Comparison of 116 Radiosurgery Treatment Plans for Multi-Leaf and Cone Collimator on a Varian Edge Linac: Are Cones Superior in the Daily Routine?

Delivering focused radiation doses via linear accelerators is a crucial component of stereotactic radiosurgery (SRS) for brain metastases. The Varian Edge linear accelerator provides highly conformal radiation therapy through a high-definition multi-leaf collimator (HD120 MLC) and conical collimator (CC). HD120 MLC adapts to the shape of the target volume using movable tungsten leaves, while CC has a block of conical shape (cones). CC in SRS treatments of small brain metastases is preferred due to its mechanical stability and steeper dose fall-off, potentially sparing organs at risk (OARs) and the brain better than HD120 MLC. This study aims to determine if CC offers significant advantages over HD120 MLC for SRS treatments. For 116 metastatic lesions, CC and HD120 MLC treatment plans were created in Varian Eclipse TPS and compared based on various dose parameters, robustness tests, and QA measurements. The results indicate that CC provides no significant advantages over HD120 MLC, except for slight, clinically insignificant benefits in brain sparing and dose fall-off for the smallest lesions. HD120 MLC outperforms CC in almost every aspect, making it a better choice for irradiating brain metastases with 0.1 cm3 or higher volumes.

Adrenal Cortical Adenoma in the Spinal Canal: A Case Report and Review of the Literature.

Ectopic adrenal cortical neoplasms of the spinal cord are extremely rare. To date only 10 such cases have been described. We present a case of a 46-year-old woman with lower back pain radiating to the right gluteal and posterior femoral regions, without a history of traumatic injury. Magnetic resonance imaging (MRI) of the thoracic and lumbar spine showed an intradural, extramedullary, well-circumscribed, contrast-enhancing lesion located in the T12-L1 region, hypo- to isointense on T2-weighted imaging, and isointense on T1. Complete surgical removal of the lesion, measuring 3 × 2.5 × 1 cm, was performed. The histopathologic findings revealed the lesion was an ectopic adrenal cortical adenoma, with sheets and nests of round and polygonal cells, mostly round regular nuclei, abundant eosinophilic cytoplasm, 1 mitosis per 10 high-power fields, and without necrosis. These tumors have nonspecific MRI features and therefore can be easily confused with other common spinal tumor types such as ependymoma, schwannoma, meningioma, and metastasis. Although rare, ectopic adrenal spinal cord adenomas should be taken into account in the differential diagnosis of spinal canal intradural neoplasms.

Etomidate in neuroanesthesia for aneurysmal clipping in child with confirmed allergies to general anesthetics.

BACKGROUND: Etomidate may be given in continuous infusion for maintenance of general anesthesia, although that practice is rarely seen due to beliefs that it has possibility of interfering with cortisol synthesis. However, etomidate is sometimes preferable choice as it has least influence on hemodynamics and rarely causes allergic reactions. CASE DESCRIPTION: We describe a case of 13-year-old boy with aneurysm of left middle cerebral artery, planned for aneurysmal clipping, and previously treated for ruptured aneurysm of right middle cerebral artery. As he was tested and proved allergic to most of the anesthetic drugs, and stable hemodynamic conditions were of most importance during planned neurosurgery, general anesthesia was maintained with etomidate infusion. He was prepared with metilprednisolon, antihistaminic, and ranitidine before the surgery. Cortisol and adrenocorticotropic hormone levels were measured on three consecutive postoperative days. Only cortisol value, in the morning the day after the surgery, was below reference range, with the values back to normal until that evening. He was dismissed from the intensive care unit with Glasgow Coma Score 15. CONCLUSION: Etomidate may be a choice for neuroanesthesia in specific group of people. We have good experience with our algorithm for continuous infusion of etomidate, with serum cortisol values in the reference range, if corticosteroids were not given before the surgery. Administration of metilprednisolon may diminish influence of perioperative stress on cortisol synthesis inhibition.

Cerebral Bypass Surgery for Internal Carotid Artery Occlusion, Complex Supraclinoid Carotid Artery Aneurysm, and Tumors: A Report of Four Cases.

Despite growing popularity of endovascular techniques, certain subsets of patients with cerebrovascular compromise may benefit from bypass surgery. We present four cases in which pending ischemic lesion was prevented by (1) A3 resection and reanastomosis following falx meningioma removal, (2) rescue superficial temporal artery-middle cerebral artery (STA-MCA) bypass after pituitary adenoma surgery, (3) STA-MCA bypass for chronic internal carotid artery occlusion, and (4) external carotid artery-MCA bypass using radial artery grafting. Following the procedure, there were no further clinical or radiological deteriorations and long-term patency was confirmed in all four cases.

Tentorial alignment and its relationship to cisternal dimensions of the pineal region: MRI anatomical study with surgical implications using the new clivotentorial method.

OBJECTIVES: Tentorial alignment and dimensions of posterior fossa cisterns are measurements whose variability can decrease surgical freedom if not taken into account when choosing the approach to the pineal region. The aim is to provide quantitative anatomical information regarding these dimensions, and to discuss their relevance in two most commonly used approaches to this region: the occipital transtentorial and supracerebellar-infratentorial approach. PATIENTS AND METHODS: A retrospective study of midsagittal T1-weighted MRI images of 410 randomly selected healthy subjects was performed. The clivus-tentorium (C-T) angle was measured to assess tentorial alignment. The following distances were used as craniocaudal cisternal measurements: quadrigeminal cistern = superior colliculi - inferior part of the splenium of corpus callosum (SC-ISCC), and superior cerebellar cistern = vermis - inferior part of the splenium of corpus callosum (VER-ISCC). RESULTS: Median C-T angle value was 19 ±â€¯7°, the quadrigeminal cistern height 6.7 ±â€¯1.6 cm, and the superior cerebellar cistern height 10.4 ±â€¯2.6 cm. The C-T angle was negatively correlated with the SC-ISCC distance (r = -0.271; p <  0.001) and the VER-ISCC distance (r = -0.052, p >  0.001). The SC-ISCC distance was positively correlated with the VER-ISCC distance (r = 0.282; p < 0.001). CONCLUSION: Our new method of measuring tentorial alignment provides a simple and effective aid in preoperative planning. For the first time, we present data on craniocaudal dimensions of posterior fossa cisterns, their relationship with tentorial alignment, and discuss their relevance in SCIT and OT approaches.

Extranodal right-optic nerve Rosai-Dorfman disease: A rare localization case report.

BACKGROUND: Rosai-Dorfman is a rare disease that usually occurs in young adults. It is characterized with massive painless cervical lymphadenopathy and histiocyte proliferation. Isolated intracranial involvement is extremely rare. Our aim is to present a new rare case of extranodal Rosai-Dorfman disease that involved the right optic nerve in a 4-year-old boy. CASE DESCRIPTION: A 4-year-old boy with right-sided convergent strabismus and amblyopia lasting for 1 year was treated at the Department of pediatric ophthalmology. Initial optical fundus examination was normal. Examination repeated after 1 year noted the atrophy of the optic nerve papilla. Visual evoked potentials of the right eye showed normal findings of prechiasmatic visual pathway with severe dysfunction of the right optic nerve. Magnetic resonance imaging (MRI) of the brain and orbits showed expansive changed and elongated right optic nerve with contrast enhancement, and smaller lesion in the right temporal operculum region visible in T2 and fluid-attenuated inversion recovery sequence. Through small eyebrow "keyhole" osteoplastic frontoorbital craniotomy the fusiform enlarged (to 2 cm) right optic nerve was identified, resected between the eyeball and optic chiasm, and transferred for pathohistological analysis. Early postoperative course had no complications. Histological, immunohistochemical, and ultrastructural analyses revealed extranodal Rosai-Dorfman disease. Right periorbital edema was verified on the 7th postoperative day and regressed to supportive therapy. Control multi slice computed tomography (MSCT) and MRI of endocranium and orbits showed total tumor removal with no signs of complications. CONCLUSION: Although rare, extranodular intracranial Rosai-Dorfman disease should be taken into account in the differential diagnosis of intracranial and intraorbital lesions, especially in the pediatric age group.

Personality Changes Following Brain Artery Aneurysm Surgery

Neuropsychological testing of patients in the course of their recovery from brain injuries enables analysis of cognitive deficiencies and/or emotional changes. The principle study objective was to define organic and/or reactive personality changes and the course of these changes in the function of the time span following brain artery aneurysm surgery in both female and male patients. The study was carried out at the Clinical Department of Neurosurgery, Zagreb University Hospital Center in Zagreb. The data refer to the period from 1989 to 2012 collected in two time intervals, i.e. 11 months and 12-48 months following brain artery aneurysm surgery. Of 72 patients included in the study, there were 28 male and 44 female patients. Neuropsychological testing consisted of clinical interview, clinical assessment of frontal lobe syndrome, Cornell personality questionnaire and Emotional Profile Index. Study results showed evidence of frontal lobe syndrome in 32% of patients on first testing and significant recovery on retesting, when only 17% of patients presented with frontal lobe syndrome. The reactive personality changes found in both testing intervals indicated increased neuroticism. In the first testing period, asthenic syndrome occurred most often, followed by conversion and aggressive-antisocial syndromes, while in the second testing interval asthenic syndrome was most pronounced and conversion and antisocial syndromes showed the same level of expression. The results also showed higher depressive and disorganizing states, which were even more pronounced in the second testing interval. As regards sex differences, the inclination toward cardiovascular somatization and destructiveness was more expressed in females than in males, showing a tendency of aggravation with increasing the time span following surgery. It may be concluded that the study has contributed to better understanding of organic and/or reactive personality changes in patients undergoing brain artery aneurysm surgery.

[CLINICAL GUIDELINES FOR DIAGNOSING, TREATING AND MONITORING OF ADULT PATIENTS WITH GLIOMAS OF CENTRAL NERVOUS SYSTEM]. / KLINICKE UPUTE ZA DIJAGNOZU, LIJECENJE I PRACENJE ODRASLIH BOLESNIKA OBOLJELIH OD GLIOMA SREDISNJEGA ZIVCANOG SUSTAVA.

Gliomas of the central nervous system are glial cell tumors that are divided in low and high grade group. Multidisciplinary approach to treatment consists of surgery, radiotherapy and chemotherapy. The type and order of treatment depend on the characteristics of the tumor and the patient. We present the clinical guidelines for diagnostic procedures, surgical treatment, oncological treatment and follow up of patients with this type of tumor in the Republic of Croatia.

General recommendations for the management of aneurysmal subarachnoid hemorrhage.

Subarachnoid hemorrhage is a neurologic emergency and a detrimental cerebrovascular event with a high rate of death and complications. Recommendations have been developed and based on literature search, evaluation of the results of large international clinical trials, collective experience of the authors, and endorsed by the Croatian Society of Neurovascular Disorders, Croatian Society of Neurology including Section for Neurocritical Care, Croatian Neurosurgical Society, Croatian Society for Difficult Airway Management and Croatian Medical Association. The aim of these guidelines is to provide current and comprehensive recommendations and to assist physicians in making appropriate decisions in the management of subarachnoid hemorrhage. Evidence based information on the epidemiology, risk factors and prognosis, as well as recommendations on diagnostic work up, monitoring and management are provided, with regard to treatment possibilities in Croatia.

Recommendations for the management of medical complications in patients following aneurysmal subarachnoid hemorrhage.

These are evidence based guidelines for the management of medical complications in patients following aneurysmal subarachnoid hemorrhage, developed and endorsed by the Croatian Society of Neurovascular Disorders, Croatian Society of Neurology including Section for Neurocritical Care, Croatian Neurosurgical Society, Croatian Society for Difficult Airway Management and Croatian Medical Association. They consist of recommendations for best monitoring, medical treatment and interventions based on the literature, evaluation of the results of large international clinical trials, and collective experience of the authors.

Treatment of giant and large fusiform middle cerebral artery aneurysms with excision and interposition radial artery graft in a 4-year-old child: case report.

BACKGROUND AND IMPORTANCE: We report an unusual case of complex giant and large fusiform aneurysms not amenable for clipping or coiling in a 4-year-old child managed with aneurysm resection and radial artery interposition graft. CLINICAL PRESENTATION: A 4-year-old child presented with repeated severe headache and vomiting. Computed tomography, magnetic resonance imaging, and magnetic resonance angiography and digital subtraction angiography showed a giant fusiform aneurysm on the right middle cerebral artery (MCA). Because of the complex shape, endovascular treatment or clip reconstruction was not possible, and a bypass procedure was planned. Right frontotemporal craniotomy and orbitotomy was performed. Two aneurysms involving the M1 segment of the MCA were found in line, 1 giant, and the other large in size. The aneurysms were resected and treated with short radial artery interposition graft, which was narrower than the proximal or distal MCA. The child recovered normally, and the bypass was patent after 1 year. CONCLUSION: Large fusiform MCA aneurysms may be difficult to treat, but there are treatment options that include a bypass procedure. Resection and short interposition radial artery graft is an excellent but rare treatment option in a very young child. This was a very successful treatment in this child.

Clinical and neurophysiological changes in patients with pineal region expansions.

In the last 20 years neurological and neurosurgical follow up of our patients with pineal region expansions (118 patients) pointed to certain clinical and neurophysiological regularities. We performed retrospective study which included 84 patients with pineal region expansions in the period from 1992 to 2009. The study included 55 women and 29 men, mean age 30.08 +/- 13.93 years, with positive brain magnetic resonance imaging (MRI)--70 patients (83.4%) had simple pineal gland cysts, and 14 patients (16.67%) had expansive process in pineal region with compressive effect. All patients had headache, while 32 patients (38%) had epileptic phenomena--primary generalized seizures. Patients had common electroencephalography (EEG) pattern with paroxysmal discharges of 3Hz (or more than 3 Hz) spike-and-wave complexes. Operation with supracerebellar infratentorial approach was performed in 70 patients. In most of our patients indication for the operation was established based on the size of the cyst (15 mm or more), with the signs of compression on the quadrigeminal plate and compression of the surrounding veins, which could result in seizures and EEG changes verified in our group of patients. Pathohistological analysis revealed pineocytomas in 11 cases (15.71%), pinealoblastomas in 2 cases (2.86%), one case of teratoma (1.43%), while 56 patients had pineal gland cysts (80%). Following surgery clinical condition improved in all patients--patients became seizure-free and headaches significantly decreased. Other symptoms including diplopiae, nausea, vomiting, vertigo as well as blurred vision also disappeared. There were no complications after surgical procedures. This study points to often appearance of seizures that clinically and neurophysiologically present as primary generalized epilepsy in patients with pineal region expansions. Our hypotheses are that mass effect on the surrounding veins that affects normal perfusion, compressive effect on the quadrigeminal plate and the aqueduct of the midbrain, hemosiderin deposists, as well as secretion disturbances of anticonvulsive agent melatonin can be involved in the pathogenesis of seizures. We suggest to perform high resolution brain MRI with special demonstration of pineal region in all young patients that have seizures and specific EEG changes.

Leptomeningeal and intramedullary metastases of glioblastoma multiforme in a patient reoperated during adjuvant radiochemotherapy.

Despite huge advances in medicine, glioblastoma multiforme (GBM) remains a highly lethal, fast-growing tumour that cannot be cured by currently available therapies. However, extracranial and extraneural dissemination of GBM is extremely rare, but is being recognised in different imaging studies. To date, the cause of the GBM metastatic spread still remains under discussion. It probably develops at the time of intracranial progression following a surgical procedure. According to other hypothesis, the metastases are a consequence of spontaneous tumour transdural extension or haematogenous dissemination. We present a case of a 59-year-old woman with symptomatic leptomeningeal and intramedullary metastases of GBM who has been previously surgically treated with primary subtotal resection and underwent a repeated surgery during adjuvant radiotherapy and chemotherapy with temozolomide. Today, the main goal of surgery and chemoradiotherapy is to prevent neurologic deterioration and improve health-related quality of life. With this paper, we want to present this rare entity and emphasise the importance of a multidisciplinary approach, a key function in the management of brain tumour patients. The prognosis is still very poor although prolongation of survival can be obtained. Finally, although rare, our case strongly suggests that clinicians should be familiar with the possibility of the extracranial spread of GBM because as treatment improvements provide better control of the primary tumour and improving survival, metastatic disease will be increasingly encountered.

Vagus nerve stimulation in the treatment of patients with pharmacoresistant epilepsy: our experiences.

Vagus nerve stimulation (VNS) for the treatment of refractory partial epileptic seizures with or without secondary generalisation in patients older than 12 years was approved in Europe in 1994 and in the United States in 1997. We have studied the efficacy of VNS in patients with pharmacoresistant epilepsy hospitalized in the Neurology Department of the University Hospital Centre Zagreb. From 1997 to 2001 we have implanted VNS in 11 patients with pharmacoresistant epilepsy, who were magnetic resonance imaging (MRI) negative and from May 2007 to May 2009 in 11 patients with pharmacoresistant epilepsy, 9 of them were MRI positive, and were inoperable due to localisation of the pathomorphologic changes (ganglioglioma, hamartoma, various types of cortical dysplasia, porencephalic cysts), 2 were MR negative. In the group of MRI negative patients 1 patient had complex partial seizures (CPS), 6 patients had CPS with secondary generalisation, 2 patients had primary generalized epilepsy (PGE) including myoclonic, absence, atonic and tonic-clonic seizures, one patient had PGE and CPS, and 3 patients had Lennox-Gastaut syndrome (LGS). In the group of MRI positive patients one patient had elementary partial seizures (EPS) and CPS, two patients had EPS and CPS with secondary generalisation, one patient had CPS, 3 patients had CPS with secondary generalisation, and 2 patients had CPS with secondary generalisation as well as atonic seizures. After continuous follow-up of 11 MRI negative patients during 5 years and 2 MRI negative patients during one year there was decrease in mean-seizure frequency of 51.67%. After continuous follow-up of 9 MRI positive patients during 2 years there was decrease in mean-seizure frequency of 61.9%. The most frequent side effects were hoarseness, throat pain and cough in the "on phase" of the VNS, but they were mild and transitory. We can conclude that VNS was effective mode of therapy in our group of patients with pharmacoresistant epilepsy.

The application of ultrasound in neuroendoscopic procedures: first results with the new tool "NECUP-2".

In this paper, our experience with originally constructed Neurosurgical Endoscopic Contact Ultrasound Probe "NECUP-2" in neuroendoscopy is reported. Between June 1997 and June 2007, 132 neuroendoscopic procedures have been performed: 102 endoscopic thrid ventriculostomies (ETV), 15 arachnoid cysts and 5 intraventricular tumours operations. The "NECUP-2" was applied effectively in all cases in which blunt perforation was not possible: 38/102 ETY, 10/10 septostomies, 15/15 arachnoid cysts. In five cases of intraventricular tumours, neuroendoscopic procedure was combined with open microsurgery for tumour removal with preservation of vascular structures. There were no "NECUP-2" related complications. Of postoperative complications, we had liquorrhea (9 patients), and symptoms of meningitis (6 patients). In the follow-up period (6 months to 6 years), we had a patency rate of 80% (50/63 patients). All patients improved in clinical status. According to the first results, it seems that ultrasonic contact probe NECUP-2 presents a new device in neurosurgical armamentarium that can be used in various fields of neurosurgery. With minimal and controlled lesion that is produced at the tip of the probe, it can be used in highly demanding operations such as third ventriculostomy and tumour resection.

Methods for measuring acoustic power of an ultrasonic neurosurgical device.

Measurement of the acoustic power in high-energy ultrasonic devices is complex due to occurrence of the strong cavitation in front of the sonotrode tip. In our research we used three methods for characterization of our new ultrasonic probe for neuroendoscopic procedures. The first method is based on the electromechanical characterization of the device measuring the displacement of the sonotrode tip and input electrical impedance around excitation frequency with different amounts of the applied electrical power The second method is based on measuring the spatial pressure magnitude distribution of an ultrasound surgical device produced in an anechoic tank. The acoustic reciprocity principle is used to determinate the derived acoustic power of equivalent ultrasound sources at frequency components present in the spectrum of radiated ultrasonic waves. The third method is based on measuring the total absorbed acoustic power in the restricted volume of water using the calorimetric method. In the electromechanical characterization, calculated electroacoustic efficiency factor from equivalent electrical circuits is between 40-60%, the same as one obtained measuring the derived acoustic power in an anechoic tank when there is no cavitation. When cavitation activity is present in the front of the sonotrode tip the bubble cloud has a significant influence on the derived acoustic power and decreases electroacoustic efficiency. The measured output acoustic power using calorimetric method is greater then derived acoustic power, due to a large amount of heat energy released in the cavitation process.

Telemedicine in neurosurgery: teleradiology connections in the Republic of Croatia.

In 1998, a teleradiology system was established in Croatia. It connects 34 CT, MRI and DSA scanners in 29 hospitals with a referral centre in the neurosurgery department in Zagreb. In the first three years of its use, the network saved more than 400,000 km of patient transportation (i.e. without a teleconsultation, all of the patients would have had to be transported to the nearest referral neurosurgical unit). During the first seven years, an archive with 25,366 expert opinions was collected. A total of 7103 (28%) expert opinions were provided for the distant regional hospitals. The most common diagnoses for patients from regional hospitals were neurotrauma (53%), cerebrovascular diseases (22%) and brain tumours (19%). The teleradiology system was used less often for lumbar disc disease (4%), hydrocephalus or other neurosurgical disorders (2%). The most valuable results from teleradiology were the decisions about proper and effective patient treatment. In Croatia, the national teleradiology network for neurosurgery has speeded up therapy, avoided unnecessary travelling for patients and reduced costs.

[Delusional disorder of the paranoid type and unruptured intracerebral aneurysm--is there an association?]. / Sumanuti poremecaj paranoidnog tipa i nerupturirana intracerebralna aneurizma--postoji li povezanost?

INTRODUCTION: Contrary to ruptured intracerebral aneurysm, according to our knowledge, not many papers have been published dealing with the relation of psychic/neuropsychological symptoms and unruptured intracerebral aneurysm (UIA). As to our knowledge, there is no published paper relating delusional disorder, paranoid type (DD-PT) and UIA, which can have important clinical implication. AIM, METHOD AND RESULTS: We describe a case of a woman who had DD-PT and UIA. The patient in her fifties, a typist with elementary school education, presented to the psychiatrist with the symptoms of irritability, insomnia, suspiciousness and paranoid ideas lasting for about a year. She showed clear symptoms of a delusional disorder. The psychiatrist established the diagnosis of DD-PT according to ICD-10. Olanzapine therapy, 10 mg day, was introduced immediately, causing partial improvement. In further diagnostic procedure, psychological tests were performed. The finding confirmed the diagnosis and average intellectual efficacy. The additional findings of impaired verbal fluency (VF) and hand tremor signalized an organic origin. The patient was referred to a neurologist, who assessed hand tremor, but otherwise the finding was normal. Brain CT revealed the possible UIA. Neurological hospitalization was quickly organized, and the definitive diagnosis of basilar artery aneurysm of 22 mm in diameter was made by angiography. Several days later, osteoplastic supraorbital craniotomy was performed at the neurosurgical department, with right sided keyhole approach in microsurgical technique, and the aneurysmal neck was clipped. The postoperative course was accompanied by meningitis treated with antibiotics. In neurological status, cerebellar symptomatology, tremor of the left hand, mild hemiparesis on the left side and the right eyelid ptosis persisted. Paranoid delusions were absent, but depressive symptoms emerged. Eight months after the surgery (approx. 11 months after the first test), control psychological testing was performed. The finding showed depression with significant perceptive disorganization. The VF result was within the normal limits. The patient is still being continuously followed-up. During preliminary diagnostic work-up, the possible organic cause and/or relation was suspected, based only on the psychiatric assessment and psychological report, because neurological status was free from any abnormalities other than tremor of the hands. CONCLUSION: The reported case confirmed the importance of detailed psychiatric interview and psychological testing in persons with psychic disorders, as well as the importance of multidisciplinary approach in the diagnosis and therapy. In this case, we could not find the exact way of connection between DD-PT and UIA.

[Isolated cervical spinal cord hemangioblastoma--case report]. / Izolirani hemangioblastom vratne kraljeznicne mozdine--prikaz bolesnika.

Hemangioblastomas are rare tumors which account for 0.9-2.1% of central nervous system neoplasms. The most common site of hemangioblastomas is the cerebellum, while they are rarely located in spinal cord, cerebrum and brain stem. Hemangioblastomas occur as a sporadic entity, and as a manifestation of von Hippel-Lindau syndrome. A 33-year old patient with isolated cervical spinal cord hemangioblastoma is presented.