Theoretical approaches: Neurosurgery is a wide and sophisticated field and given the variety of neurological issues, this thesis focuses on the brain (vascular issues and tumors). Goals: This thesis has two goals. 1. To single out the specifics of caring for patients after brain surgery (of selected conditions). 2. To find out, whether the nurses know the specifics of caring for a patient after brain surgery. Hypotheses and research questions: H1: Nurses with tertiary education have greater theoretical knowledge of caring for patients after brain surgery than the nurses without tertiary education. H2: Nurses after getting the job of caring for patients after brain surgery didn't have an instructor.H3: Nurses after getting the job of caring for patients after brain surgery, most commonly struggle with an external ventricular drainage system. H4: Nurses most commonly gain the required knowledge to care for patients after brain surgery from literature. Research question 1: What is the level of knowledge of novice nurses about the specifics of caring for a patient with a brain condition? Methodology: The research was split in two parts. For the quantitative part of the research, the questionnaire method was selected. The questionnaire had 22 questions, 17 of them closed, 4 of them semi-open, 1 was an open question. The researchers handed out 300 questionnaires and received 246 (82%) of them back. 49 questionnaires had to be discarded as invalid. The final research sample consisted of 197 (100%) filled-out questionnaires. For the qualitative part of the research, the method of semi-structured interviews with open questions was selected. There were a total of 8 interviews conducted. Results: The goal of quantitative part of the research was to confirm or disprove the 4 hypotheses. H1: Nurses with tertiary education have greater theoretical knowledge of caring for patients after brain surgery than the nurses without tertiary education. Based on the data, we can see that the knowledge of nurses with tertiary education is not different from the knowledge of nurses without tertiary education. H1 was disproved. H2: Nurses after getting the job of caring for patients after brain surgery didn't have an instructor. Based on the questionnaire data, nurses did have an instructor. H2 was disproved. H3: Nurses after getting the job of caring for patients after brain surgery, most commonly struggle with an external ventricular drainage system. Based on the research data, an external ventricular drainage system is indeed the most commonly quoted problematic procedure when caring for a patient after brain surgery. H3 was confirmed. H4: Nurses most commonly gain the required knowledge to care for patients after brain surgery from literature. The research shows that this is not the case. Nurses most commonly learn the specifics of caring for patients after brain surgery from their instructors. H4 was disproved. For the qualitative part of the research, the method of semi-structured interviews with open questions was selected. The research question was: What is the level of knowledge of novice nurses about the specifics of caring for a patient with a brain condition? The interviews have shown that the knowledge of novice nurses about the specifics of caring for patients with a brain condition is on an appropriate level they know the specifics of caring for patients after brain surgery. Conclusion:The conducted original research as well as secondary literature has led us to several questions and recommendations: Is the nurse who has just started at the neurosurgery division properly being instructed about the specifics of her new job and is the adaptation process being conducted in the proper fashion? The results of this thesis suggest that a "Caring for patients in neurosurgery" manuscript could be written for general care nurses just starting at neurosurgery. This option was mentioned by some of the respondents in the questionnaire research

O interesse crescente pelo tema qualidade de vida no campo da neurocirurgia é notório, tanto para avaliar o impacto da doença e a eficácia dos tratamentos, quanto para avaliar o impacto físico e psicossocial nas pessoas acometidas. Encontramos na literatura poucos estudos que discutem o tema sistematicamente, utilizando instrumentos que possibilitem abarcar as dimensões que compõe o que denominamos qualidade de vida. O objetivo principal deste estudo foi avaliar a qualidade de vida antes e a evolução após três, seis e doze meses da ressecção de meningeomas. Foi realizado estudo prospectivo de 29 pacientes portadores de meningeomas benignos (17 mulheres e 12 homens), com idade variando entre 28 e 76 anos. Para avaliação da qualidade de vida foram utilizados dois instrumentos, o Perfil de Saúde de Nottingham (PSN) e o Questionário de Dimensões de Saúde de Innsbruck para Pacientes Neurocirúrgicos (DSI-NC). Foram encontradas diferenças significativas nos escores totais das escalas PSN e DSI-NC, quando comparadas às avaliações nos quatro momentos (pré, após três, seis e doze meses). Observou-se melhora significativa nos domínios Dor, Reações Emocionais, Habilidades Físicas, Sono, Comunicação, Condição Física, Independência e Condição Psicológica. Nas dimensões restantes (Função do Sistema Nervoso Autônomo, Nível de Energia, Isolamento e Interação Social) observou-se somente tendência à redução dos sintomas. Neste estudo, pode-se constatar que os pacientes submetidos à intervenção cirúrgica para ressecção de meningeomas, apresentaram melhora significativa da qualidade de vida, com maior intensidade até os primeiros três meses. Cabe ressaltar que dos três aos seis meses ocorreu certa estabilização no quadro (pelo impacto da elevação dos sintomas nos domínio Reações Emocionais) e nova redução dos sintomas aconteceu até os doze meses da intervenção. Considerando os resultados obtidos, parece relevante iniciar um trabalho terapêutico preventivo após três meses da intervenção cirúrgica, para que sejam abordadas questões de ordem afetivo-emocional. O tamanho da amostra impossibilitou análises mais específicas com relação à fatores como idade, escolaridade, grau de ressecção e localização do meningeoma, fatores estes que devem ser melhor explorados em estudos posteriores / The growing interest in studying quality of life within the neurosurgical field is noticeable, in as much to evaluate the disease impact and the treatment efficiency as to evaluate the physical and psychosocial impacts on those taken by the illness. Few are the studies found in the literature discussing this matter methodically, using instruments which enable us to embrace the composing dimensions of what we call quality of life. This study aimed mainly to evaluate the quality of life before and the development after three, six and twelve months from the meningeoma resection. A prospective study was carried out with 29 patients carrying benign meningeoma (17 women and 12 men) whose ages ranged from 28 and 76 years old. In order to evaluate the quality of life two instruments were used: the Nottingham Health Profile (NHP) and the Innsbruck Health Dimensions Questionnaire for Neurosurgical Patients (IHD-NS). Meaningful differences in the total score were found between NHP and IHD-NS scales when compared to the evaluation over the four moments. A relevant improvement was noticed in the following domains: Pain, Emotional Reactions, Physical Abilities, Sleepiness, Communication, Physical Condition, Independence and Psychological Condition. In the remaining dimensions domains (Autonomic Nervous System, Energy Level, Isolation and Social Interaction) we only observed that the symptoms were tending towards a reduction. In this study we could observe that the patients, who were submitted to the surgical intervention for the meningeoma resection, presented a relevant improvement in their quality of life, with greater intensity up to the first three months. It is worth noticing that between three and six months the patients situation revealed certain stabilization (for the impact caused by the increasing symptoms in the Emotional Reactions domain) and a new reduction of the symptoms took place up to twelve months from intervention. Considering the achieved results, it seems relevant to begin a preventive therapeutic procedure after three months from surgical intervention, in order to approach affective-emotional matters. The sample amplitude disabled us from making more specific analysis concerning age, school educational level, resection level and meningeoma location, such matters must be better exploited in further studies

Aim: A retrospective study of cases of childhood spinal compression over a 30-year period (1963-1992) was undertaken in order to determine the trend in incidence, aetiology, diagnosis, treatment and prognosis. Patients and Methods: The study includes children less than 15 years of age who were treated for spinal compression at the Red Cross War Memorial Children's Hospital, Maitland Cottage Hospital and Groote Schuur Hospital. Children who had tuberculosis of the spine without a neurological deficit, were excluded. The study also excludes dysraphism and non-compressive causes of paraplegia, such as Guillain-Barre Syndrome and poliomyelitis.

This thesis discloses findings from a scoping review of Social and Structural Determinant of Health (SSDOH)-related academic and grey literature from neurosurgery and fields with neurosurgical overlap. The purpose of this thesis is to identify which social determinants have been assessed, for which surgical procedures they were evaluated, and what disparities were found. To identify studies to include or consider for this systematic review, the review team worked with a medical librarian to develop detailed search strategies for each database. Studies were screened by title and abstract independently by two reviewers. Disagreements between reviewers were resolved by a third reviewer, blinded to the decisions of the primary reviewers. The scoping review of the SSDOH in neurosurgical outcomes identified 99 studies from the year 1990 to 2020. Identified studies were targeted predominantly toward spine surgery patients, evenly distributed in analyses of gender, race and economic stability. The relatively low volume of neurosurgical papers focused on the SSDOH and emphasis on one subspecialty demonstrates the need for an expanded interest in the SSDOH in neurosurgery. / Urban Bioethics

Hydrocephalus can impact all areas of health, including physical, cognitive, and psychosocial functioning. Etiology can be a major factor in health outcomes, but prior research on psychosocial functioning in hydrocephalus has been with limited etiologies. This study examined psychosocial functioning using the Behavioral Assessment System for Children, Third Edition (BASC-3) and the Hydrocephalus Outcome Questionnaire (HOQ) in children aged 5-17 years old. BASC-3 and HOQ parent report scores were compared between hydrocephalus etiologies. Medical factors (number of CSF diversion procedures, history of seizures, and years with hydrocephalus) and SES factors (family income, parent education, and parent occupational status) were examined as potential predictors for psychosocial outcomes. BASC-3 attention and executive functioning and HOQ social-emotional scales differed between etiologies. Years with hydrocephalus and a history of seizures were significant predictors for some BASC-3 scales and the HOQ social-emotional scale. SES variables did not predict any psychosocial outcomes examined. These results provide evidence that children who have had surgery for their hydrocephalus may be at increased risk of psychosocial difficulties, and that etiology and medical history may be contributing factors.

Pesquisas sobre o transtorno obsessivo-compulsivo (TOC) que reunem pacientes em subgrupos homogêneos a partir de dimensões de sintomas, e as que investigam sua validade utilizando métodos genéticos, de neuroimagem e de resposta terapêutica, têm produzido resultados de valor heurístico. Em particular, a dimensão de colecionismo mostrou ser a mais distinta quanto às características neurobiológicas e a mais associada à pior resposta aos tratamentos farmacológicos e psicoterápicos. Paralelamente, novos métodos de tratamento neurocirúrgico para os casos mais refratários e graves tem sido testados no TOC, atingindo mais eficácia e segurança. Entretanto, não há registro na literatura de uma investigação sistemática da relação entre a presença de dimensões de sintomas antes das cirurgias e o resultado clínico. O objetivo deste estudo foi investigar se dimensões de sintomas, em particular o colecionismo, poderiam influenciar a resposta terapêutica às neurocirurgias límbicas para o tratamento do TOC. Informações de 77 pacientes submetidos à cirurgias ablativas para o tratamento de TOC em três centros de pesquisa das cidades de São Paulo (Brasil, n=17), Boston (EUA, n=37) e Estocolmo (Suécia, n=23) foram analisadas utilizando a Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS; São xvi Paulo) ou a Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC; Boston e Estocolmo) para a estratificação em dimensões de sintomas, e os escores YBOCS para avaliações de resultado clinico. Após os procedimentos, houve uma diminuição média de 34,2% nos escores YBOCS (IC 95% de 27,2% a 41,3%), com um tempo de seguimento médio de 34,8 meses, sem diferença significativa entre os centros de pesquisa ou em relação ao tipo de cirurgia (capsulotomia, São Paulo e Estocolmo; cingulotomia, Boston). Pacientes com dimensão de colecionismo apresentaram pior resposta ao tratamento (redução média dos escores YBOCS de 22,70% [DP = 32,23] para pacientes com colecionismo versus 41,60% [DP = 25,99] para pacientes sem colecionismo, p=0,006). Pacientes com dimensão de pensamentos proibidos também revelaram pior resposta ao tratamento (redução média dos escores YBOCS de 30,10% [DP = 29,61] para pacientes com pensamentos proibidos versus 51,33% [DP = 32,74] para pacientes sem pensamentos proibidos, p=0,033), mas este efeito dependeu da co-ocorrência das dimensões de pensamentos proibidos e colecionismo. Ao se utilizar um modelo de análise de variância (ANOVA), apenas a influência negativa do colecionismo se manteve: a redução média dos escores YBOCS em todos os pacientes foi de 13 pontos, mas em pacientes com colecionismo essa redução foi de 7 pontos (p=0,002). Concluindo, a presença da dimensão de colecionismo no momento pré-operatório associou-se à redução da melhora clínica decorrente da intervenção neurocirúrgica / Research on obsessive-compulsive disorder (OCD) using symptom dymension strategies to identify more homogeneous patient subgroups, coupled with genetic, neuroimaging, and treatment outcome studies, has produced results of heuristic value. In particular, the hoarding dimension has more distinct neurobiological characteristics and has been associated with worse response to pharmachological and psychoterapeutic treatments. At the same time, the most severe and treatment refractory cases of OCD have been treated with novel neurosurgical techniques, with better efficacy and safety profiles. However, the association between symptom dimensions prior to surgery and the treatment outcome after the limbic procedure has not been sistematically investigated in the literature so far. The objective of this study was to investigate if symptom dymensions, in particular hoarding, could influence treatment outcome of limbic neurosurgeries for OCD. Information on 77 patients that underwent limbic ablative procedures for OCD from three research centers at Sao Paulo (Brazil, n=17), Boston (USA, n=37), and Stockholm (Sweden, n=23) were collected and analyzed. Symptom stratification was obtained using the Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS; Sao Paulo) or the Yale-Brown xix Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC; Boston and Stockholm) and treatment outcome was defined using YBOCS scores. Mean YBOCS scores reduced 34.2% after surgery (CI 95% = 27.2% to 41.3%) with a mean follow-up of 34.8 months. There was no significant difference among centers or in relation to the method of surgical intervention (capsulotomy, Sao Paulo and Stockholm; cingulotomy, Boston). Patients with hoarding symptoms had worse response to treatment (mean YBOCS reduction of 22.70% [SD = 32.23] for hoarding patients vs. 41.60% [SD = 25.99] for patients without hoarding symptoms, p=0,006). Patients with forbidden thoughts symptoms apparently also had worse response to treatment (mean YBOCS reduction of 30.10% [SD = 29.61] for patients with forbidden thoughts vs. 51.33% [SD = 32.74] for patients without this symptom dymension, p=0,033), but this effect proved dependent on the co-occurence of forbidden thoughts with hoarding dymensions. Indeed, using an analisys of variance model (ANOVA) only the negative influence of the hoarding dymension remained: patients without hoarding had a mean YBOCS redution of 13 points, while in patients with hoarding symptoms the mean reduction was of 7 points (p=0.002). In conclusion, the pre-operative presence of the hoarding dymension was associated with worst clinical outcome after the neurosurgical procedures

Pesquisas sobre o transtorno obsessivo-compulsivo (TOC) que reunem pacientes em subgrupos homogêneos a partir de dimensões de sintomas, e as que investigam sua validade utilizando métodos genéticos, de neuroimagem e de resposta terapêutica, têm produzido resultados de valor heurístico. Em particular, a dimensão de colecionismo mostrou ser a mais distinta quanto às características neurobiológicas e a mais associada à pior resposta aos tratamentos farmacológicos e psicoterápicos. Paralelamente, novos métodos de tratamento neurocirúrgico para os casos mais refratários e graves tem sido testados no TOC, atingindo mais eficácia e segurança. Entretanto, não há registro na literatura de uma investigação sistemática da relação entre a presença de dimensões de sintomas antes das cirurgias e o resultado clínico. O objetivo deste estudo foi investigar se dimensões de sintomas, em particular o colecionismo, poderiam influenciar a resposta terapêutica às neurocirurgias límbicas para o tratamento do TOC. Informações de 77 pacientes submetidos à cirurgias ablativas para o tratamento de TOC em três centros de pesquisa das cidades de São Paulo (Brasil, n=17), Boston (EUA, n=37) e Estocolmo (Suécia, n=23) foram analisadas utilizando a Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS; São xvi Paulo) ou a Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC; Boston e Estocolmo) para a estratificação em dimensões de sintomas, e os escores YBOCS para avaliações de resultado clinico. Após os procedimentos, houve uma diminuição média de 34,2% nos escores YBOCS (IC 95% de 27,2% a 41,3%), com um tempo de seguimento médio de 34,8 meses, sem diferença significativa entre os centros de pesquisa ou em relação ao tipo de cirurgia (capsulotomia, São Paulo e Estocolmo; cingulotomia, Boston). Pacientes com dimensão de colecionismo apresentaram pior resposta ao tratamento (redução média dos escores YBOCS de 22,70% [DP = 32,23] para pacientes com colecionismo versus 41,60% [DP = 25,99] para pacientes sem colecionismo, p=0,006). Pacientes com dimensão de pensamentos proibidos também revelaram pior resposta ao tratamento (redução média dos escores YBOCS de 30,10% [DP = 29,61] para pacientes com pensamentos proibidos versus 51,33% [DP = 32,74] para pacientes sem pensamentos proibidos, p=0,033), mas este efeito dependeu da co-ocorrência das dimensões de pensamentos proibidos e colecionismo. Ao se utilizar um modelo de análise de variância (ANOVA), apenas a influência negativa do colecionismo se manteve: a redução média dos escores YBOCS em todos os pacientes foi de 13 pontos, mas em pacientes com colecionismo essa redução foi de 7 pontos (p=0,002). Concluindo, a presença da dimensão de colecionismo no momento pré-operatório associou-se à redução da melhora clínica decorrente da intervenção neurocirúrgica / Research on obsessive-compulsive disorder (OCD) using symptom dymension strategies to identify more homogeneous patient subgroups, coupled with genetic, neuroimaging, and treatment outcome studies, has produced results of heuristic value. In particular, the hoarding dimension has more distinct neurobiological characteristics and has been associated with worse response to pharmachological and psychoterapeutic treatments. At the same time, the most severe and treatment refractory cases of OCD have been treated with novel neurosurgical techniques, with better efficacy and safety profiles. However, the association between symptom dimensions prior to surgery and the treatment outcome after the limbic procedure has not been sistematically investigated in the literature so far. The objective of this study was to investigate if symptom dymensions, in particular hoarding, could influence treatment outcome of limbic neurosurgeries for OCD. Information on 77 patients that underwent limbic ablative procedures for OCD from three research centers at Sao Paulo (Brazil, n=17), Boston (USA, n=37), and Stockholm (Sweden, n=23) were collected and analyzed. Symptom stratification was obtained using the Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS; Sao Paulo) or the Yale-Brown xix Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC; Boston and Stockholm) and treatment outcome was defined using YBOCS scores. Mean YBOCS scores reduced 34.2% after surgery (CI 95% = 27.2% to 41.3%) with a mean follow-up of 34.8 months. There was no significant difference among centers or in relation to the method of surgical intervention (capsulotomy, Sao Paulo and Stockholm; cingulotomy, Boston). Patients with hoarding symptoms had worse response to treatment (mean YBOCS reduction of 22.70% [SD = 32.23] for hoarding patients vs. 41.60% [SD = 25.99] for patients without hoarding symptoms, p=0,006). Patients with forbidden thoughts symptoms apparently also had worse response to treatment (mean YBOCS reduction of 30.10% [SD = 29.61] for patients with forbidden thoughts vs. 51.33% [SD = 32.74] for patients without this symptom dymension, p=0,033), but this effect proved dependent on the co-occurence of forbidden thoughts with hoarding dymensions. Indeed, using an analisys of variance model (ANOVA) only the negative influence of the hoarding dymension remained: patients without hoarding had a mean YBOCS redution of 13 points, while in patients with hoarding symptoms the mean reduction was of 7 points (p=0.002). In conclusion, the pre-operative presence of the hoarding dymension was associated with worst clinical outcome after the neurosurgical procedures

Radio frequency (RF) lesioning and deep brain stimulation (DBS) are the two prevailing surgical treatments for movement disorders within the field of stereotactic and functional neurosurgery. For RF-lesioning, a small volume of brain tissue is coagulated and knowledge of the lesion size and growth is of great importance for the safety and outcome of the procedure. This thesis deals with adapting the laser Doppler perfusion monitoring (LDPM) technique for measurements in brain tissue during RF-lesioning. The relation between LDPM signal changes and developed lesion size was investigated. LDPM measurements were evaluated both in vitro (albumin protein solution) and in vivo in the porcine brain during RF-lesioning corresponding to a bilateral thalamotomy in man. The investigated signals from the LDPI measurements can be used for following the lesioning time course and to detect if a lesion was created, both in vitro and in the animal model. For the albumin model, both the total backscattered light intensity and the perfusion signal can be used as markers for estimating the final coagulation size, while in the animal model this conclusion was not statistical verified. Independent on surgical method, RF-lesioning or DBS, intracerebral guidance is an important aspect within stereotactic and functional neurosurgery. To increase the accuracy and precision of reaching the correct target, different methods for intracerebral guidance exist, such as microelectrode recording and impedance methods. In this thesis, the possibility of developing an optical intracerebral guidance method has been investigated. Diffuse reflectance spectroscopy served as technology and all measurements were performed stereotactically in both porcine and human brain. Measurements of white and gray matter showed large differences, with higher reflectivity for white brain matter, both in porcine and in human brain. For the human measurements during DBS-implants, large differences between white matter and functional targets were found. Additionally, differences between native and lesioned porcine brain matter were detected. Both studies support the idea of using diffuse reflectance spectroscopy for developing an intracerebral guidance method.

La recherche montre que l’insula est impliquée dans le traitement d’informations intéroceptives, émotionnelles et relevant de fonctions exécutives de haut niveau. L’hypothèse des marqueurs somatiques propose que ces fonctions vraisemblablement séparées travaillent plutôt de concert au sein d’un système neural dont le rôle consiste à extraire les messages émotionnels des signaux corporels. Si l’insula exerce effectivement un rôle de modulateur des sensations corporelles et des processus cognitifs découlant de ceux-ci, des lésions au cortex insulaire risquent d’occasionner des altérations au niveau de l’expérience émotionnelle, des fonctions exécutives et de la personnalité. La présente étude a pour but de mesurer ces changements chez 19 patients ayant subi une insulectomie unilatérale dans le cadre de leur traitement de l’épilepsie. Ces patients ont été comparés à un groupe contrôle composé de 19 patients épileptiques ayant subi une résection du lobe temporal. Les participants ont été évalués par l’entremise du Iowa Scales of Personality Change (ISPC), rempli par un proche du patient. Les résultats montrent que les patients du groupe insulaire exhibent des changements qui dénotent une dérégulation émotionnelle à long terme, caractérisée par une augmentation modérée de l’irritabilité, de la labilité émotionnelle, de l’anxiété et de la frugalité, tous des changements qui, outre l’anxiété, n’ont pas été observés chez les patients temporaux. Cependant, pour ce qui est des fonctions exécutives, aucun changement significatif n’a été noté. De plus, la comparaison pré- et post opératoire des scores des deux groupes aux items de l’ISPC ne s’est pas avérée significative. Globalement, les résultats suggèrent que l’insula joue probablement un rôle accessoire au sein du modèle proposé par l’hypothèse des marqueurs somatiques et que les résections unilatérales partielles ou complètes de l’insula ne risquent pas d’occasionner de changements prononcés de la personnalité. / Research has shown that the insula is involved in the processing of information relating to interoceptive, emotional and executive functions. It was proposed that these two seemingly separate functions may work conjointly as part of a large neural circuit tasked with the extraction of emotional information from bodily signals. It was hypothesized that, if the insula does indeed modulate feelings and the cognitive processes which derive from them, insular damage would result in alterations of emotional experience, executive functions and personality. To that effect, we examined such changes in a group of patients (n = 19) who underwent epilepsy surgery involving partial or complete resection of the insula, and compared them to a group of patients who underwent temporal lobe epilepsy surgery (n = 19) as a lesion-control group. Participants were assessed on the Iowa Scales of Personality Change, filled by a close relative at least six months after surgery. While pre- vs. post-surgery changes did not significantly differ between groups on any of the outcome variables, insular resections were associated with mild but significant increases in irritability, emotional lability, anxiety, and frugality postoperatively, which, with the exception of increased anxiety, were not found among temporal patients. Against our initial prediction, the surgery did not lead to executive functioning deficits. Overall, our results support the notion that the insula most likely holds an accessorial role in the model proposed by the somatic marker hypothesis, and that there isn’t a risk of dramatic personality change as a result of the partial or complete unilateral surgical removal of the insula.

INTRODUÇÃO: Embora a craniotomia pterional e suas variantes sejam os acessos mais utilizados em neurocirurgia, poucos estudos analisaram de forma quantitativa a exposição fornecida em cada uma delas. OBJETIVOS: Neste estudo, realizou-se avaliação comparativa das exposições cirúrgicas fornecidas pelas craniotomias pterional (PT), pré-temporal (PreT) e orbitozigomática (OZ) por meio de medidas quantitativas da área de exposição cirúrgica ao redor círculo arterial do cérebro, exposição angular e exposição linear da artéria basilar na fossa interpeduncular e cisterna pré-pontina. MÉTODOS: Oito cadáveres adultos frescos, com tempo máximo de 24 horas após a morte, foram utilizados no estudo. As craniotomias foram realizadas sequencialmente no mesmo cadáver, em um único lado, iniciando-se com a PT, seguido da PreT e terminando com a OZ. Após cada craniotomia, calculou-se a área de exposição cirúrgica, delimitada pelos seguintes pontos: (1) ponto mais lateral da fissura orbitária superior ipsilateral; (2) bifurcação da artéria cerebral média (ACM) ipsilateral; (3) ponto mais distal da artéria cerebral posterior (ACP) ipsilateral; (4) ponto mais distal da ACP contralateral; (5) ponto mais distal da ACM contralateral; (6) ponto mais lateral na asa menor do esfenoide contralateral. Calculou-se ainda, após cada craniotomia, a exposição angular nos eixos horizontal e vertical das seguintes estruturas vasculares: (1) bifurcação da ACM ipsilateral; (2) bifurcação da artéria carótida interna (ACI) ipsilateral; (3) topo da artéria basilar; (4) ponto médio da artéria comunicante anterior; (5) bifurcação da ACI contralateral; (6) ponto mais distal da ACM contralateral. Por fim, após cada craniotomia, mediu-se a exposição linear da artéria basilar na fossa interpeduncular e cisterna pré-pontina. Todas as aferições foram feitas utilizando-se um sistema de neuronavegação computadorizado. RESULTADOS: A OZ apresentou maior exposição cirúrgica em torno do círculo arterial do cérebro (PT = 844,7 ± 233,3 mm2; PreT = 1.134 ± 223,3 mm2; OZ = 1.301,3 ± 215,9 mm2) com aumento de 456,7 mm2 em relação à PT (p < 0,01) e de 167,4 mm2 comparado com a PreT (p < 0,05). A exposição linear da artéria basilar aumentou significativamente com a extensão da craniotomia PT para a PreT e sequencialmente para a OZ. A extensão da PT para PreT e OZ aumentou a exposição angular em todas as medições. Ao compararmos as craniotomias PreT e OZ encontramos um aumento na exposição angular horizontal do topo da artéria basilar (p = 0,02) e bifurcação da artéria carótida interna contralateral (p = 0,048). CONCLUSÕES: A craniotomia OZ oferece vantagens cirúrgicas significativas em relação à PT e PreT, no que diz respeito à área de exposição cirúrgica e exposição linear da artéria basilar. A remoção de parte da margem orbital e do arco zigomático forneceu aumento significativo da exposição angular, proporcionando maior liberdade cirúrgica para acessar estruturas da fossa interpeduncular, cisterna pré-pontina e cisternas subaracnóideas contralaterais. Os dados apresentados no estudo, somados à experiência do cirurgião podem auxiliar na escolha do melhor acesso cirúrgico para cada lesão a ser tratada / INTRODUCTION: Although pterional craniotomy and its variants are the most used approaches in neurosurgery, few studies have analyzed quantitatively the exposure provided by each of them. OBJECTIVES: In this study we compared the surgical exposures provided by pterional (PT), pretemporal (PreT) and orbitozygomatic (OZ) approaches through quantitative measurements of area of surgical exposure around the circle of Willis, angular exposures, and linear exposure of basilar artery in the interpeduncular fossa and prepontine cistern. METHODS: Eight adult fresh cadavers were used within 24 hours after death. The craniotomies were sequentially performed in the same cadaver, first starting with the PT, followed by the PreT, ending up with the OZ. After each craniotomy the area of surgical exposure was calculated, delimited by the following points: (1) lateral aspect of the superior orbital fissure in the ipsilateral sphenoid wing; (2) bifurcation of ipsilateral middle cerebral artery (MCA); (3) most posterior visible point of the ipsilateral posterior cerebral artery (PCA); (4) most posterior visible point of the contralateral PCA; (5) most distal visible point of the contralateral MCA; (6) most lateral visible point of the contralateral lesser sphenoid wing. After each craniotomy, the angular exposure in the horizontal and vertical axes of the following vascular structures was calculated: (1) bifurcation of the ipsilateral MCA; (2) bifurcation of the ipsilateral internal carotid artery (ICA); (3) basilar artery tip; (4) middle point of anterior communicating artery; (5) bifurcation of the contralateral ICA; (6) most distal point of the contralateral MCA. Finally, after each craniotomy, linear exposure of the basilar artery was measured in the interpeduncular fossa and prepontine cistern. All measurements were performed using a computerized neuronavigation system. RESULTS: OZ presented a wider surgical exposure of the circle of Willis (PT = 844.7 ± 233.3 mm2; PreT = 1134 ± 223.3 mm2; OZ = 1301.3 ± 215.9 mm2) with an increase of 456.7 mm2 in relation to the PT (p < 0.01) and of 167.4 mm2 to the PreT (p < 0.05). The linear exposure of the basilar artery significantly increased with the craniotomy extension to the PreT and then to OZ. The extension from PT to PreT and OZ increases angles in all measurements. When comparing the PreT and OZ we found an increase in the horizontal angular exposure to the basilar tip (p = 0.02) and contralateral ICA bifurcation (p = 0.048). CONCLUSIONS: The OZ approach offered significant surgical advantages compared to the traditional PT and PreT regarding to the area of exposure and linear exposure to basilar artery. With regards to the angular exposure, the orbital rim and zygomatic arch removal provided greater surgical freedom to access structures of the interpeduncular fossa, prepontine cistern, and contralateral subarachnoid cisterns. The data presented in the study added to the experience of the surgeon can help in choosing the best individualized surgical approach