Felix Mircea Brehar

Intraoperative neuronavigation integrated high resolution 3D ultrasound for brainshift and tumor resection control

Abstract INTRODUCTION: The link between the neurosurgeon’s knowledge and the scientific improvements made a dramatic change in the field expressed both in impressive drop in the mortality and morbidity rates that were operated in the beginning of the XXth century and in operating with high rates of success cases that were considered inoperable in the past. Neuronavigation systems have been used for many years on surgical orientation purposes especially for small, deep seated lesions where the use of neuronavigation is correlated with smaller corticotomies and with the extended use of transulcal approaches. The major problem of neuronavigation, the brainshift once the dura is opened can be solved either by integrated ultrasound or intraoperative MRI which is out of reach for many neurosurgical departments. METHOD: The procedure of neuronavigation and ultrasonic localization of the tumor is described starting with positioning the patient in the visual field of the neuronavigation integrated 3D ultrasonography system to the control of tumor resection by repeating the ultrasonographic scan in the end of the procedure. DISCUSSION: As demonstrated by many clinical trials on gliomas, the more tumor removed, the better long term control of tumor regrowth and the longer survival with a good quality of life. Of course, no matter how aggressive the surgery, no new deficits are acceptable in the modern era neurosurgery. There are many adjuvant methods for the neurosurgeon to achieve this maximal and safe tumor removal, including the 3T MRI combined with tractography and functional MRI, the intraoperative neuronavigation and neurophysiologic monitoring in both anesthetized and awake patients. The ultrasonography integrated in neuronavigaton comes as a welcomed addition to this adjuvants to help the surgeon achieve the set purpose. CONCLUSION: With the use of this real time imaging device, the common problem of brainshift encountered with the neuronavigation systems is covered and any eventual tumor residue can be spotted by ultrasonography and resected

Brain metastases of neuroendocrine tumor with unknown primary location - Case report

Abstract Neuroendocrine tumors are tumors derived from the cells of the neuroendocrine system. The majority of metastases of neuroendocrine tumors occur in liver, lungs and bone. The brain is an uncommon site of metastasize for this type of tumor. The authors of this paper present a case of brain metastases of neuroendocrine tumor with undetermined primary location. The patient, a 35 yearsold man, was admitted in our clinic with headache, nausea, vomiting and a mild right facial paresis. Head CT scan and cerebral MRI identified two lesions: one larger lesion with mixed solid and cystic components located in the left basal ganglia and thalamus and a second cystic lesion located deep in the right parietal lobe. All complementary investigations (including thoracic CT scan and whole-body MRI) failed to reveal the primary tumor location. Due to the high vital-risks associated with the open surgical procedure, the patient and his family chose the less invasive procedure of stereotactic biopsy. Postoperatively the patient had no additional neurologic deficits, presenting only the initial mild right central facial paresis. The result of immunohistochemistry examination was cerebral metastases of neuroendocrine tumor. The patient was directed to the Institute of Oncology Fundeni for further investigations and therapeutically management. In conclusion, even if these are rare tumors which rarely metastasize in the brain, the neurosurgeons should take in consideration this pathology when they examine a patient with multiple cerebral lesions with unknown location of primary tumor.

Preferential Association of Lissencephaly-1 Gene Expression with CD133+ Glioblastoma Cells

Lissencephaly-1 (Lis1) protein is a dynein-binding protein involved in neural stem cell division, morphogenesis and motility. To determine whether Lis1 is a key factor in glioblastoma, we evaluated its expression and function in CD133+ glioblastoma cells. Global, Lis1 gene expression is similar in glioblastoma and normal samples. Interestingly, immunohistochemistry data indicate increased Lis1 expression colocalized with CD133 in a subset of glioma cells, including the tumor cells with perivascular localization. Lis1 gene expression is increased up to 60-fold in CD133 positive cells isolated from primary cultures of glioblastoma and U87 glioblastoma cell line as compared to CD133 negative cells. To investigate the potential role of Lis1 in CD133+ glioblastoma cells, we silenced Lis1 gene in U87 cell line obtaining shLis1-U87 cells. In shLis1-U87 cell culture we noticed a significant decrease of CD133+ cells fraction as compared with control cells and also, CD133+ cells isolated from shLis1-U87 were two times less adhesive, migratory and proliferative, as compared with control transfected U87 CD133+ cells. Moreover, Lis1 silencing decreased the proliferative capacity of irradiated U87 cells, an effect attributable to the lower percentage of CD133+ cells. This is the first report showing a preferential expression of Lis1 gene in CD133+ glioblastoma cells. Our data suggest a role of Lis1 in regulating CD133+ glioblastoma cells function.

Challenges in a case of ophthalmic artery aneurysm associated with abnormal internal carotid arteries

Ophthalmic artery aneurysms account for 5% of all cerebral aneurysms and are an important cause of morbidity and mortality related to subarachnoid hemorrhage. The diagnosis is often made only when the aneurysm is large enough to become symptomatic. They remain technically challenging for both neurosurgeon and interventional radiologist. We present the case of a 62-year-old woman admitted for transient loss of consciousness, followed by generalized tonic-clonic seizures. Computed tomography (CT) showed a subarachnoid hemorrhage (SAH), clinically graded as Hunt and Hess III. Magnetic resonance imaging (angioMR) and the four-vessel digital subtraction angiography (DSA) identified a ruptured, 8 mm left ophthalmic artery aneurysm. Embolization was the first therapeutic choice. Nevertheless, the attempt had to be aborted due to a combination of a hypoplastic right internal carotid artery (ICA) and an irregular atheromatous plaque on the left ICA, rendering the procedure unduly hazardous. Therefore, microsurgical clipping of the aneurysm became the procedure of choice. Postoperatively, the patient was in good condition, with no visual and neurological deficits. At 6 months follow up, she was assigned maximum scores of 5 and 8 on the Glasgow Outcome Scale (GOS) and Extended GOS (GOS-E), respectively. Aneurysm rupture represents a neurosurgical emergency and an early intervention (less than 48 h) is recommended to maximize the chances of deficit-free survival. The peculiarities of this case consisted in the combination between the size and the location of the aneurysm, abrupt presentation, and the impossibility of embolization due to bilateral ICA abnormalities, congenital (hypoplastic right ICA) and acquired (extensively atherosclerotic left ICA).

Surgical management of symptomatic spinal cord and intracerebral cavernomas in a multiple cavernomas case

Abstract Multiple cavernous malformations are associated with familial cases and are present in 10-20% of all cavernoma cases. 5% of cavernomas are located intramedullary and of these only 10% present multiple cavernomas. With the availability of echo gradient MRI the cases of multiple cavernomas are diagnosed earlier and it is not rare that it uncovers multiple cavernomas in cases where only a single lesion can be identified on regular MRI sequences. We present the case of a 55 years old woman presented with a two years history of mild backache, followed by progressive lower legs motor deficit and urinary retention. The spine MRI showed an intramedullary T2/3 lesion and the cerebral MRI established the diagnosis of multiple cavernomas. One year after the intramedullary cavernoma was operated with success, she developed generalized seizures and a new cerebral MRI showed bleeding and volume growth of one right temporal pole cavernoma. The cerebral lesion was resected successfully and the patient was discharged free of seizures. This familial type multiple cavernomas cases should be screened and followed with repeated brain and spine MRI’s every year.

Current perspectives concerning the multimodal therapy in Glioblastoma

Abstract GBM (Glioblastoma) is the most common, malignant type of primary brain tumor. It has a dismal prognosis, with an average life expectancy of less than 15 months. A better understanding of the tumor biology of GBM has been achieved in the past decade and set up new directions in the multimodal therapy by targeting the molecular paths involved in tumor initiation and progression. Invasion is a hallmark of GBM, and targeting the complex invasive mechanism of the tumor is mandatory in order to achieve a satisfactory result in GBM therapy. The goal of this review is to describe the tumor biology and key features of GBM and to provide an up-to-date overview of the current identified molecular alterations involved both in tumorigenesis and tumor progression.

Severe TBI with complex craniofacial fractures followed by cranioorbitar reconstruction

Abstract Young age is associated with better outcome in patients with severe traumatic brain injury (TBI). Still the reported mortality rate in patients that present in profound coma Glasgow Coma Scale (GCS) -3 pts is very high, even approaching 100% in the presence of fixed and dilated pupils in some series. We report a case of a 25 years old patient with a severe TBI in a car crush and presented in severe coma with a bilateral frontal and right temporal brain laceration with extended posttraumatic subarachnoid hemorrhage and a complex cominutive right frontal, maxillary and zygomatic fracture corresponding to Le Fort III fracture. After a difficult postoperative course with complications of tracheostomy like candidosis and bronchopneumony, then after a slowly progressive recovery, the patient was hemiparetic and with a persistent right 3rd nerve paresis at 6 weeks after the traumatic event, but was able to speak and to ambulate with assistance. Given the large bony defect that remained, a frontal and facial bony reconstruction was made by an interdisciplinary team using titanium plates and screws. Considering the excellent results in this case we advocate that young patients who suffered severe TBI even if they present in a very bad neurological shape should be given access to the best treatment.

Cerebral revascularization: direct versus indirect bypass. Case presentation and review

Abstract Since 1985 when the EC-IC bypass study results were published and less procedures were performed for cerebral ischemia, the EC-IC bypass even high or low flow and the IC-IC bypass as flow replacement procedures gain acceptance for many neurosurgical pathologies, from extrinsic and intrinsic tumors requiring large vessels sacrifice to large giant and fusiform aneurysms. In recent years, after the results of Carotid Occlusion Surgery Study (COSS) and the Japanese EC-IC trial published their results the indications for extracranial-intracranial (EC-IC) by-pass expanded, including both extracranial carotid artery occlusive disease and intracranial atherosclerotic disease. The authors make a literature review of the indications for cerebral revascularization, with focus on the direct STA-MCA and indirect (EDAMS) revascularization techniques as a treatment for ischemic stroke. They present two cases of Moyamoya disease one treated with combined approaches and one with indirect approach and discuss the technical skills the surgeon should acquire in order to perform an anastomosis, focusing on the details of STA-MCA bypass, concluding that a combined approach gives better neurological results visible shortly after the surgery.

Radio-induced brain lesions

Abstract Introduction : Radiotherapy, an important tool in multimodal oncologic treatment, can cause radio-induced brain lesion development after a long period of time following irradiation. Material and method : We report 4 cases with radio-induced brain lesions, admitted into the Fourth Department of Neurosurgery, Emergency Clinical Hospital Bagdasar-Arseni, during a 4 years period of time. Results : Two patients had meningiomas and two had unruptured cavernomas. Other side effects of radiotherapy, such as diffuse brain atrophy, leukoencephalopathy, optic atrophy, panhypopituitarism were also noted. The two patients with large meningiomas underwent surgery, with good outcome. Observation was the choice for the two asymptomatic cavernomas. Panhypopituitarism needed synthetic hormonal replacement therapy. Conclusions : Radiotherapy can cause long-term complications and can induce development of new brain lesions into previous radiation area. Meningiomas and cavernomas can be radio-induced brain lesions. Meningiomas can grow to large size, requiring surgery. Unruptured asymptomatic cavernomas can be left in place and patients are followed clinical and with serial imaging. Other findings after radiotherapy are diffuse brain atrophy, leukoencephalopathy, optic atrophy and panhypopituitarism.