Talat Kırış

Cerebral vasospasm following subarachnoid hemorrhage: time for a new world of thought

Abstract Objective: Delayed cerebral vasospasm has long been recognized as an important cause of poor outcome after an otherwise successful treatment of a ruptured intracranial aneurysm, but it remains a pathophysiological enigma despite intensive research for more than half a century. Method: Summarized in this review are highlights of research from North America, Europe and Asia reflecting recent advances in the understanding of delayed ischemic deficit. Result: It will focus on current accepted mechanisms and on new frontiers in vasospasm research. Conclusion: A key issue is the recognition of events other than arterial narrowing such as early brain injury and cortical spreading depression and of their contribution to overall mortality and morbidity.

Posterior fossa epidural hematomas in children: clinical experience with 40 cases

OBJECT Traumatic posterior fossa epidural hematoma (PFEDH) is rare, but among children it may have a slightly higher incidence. With the widespread use of CT scanning, the diagnosis of PFEDH can be established more accurately, leading to an increased incidence of the lesion and possibly to a better patient prognosis. This study presents 40 pediatric cases with PFEDH. METHODS The authors assessed the type of trauma, clinical findings on admission, Glasgow Coma Scale scores, CT findings (thickness of the hematoma, bone fracture, compression of the fourth ventricle, and ventricle enlargement), type of treatment, clinical course, and prognosis. Early postoperative CT scans (within the first 6 hours) were obtained and reviewed in all surgical cases. RESULTS Twenty-nine patients underwent surgery and 11 patients received conservative therapy and close follow-up. All patients fared well, and there was no surgical mortality or morbidity. CONCLUSIONS Based on the data in this large series, the authors conclude that PFEDH in children can be treated in experienced centers with excellent outcome, and there is no need to avoid surgery when it is indicated.

Fluorescein-Guided Resection of Intramedullary Spinal Cord Tumors: Results from a Preliminary, Multicentric, Retrospective Study

BACKGROUND Intramedullary spinal cord tumors (IMSCTs) are rare, heterogenous lesions that are usually enhanced on preoperative magnetic resonance imaging (MRI) because of a damaged blood-brain barrier. Sodium fluorescein is a dye that accumulates in areas of the central nervous system with a damaged BBB. Given the pattern of MRI contrast enhancement of the majority of IMSCTs, the use of this fluorescent tracer could improve tumor visualization and quality of resection. In this article, we present the first experience with the application of fluorescein-guided technique for surgical removal of IMSCTs. METHODS Eleven patients (6 men, 5 women; mean age, 50.1 years), harboring 5 ependymomas, 3 hemangioblastomas, 1 astrocytoma, 1 pilocytic astrocytoma, and 1 glioneuronal tumor forming rosettes were included. Sodium fluorescein (5 mg/kg) was injected immediately after patient intubation. Tumors were removed with microsurgical technique and standard neurophysiological monitoring, under YELLOW 560 filter (Pentero 900) visualization. Surgical reports were reviewed regarding usefulness and grade of fluorescein staining. Postoperative MRI was performed within 72 hours after surgery, and postoperative clinical outcome was registered. RESULTS No adverse events were registered. Fluorescent staining was reported in 9 of 11 cases (82%), all of them enhancing on preoperative MRI (100% of ependymomas, 100% of pilocytic astrocytomas, 100% of hemangioblastomas). No fluorescence was reported in 1 astrocytoma and 1 glioneuronal tumor-forming rosette. Intraoperative fluorescence was considered helpful for tumor resection in 9 of 11 cases (82%). Gross total resection was obtained in 8 of 11 cases (72.7%). CONCLUSIONS Our results suggest that fluorescein-guided surgery is a safe and effective technique that can be used during the surgical resection of IMSCTs presenting with contrast-enhancement on preoperative MRI.

Intraventricular albumin: an optional agent in experimental post-traumatic brain edema

Abstract Hypothesis: Human albumin may be effective in the treatment of posttraumatic brain edema due to its hyperoncotic features. Therefore, the aim of the experimental study presented in this paper has two points: the first is to evaluate the efficacy of intraventricular hyperoncotic human albumin on post-traumatic brain edema and the second is to try to show the appropriate posttraumatic time window for albumin administration. Method: Traumatic brain injury and subsequent edema was formed by a model of impact acceleration injury in rats. Human albumin was administered via intraventricular route by using a stereotactic head holder. All animals in each group were decapitated 24 hours after the procedure and the effect of albumin was evaluated by measurement of tissue specific gravity. Results: Tissue specific gravity decreased in edematous tissue (trauma indicator), increased after albumin administration at the 12th (p<0.001), and both at the 1st and 12th hour of the trauma (edema treatment; p<0.001). On the other hand, albumin administered at the 12th, and at both the 1st and 12th hours in the rats without trauma has caused the formation of the brain edema. Conclusion: We conclude that human albumin is effective in cytotoxic, but not in vasogenic edema and exerts its best anti-edematous effect at the 12th hour of severe head trauma and this study may help future studies that will try to show the effects of albumin with different time modalities after severe head injury.

Clinical features, prothrombotic risk factors, and long-term follow-up of eight pediatric Moyamoya patients.

Background and Purpose The aim of this study was to elucidate the clinical features, prothrombotic risk factors, and outcome of pediatric Moyamoya patients. Methods Patients diagnosed with Moyamoya disease at a tertiary center between January 2000 and December 2006 were enrolled in this study. The clinical presentations, underlying diseases, prothrombotic risk factors, family history of thrombosis, radiological findings, treatment, and outcome of the patients were reviewed retrospectively. Results Eight patients with angiographically proven Moyamoya disease were identified, one of whom had neurofibromatosis type I and one had Down syndrome. The age at diagnosis varied between 19 months and 11 years (73.4±41.8 months, mean±SD). The follow-up period after diagnosis was 52.5±14.8 months. In six patients, the initial clinical presentation was hemiparesis. None of the patients had any identifiable prothrombotic factors. Despite medical and surgical treatment, three patients had recurrences and one died. Only two patients recovered without sequelae. Conclusions The value of prothrombotic risk factor evaluation appears to be limited in Moyamoya patients; the outcome for pediatric patients remains dismal.

Effect of Visible Light on Vasospasticity of Post–Subarachnoid Hemorrhage Cerebrospinal Fluid

Background and Objective Cerebral vasospasm (CV) is a serious complication of subarachnoid hemorrhage (SAH) with high morbidity and mortality rates. The mechanism of CV has not been determined. There are many theories related to this unsolved issue, one of which supports CV as a two‐stage phenomenon from a pathophysiologic perspective. The first stage consists of inhibition of neuronal nitric oxide synthase by oxyhemoglobin, which results in a decrease of nitric oxide (NO) production. The second stage consists of an increase in the levels of asymmetric dimethylarginine through bilirubin oxidation products (BOXes), which are oxidized by‐products of hemoglobin metabolism. These in turn inhibit endothelial nitric oxide synthase (eNOS), which results in the blockage of the second NO production mechanism. BOXes are sensitive to visible light, as is their precursor bilirubin. The hypothesis of CV prevention using the photosensitivity of BOXes was tested in this study. Material and Methods Cerebrospinal fluid (CSF) obtained from two patients with SAH was divided in half and either exposed to a standard dose of visible light or not exposed to any light. The CSF was spectrophotometrically investigated and the concentration of BOXes was measured. A comparison between CSF samples exposed to light and not exposed to light was made. Using two groups of 16 rats each, the vasospastic effect of the CSF exposed and not exposed to light on arteries of the cortical surface was measured. The cortex was exposed using the cranial window. Results Spectrophotometric analysis revealed that the concentration of BOXes in the CSF decreased significantly after being exposed to visible light (p < 0.001). There was a significant difference of the vasospastic effect of CSF on exposed cortical arteries (p < 0.001). Conclusion The concentration of BOXes and the vasospastic effect of CSF taken from patients with SAH were significantly reduced after being exposed to visible light if compared with CSF not exposed to light.

Clinical course of nontraumatic nonaneurysmal subarachnoid hemorrhage: a single institution experience over 10 years and review of the contemporary literature

AIM To report our experience with a relatively large series of patients with non-traumatic non-aneurysmal subarachnoid hemorrhage (NNSAH) to identify the prognosis associated with different bleeding patterns as well as a further diagnostic work-up to determine the underlying cause. MATERIAL AND METHODS Between January 2004 and December 2014, 81 patients with angiography-negative non-traumatic subarachnoid hemorrhage (SAH) were treated at our institution. Diagnosis was confirmed with a typical history of spontaneous SAH and cranial computed tomography (CT) scan or lumbar puncture (LP). The patients were grouped according to the bleeding pattern on the CT scan: Group 1: Perimesencephalic (PM) SAH (n=33, 40.7%); Group 2: Non-perimesencephalic (nPM) SAH (n=41, 50.6%); and Group 3: CT-negative NNSAH (n=7, 8.6%). The clinical course, hospitalization period, and complications were noted. All patients underwent an initial four-vessel digital subtraction angiography (DSA). Cranial magnetic resonance imaging (MRI), repeat DSA investigations and spinal MRI were performed in all patients. RESULTS The mean hospital stays were 6.3, 14.7 and 10.1 days for patient groups 1, 2, and 3, respectively. The mortality rate was 1.2% (1 patient) in our series. Repeat DSA investigations were positive in two patients (2.5%), both from Group 2 (4.9%). Cranial MRI revealed 100% negative results. Spinal MRI revealed positive results in three patients from Group 2 (7.3%). CONCLUSION We suggest our diagnostic work-up for patients with nPM-SAH, namely repeat DSA and spinal MRI, until an evidence-based guideline is established for the patient management.

Life-threatening parkinsonism-hyperpyrexia syndrome following bilateral deep brain stimulation of the subthalamic nucleus

Parkinsonism-hyperpyrexia syndrome (PHS), or neuroleptic malignant syndrome (NMS), is a neurophysiologic reaction to the acute withdrawal/decrease of central dopamine levels. It is a severe complication characterized by rigidity, change in consciousness level, fever, hypertension, and autonomic instability, that can be fatal. To the best of our knowledge, PHS following deep brain stimulation (DBS) of subthalamic nucleus (STN) surgery due to anti-Parkinson drug discontinuation has been previously reported only six times. Half of these cases resulted in fatalities. Herein, we report on an early diagnosed case of PHS following bilateral STN-DBS which was successfully treated with the administration of dopamine agonists, fluid replacement, and activation of DBS.

Primary Malignant Tumor of the Brachial Plexus Mimicking Schwannoma: Case Report

Primary malignant tumors of the brachial plexus are rarely encountered compared to the benign pathologies of the region. In this report, we present a case with a primary malignant tumor of the brachial plexus which presented difficulties in making differential diagnosis between malignant peripheral nerve sheath tumor and synovial sarcoma based on its pathology, and operated with a suggestive diagnosis of a schwannoma. The diagnostic tests, surgical approach and treatment modalities were discussed in the light of current literature.