Asymptomatic brain tumor detected at brain check-up

Brain check-up was performed in 4000 healthy subjects who underwent medical and radiological examinations for possible brain diseases in our hospital from April 1996 to March 2000. Magnetic resonance imaging revealed 11 brain tumors which consisted of six meningiomas, three pituitary adenomas, one astrocytoma, and one epidermoid cyst. The detection rate of incidental brain tumor in our hospital was 0.3%. Nine patients underwent surgery, with one case of morbidity due to postoperative transient oculomotor nerve paresis. The widespread use of brain check-up may increasingly detect asymptomatic brain tumors. Surgical indications for such lesions remain unclear, and the strategy for treatment should be determined with consideration of the patient's wishes.     

Clinical application of brain hypothermia therapy for acute brain insults

Brain hypothermia therapy has been expected to lead to good neurological outcome in acute brain insults. There are a few positive results which have been proven by multicenter randomized clinical trials (RCT) in the cardiopulmonary arrest (CPA) in patients with ventricular fibrillation. Among these clinical trials, early application of hypothermia, maintenance of cerebral blood flow during hypothermia therapy and prevention of quick rewarming are pointed out to result in good outcome from clinical experiences. For brain hypothermia therapy to become an effective method for acute brain insults, indications, brain oriented intensive cares and biomarkers for the therapy must be established. RCT in acute brain insults beside CPA victims are needed in the near future.     

Assessment of brain shift related to deep brain stimulation surgery

Deep brain stimulation (DBS) surgery can significantly improve the quality of life for patients suffering from movement disorders, but the success of the procedure depends on the implantation accuracy of the DBS electrode array. Pre-operative surgical planning and navigation are based on the assumption that the brain tissue is rigid between the time of the acquisition of the pre-operative image set and the time of surgery. A shift of deep brain structures by only a few millimeters can potentially increase the number of required microelectrode and/or macroelectrode tracks and decrease implantation accuracy. We studied 25 subjects that underwent DBS surgery and analyzed brain shift between pre-operative and post-operative 3D MRI scans. Brain shift of up to 4 mm was observed in deep brain structures. On average, the recorded shift was in the direction of gravity, with deeper structures experiencing smaller shift than more superficial structures. The main conclusion of the study is that the brain shift is comparable to the size of the targets in deep brain stimulation surgery and should not be ignored. Techniques that minimize the amount of brain shift may therefore lead to increased accuracy of DBS lead implantation.     

Platelet-activating factor and progressive brain damage following focal brain injury

The effects of a platelet-activating factor (PAF) antagonist on brain edema, cortical microcirculation, blood-brain barrier (BBB) disruption, and neuronal death following focal brain injury are reported. A neodymium:yttrium-aluminum-garnet (Nd:YAG) laser was used to induce highly reproducible focal cortical lesions in anesthetized rats. Secondary brain damage in this model was characterized by progressive cortical hypoperfusion, edema, and BBB disruption in the vicinity of the hemispheroid lesion occurring acutely after injury. The histopathological evolution was followed for up to 4 days. Neuronal damage in the cortex and the hippocampus (CA-1) was assessed quantitatively, revealing secondary and progressive loss of neuronal tissue within the first 24 hours following injury. Pretreatment with the PAF antagonist BN 50739 ameliorated the severe hypoperfusion in 12 rats (increasing local cerebral blood flow from a mean +/- standard error of the mean of 40.5% +/- 8.3% to 80.2% +/- 7.8%, p less than 0.01) and reduced edema by 70% in 10 rats (p less than 0.05) acutely after injury. The PAF antagonist also reduced the progression of neuronal damage in the cortex and the CA-1 hippocampal neurons (decrease of neuronal death from 88.0% +/- 3.9% to 49.8% +/- 4.2% at 24 hours in the cortex and from 40.2 +/- 5.0% to 13.2% +/- 2.1% in the hippocampus in 30 rats; p less than 0.05). This study provides evidence to support progressive brain damage following focal brain injury, associated with secondary loss of neuronal cells. In this latter process, PAF antagonists may provide significant therapeutic protection in arresting secondary brain damage following cerebral ischemia and neurological trauma.     

颅脑外伤后进展性脑损害的研究进展

颅脑外伤后进展性脑损害,包括脑出血、脑缺血、脑水肿,都是影响颅脑外伤预后的重要因素.本文复习文献,对颅脑外伤后进展性脑损害的发病率、发生机制、早期诊断方法、治疗和预后等相关问题的研究进展进行了综述.     

Effect of AVP on brain edema following traumatic brain injury

Objective: To evaluate plasma arginine vasopressin (AVP) level in patients with traumatic brain injury and investigate the role of AVP in the process of brain edema. Methods: A total of 30 patients with traumatic brain injury were involved in our study. They were divided into two groups by Glasgow Coma Scale: severe traumatic brain injury group (STBI, GCS≤8) and moderate traumatic brain injury group ( MTBI, GCS >8). Samples of venous blood were collected in the morning at rest from 15 healthy volunteers (control group) and within 24 h after traumatic brain injury from these patients for AVP determinations by radioimmunoassay. The severity and duration of the brain edema were estimated by head CT scan. Results: plasma AVP levels (ng/L) were (mean±SD): control, 3. 06±1. 49; MTBI, 38. 12±7. 25; and STBI, 66. 61±17. 10. The plasma level of AVP was significantly increased within 24 h after traumatic brain injury and followed by the reduction of GCS, suggesting the deterioration of cerebral injury (P<0. 01). And the AVP level was correlated with the severity (STBI r =0.919, P < 0.01; MTBI r = 0.724, P < 0.01) and the duration of brain edema (STBI r = 0. 790, P < 0. 01; MTBI r = 0. 712, P<0.01). Conclusions: The plasma AVP level is closely associated with the severity of traumatic brain injury. AVP may play an important role in pathogenesis of brain edema after traumatic brain injury.     

Comparison of stereotactic brain biopsy to interventional magnetic-resonance-imaging-guided brain biopsy

Lesions within the brain are commonly sampled using stereotactic techniques. The advent of interventional magnetic resonance (MR) imaging now allows neurosurgeons to interactively investigate specific regions with exquisite visualization. We compared the safety and efficacy of this new surgical approach with stereotaxis. From February 1991 to June 1998, 134 stereotactic and 35 interventional MR-guided brain biopsies were performed. Stereotactic biopsies utilized preoperative scanning. Interactive scanning was used to confirm accurate positioning of the biopsy needle within the region of interest. Intraoperative pathologic examination of biopsy material was performed to verify the presence of diagnostic tissue in both biopsy groups. Intra- and postoperative MR imaging was obtained to exclude the presence of intraoperative hemorrhage. Recently, MR spectroscopic targeting has been utilized in 6 patients. In the stereotactic group, 129/134 (96%) biopsies were diagnostic. One patient had a transient hemiparesis after a brain stem biopsy and another suffered a fatal hemorrhage for a morbidity rate of 0.7% and a mortality rate of 0.7%. In reviewing 7,471 stereotactic biopsies, the morbidity was 3.5%, mortality 0.7% and diagnostic yield 91%. All 35 MR-guided brain biopsies were diagnostic (100%). MR spectroscopy was accurate in all cases in distinguishing recurrent tumor (5 cases) from radiation necrosis (1 case). One patient (3%) suffered a transient hemiparesis following a pontine biopsy and another patient (3%) developed a postoperative scalp cellulitis. No patient sustained a clinically or radiologically significant hemorrhage as determined by the immediate postbiopsy, intraoperative MR imaging. Interventional MR-guided brain biopsy is a safe and effective technique for evaluating lesions of the brain with morbidity and mortality rates comparable to those of stereotaxis. MR-guided biopsy appears to have a higher diagnostic yield than stereotaxis, which may reflect the ability to perform interactive, intraoperative scanning with that technique.     

Decompressive craniectomy in traumatic brain injury and malignant brain infarction

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury and malignant cerebral infarction. After failure of general therapeutic maneuvers and first line therapies, "second tier" therapies have to be considered. Decompressive craniectomy is an advanced treatment option for controlling intracranial pressure (ICP). In this review indications and techniques of decompressive craniectomy are described and current literature is discussed. The author concludes that decompressive craniectomy is no routine, but should be considered in individual cases.