Extended Middle Cranial Fossa Approach for Lesions Invading Infratemporal Fossa: Anatomic Study and Clinical Application.

Skull base tumors arising from the middle cranial fossa and invading of the infratemporal fossa (ITF) and middle cranial fossa are challenging for neurosurgeons, because of complex anatomy and critical neurovascular structure involvement. The first pioneering ITF approaches resulted in invasive procedures and carried a high rate of surgical morbidity. However, the acquisition of deep anatomical knowledge, and the development operative skills and reconstruction techniques allowed surgeons to achieve total or near total resection of many ITF lesions with a low morbidity rate. In Video 1 we illustrate our technique for the anterior ITF approach for the surgical treatment of a middle cranial fossa meningioma invading the ITF. This surgical video describes the anterior ITF approach in 2 steps. First, a standard extradural middle fossa approach subtemporal approach is performed on a cadaveric specimen, illustrating the anterior extension to the cavernous sinus. Second, the anterior ITF approach is performed for the surgical treatment of a temporal lobe meningioma with extension to the anterior ITF. This technique provides a minimally invasive approach for treating middle fossa lesions with anterior ITF extension.

Extradural middle fossa approach. Proposal of a learning method: the "rule of two fans." Technical note.

The extradural middle fossa approach is used to access lesions of the petroclival and cavernous sinus regions. It may be included in combined petrosal and anterolateral transcavernous approaches. Technically, it is a demanding exposure that provides a wide extradural corridor between the 5th, 7th, and 8th cranial nerves. Its major advantages are that it offers extradural dissection, limits temporal lobe retraction, and avoids the transposition of nerves or vessels. Its disadvantages are primarily related to the complicated anatomy of the petrous apex from the middle fossa trajectory, which can be unfamiliar to neurosurgeons. To facilitate the first attempts with this relatively uncommon approach during dissections of human cadaveric injected heads and isolated temporal bones, we developed a simple learning method useful for localizing all anatomical structures. Using this "rule of two fans," vascular, nervous, fibrous, and osseous structures are localized within two bordering fans with a 90-degree relationship to each other.

Benign metastasizing leiomyoma to skull base and spine: a report of two cases.

OBJECTIVE AND IMPORTANCE: We report two patients with benign uterine leiomyoma metastasizing to the nervous system, respectively, to the skull base and to the spine. Although primary cranial and metastatic spinal leiomyomas have been rarely described, to our knowledge no case of benign leiomyoma metastasizing to the skull base has been reported before. CLINICAL PRESENTATION: Two female patients with history of hysterectomy for benign leiomyoma, subsequently metastasizing to the lungs and smooth muscles of the skin, presented with a focal neurologic deficit. Magnetic resonance imaging revealed a sacral mass in one case and a skull base tumor in the other. INTERVENTION: Both patients underwent surgery for resection of the lesions. Good postoperative results were obtained. Histologic examination of the surgical specimen revealed a benign metastasizing leiomyoma. CONCLUSION: Benign metastasizing leiomyoma should be considered in the differential diagnosis of mass lesions in the sacral spine and skull base in patients who have a history of uterine leiomyoma or benign metastases of the same disease in organs outside the nervous system.

Hemilingual spasm: a new neurosurgical entity? Case report.

Hemilingual spasm is a little-known movement disorder, presenting as intermittent paroxysmal involuntary contractions of half of the tongue muscles. The authors report a case of hemilingual spasm caused by an arachnoid cyst. After marsupialization of the cyst, the patient's symptoms immediately resolved. There has been no recurrence of hemilingual spasm during the follow-up period of more than 40 months.