Ferdinando Caranci

Epidemiology and genetics of intracranial aneurysms

Intracranial aneurysms are acquired lesions (5-10% of the population), a fraction of which rupture leading to subarachnoid hemorrhage with devastating consequences. Until now, the exact etiology of intracranial aneurysms formation remains unclear. The low incidence of subarachnoid hemorrhage in comparison with the prevalence of unruptured IAs suggests that the vast majority of intracranial aneurysms do not rupture and that identifying those at highest risk is important in defining the optimal management. The most important factors predicting rupture are aneurysm size and site. In addition to ambiental factors (smoking, excessive alcohol consumption and hypertension), epidemiological studies have demonstrated a familiar influence contributing to the pathogenesis of intracranial aneurysms, with increased frequency in first- and second-degree relatives of people with subarachnoid hemorrhage. In comparison to sporadic aneurysms, familial aneurysms tend to be larger, more often located at the middle cerebral artery, and more likely to be multiple. Other than familiar occurrence, there are several heritable conditions associated with intracranial aneurysm formation, including autosomal dominant polycystic kidney disease, neurofibromatosis type I, Marfan syndrome, multiple endocrine neoplasia type I, pseudoxanthoma elasticum, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II and IV. The familial occurrence and the association with heritable conditions indicate that genetic factors may play a role in the development of intracranial aneurysms. Genome-wide linkage studies in families and sib pairs with intracranial aneurysms have identified several loci on chromosomes showing suggestive evidence of linkage, particularly on chromosomes 1p34.3-p36.13, 7q11, 19q13.3, and Xp22. For the loci on 1p34.3-p36.13 and 7q11, a moderate positive association with positional candidate genes has been demonstrated (perlecan gene, elastin gene, collagen type 1 A2 gene). Moreover, 3 of the polymorphisms analyzed in 2 genes (endothelial nitric oxide synthase T786C, interleukin-6 G572C, and interleukin-6 G174C) were found to be significantly associated with ruptured/unruptured aneurysms: the endothelial nitric oxide synthase gene single-nucleotide polymorphisms increased the risk, while IL-6 G174C seemed protective. More recently, two genomic loci (endothelin receptor A and cyclin-dependent kinase inhibitor 2BAS) have been found to be significantly associated with intracranial aneurysms in the Japanese population; endothelin-1 is a potent vasoconstrictor produced by the endothelial cells. Until now, there are no diagnostic tests for specific genetic risk factors to identify patients who are at a high risk of developing intracranial aneurysms. Knowledge of the genetic determinants may be useful in order to allow clues on stopping aneurysm formation and obtain diagnostic tools for identifying individuals at increased risk. Further multicenter studies have to be carried out.

Reversible focal splenial lesions

Reversible focal lesions in the splenium of the corpus callosum (SCC) have recently been reported.They are circumscribed and located in the median aspect of the SCC. On MRI, they are hyperintense on T2-W and iso-hypointense on T1-W sequences, with no contrast enhancement. On DWI, SCC lesions are hyperintense with low ADC values, reflecting restricted diffusion due to cytotoxic edema. The common element is the disappearance of imaging abnormalities with time, including normalization of DWI. Clinical improvement is often reported. The most established and frequent causes of reversible focal lesions of the SCC are viral encephalitis, antiepileptic drug toxicity/withdrawal and hypoglycemic encephalopathy. Many other causes have been reported, including traumatic axonal injury. The similar clinical and imaging features suggest a common mechanism induced by different pathological events leading to the same results. Edema and diffusion restriction in focal reversible lesions of the SCC have been attributed to excitotoxic mechanisms that can result from different mechanisms; no unifying relationship has been found to explain all the pathologies associated with SCC lesions. In our opinion, the similar imaging, clinical and prognostic aspects of these lesions depend on a high vulnerability of the SCC to excitotoxic edema and are less dependent on the underlying pathology. In this review, the relevant literature concerning reversible focal lesions in the SCC is analyzed and hypotheses about their pathogenesis are proposed.

Predictors of remission of hyperprolactinaemia after long‐term withdrawal of cabergoline therapy

Background  Remission rates of 76, 69·5 and 64·3% have been reported in patients with nontumoural hyperprolactinaemia (NTH), microprolactinoma and macroprolactinoma, respectively, 2–5 years after cabergoline (CAB) withdrawal.

Endovascular treatment of cerebral aneurysms using flow-diverter devices: A systematic review.

Background Flow-diverter devices (FDDs) are new-generation stents placed in the parent artery at the level of the aneurysm neck to disrupt the intra-aneurysmal flow thus favoring intra-aneurysmal thrombosis. Objective The objective of this review article is to define the indication and results of the treatment of intracranial aneurysms by FDD, reviewing 18 studies of endovascular treatment by FDDs for a total of 1704 aneurysms in 1483 patients. Methods The medical literature on FDDs for intracranial aneurysms was reviewed from 2009 to December 2014. The keywords used were: “intracranial aneurysms,” “brain aneurysms,” “flow diverter,” “pipeline embolization device,” “silk flow diverter,” “surpass flow diverter” and “FRED flow diverter.” Results The use of these stents is advisable mainly for unruptured aneurysms, particularly those located at the internal carotid artery or vertebral and basilar arteries, for fusiform and dissecting aneurysms and for saccular aneurysms with large necks and low dome-to-neck ratio. The rate of aneurysm occlusion progressively increases during follow-up (81.5% overall rate in this review). The non-negligible rate of ischemic (mean 4.1%) and hemorrhagic (mean 2.9%) complications, the neurological morbidity (mean 3.5%) and the reported mortality (mean 3.4%) are the main limits of this technique. Conclusion Treatment with FDDs is a feasible and effective technique for unruptured aneurysms with complex anatomy (fusiform, dissecting, large neck, bifurcation with side branches) where coiling and clipping are difficult or impossible. Patient selection is very important to avoid complications and reduce the risk of morbidity and mortality. Further studies with longer follow-up are necessary to define the rate of complete occlusion.

Learning From Errors in Radiology: A Comprehensive Review

An important goal of error analysis is to create processes aimed at reducing or preventing the occurrence of errors and minimizing the degree of harm. The discovery of any errors presents an opportunity to study the types that occur and to examine their sources and develop measures to prevent them from recurring. The development of an effective system for detecting and appropriately managing errors is essential to substantially attenuate their consequences. At this stage, the error analysis process identifies contributing factors to enable the implementation of concrete steps to prevent such errors from occurring in the future. Active and comprehensive management of errors and adverse events requires ongoing surveillance processes. Educational programs, morbidity and mortality meetings, and a comprehensive and respected root cause analysis process are also essential components of this comprehensive approach. To reduce the incidence of errors, health care providers must identify their causes, devise solutions, and measure the success of improvement efforts. Moreover, accurate measurements of the incidence of error, based on clear and consistent definitions, are essential prerequisites for effective action.

Flow diverter device for the treatment of small middle cerebral artery aneurysms

Purpose Experience with the endovascular treatment of middle cerebral artery (MCA) aneurysms by flow diverter devices (FDD) is still limited. This study examines the results and complications of FDD for small aneurysms at this location. Methods From February 2010 to December 2013, 14 patients (10 women; mean age 59 years) with 15 small MCA aneurysms were treated with FDD. All procedures were performed with the Pipeline embolization device (PED). Results Complete occlusion was obtained in 12/15 aneurysms (80%) and partial occlusion in 3 (20%). Among 13 aneurysms with a side branch, this was patent at the angiographic control in 4 cases, showed decreased filling in 6, and was occluded in 3 (with neurological deficits in 2). All PEDs were patent at follow-up. Post-procedural ischemic complications occurred in 4 (27%) procedures with permanent neurological deficit (modified Rankin score 2) in 3 (21%). No early or delayed aneurysm rupture, no subarachnoid or intraparenchymal hemorrhage and no deaths occurred. Conclusions Endovascular treatment with FDD is a relatively safe treatment for small MCA aneurysms resulting in a high occlusion rate. The findings of this study suggest that complete occlusion after endovascular treatment with FDD can be delayed (>6 months). Ischemic complications may occur as early or delayed, particularly at clopidogrel interruption.

Treatment of intracranial aneurysms by flow diverter devices: Long-term results from a single center

OBJECTIVES Flow-Diverter Devices (FDD) are a new generation stents designed for the treatment of the intracranial aneurysms. This article reports the long-term results (2-4 years) of this treatment from a single-center. METHODS From November 2008 to January 2012, 35 patients (29 females and 6 males; mean age 53.9 y) with 39 intracranial aneurysms were treated by FDD. Five patients (14.3%) had ruptured aneurysms and 30 (85.7%) had no previous hemorrhage. The procedures were performed in 5 patients (14.3%) with SILK and in 30 (85.7%) with PED. In 3 patients FDDs were used as a second treatment after failure of previous coiling (2 cases) or stenting (one case). The 39 aneurysms were in supraclinoid ICA in 26 (66.7%), cavernous ICA in 2 (5.1%), PCoA in 4 (10.2%), MCA in 5 (12.9%), SCA in 1 (2.6%) and PICA in 1 (2.6%). The aneurysms were small (<10mm) in 32 cases (82%), large (11-25mm) in 6 (15.3%) and giant in 1 (2.6%). The occlusion rate according to the aneurysm location, size and neck and the complications were evaluated. RESULTS Peri-procedural complications included transient dysarthria (2 patients), vasospasm with acute intra-stent aggregation (one), microwire rupture (one) and failure of the stent opening (one). The follow-up was made between 24 and 62 months (mean 41 months); clinical examination and CTA were performed at 1, 3, 6 and 12 months after the procedure. The complete occlusion was confirmed by CTA and DSA. MRI with angiographic-studies was taken every year. Complete occlusion was obtained in 35 aneurysms (92.1%) and subtotal in 3 (7.9%). Complete occlusion occurred at 3 months in 24 cases (68.6%), within 3 and 6 months in 9 (25.7%). The rate and time of complete occlusion were not correlated with the aneurysm size. MCA aneurysms mainly showed partial occlusion (2/3 cases). Besides, large-neck aneurysms and those with a vessel arising from the sac mainly showed late (>6 months) or partial occlusion. CONCLUSION FDD are a safe and efficacious treatment of intracranial aneurysms, resulting in high occlusion rate and low incidence of complications. It should be the treatment of choice for the large-neck aneurysm of the ICA.

Orbital Fractures: Role of Imaging

The orbit may be injured directly or indirectly. Blunt and penetrating trauma occurs with equal frequency. Soft tissue swelling often obscures direct clinical evaluation of the globe, limits ocular motion, and may limit clinical assessment of vision. Plain film radiographs of the orbits and sinuses are rarely used for diagnosis in orbital trauma. Computed tomography is considered the imaging modality of choice in this circumstance, as it is deemed to be the most accurate method in detecting fractures. The protocol is based on obtaining thin-section axial scans and multiplanar reformatted images, both are useful tools to guide treatment. Orbital fractures are not considered an ophthalmologic emergency unless there is visual impairment or globe injury. Surgical repair is indicated for patients who have persistent diplopia or cosmetic concerns (enophthalmos) and generaly is not performed until swelling subsides 7-10 days after injury.

1H-MR spectroscopy indicates prominent cerebellar dysfunction in benign adult familial myoclonic epilepsy

Purpose:  To investigate the neurochemical pattern in patients with benign adult familial myoclonic epilepsy (BAFME/FAME), an inherited form of myoclonic epilepsy, by proton magnetic resonance (MR) spectroscopy (1H‐MRS).

Neck neoplastic conditions in the emergency setting: role of multidetector computed tomography.

Emergent conditions resulting from head and neck neoplasms and their treatment include acute airway obstruction, hemorrhage, spinal cord compression, bilateral vocal cord paralysis, and septic thrombophlebitis. These conditions require accurate diagnosis and rapid intervention to avoid severe permanent damage or death. Successful treatment requires a coordinated response by emergency medicine physicians, otolaryngologists, vascular surgeons, and radiologists. We review these head and neck oncological conditions, which present emergently, with a focus on radiological evaluation and interpretation.