Recognizing megatsunamis in Mediterranean deep sea sediments based on the massive deposits of the 365 CE Crete event.

The Mediterranean Sea hosts two subduction systems along the convergent Africa-Eurasia plate boundary that have produced strong ground shaking and generated tsunamis. Based on historical descriptions and sedimentary records, one of these events, in 365 CE, impacted a broad geographical area, including tsunami evidence for distances of 700-800 km from the source event, qualifying it as a 'megatsunami'. Understanding how megatsunamis are produced, and where they are more likely, requires a better understanding of the different secondary processes linked to these events such as massive slope failures, multiple turbidity current generation, and basin seiching. Our sedimentary records from an extensive collection of cores located in distal and disconnected basins, identify turbidites which are analyzed using granulometry, elemental (XRF), micropaleontological, and geochemical data in order to reconstruct their coastal or marine source. The results show that the 365 CE basin floor sediments are a mixture of inner shelf and slope materials. The tsunami wave produced multiple far-field slope failures that resulted in stacked basal turbidites. It also caused transport of continent-derived organic carbon and deposition over basal turbidites and into isolated basins of the deep ocean. The composition of sediment in isolated basins suggests their deposition by large-scale sheet like flows similar to what has been caused by the Tohoku earthquake associated tsunamis. This is significant for rectifying and resolving where risk is greatest and how cross-basin tsunamis are generated. Based on these results, estimates of the underlying deposits from the same locations were interpreted as possible older megatsunamis.

Cavernous hemangioma of the cavernous sinus. Complete disappearance of the neoplasma after subtotal excision and radiation therapy. Case report.

A case of a 46-year-old woman with a left cavernous sinus hemangioma is reported. The onset of symptoms consisted in left orbital pain and ocular diseases. The suspected diagnosis were among Tolosa-Hunt syndrome and, after neuroimaging researches, cavernous sinus meningioma, trigeminal neurinoma, craniopharyngioma and adenoma with extrasellar extension. The lesion was partially removed with additional neurological deficit of the left 3rd cranial nerve. The patient underwent 7 months later focal radiation therapy of 45 Gray and a 19 months follow-up showed the complete disappearance of the mass and partial recovery of the 3rd cranial nerve function.

Incidence of asymptomatic berry aneurysms among patients undergoing carotid endarterectomy.

BACKGROUND: Scattered reports of literature suggest the hypothesis that patients suffering from a severe stenosis of extracranial carotid artery may present an increased rate of intracranial berry aneurysms caused by the hemodynamic stress on the side opposite to the stenosis, namely on physiological shunts. However, this hypothesis has never been verified upon a large and homogeneous series focused on the argument. MATERIALS AND METHODS: We reviewed a consecutive series of 405 patients submitted to carotid endarterectomy for stenosis greater or equal to 70%. RESULTS: Thirteen aneurysm were found in 11 patients (2.6%). Our patients showed a slight increase of incidence regards to general population (1%), maybe due to the large number of aged patients among our subpopulation. Preoperative TCD evaluation showed the presence of increased flow velocities in the physiological shunts, namely the anterior cerebral artery and the anterior communicating artery, in 65% of the patients, and angiography confirmed the redistribution of intracranial circulation. Nevertheless, according to aneurysm location, no statistically significant correlation (0.3 < p < 0.4) was found between the presence of an aneurysm and the values of velocity in these arteries. CONCLUSIONS: As regards the etiology of berry aneurysms, these data suggest that increased hemodynamic stress per se is not sufficient to cause the origin of berry aneurysms. Maybe, a role is possible only if either congenital, or acquired and age-related factor, peculiar of cerebral arteries, coexist.

Management of symptomatic carotid stenoses with coincidental intracranial aneurysms.

There are at present strong indications for surgery in patients suffering from symptomatic extracranial carotid stenoses of > 70%. Surgery of coincidental aneurysms is a still debated problem, but there is general agreement that it is indicated in selected cases according to the patient's life-expectancy and size and site of the aneurysm. The coexistence of these two lesions raises a decision-making problem. We reviewed 389 endarterectomies and found 12 intracranial berry aneurysms in 10 (2.6%) patients. All the 10 patients were harbouring a symptomatic carotid stenosis of > 70%. Since the correction of a stenosis increases blood flow to an aneurysm, our approach was to first operate on the intracranial lesion and then the stenosis in 7 patients harbouring aneurysms > 5 mm. Two patients affected by small aneurysms < 5 mm of an A2 azygos and left internal carotid artery underwent left endarterectomy only. The last patient was submitted first to percutaneous angioplasty of a left stenosis, then to open surgery of a contralateral middle cerebral aneurysm and finally to intravascular occlusion of a small aneurysm of the left internal carotid bifurcation by menas of a coil; this policy was adopted in order to restore normal haemodynamic conditions before the intracranial procedure. There was no mortality or permanent morbidity following surgery for aneurysm or endarterectomy. Transient morbidity occurred in 2 cases after clipping of aneurysms of the anterior communicating and middle cerebral arteries. Our results suggest that surgery of coincidental aneurysms may give good results even when there is a severe symptomatic stenosis in the neck. Moreover, the presence of a small intracranial aneurysm does not seem to be an additional risk factor for endarterectomy. When the lesions are on different sides, it may be better to treat the stenosis first if it decreases the ipsilateral cerebral blood flow.