Endovascular Treatment of an Arteriovenous Malformation Associated with a Double Origin of the Posterior Inferior Cerebellar Artery

<b><i>Introduction:</i></b> A double origin of the posterior inferior cerebellar artery (DOPICA) is a rare anatomical variant. Posterior fossa arteriovenous malformations (AVMs), especially cerebellar AVMs, are also not common. Consequently, the association of a DOPICA with a cerebellar AVM is even rare. <b><i>Case Presentation:</i></b> We present a rare case of a pediatric cerebellar AVM supplied by a branch of a DOPICA which was treated endovascularly with NBCA. Total obliteration was achieved in the immediate controls and at 1-year follow-up. <b><i>Conclusion:</i></b> Navigation through tortuous and long branches from a DOPICA is technically feasible. Although NBCA cure rates are relatively low, when the microcatheter can no longer navigate through the feeding artery, a correct dilution of NBCA with lipiodol can provide adequate penetration of this embolic agent, to obliterate the AVM nidus completely.

Moving in unison after perceptual interruption

Humans interact in groups through various perception and action channels. The continuity of interaction despite a transient loss of perceptual contact often exists and contributes to goal achievement. Here, we study the dynamics of this continuity, in two experiments involving groups of participants ($$N=7$$ N = 7 ) synchronizing their movements in space and in time. We show that behavioural unison can be maintained after perceptual contact has been lost, for about 7s. Agent similarity and spatial configuration in the group modulated synchronization performance, differently so when perceptual interaction was present or when it was memorized. Modelling these data through a network of oscillators enabled us to clarify the double origin of this memory effect, of individual and social nature. These results shed new light into why humans continue to move in unison after perceptual interruption, and are consequential for a wide variety of applications at work, in art and in sport.

Diaspora

Diaspora as a concept and a particular phenomenon of migration has a double origin: etymologically, it comes from the Greek verb diaspeirein, meaning to scatter; historically, it refers to the dispersal of the Jews from their ancestral land after the destruction of the Second Temple in 586 bce. The term has been applied to the involuntary displacement of other peoples—for example, the African, Armenian, and Irish diasporas—but the Jewish diaspora has served as the principal paradigm of diasporic experience. Based on the Jewish “prototypical” case, the concept has been commonly defined as encompassing a collective identity shaped by the trauma that accompanies a group’s forced departure from its ancestral land and its emotional and material attachment to the origins that is sustained by the desire to return home or by symbolic manifestations of nostalgia. Although scholars have identified different kinds of diasporas—labor, trading, imperial diasporas—the term has maintained its emphasis on dislocation and loss, evoking at once the experience and politics of dispossession and ethnic identification. Since the second half of the 20th century, however, this understanding of diaspora has expanded to embrace a range of displaced communities—immigrants, migrants, exiles, refugees—and has thus come to be identified with global mobilities as an aftereffect of modernity. The malleability of the concept has given rise to many debates about its meaning, application, and methodology, especially since the late 1980s when diaspora began to attract systematic critical attention. The study of diaspora is generally characterized by both a centripetal and a centrifugal approach: the former, holding up the home nation as the ultimate reference point and thus viewing diasporas as distinct and cohesive entities, is concerned with demarcating the boundaries of the term by establishing categorical definitions and typologies; the latter, viewing diaspora as inhabiting an interstitial space in relation to the receiving nation and thus as a hybrid formation and social condition, is interested in diasporic subjectivity as a question of becoming. This opening up of the concept of diaspora, along with the increased global flow of people and parallel developments in other fields, has meant that, since the latter part of the 20th century, diaspora is examined in the adjacent contexts of globalization, postcolonialism, multiculturalism, transnationalism, and hybridity.

Coiling for a saccular aneurysm on the caudal channel in double origin of the posterior inferior cerebellar artery

Background Double origin of the posterior inferior cerebellar artery (DOPICA) is a rare cranial imaging finding with an incidence of 0.36–6% reported in various retrospective studies. Aneurysms on a DOPICA are even rarer. Case description A 34-year-old women hospitalised for subarachnoid haemorrhage showed a ruptured aneurysm arising from the caudal channel of the DOPICA. Endovascular treatment was selected, and the aneurysm was successfully and completely embolised using two coils. Conclusions To date, a total of three previous saccular aneurysms of the DOPICA itself have been reported, all of which were treated using endovascular methods. Our case is the first report of a ruptured saccular aneurysm arising from the non-branching segment of the caudal channel of the DOPICA.

Reimplantation Bypass Using One Limb of a Double-Origin Posterior Inferior Cerebellar Artery for Treatment of a Ruptured Fusiform Aneurysm: Case Report

BACKGROUND AND IMPORTANCE Posterior inferior cerebellar artery (PICA) aneurysms are uncommon, and aneurysms associated with anatomical PICA variants are even rarer. Although often treated endovascularly, aneurysms associated with anatomical PICA variants may not be suitable for endovascular intervention because of the risk of compromise of brainstem perforators and may be more amenable to open techniques. This case report describes the successful treatment of an aneurysm associated with a double-origin PICA (DOPICA) by distally reimplanting one of the PICA limbs. CLINICAL PRESENTATION A 78-yr-old man with a Hunt-Hess grade III, Fisher grade IV subarachnoid hemorrhage secondary to a ruptured distal right PICA aneurysm associated with a DOPICA was treated with PICA-PICA bypass and trapping of the aneurysm. This is the first reported case in the literature of successful bypass of a DOPICA-associated aneurysm. Radiographically, the bypass remained patent with successful obliteration of the aneurysm, and at discharge from the hospital, the patient had a Glasgow Coma Scale score of 15 and modified Rankin Scale score of 3. CONCLUSION This case demonstrates a novel reimplantation bypass for a ruptured aneurysm that exploits this rare variant anatomy of a DOPICA.