths of all three screw insertion techniques, based on the standard description through the vertebrae from C3 to C7. RESULTS: The maximum possible length of the Attallah screw of 20.7 ± 2.5 mm (mean value ± SD) is only 2.4 mm shorter than the pedicle screw (23.1 ± 1.8 mm) along the SCS. The lateral mass screw is with 10.2 ± 1.3 mm full 12.9 mm shorter than the pedicle screw. CONCLUSIONS: The maximum possible length of the Attallah screw is close to that of the pedicle screw and significantly greater than that of the lateral mass screw. We provide a fixation method comparable to the pedicle screw in its strength and to the lateral mass screw in its safety.

[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.

Radiological analyses of the dimensions of the pedicle and dorsal part of the transverse process of subaxial vertebrae in the context of cervical spine surgery.

BACKGROUND: Knowledge of the anatomical dimensions of distinct areas of the vertebral bodies and vertebral arches of the subaxial cervical spine are indispensable in the planning of osteosynthesis. The minute dimensions and complex anatomical orientation of the posterior vertebral arch structures in the subaxial spine render the insertion of screws - where needed - a challenging procedure. The pedicle option carries the risk of serious complications while the alternative of lateral mass only permits the insertion of short screws. OBJECTIVE: The transverse process of the subaxial vertebrae offers unique possibilities on all counts and seems quite comparable in its dimensions with the pedicle. To our knowledge it has not been used previously for the insertion of screws in the subaxial spine. METHODS: Therefore, the scans of 66 cervical spines were analysed for distinct lines of both structures. RESULTS: The widths and lengths of the dorsal part of the transverse processes and of the pedicles are similar between both sides. Clear differences between females and males could be observed. The widths of both structures were closer to each other in C3 than in C4 to C7, while the lengths derived the most in C7. CONCLUSION: The dorsal part of the transverse process might be suitable for the insertion of screws to stabilize the vertebral arch of the subaxial cervical spine. Gender adaptation might be required.