Intraparenchymal schwannomas: report of two new cases studied with MRI and review of the literature.

Intraparenchymal schwannomas are very rare tumours. We present two young adult patients operated for this type of lesion who show no signs of recurrence 2 years after surgery. These tumours have a bimodal peak of presentation: most occur in young patients under 25 years, and the rest present in the elderly. Characteristically they show both Antoni A and Antoni B areas, intense inmunoreactivity to S-100 and Vimentin protein, and none to EMA or CD34. Electron microscopy is diagnostic when basal membrane is found around the cytoplasmatic processes. MRI spectroscopy depicts increased myoinositol, choline and lipids, and perfusion MR demonstrates high rCBV with a characteristic curve due to the total absence of blood brain barrier. An origin in the Schwann cells of the perivascular nervous plexus in the subarachnoid space is the most accepted theory for the histogenesis of these tumours. We propose to perform the characterization of a series of markers such as SOX-10 in every new case in order to prove that theory.

[Embolization of indirect carotid-cavernous sinus fistula through the ophthalmic vein]. / Embolización de fístula cavernosa indirecta a través de la vena oftálmica superior.

Indirect or dural carotid cavernous fistulas are abnormal connections between the cavernous sinus and meningeal branches of the external and/or internal carotid arteries. Most of them are idiopathic and occurs spontaneously. Symptoms vary from a tiny episcleral injection to a severe visual loss. Conservative therapy is recomended in cases with few symptoms and no leptomeningeal drainage, as spontaneous resolution is not infrequent. Whenever symptoms worsen, treatment of the fistula should be prescribed. Nowadays, transvenous endovascular treatment consisting of packing the cavernous sinus is the first choice. In most cases, cavernous sinus can be approached through the inferior petrosal sinus. However, sometimes that is not possible, and an approach directly through the superior ophthalmic vein could be necessary. We report a case of a patient with a dural carotid cavernous fistula treated with embolization of the cavernous sinus through the ophthalmic vein.

Embolización de fístula carótido cavernosa indirecta a través de la vena oftálmica superior / Embolization of indirect carotid-cavernous sinus fistula through the ophthalmic vein

Las fístulas carótido cevernosas (FCC) indirectaso durales son comunicaciones entre el seno cavernoso y ramas extradurales de la arteria carótida interna, la carótida externa o ambas. La mayoría de las FCC indirectas son idiopáticas y aparecen espontáneamente. Los síntomas pueden variar desde una leve inyección conjuntival y escleral hasta la reducción severa de la agudeza visual. En casos poco sintomáticos y sin drenaje leptomeníngeo, el tratamiento conservador estaría indicado inicialmente, pues existe la posibilidad del cierre espontáneo de la fístula. Cuando la sintomatología progresa, requieren algún tipo de tratamiento para cerrarla. Hoy en día, el tratamiento endovascular es el de elección, y la vía transvenosa, con sellado o empaquetado del SC, ha demostrado mayor efectividad que la transarterial. En la mayoría de los casos se puede acceder al SC a través del seno petroso inferior. Sin embargo, en ocasiones no es posible el acceso a la FCC por vía venosa transfemoral, siendo necesario un abordaje directo a la vena oftálmica superior (VOS). Presentamos un caso de FCC indirecta tratada mediante abordaje directo a la VOS y embolización del seno cavernoso

Indirect or dural carotid cavernous fistulas are abnormal connections between the cavernous sinus and meningeal branches of the external and/or internal carotid arteries. Most of them are idiopathic and occurs spontaneously. Symptoms vary from a tiny episcleral injection to a severe visual loss. Conservative therapy is recommended in cases with few symptoms and no leptomeningeal drainage, as spontaneous resolution is not infrequent. Whenever symptoms worsen, treatment of the fistula should be prescribed. Nowadays, transvenousendo vascular treatment consisting of packing the cavernous sinus is the first choice. In most cases, cavernous sinus can be approached through the inferior petrosal sinus. However, sometimes that is not possible, and an approach directly through the superior ophthalmic vein could be necessary. We report a case of a patient with a dural carotid cavernous fistula treated with embolization of the cavernous sinus through the ophthalmic vein

[Subarachnoid hemorrhage caused by a dissecting carotid artery aneurysm]. / Hemorragia subaracnoidea como forma de presentación de aneurisma disecante carotídeo.

Dissecting aneurysms of the carotid artery as a cause of subarachnoid hemorrhage are rare. However, the association of arterial dissection with the etiology of some aneurysms of the dorsal or anterior wall of the carotid artery, carotid trunk or "blister-like" aneurysms has increased the interest in the description of dissecting aneurysms, as they are difficult to treat and require non-habitual surgical techniques. We present the case of a patient that presented with a poor grade subarachnoid hemorrhage secondary to a right carotid artery dissecting aneurysm characterised in angiography by a carotid artery stenosis accompanied by a post-stenotic dilatation and the finding of a saccular aneurysm that increased in size in the follow-up study. A carotid occlusion test showed an asymmetry in the opacification of the venous phase indicating the need for a revascularization procedure prior to arterial sacrifice. A high flow EC-IC bypass was performed using a saphenous vein graft prior to right carotid artery occlusion without morbidity. Eight months after the procedure the patient is free of neurological deficit. Control image studies demonstrate the resolution of the carotid lesion and the bypass permeability. We discuss the difficulties in the diagnosis of these aneurysms, their clinical and imaging characteristics and the problems related to their treatment as they often require arterial sacrifice with or without prior cerebral revascularization.

Hemorragia subaracnoidea como forma de presentación de aneurisma disecante carotídeo / Subarachnoid hemorrhage caused by a disecting carotid artery aneurysm

Las disecciones carotídeas se presentan con muy poca frecuencia en forma de hemorragia subaracnoidea. Sin embargo, la implicación de la disección arterial en la patogenia de algunos aneurismas de la pared dorsal o anterior de la carótida, tronco carotídeo y aneurismas“blister-like”, ha hecho que cobre interés la descripción de los aneurismas disecantes, ya que con frecuencia son lesiones de difícil tratamiento y requieren de técnicas quirúrgicas no habituales. Presentamos el caso de una enferma que debutó con una hemorragia subaracnoidea en mal grado clínico secundaria a un aneurisma disecante de la carótida interna derecha, caracterizado por la presencia en el estudio angiográfico de una estenosis carotídea asociada a una dilatación postestenótica y al hallazgo de una lesión sacular que creció en el estudio de control. Se realizó un test de oclusión carotídea que mostró una asimetría en la aparición del drenaje venoso que determinó la conveniencia de practicar un by-pass extraintracraneal de alto flujo con injerto de safena para su tratamiento mediante sacrificio de la carótida interna. Ocho meses tras la cirugía la enferma no presenta focalidad neurológica alguna y los estudios de imagen muestran una resolución de la lesión carotídea con permeabilidad del bypass. Se discuten las dificultades en el diagnóstico de estos aneurismas, sus características clínicas y radiológicas y los problemas en su tratamiento que casi siempre requieren de sacrificio arterial con o sin revascularización cerebral previa

Dissecting aneurysms of the carotid artery as a cause of subarachnoid hemorrhage are rare. However, the association of arterial dissection with the etiology of some aneurysms of the dorsal or anterior wall of the carotid artery, carotid trunk or “blister-like” aneurysms has increased the interest in the description of dissecting aneurysms, as they are difficult to treat and requiren on-habitual surgical techniques. We present the case of a patient that presented with a poor grade subarachnoid hemorrhage secondary to a right carotid artery dissecting aneurysm characterised in angiography by a carotid artery stenosis accompanied by a post-stenotic dilatation and the finding of a saccular aneurysm that increased in size in the follow-up study. A carotid occlusion test showed an asymmetry in the opacification of the venous phase indicating the need for a revascularization procedure prior to arterial sacrifice. A high flow EC-IC bypass was performed using a saphenous vein graft prior to right carotid artery occlusion without morbidity. Eight months after the procedure the patientis free of neurological deficit. Control image studies demonstrate the resolution of the carotid lesion and the bypass permeability. We discuss the difficulties in the diagnosis of these aneurysms, their clinical and imaging characteristics and the problems related to their treatment as they often require arterial sacrifice with or without prior cerebral revascularization