Different pathologies may be located at the petrous apex. The primary surgical approaches used to remove such lesions are the pterional, subtemporal, presigmoid, and retrosigmoid. Each has advantages and disadvantages, and the distance to the petrous apex varies with the approach. Anatomical variations in cranial morphology may interfere with these distances. Dolichocephalic skulls have a longer anteroposterior axis than brachycephalic ones.Three hundred computed tomographic scans and 65 dry human skulls were analyzed to determine if cranial morphology could indicate the shortest distance to the petrous apex. The distance between the external cortical table of the skull and the petrous apex in each surgical approach was measured. The lengths of the anteroposterior axis (L) and the widths of the lateral axis (W) were measured to determine the cranial index (W/L Â 100).This distance was longest in skulls with a high cranial index (brachycephalic) independent of the approach used. Statistical analysis showed that the distance to the previous apex was longest in the retrosigmoid approach and shortest in the pterional approach in all kinds of skulls. Brachycephalic skulls lose this ellipsoidal shape and the anterior laterolateral diameter is smaller than the posterior laterolateral diameter. Consequently, the distance from the cortical skull table to the petrous apex is shorter in brachycephalic skulls using all surgical approaches described in this article.

-Sixteen patients with sellar tumors that were treated surgically and who had pre-operative somatotrophic and corticotrophic function deficits were submitted to pre-and early post-operative insulin tolerance tests (ITTs). Seven patients had non-functioning adenomas, 5 had prolactinomas, 3 had craniopharyngioma and 1 had cordoma of the clivus. All patients had macro-tumors and none received radiotherapy within the studied period. Seven patients had GH, 4 had Cortisol and 5 had both GH/cortisol function pre-operative deficit. Five patients with isolated GH, 4 with isolated Cortisol and 3 with both GH/cortisol deficiencies showed a postoperative functional recovery. New Cortisol secretion deficits were observed in 2 patients postoperatively and both required long-term steroid replacement. These data suggest that preoperative endocrine deficits may be reversible after surgical decompression of the sellar region and that new endocrine deficits are rarely seen after surgery. All such patients should be tested postoperatively from an endocrinological point of view to reevaluate the need for replacement therapies.KEY WORDS: pituitary tumors, transesphenoidal surgery, endocrine deficits.Evolução das funções somatotrófica e corticotrófica após cirurgia transesfenoidal em pacientes com tumores selares e deficits endócrinos pré-operatórios RESUMO -Dezesseis pacientes com tumores da região selar que foram tratados cirurgicamente e que possuíam deficits funcionais dos eixos somatotrófico ou corticotrófico foram submetidos a teste de tolerância à insulina pré-e pós-operatoriamente. Sete pacientes possuíam adenomas não-funcionantes, 5 possuíam prolactinomas, 3 craniofaringiomas e 1 possuía cordoma de clivus. Todos os pacientes possuíam macrotumores e nenhum deles foi submetido a radioterapia durante o período do estudo. Sete pacientes possuíam deficiência isolada do setor somatotrófico, 4 isolada do setor corticotrófico e 5 possuíam deficiência de ambos os setores. Cinco pacientes com deficiência isolada do setor somatotrófico, 4 com deficit isolado do setor corticotrófico e 3 com deficiência nos dois setores obtiveram melhora funcional pós-operatoriamente. Novos deficits do setor corticotrófico ocorreram em 2 pacientes, que necessitaram reposição de esteróides por longo prazo. Estes dados sugerem que deficits endócrinos pré-operatórios podem ser revertidos pela descompressão cirúrgica da região selar e que novos deficits causados pela cirurgia são raros. Estes pacientes devem ser retestados pós-operatoriamente do ponto de vista endócrino para se determinar a necessidade de terapia de reposição hormonal. PALAVRAS-CHAVE: tumores pituitários, cirurgia transesfenoidal, deficits endócrinos.Hypogonadotrophic hypogonadism and growth hormone deficiency (GHd) are the most common hormonal abnormalities in patients with tumors in the sellar region 1,18 .

Maffucci's syndrome is a rare clinical condition that presents difficulties concerning its diagnosis and management. It is characterized by the presence of multiple enchondromas and cutaneous hemangiomas. Intracranial chondrosarcomas may be associated with this syndrome. Immunohistochemical studies are necessary to differentiate chondrosarcomas from chordomas. The treatment of choice for cranial base chondrosarcomas is total removal of the lesion. Total removal may be very difficult to achieve because of the involvement of neurovascular structures. Alternative therapies, such as proton beam radiosurgery, should be considered. In this case, radical removal of the tumor was possible using a transzygomatic approach. Gross total removal of large cranial base chondrosarcomas is possible, but a longer follow-up period is necessary to ascertain that radical resection was achieved.

Intracerebral cavernous angiomas may cause hemorrhage, epileptic seizures and neurological deficits. The diagnosis of these lesions became easier with the advent of the magnetic resonance image (MRI). Radical resection is the treatment of choice. Due to frequent subcortical or deep location, image-guided techniques, such as stereotactic-guided surgery, offer many advantages as smaller skin incision and craniotomy, less brain manipulation with consequently lower morbidity. We present a series of nine cavernous angiomas treated by stereotactic-guided radical surgical resection. The diagnosis was done by MRI and confirmed by pathologic studies in all cases. Mean age of patients was 30 years old (range 20-54 years). Postoperative morbidity occurred in two cases: one patient had a convulsion on the third postoperative day and the other presented dysphasia and hemiparesis on the second postoperative day, both with total recovery. Total resection of the lesion was possible in all cases with no neurological deficit.

Stereotactic surgery for Parkinson's disease can be performed using different neuroimaging methods. Ventriculography has been used to locate the coordinates of the structures close to the third ventricle. Although it has several potential disadvantages related to the intraventricular injection of iodine contrast, it is considered a precise method. Computed tomography and magnetic resonance imaging have been used in some centers. In order to compare their efficacy, 50 stereotactic thalamotomies for Parkinson's disease were performed using either ventriculography (VE) (25) or magnetic resonance imaging (MRI) (25). In 14 out of 25 VE procedures, computed tomography (CT-scan) was also used and showed a significant mean difference of coordinate Y and Z. The clinical results employing either VE or MRI were similar, with 80% abolition of tremor in the VE group, and 84% in the MRI group, after a follow up period of at least 3 months. Another 12% of VE and 16% of MRI group showed significant improvement of tremor. Complication rate was 4% in both groups. MRI-guided stereotactic thalamotomy in Parkinson's disease has shown good clinical results, comparable to VE-guided stereotaxis.