Evaluation of cerebral hemodynamics by transcranial Doppler ultrasonography and its correlation with intracranial pressure in an animal model of intracranial hypertension / Avaliação da hemodinâmica encefálica utilizando Doppler transcraniano e sua correlação com a pressão intracraniana em um modelo animal de hipertensão intracraniana

ABSTRACT Background: Transcranial Doppler has been tested in the evaluation of cerebral hemodynamics as a non-invasive assessment of intracranial pressure (ICP), but there is controversy in the literature about its actual benefit and usefulness in this situation. Objective: To investigate cerebral blood flow assessed by Doppler technique and correlate with the variations of the ICP in the acute phase of intracranial hypertension in an animal model. Methods: An experimental animal model of intracranial hypertension was used. The experiment consisted of two groups of animals in which intracranial balloons were implanted and inflated with 4 mL (A) and 7 mL (B) for controlled simulation of different volumes of hematoma. The values of ICP and Doppler parameters (systolic [FVs], diastolic [FVd], and mean [FVm] cerebral blood flow velocities and pulsatility index [PI]) were collected during the entire procedure (before and during hematoma simulations and venous hypertonic saline infusion intervention). Comparisons between Doppler parameters and ICP monitoring were performed. Results: Twenty pigs were studied, 10 in group A and 10 in group B. A significant correlation between PI and ICP was obtained, especially shortly after abrupt elevation of ICP. There was no correlation between ICP and FVs, FVd or FVm separately. There was also no significant change in ICP after intravenous infusion of hypertonic saline solution. Conclusions: These results demonstrate the potential of PI as a parameter for the evaluation of patients with suspected ICP elevation.

RESUMO Antecedentes: O Doppler transcraniano (DTC) é uma técnica não invasiva para a avaliação da hemodinâmica cerebral, porém existem controvérsias na literatura sobre sua aplicabilidade preditiva em situações de elevada pressão intracraniana (PIC). Objetivo: Investigar o fluxo sanguíneo cerebral pelo DTC e correlacioná-lo com as variações da PIC na fase aguda da hipertensão intracraniana em modelo animal. Métodos: Dois grupos de animais (suínos) foram submetidos a hipertensão intracraniana secundária à indução de diferentes volumes de hematoma, por meio da insuflação de balão intracraniano controlado com 4 e 7 mL de solução salina fisiológica (grupos A e B, respectivamente). Em seguida, administrou-se infusão venosa de solução salina hipertônica (SSH 3%). Foram coletados os valores dos parâmetros de PIC e DTC (velocidade sistólica [FVs], diastólica [FVd] e média [FVm] do fluxo sanguíneo cerebral), bem como o índice de pulsatilidade (IP). Comparações entre os parâmetros do DTC e o monitoramento da PIC foram realizadas. Resultados: Vinte porcos foram estudados, dez no grupo A e dez no grupo B. Correlação significativa entre IP e PIC foi obtida, principalmente logo após a elevação abrupta da PIC. Não houve correlação entre PIC e FVs, FVd ou FVm separadamente. Também não houve alteração significativa na PIC após a infusão de SSH. Conclusões: Esses resultados demonstram o potencial do IP como um bom parâmetro para a avaliação de pacientes com suspeita de elevação da PIC.

Evaluation of cerebral hemodynamics by transcranial Doppler ultrasonography and its correlation with intracranial pressure in an animal model of intracranial hypertension.

BACKGROUND: Transcranial Doppler has been tested in the evaluation of cerebral hemodynamics as a non-invasive assessment of intracranial pressure (ICP), but there is controversy in the literature about its actual benefit and usefulness in this situation. OBJECTIVE: To investigate cerebral blood flow assessed by Doppler technique and correlate with the variations of the ICP in the acute phase of intracranial hypertension in an animal model. METHODS: An experimental animal model of intracranial hypertension was used. The experiment consisted of two groups of animals in which intracranial balloons were implanted and inflated with 4 mL (A) and 7 mL (B) for controlled simulation of different volumes of hematoma. The values of ICP and Doppler parameters (systolic [FVs], diastolic [FVd], and mean [FVm] cerebral blood flow velocities and pulsatility index [PI]) were collected during the entire procedure (before and during hematoma simulations and venous hypertonic saline infusion intervention). Comparisons between Doppler parameters and ICP monitoring were performed. RESULTS: Twenty pigs were studied, 10 in group A and 10 in group B. A significant correlation between PI and ICP was obtained, especially shortly after abrupt elevation of ICP. There was no correlation between ICP and FVs, FVd or FVm separately. There was also no significant change in ICP after intravenous infusion of hypertonic saline solution. CONCLUSIONS: These results demonstrate the potential of PI as a parameter for the evaluation of patients with suspected ICP elevation.

Pterional, Pretemporal, and Orbitozygomatic Approaches: Anatomic and Comparative Study.

OBJECTIVE: Although pterional craniotomy and its variants are the most used approaches in neurosurgery, few studies have evaluated their precise indications. We evaluate the pterional (PT), pretemporal (PreT), and orbitozygomatic (OZ) approaches through quantitative measurements of area, linear, and angular exposures of the major intracranial vascular structures. METHODS: Eight fresh, adult cadavers were operated with the PT, followed by the PreT, and ending with the OZ approach. The working area, angular exposure of vascular structures and linear exposure of the basilar artery were measured. RESULTS: The OZ approach presented a wider area (1301.3 ± 215.9 mm2) with an increase of 456.7 mm2 compared with the PT and of 167.4 mm2 to the PreT (P = 0.011). The extension from PT to PreT and OZ increases linear exposure of the basilar artery. When comparing the PreT and OZ, we found an increase in the horizontal and vertical angle to the bifurcation of the ipsilateral middle cerebral artery (P = 0.005 and P = 0.032, respectively), horizontal angle to the basilar artery tip (P = 0.02), and horizontal angle to the contralateral ICA bifurcation (P = 0.048). CONCLUSIONS: The OZ approach offered notable surgical advantages compared with the traditional PT and PreT regarding to the area of exposure and linear exposure to basilar artery. Regarding angle of attack, the orbital rim and zygomatic arch removal provided quantitatively wider exposure and increased surgical freedom. A detailed anatomic study for each patient and surgeon experience must be considered for individualized surgical approach indication.

Longitudinal changes in brain volumetry and cognitive functions after moderate and severe diffuse axonal injury.

BACKGROUND AND OBJECTIVE: Diffuse axonal injury (DAI) induces a long-term process of brain atrophy and cognitive deficits. The goal of this study was to determine whether there are correlations between brain volume loss, microhaemorrhage load (MHL) and neuropsychological performance during the first year after DAI. METHODS: Twenty-four patients with moderate or severe DAI were evaluated at 2, 6 and 12 months post-injury. MHL was evaluated at 3 months, and brain volumetry was evaluated at 3, 6 and 12 months. The trail making test (TMT) was used to evaluate executive function (EF), and the Hopkins verbal learning test (HVLT) was used to evaluate episodic verbal memory (EVM) at 6 and 12 months. RESULTS: There were significant white matter volume (WMV), subcortical grey matter volume and total brain volume (TBV) reductions during the study period (p < 0.05). MHL was correlated only with WMV reduction. EF and EVM were not correlated with MHL but were, in part, correlated with WMV and TBV reductions. CONCLUSIONS: Our findings suggest that MHL may be a predictor of WMV reduction but cannot predict EF or EVM in DAI. Brain atrophy progresses over time, but patients showed better EF and EVM in some of the tests, which could be due to neuroplasticity.

Traumatic Brain Injury Research in Brazil: A Bibliometric Study

Traumatic brain injury (TBI) is responsible for high rates of morbidity and mortality, constituting an important public health problem throughout the world. Improving medical research on systemic trauma is a critical issue to understand its impact and develop strategies for prevention and treatment. This paper presents an overview of medical research performed in Brazil about TBI comparing it with the production on the same topic with other countries and with publications about different neurological and non-neurological diseases. It is possible to notice that Brazil has a deficiency in the scientific production on TBI given its importance. Greater integration between the research centers could help meliorate the production and quality of the papers and encourage further studies on the theme, in the quest to minimize the shortage of publications that can be seen today.

O trauma cranioencefálico (TCE) é responsável por altas taxas de morbidade e mortalidade, constituindo um importante problema de saúde pública em todo o mundo. Melhorar a investigação médica sobre trauma sistêmico é uma questão crítica para compreender seu impacto e desenvolver estratégias para a sua prevenção e tratamento. Este artigo apresenta uma visão geral da pesquisa médica realizada no Brasil sobre TCE comparando-a com a produção sobre o mesmo tema com outros países e com publicações sobre diferentes doenças neurológicas e não neurológicas. É possível notar que o Brasil tem uma deficiência na produção científica sobre TCE dada a sua importância. Maior integração entre os centros de pesquisa poderia ajudar a aperfeiçoar a produção e a qualidade dos trabalhos e incentivar novos estudos sobre o tema, na busca de minimizar a escassez de publicações vista atualmente.

Current clinical approach to patients with disorders of consciousness.

In clinical practice, hospital admission of patients with altered level of consciousness, sleepy or in a non-responsive state is extremely common. This clinical condition requires an effective investigation and early treatment. Performing a focused and objective evaluation is critical, with quality history taking and physical examination capable to locate the lesion and define conducts. Imaging and laboratory exams have played an increasingly important role in supporting clinical research. In this review, the main types of changes in consciousness are discussed as well as the essential points that should be evaluated in the clinical management of these patients.

Current clinical approach to patients with disorders of consciousness / Abordagem clínica atual do paciente com distúrbios de consciência

Summary In clinical practice, hospital admission of patients with altered level of consciousness, sleepy or in a non-responsive state is extremely common. This clinical condition requires an effective investigation and early treatment. Performing a focused and objective evaluation is critical, with quality history taking and physical examination capable to locate the lesion and define conducts. Imaging and laboratory exams have played an increasingly important role in supporting clinical research. In this review, the main types of changes in consciousness are discussed as well as the essential points that should be evaluated in the clinical management of these patients.

Resumo Abordagem Na prática clínica é extremamente comum a admissão hospitalar de pacientes com nível de consciência alterado, sonolentos ou em estado não responsivo. Essa condição clínica demanda uma investigação eficaz e um tratamento precoce. É fundamental a realização de uma avaliação focada e objetiva, com a realização de anamnese e exame físico de qualidade para localizar a lesão e definir condutas. Exames de imagem e laboratoriais têm desempenhado papéis cada vez mais relevantes no suporte à investigação clínica. Nesta revisão, são discutidos os principais tipos de alterações de consciência e os pontos imprescindíveis que devem ser avaliados na abordagem clínica desses pacientes.

Considerações sobre o modelo experimental de hipertensão intracranianae avaliação do sistema de microchip para monitoração de pressão epidural / Experimental model of intracranial hypertension and evaluation of the microchip system for epidural pressure monitoring of epidural pressure

Objetivo: Neste trabalho temos o objetivo de avaliar a acura?cia do sistema de aferic?a?o da pressão intracraniana (PIC) epidural com microchip. Me?todos: Foram estudados 27 sui?nos sob anestesia geraI, devidamente assistidos com monitoração ventilatória e hemodina?mica. Durante o experimento foi reproduzido um processo expansivo intracerebral programado no lobo frontal direito. O experimento constou de tre?s grupos (A, B e C) com hipertensão intracraniana gerada com balão reproduzindoum hematoma intracerebral. Em todos os grupos foram calibrados os para?metros normais: os dois sistemas de PIC foram comparados e estudados quanto a? correlação dos valores aferidos. Resultados: O comportamento médio da PIC ao longo dos momentos de avaliac?a?o foi estatisticamente diferente entre os grupos (p < 0,001). A reprodução de ressangramento resultou em elevac?a?o significativa da PIC (p < 0,001). Avaliando-se a acura?cia comparativa geral, verificou-se um coeficiente de correlação intraclasse de 0,8. Conclusa?o: O modelo de hipertensa?o intracraniana por bala?o em sui?nos e? facti?vel e confia?vel na gerac?a?o de hipertensa?o intracraniana. O sistema de aferic?a?o de pressa?o intracranianaepidural apresenta elevado coeficiente de correlac?a?o com o sistema de aferic?a?o parenquimatoso na avaliac?a?o global.

Objective: In this paper we aim to evaluate the accuracy of the measurement with microchip epidural system. Methods: Twenty-seven pigs with were studied, under generaI anesthesia, properly assisted with ventilation and hemodynamic monitoring. During the experiment, we have simulated frontal intracerebral expansive process. The experiment consisted of three groups (A, B and C) with intracranial hypertension generated with the simulation of an intracerebral hematoma. The two systems were compared andstudied as the correlation of the measured values. Results: The average behavior of the increased intracranial pressure (ICP) over the time points are statistically different between groups (p < 0.001). The simulation of rebleeding resulted in a significant increase in ICP (p < 0.001). Evaluating the overall comparative accuracy there was an intraclass correlation coefficient of 0.8. Conclusion: The model of intracranial hypertension balloon in pigs is feasible and reliable in generating intracranial hypertension. The system for measuring intracranial epidural pressure has a high correlation coefficient with the system parenchymal gauging the overall evaluation.

Embolia gordurosa encefálica / Cerebral fat embolism

A embolia gordurosa é constituída pela presença de glóbulos de gordura dentro da microcirculação periférica e pulmonar, com ou sem quadro clínico. Há uma fase precoce, representada por uma obstrução mecânica, e uma fase tardia, representada por um fenômeno inflamatório, que se inicia aproximadamente 48 a 72 horas após a obstrução mecânica. O diagnóstico clínico da síndrome de embolia gordurosa pode ser auxiliado pelos critérios de Gurd-Wilson e deve ser suspeitado em doentes com traumatismo e fraturas de ossos longos e deterioração neurológica de forma inexplicada. É necessário no mínimo um critério maior (insuficiência respiratória, sinais neurológicos não relacionados ao traumatismo craniano e manifestações dermatológicas) e quatro menores ou dois maiores. Exames complementares são geralmente inespecíficos. A tomografia de crânio pode estar normal. A ressonância magnética de encéfalo pode mostrar áreas puntiformes que costumam desaparecer em 20 dias, sugerindo que a lesão pode ser predominantemente inflamatória, e não necrótico-isquêmica. Um tratamento específico para a síndrome de embolia gordurosa não existe. Ele consiste no suporte cardiopulmonar e neurológico, além de prevenção e diagnóstico precoce, auxiliando nos cuidados com o doente.

Fat embolism is constituted by the presence of fat globules in the peripheral microcirculation and lung with or without symptoms. There is an early stage, represented by a mechanical obstruction, and a late phase, represented by an inflammatory process, which begins approximately 48-72 hours after the mechanical obstruction. The clinical diagnosis of the syndrome of fat embolism can be aided by the criteria of Gurd-Wilson, and must be suspected in patients with trauma and long bone fractures and unexplained neurological deterioration. It is necessary at least one major criteria (respiratory failure, neurological signs unrelated to head trauma and skin lesions) and four small or two larger ones. Additional tests are usually nonspecific. CT scan may be normal. MRI may show punctate areas that usually disappear in 20 days, suggesting that the inflammatory lesion may be predominantly necrotic and non-ischemic. Specific treatment for fat embolism syndrome does not exist. It is the neurological and cardiopulmonary support, and prevention and early diagnosis, assisting in patient care.

Gunshot wound to the upper cervical spine leading to instability.

Gunshot wounds (GSW) to the cervical spine leading to instability are rare. Also, the presence of vital vascular and neurological structures in the surround area lead to death or severe disability in the vast majority of cases. In this brief report, we present a rare case of C1 fracture due to GSW leading to instability of the atlanto-occipital joint in a neurologically intact patient.

Experimental model of intracranial hypertension with continuous multiparametric monitoring in swine.

OBJECTIVE: Intracranial hypertension (IH) develops in approximately 50% of all patients with severe traumatic brain injury (TBI). Therefore, it is very important to identify a suitable animal model to study and understand the pathophysiology of refractory IH to develop effective treatments. METHODS: We describe a new experimental porcine model designed to simulate expansive brain hematoma causing IH. Under anesthesia, IH was simulated with a balloon insufflation. The IH variables were measured with intracranial pressure (ICP) parenchymal monitoring, epidural, cerebral oximetry, and transcranial Doppler (TCD). RESULTS: None of the animals died during the experiment. The ICP epidural showed a slower rise compared with parenchymal ICP. We found a correlation between ICP and cerebral oximetry. CONCLUSION: The model described here seems useful to understand some of the pathophysiological characteristics of acute IH.

Experimental model of intracranial hypertension with continuous multiparametric monitoring in swine / Modelo Experimental de Hipertensao Intracraniana com monitorizacao multiparametrica continua em suinos

Objective Intracranial hypertension (IH) develops in approximately 50% of all patients with severe traumatic brain injury (TBI). Therefore, it is very important to identify a suitable animal model to study and understand the pathophysiology of refractory IH to develop effective treatments. Methods We describe a new experimental porcine model designed to simulate expansive brain hematoma causing IH. Under anesthesia, IH was simulated with a balloon insufflation. The IH variables were measured with intracranial pressure (ICP) parenchymal monitoring, epidural, cerebral oximetry, and transcranial Doppler (TCD). Results None of the animals died during the experiment. The ICP epidural showed a slower rise compared with parenchymal ICP. We found a correlation between ICP and cerebral oximetry. Conclusion The model described here seems useful to understand some of the pathophysiological characteristics of acute IH. .

Objetivo A hipertensão intracraniana (HIC) ocorre em até 50% de todos os pacientes com traumatismo cranioencefálico (TCE). Por isso, é importante estabelecer um modelo animal adequado para estudar a fisiopatologia da HIC refratária, com a perspectiva de desenvolver tratamentos eficazes. Métodos Os animais foram submetidos a um protocolo padrão de anestesia. A hipertensão intracraniana foi estabelecida através de insuflação de um balão. As variáveis HIC foram medidas com a pressão intracraniana (PIC) do parênquima, oximetria, epidural e doppler transcraniano. Resultados A PIC epidural apresentou elevação mais lenta, comparada com a PIC parenquimal. Houve correlação entre a PIC e a oximetria cerebral. O registro da PIC, oximetria e índice de pulsatilidade foi realizado em todos os animais sem dificuldade. Conclusão O modelo descrito parece ser útil para a compreensão de algumas características fisiopatológicas na HIC aguda. .

Alterações neuroendócrinas em pacientes com traumatismo cranioencefálico / Neuroendocrine disorders in traumatic brain injury patients

O traumatismo cranioencefálico (TCE) corresponde a uma das principais causas de morte em adultos jovens. Alguns pacientes com TCE podem ser vítimas de várias alterações hormonais decorrentes do trauma. Algumas são facilmente reconhecíveis, como diabetes insipidus, enquanto outras podem passar despercebidas inicialmente, como a deficiência do hormônio do crescimento (GH). As alterações neuroendócrinas após a ocorrência de trauma podem cursar com deficiências da hipófise anterior, da posterior ou de ambas, acometer apenas um eixo hormonal ou vários e, ainda, ser transitórias ou permanentes. A grande maioria dos pacientes que apresentam disfunção neuroendócrina foi vítima de traumas considerados moderados ou graves pela escala de Glasgow. No entanto, a maioria dos estudos não evidenciou relação entre a gravidade da lesão e a ocorrência de alteração hipofisária pósTCE. As deficiências hipofisárias devem ser tratadas precocemente, uma vez que déficits hormonais hipofisários dificultam a recuperação dos pacientes traumatizados, constituindo-se em fator de pior prognóstico. Apesar da frequência com que ocorrem os TCE, existem poucos estudos a respeito das complicações neuroendócrinas decorrentes...

Traumatic brain injury (TBI) is one of the main causes of death in young adults. Some cases of TBI could lead to the development of easily recognizable diabetes insipidus. In other cases it can lead to alterations in the endocrine axis that are more difficult to notice at the beginning and that can occur together with other hormone deficiencies. The majority of patients with neuroendrocrine dysfunction were TBI victims with a Glasgow Coma Scale scores of 3-13 (moderate and severe trauma). However, previous studies did not show correlationships between the severity of injury and pan-hypopituitarism after TBI. The pituitary disorders have to be treated as soon as possible because it makes the recovery of TBI patients more difficult and lead to a worse prognosis. Despite the number of studies about TBI, actually there are only a few studies concerning the secondary neuroendocrine complications...

3D preoperative planning in the ER with OsiriX®: when there is no time for neuronavigation.

The evaluation of patients in the emergency room department (ER) through more accurate imaging methods such as computed tomography (CT) has revolutionized their assistance in the early 80s. However, despite technical improvements seen during the last decade, surgical planning in the ER has not followed the development of image acquisition methods. The authors present their experience with DICOM image processing as a navigation method in the ER. The authors present 18 patients treated in the Emergency Department of the Hospital das Clínicas of the University of Sao Paulo. All patients were submitted to volumetric CT. We present patients with epidural hematomas, acute/subacute subdural hematomas and contusional hematomas. Using a specific program to analyze images in DICOM format (OsiriX(®)), the authors performed the appropriate surgical planning. The use of 3D surgical planning made it possible to perform procedures more accurately and less invasively, enabling better postoperative outcomes. All sorts of neurosurgical emergency pathologies can be treated appropriately with no waste of time. The three-dimensional processing of images in the preoperative evaluation is easy and possible even within the emergency care. It should be used as a tool to reduce the surgical trauma and it may dispense methods of navigation in many cases.