Anatomía radiológica de la base de cráneo y los nervios craneales parte 2: Nervios craneales / Skull base and cranial nerves radiologic anatomy part 2: Cranial nerves

Resumen: La anatomía de la base del cráneo es compleja. Numerosas estructuras neurovasculares vitales pasan a través de múltiples canales y agujeros ubicados en la base del cráneo. Con el avance de la tomografía computarizada (TC) y la resonancia magnética (RM), es posible la localización cada vez más precisa de lesiones y la evaluación de su relación con las estructuras neurovasculares adyacentes. El trayecto de los nervios craneales sigue un recorrido conocido y se transmiten a la cara y cuello por los forámenes de base de cráneo. La tomografía computada y la resonancia magnética son complementarias entre sí y, a menudo, se usan juntas para demostrar la extensión total de la enfermedad. La segunda parte de esta revisión se centra en el estudio radiológico de los nervios craneales.

Abstract: The skull base anatomy is complex. Many vital neurovascular structures course through the skull base canals and foramina. With the advancement of CT and MRI, the localization of lesions has become more precise as their relationship with adjacent neurovascular structures. There is a known course of the cranial nerves as well as their skull base exiting foramina to the head and neck. CT and MRI are complimentary modalities and are often used together to map the full extent of disease. The second article in this review focus on the radiologic study of the cranial nerves.

Síndrome de Tolosa-Hunt, uma oftalmoplegia dolorosa / Tolosa Hunt Syndrome, a painful ophthalmoplegia

Resumo A síndrome de Tolosa-Hunt (STH) é uma doença rara caracterizada por oftalmoplegia dolorosa unilateral de início súbito causada por uma inflamação granulomatosa inespecífica no seio cavernoso ou fissura orbital superior (ou ambos). A oftalmoparesia ocorre quando os nervos cranianos III, IV e VI são acometidos pela inflamação. Disfunções pupilares podem estar presentes e está relacionado com acometimento das fibras simpáticas que passam pelo seio cavernoso na porção da artéria carótida interna ou fibras parassimpáticas ao redor do nervo oculomotor. O acometimento do primeiro ramo do trigêmeo pode provocar parestesia território correspondente à distribuição desde ramo (testa). Raramente, pode haver extensão da inflamação para além do seio cavernoso ou fissura orbital superior podendo acometer também o nervo óptico. Há uma boa resposta com o uso de corticoides e pode haver remissões espontâneas. Recidivas ocorrem em 40% dos casos. A doença é mais comum após a segunda década de vida. Afeta ambos os gêneros de forma igualitária. O presente estudo trata-se de um relato de caso de um paciente que se apresentou com oftalmoplegia dolorosa de início súbito à direita com 4 dias de evolução seguido de amaurose ipslateral após um dia do início da dor.

Abstract Tolosa-Hunt syndrome (STH) is a rare disease characterized by sudden onset unilateral painful ophthalmoplegia caused by non-specific granulomatous inflammation in the cavernous sinus or superior orbital fissure (or both). Ophthalmoparesis occurs when the cranial nerves III, IV and VI are affected by inflammation. Pupillary dysfunctions may be present and is related to involvement of the sympathetic fibers that pass through the cavernous sinus in the portion of the internal carotid artery or parasympathetic fibers around the oculomotor nerve. The involvement of the first branch of the trigeminal can cause paresthesia corresponding to the distribution from the first branch (forehead). Rarely, there may be extension of inflammation beyond the cavernous sinus or superior orbital fissure and may also affect the optic nerve. There is a good response with the use of corticosteroids and there may be spontaneous remissions. Relapses occur in 40% of cases. The disease is most common after the second decade of life. It affects both genders equally. The present study is a case report of a patient who presented with painful ophthalmoplegia of sudden onset on the right with 4 days of evolution followed by ipsilateral amaurosis after one day of onset of pain.

Anatomía radiológica de la base de cráneo y los nervios craneales parte 1: generalidades y base de cráneo / Skull base and cranial nerves radiologic anatomy part 1: basics and skull base

La anatomía de la base del cráneo es compleja. Numerosas estructuras neurovasculares vitales pasan a través de múltiples canales y formámenes de la base del cráneo. Con el avance de la tomografía computarizada (TC) y la resonancia magnética (RM) es posible la localización cada vez más precisa de lesiones y la evaluación de su relación con las estructuras neurovasculares adyacentes. El trayecto de los nervios craneales sigue un recorrido conocido y se transmiten a la cara y cuello a través de los forámenes de base de cráneo. La TC y la RM son complementarias entre sí y, a menudo, se usan en conjunto para demostrar la extensión completa de la enfermedad. La primera parte de esta revisión se centra en generalidades del estudio radiológico y anatomía de base de cráneo.

The skull base anatomy is complex. Many vital neurovascular structures course through the skull base canals and foramina. With the routine use of CT and MRI, the localization of lesions has become more precise as well as their relationship with adjacent neurovascular structures. There is a known anatomical course of the cranial nerves and their skull base s they course through the foramina towards the head and neck. CT and MRI are complimentary modalities and are often used together to map the full extent of disease. The first part of this review article series focus on the radiologic approach to disease and the skull base anatomy.