Masseter-to-Facial Cranial Nerve Anastomosis: A Report of 30 Cases.

BACKGROUND: Facial nerve paralysis (FP) is a possible complication of cerebellopontine angle tumor surgery. Several donor nerves have been used in the past for facial reanimation. We report the results of 30 cases of masseter-to-facial anastomosis. OBJECTIVE: To prospectively evaluate the efficacy of V to VII anastomosis after FP. METHODS: In a prospective study, we included 30 consecutive patients with FP (20 women and 10 men) whose mean age was 48.8 yr (32-76 yr). In almost all cases, FP developed after cerebellopontine angle tumor surgery (29 patients), whereas in one case, FP occurred after skull base trauma. Pre- and postoperative evaluation of facial nerve function was performed using the House-Brackmann (HB) scale and the Sokolovsky scale, as well as by electromyography. Follow-up ranged from 11 to 51 mo and averaged 22 mo. RESULTS: All patients achieved functional recovery of the facial nerve from VI to either III or IV HB degree. Patients with short time FP showed significantly better postoperative recovery. CONCLUSION: The results of the V to VII anastomosis demonstrate a significant improvement of facial nerve function and virtually no complications.

What Tactics Should a Surgeon Choose to Treat a Black Extracerebral Tumor? A Case Report of Psammomatous Melanotic Schwannoma of the Meckel Cave and Literature Review.

BACKGROUND: Neoplasms located in the Meckel cave account for 0.2%-0.5% of all intracranial tumors. This area is the site of many types of pathologic lesions, most often trigeminal nerve schwannomas and meningiomas. Melanin-containing tumors are rare in this area. These tumor types can be suspected if the magnetic resonance characteristics of a tumor has some differences in comparison with other types of central nervous system neoplasms. In fact, differential diagnosis of melanotic tumors is based mainly on the histopathologic criteria and immunohistochemical profile. This article presents a case report of melanotic schwannoma of the Meckel cave and a literature review of the problem. CASE DESCRIPTION: A 23-year-old man underwent a 2-stage surgery for a dumbbell pigmented mass lesion located in the Meckel cave. No signs of recurrence were seen on follow-up magnetic resonance imaging (MRI) 3.5 years after the operation. CONCLUSIONS: Melanin-containing tumor can be suspected in the presence of radiologic characteristics, such as a hyperintense MRI signal on T1-weighted images and a hypointense signal on T2-weighted images. If a black extracerebral tumor is detected, the main course of surgical treatment is maximal excision despite it possibly being a malignant melanoma and the temptation to perform partial resection because of an unfavorable prognosis. Chemotherapy can be justified in the presence of an aggressive melanotic schwannoma.

Sr2GaScO5, Sr10Ga6Sc4O25, and SrGa0.75Sc0.25O2.5: a play in the octahedra to tetrahedra ratio in oxygen-deficient perovskites.

Three different perovskite-related phases were isolated in the SrGa(1-x)Sc(x)O(2.5) system: Sr(2)GaScO(5), Sr(10)Ga(6)Sc(4)O(25), and SrGa(0.75)Sc(0.25)O(2.5). Sr(2)GaScO(5) (x = 0.5) crystallizes in a brownmillerite-type structure [space group (S.G.) Icmm, a = 5.91048(5) Å, b = 15.1594(1) Å, and c = 5.70926(4) Å] with complete ordering of Sc(3+) and Ga(3+) over octahedral and tetrahedral positions, respectively. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) (x = 0.4) was determined by the Monte Carlo method and refined using a combination of X-ray, neutron, and electron diffraction data [S.G. I4(1)/a, a = 17.517(1) Å, c = 32.830(3) Å]. It represents a novel type of ordering of the B cations and oxygen vacancies in perovskites. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) can be described as a stacking of eight perovskite layers along the c axis ...[-(Sc/Ga)O(1.6)-SrO(0.8)-(Sc/Ga)O(1.8)-SrO(0.8)-](2).... Similar to Sr(2)GaScO(5), this structure features a complete ordering of the Sc(3+) and Ga(3+) cations over octahedral and tetrahedral positions, respectively, within each layer. A specific feature of the crystal structure of Sr(10)Ga(6)Sc(4)O(25) is that one-third of the tetrahedra have one vertex not connected with other Sc/Ga cations. Further partial replacement of Sc(3+) by Ga(3+) leads to the formation of the cubic perovskite phase SrGa(0.75)Sc(0.25)O(2.5) (x = 0.25) with a = 3.9817(4) Å. This compound incorporates water molecules in the structure forming SrGa(0.75)Sc(0.25)O(2.5)·xH(2)O hydrate, which exhibits a proton conductivity of ∼2.0 × 10(-6) S/cm at 673 K.