Surgical Approaches to the Petrous Apex: Distances and Relations with Cranial Morphology

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 × 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

Comparison of MRI-guided and ventriculography-based stereotactic surgery for Parkinson's disease Estudo comparativo de cirurgia estereotáxica guiada por ressonância magnética e ventriculografia para doença de Parkinson

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.A cirurgia estereotáxica para doença de Parkinson (DP) pode ser realizada com diferentes métodos de neuroimagem. A ventriculografia (VE) tem sido empregada para determinar as coordenadas estereotáxicas das estruturas próximas ao terceiro ventrículo. Apesar de várias desvantagens relacionadas com a injeção intraventricular de contraste iodado, é considerada como uma técnica precisa. A tomografia computadorizada (TC) e a ressonância magnética (RM) têm sido utilizadas em alguns centros. Para comparar a eficácia dos diferentes métodos, 50 talamotomias estereotáxicas para DP foram realizadas utilizando VE (25 casos) e RM (25 casos). Em 14, dos 25 casos com VE, o emprego concomitante de TC demonstrou diferença média importante nas coordenadas Y e Z. Os resultados clínicos utilizando-se VE ou RM foram similares, com 80% de abolição de tremor no grupo com VE e 84% com RM durante seguimento mínimo de 3 meses. Além disso, 12% do grupo com VE e 16% do grupo com RM apresentaram significativa melhora do tremor. índice de 4% de complicações foi encontrado em ambos os grupos. Não houve mortalidade. A talamotomia estereotáxica guiada por RM para DP demonstrou resultados comparáveis aos obtidos com VE

Abscesso actinomicótico do cerebelo: relato de caso Actinomycotic abscess of the cerebellum: case report

Acometimento do sistema nervoso central por actinomicetos é extremamente raro. Os autores descrevem um caso de actinomicose de cerebelo, com diagnóstico estabelecido após remoção cirúrgica da lesão e tratamento com sucesso com penicilina endovenosa e oral. Breve revisão da literatura sobre o envolvimento do sistema nervoso na actinomicose é apresentada.A 38 year-old man presented fever and a clinical picture of intracranial hypertension and ataxic syndrome. A CT-scan disclosed an expanding lesion of the cerebellum. Surgical excision of the lesion was performed and pathological examination made the diagnosis of an actinomycotic abscess. The probable primary source of infection were the lungs and/or oral cavity. The postoperative course was uneventful, with complete recovery after a long period of treatment with penicillin (IV and PO). The authors review some aspects about central nervous system involvement in actinomycosis

Glioblastoma familiar

The authors describe a family with three members affected by glioblastoma. The proband patient, a 7 year-old girl, developed a rare complication, a pulmonary metastasis. Chromosomal analysis of her peripheral blood lymphocytes showed a normal karyotype (46, XX), without structural abnormalities. Cytogenetic study of the tumor cells disclosed several abnormalities: 46, XX, 7q - / 46, XX, -2, 4p-, 7p-, +15/ 46, XX. Some aspects about genetics of glial neoplasms are discussed.Os autores descrevem uma família com três membros portadores de glioblastoma. A paciente probanda, uma menina de 7 anos, apresentou metástase pulmonar. A análise cromossômica dos linfócitos periféricos revelou um cariótipo normal (46, XX). Estudo citogenético das células tumorais mostrou várias anormalidades: 46, XX, 7q- / 46, XX, -2,4p-, 7p-, +15 / 46, XX. Alguns aspectos sobre oncogênese e citogenética das neoplasias gliais são discutidos

Brainstem cysticercose simulating cystic tumor lesion: a case report

The authors report the case of a 37 year-old man with a solitary cysticercus cyst in the brainstem (pons) successfully removed through a suboccipital craniectomy. Surgery in neurocysticercosis has been indicated in patients with hydrocephalus and/or large cystic lesions. Cystic lesions in the brainstem and spinal cord may have indication for surgery for two reasons: (1) diagnosis; and (2) treatment. Aspects related to differential diagnosis and therapeutic alternatives are discussed