Invisible compression, anterior fossa tumor causing trigeminal neuralgia.

BACKGROUND: Trigeminal neuralgia secondary to posterior and middle fossae tumors, whether ipsilateral or contralateral, has been well described. However, this disabling disease has never been reported in the context of anterior fossa neoplasms. CASE DESCRIPTION: A 75-year-old female with right hemifacial pain was diagnosed with an anterior clinoid meningioma. Despite neuroimaging did not show any apparent anatomical or neurovascular conflict, a detailed MRI analysis revealed a V3 hyperintensity. Not only symptoms completely resolved after surgical resection but also this radiological sign disappeared. Nowadays, the patient remains asymptomatic and V3 hyperintensity has not reappeared during her follow-up. CONCLUSION: A surgical definitive treatment can be offered to patients suffering from trigeminal neuralgia secondary to lesions adjacent to Gasserian ganglion or trigeminal branches. In this respect, posterior and middle fossae tumors are well-reported etiologies. Nevertheless, in the absence of evident compression, other neoplasms located in the vicinity of these critical structures and considered as radiological findings may be involved in trigeminal pain. Microvascular and pressure gradient changes could be an underlying cause of these symptoms in anterior skull base lesions. Here, we report the case of a patient with uncontrollable hemifacial pain resolved after anterior clinoid meningioma removal.

Microsurgical Anatomy of the Insular Region and Operculoinsular Association Fibers and its Neurosurgical Application.

OBJECTIVE: To analyze the three-dimensional relationships of the operculoinsular compartments, using standard hemispheric and white matter fiber dissection and review the anatomy of association fibers related to the operculoinsular compartments of the Sylvian fissure and the main white matter tracts located deep into the insula. The secondary aim of this study was to improve the knowledge on this complex region to safely address tumor, vascular, and epilepsy lesions with an integrated perspective of the topographic and white matter fiber anatomy using 2D and 3D photographs. METHODS: Six cadaveric hemispheres were dissected. Two were fixed with formalin and the arteries were injected with red latex dye; the remaining four were prepared using the Kingler method and white fiber dissections were performed. RESULTS: The insula is located entirely inside the Sylvian fissure. The topographic hemispheric anatomy, Sylvian fissure, opercula, surrounding sulci and gyri, as well as the M2, M3, and M4 segments were identified. The anatomy of the insula, with the sulci and gyri and the limiting sulci, were also identified and described. The main white matter fiber tracts of the operculoinsular compartments of the Sylvian fissure as well as the main association and commissural fibers located deep in the insula were dissected and demonstrated. CONCLUSIONS: Complementing topographic anatomy with detailed study of white matter fibers and their integration can help the neurosurgeon to safely approach lesions in the insular region, improving postoperative results in the microsurgical treatment of aneurysmal lesions, insular tumors, or epilepsy surgery.