Antonio Nogueira de Almeida

Olfactory groove meningiomas: Approaches and complications

Olfactory groove meningiomas (OGM) account for 4.5% of all intracranial meningiomas. We report 21 patients with OGMs. Tumors were operated on using three surgical approaches: bifrontal (7 patients), fronto-pterional (11 patients) and fronto-orbital (3 patients). Total tumor removal (Simpson Grade 1) was achieved in 13 patients and Simpson II in 8 patients. Perioperative mortality was 4.76%. The average size of the OGM was 4.3+/-1.1cm. The overall recurrence rate was 19%. We preferred to use the pterional approach, which provides quick access to the tumor with less brain exposure. It also allows complete drainage of cisternal cerebrospinal fluid, providing a good level of brain relaxation during surgery. However, for long, thin tumors, hemostasis can be difficult using this approach.

Epilepsy surgery: historical highlights 1909-2009.

This review focuses on some historical highlights of the surgery of epilepsy, beginning with the reports of Horsley, Krause, and Cushing to which appeared in 1909, the year that The International League Against Epilepsy (ILAE) was inaugurated. We then outline key contributions from Europe and North America, and examine particularly the evolution of our understanding of temporal lobe seizures, which have now become the most common form of epilepsy amenable to surgical cure.

The First Case of Invasive EEG Monitoring for the Surgical Treatment of Epilepsy: Historical Significance and Context

Summary:  Purpose: Controversy persists about when EEG became a fundamental tool in the preoperative investigation for epilepsy surgery. We revisit Penfields first use of invasive EEG monitoring, emphasizing its historical importance for the evolution of epilepsy surgery.

DEXMEDETOMIDINE FOR AWAKE CRANIOTOMY WITHOUT LARYNGEAL MASK

OBJECTIVE This paper reports the use of dexmedetomidine in three epileptic patients with cavernous angiomas that underwent awake surgery in order to map their speech areas. METHOD Loading dose of dexmedetomidine varied from 1 microg/Kg/h to 3 microg/Kg/h over 20 minutes and maintenance dose from 0.4 microg/Kg/h to 0.8 microg/Kg/h. RESULTS There was no occurrence of hemodynamic instability, convulsions or respiratory depression. Patients tolerated well the procedure. CONCLUSION Dexmedetomidine was useful for awake craniotomy as it decreased patients level of consciousness but did not produce agitation. Laryngeal mask was not necessary to keep air ventilation.

Hemispherectomy: a schematic review of the current techniques

Anatomical hemispherectomy has been used for the treatment of seizures since 1938. However, it was almost abandoned in the 1960s after reports of postoperative fatalities caused by hydrocephalus, hemosiderosis, and trivial head traumas. Despite serious complications, the remarkable improvement of patients encouraged authors to carry out modifications on anatomical hemispherectomy in order to lessen its morbidity while preserving its efficacy. The effort to improve the technique generated several original procedures. This paper reviews current techniques of hemispherectomy and proposes a classification scheme based on their surgical characteristics. Techniques of hemispherectomy were sorted into two major groups: (1) those that remove completely the cortex from the hemisphere and (2) those that associate partial cortical removal and disconnection. Group 1 was subdivided into two subgroups based on the integrity of the ventricular cavity and group 2 was subdivided into three subgroups depending on the amount and location of the corticectomy. Grouping similar techniques may allow a better understanding of the distinctive features of each one and creates the possibility of comparing data from different authors.

Stereotactic disconnection of hypothalamic hamartoma to control seizure and behavior disturbance: case report and literature review

An 18-year-old boy with refractory epilepsy and aggressiveness associated to a hypothalamic hamartoma was submitted to a stereotactically guided lesion by thermocoagulation. The target was based on magnetic resonance (MR) images merged with computed tomography scan images taken on the day of surgery while patient was on a stereotactic frame. In order to reveal structures not discernible in MR images, the Schaltenbrand digital brain atlas was merged onto the patient’s images. Target and trajectory of the depth electrode were chosen based on three-dimensional imaging reconstructions. A surgical plan was devised to disconnect the hypothalamic hamartoma from the hypothalamus, medial forebrain bundle, fasciculus princeps, and dorsal longitudinal fasciculus. Our target was placed at the inferior portion of the posterolateral component of the hamartoma, bordering the normal hypothalamus. The patient evolved with marked lessening of aggressiveness. Seizure frequency was reduced from several seizures per day to less than one tonic-clonic seizure during sleep per month and only two episodes suggestive of partial complex seizures during daytime. These results have remained consistent over a 24-month postoperative follow-up. Functional neuroanatomy of hypothalamic connections involved in seizure propagation and aggressive behavior was reviewed.

From lateral to mesial : The quest for a surgical cure for temporal lobe epilepsy

Purpose: A gap of more than a hundred years occurred between the first accounts of mesial temporal sclerosis and recognition of its role in the pathogenesis of psychomotor seizures. This paper reviews how the understanding and surgical treatment of temporal lobe epilepsy developed, particularly from the work of Penfield, Jasper, and their associates at the Montreal Neurological Institute (MNI).

Differential expression of ID4 and its association with TP53 mutation, SOX2, SOX4 and OCT-4 expression levels.

Inhibitor of DNA Binding 4 (ID4) is a member of the helix-loop-helix ID family of transcription factors, mostly present in the central nervous system during embryonic development, that has been associated with TP53 mutation and activation of SOX2. Along with other transcription factors, ID4 has been implicated in the tumorigenic process of astrocytomas, contributing to cell dedifferentiation, proliferation and chemoresistance. In this study, we aimed to characterize the ID4 expression pattern in human diffusely infiltrative astrocytomas of World Health Organization (WHO) grades II to IV of malignancy (AGII-AGIV); to correlate its expression level to that of SOX2, SOX4, OCT-4 and NANOG, along with TP53 mutational status; and to correlate the results with the clinical end-point of overall survival among glioblastoma patients. Quantitative real time PCR (qRT-PCR) was performed in 130 samples of astrocytomas for relative expression, showing up-regulation of all transcription factors in tumor cases. Positive correlation was found when comparing ID4 relative expression of infiltrative astrocytomas with SOX2 (r = 0.50; p<0.005), SOX4 (r = 0.43; p<0.005) and OCT-4 (r = 0.39; p<0.05). The results from TP53 coding exon analysis allowed comparisons between wild-type and mutated status only in AGII cases, demonstrating significantly higher levels of ID4, SOX2 and SOX4 in mutated cases (p<0.05). This pattern was maintained in secondary GBM and further confirmed by immunohistochemistry, suggesting a role for ID4, SOX2 and SOX4 in early astrocytoma tumorigenesis. Combined hyperexpression of ID4, SOX4 and OCT-4 conferred a much lower (6 months) median survival than did hypoexpression (18 months). Because both ID4 alone and a complex of SOX4 and OCT-4 activate SOX2 transcription, it is possible that multiple activation of SOX2 impair the prognosis of GBM patients. These observational results of associated expression of ID4 with SOX4 and OCT-4 may be used as a predictive factor of prognosis upon further confirmation in a larger GBM series.

Factors of morbidity in hemispherectomies: Surgical technique×pathology

OBJECTIVE The objective of this paper is to evaluate factors of surgical morbidity from different techniques of hemispherectomy with emphasis on causative pathology. PATIENTS AND METHODS Thirty patients underwent hemispherectomy in our institution from 1987 to 2003, two presented with Sturge-Weber Syndrome (SWS), sixteen with Rasmussens Syndrome (RS), eight with established hemispheric lesions (EHL), and four with cortical development malformations (CDM). Six surgeons operated on three patients using anatomical hemispherectomies (AH), 11 patients using functional hemispherectomy (FH), and 16 patients employing hemispherotomy (HT). Surgical technique and causative pathology were studied independently as factors of morbidity in hemispherectomy. RESULTS Overall mean surgical time was 11:50+/-3:20 h and increased proportionately in pathologies with larger hemispheres. Blood transfusion was particularly influenced by the approach adopted by our team of anesthesiologists, independently of technique or pathology. Pathology was the most important factor related to hydrocephalus as two out of four patients with CDM needed ventriculoperitoneal shunt whilst none with EHL or SWS. Four patients undergoing HT and one FH presented residual bridges connecting the hemispheres, three were reoperated and are seizure free. Two patients with CDM did not improve their seizures worthwhile with surgery and other two (one with RS and other with CDM) were waiting a second procedure due to incomplete inter-hemispheric disconnection. Five patients presented infection and one died after developing meningoencephalitis. CONCLUSION Hemispherectomies are procedures where pathology and surgical technique interact narrowly. Therefore, in order to study surgical morbidity or outcome, both pathology and technique have to be analyzed independently.

The Early Years of Hemispherectomy

Today, hemispherectomy is a well-established procedure for the treatment of some sorts of catastrophic epilepsies. This, however, has not always been the case. The technique was developed to deal with brain tumors; however, the initial results were not remarkable. Moreover, when its morbidity became evident, it was almost abandoned. Had it not been for a shift in its use, with a huge increase in operations on patients with infantile hemiplegia, this surgery would certainly have disappeared. This paper focuses on the facts that surroundedToday, hemispherectomy is a well-established procedure for the treatment of some sorts of catastrophic epilepsies. This, however, has not always been the case. The technique was developed to deal with brain tumors; however, the initial results were not remarkable. Moreover, when its morbidity became evident, it was almost abandoned. Had it not been for a shift in its use, with a huge increase in operations on patients with infantile hemiplegia, this surgery would certainly have disappeared. This paper focuses on the facts that surrounded these early years.