Benign intracranial hypertension vs. intracranial arteriovenous malformation: A possible CT dilemma

Summary A nine-year-old boy, presenting only with signs of increased ICP, underwent computerized tomography. This examination demonstrated no abnormalities in the precontrast scan. Following C. E., it showed scattered areas of blood-like density in both hemispheres, as well as a presumedly abnormal vessel in the left occipital region and dilated vein of Galen, sinus rectus, and tentorial veins. The presumptive diagnosis of left occipital AVM was not confirmed by angiography, which also ruled out obstructions of the intracranial sinuses.The possible mechanism responsible for this atypical CT picture is briefly discussed in the light of pertinent literature. It is suggested that careful consideration should be given to the indications for angiography in similar cases, in the presence of a hypervascular aspect of the postcontrast CT scan, particularly if a considerable amount of contrast medium has been used.     

Analysis of intracranial pressure

Methods for the acquisition and analysis of intracranial pressure (ICP) signals are reviewed from clinical and technical perspectives. The clinical importance of ICP monitoring is presented, and methods for ICP transduction are briefly discussed. These methods include intraventricular catheters, subarachnoid screws, epidural techniques, and the new fiberoptic ICP measurement systems. Approaches to the visual analysis of the ICP waveform are presented, with special emphasis on the relationship between the ICP waveform and the arterial blood pressure signal. Methods of computer-based ICP analysis are also reviewed, including histogram and systems analysis methods. Methods to predict ICP pressure rises and to estimate intracranial compliance are also discussed. Finally, ICP monitoring is reviewed from the point of view of patient outcome. It is concluded that advanced ICP waveform analysis methods warrant further clinical evaluation to demonstrate their clinical usefulness.     

Mass lesions of the frontal lobes in acute head injuries. A comparison with temporal lesions

Summary Contusions and lacerations of the frontal lobes are very frequent; 43.4% in the whole series of traumatic brain mass lesions. Clinical, ICP, CT scan data and neuropathological findings in patients with such lesions are analysed and correlated. Moreover, the clinical features and the outcome of frontal masses undergoing surgery are also compared with similar lesions located in the temporal lobes.Frontal lesions cannot be differentiated on purely clinical grounds and the factors governing the outcome in both locations are the same. On the whole, surgical indications nowadays seem to be rather rare; only lesions behaving truly as expanding lesions with obvious intracranial hypertension benefiting from surgery.Brain contusion-laceration syndromes in general can no longer be considered separate entities. Neither should they be included in the miscellaneous group of traumatic intracranial mass lesions, since the pathophysiological significance of purely extracerebral effusions is entirely different.Traumatic contusions and lacerations and/or intracerebral haematomas, whether frontal or located elsewhere, should, instead, be considered in the context of head injuries of a different degree of gravity, as having collateral features which, on occasion, may call for surgical management.     

Combined endovascular therapy of ruptured aneurysms and cerebral vasospasm

We describe two patients with subarachnoid haemorrhage due to a ruptured intracranial aneurysm and severe symptomatic vasospasm. The aneurysm was occluded with detachable coils followed by intra-arterial infusion of papaverine to treat vasospasm as an one-stage procedure. There was significant resolution of the vasospasm. The long-term clinical outcome in one patient was excellent, the other still has minor deficits. Combined endovascular aneurysm therapy followed by intra-arterial spasmolysis with papaverine is a technically feasable therapeutic alternative in patients with symptomatic vasospasm. Received: 5 November 1999/Accepted: 12 July 2000     

急性脑肿胀去大骨瓣减压术后迟发性血肿

目的探讨外伤后急性脑肿胀去大骨瓣减压术后迟发性血肿的发病机制及临床表现，以提高该类病人的手术疗效。方法回顾性分析28例急性脑肿胀去大骨瓣减压术后迟发性颅内血肿病人的临床表现。结果外伤后急性脑肿胀去大骨瓣术后迟发性血肿的发生率为19．56％，术区继发硬膜外血肿10．87％。死亡率为32．12％。结论急性脑肿胀去大骨瓣术后迟发性血肿的发生率较高，多见于脑肿胀缓解病例，对术中出现的急性脑膨出和术后病情恶化应考虑到迟发性血肿的可能，早期的诊断是提高疗效的关键。     

PRIMARY INTRACRANIAL GERM CELL TUMORS: Clinicopathologic Review of 32 Cases

Primary intracranial germ cell neoplasms are rare tumors and constitute a heterogeneous group. We have reviewed 32 cases, over a 21-year period, from the University of Florida. The cases include 22 germinomas, 6 mixed germ cell tumors, and 4 teratomas. The clinical presentations in these cases were more closely related to the location of the tumor, that is, pineal or suprasellar, rather than the histologic subtype. Neuroimaging evaluation was useful in distinguishing between germinomas, teratomas, and other mixed germ cell tumors (MGCTs), primarily by evaluation of cystic versus solid lesions (teratoma versus germinoma), contents of cysts (teratoma versus MGCT), and infiltrative nature of the tumors (MGCT), although cytologic-histopathologic confirmation remains necessary. Germinomas responded favorably to radiation therapy with survival periods of over 16 years; MGCTs were treated with combination chemotherapy and radiation, with a markedly poorer prognosis. This study underlines the critical significance of histopathologic evaluation of the tumor in determining therapeutic interventions as well as prognosis.     

急性颅内血肿清除后继发对侧迟发性血肿

目的：急性外伤性颅内血肿清除的术中及术后，如及时发现对侧迟发性血肿并治疗可提高疗效。方法：在术中发生急性脑肿胀时应在对侧钻颅探查或术后病人恶化时行ＣＴ检查。结果：治疗３０例对侧迟发血肿病人其中１０例死亡，手术死亡率为３３．３％。结论：在清除急性外伤性颅内血肿时发生急性脑肿胀或术后病情恶化应想到对侧可能是迟发性血肿形成，宜尽早钻颅探查或复查ＣＴ，早诊早治可改善预后。     

Permanent low-activity iodine-125 implants for cerebral metastases

Beginning in 1987, selected patients with metastatic braintumors were treated with permanent implants of low-activityradioactive iodine-125 (¹²⁵I) seeds. These patients underwent craniotomy,gross total resection of the metastatic lesion, andplacement of the seeds. In general, criteria fortreatment included the presence of a recurrent tumorwith a volume too large to permit radiosurgery,and a Karnofsky Performance Score of 70 orhigher. Thirteen patients underwent 14 implant procedures; allreceived external whole-brain radiotherapy. Implant dose ranged from43 Gy to 132 Gy, with a meanof 83 Gy. Survival after implantation ranged from2 weeks to almost 9 years, with amedian of 9 months. Clinical and radiographic localcontrol was obtained in 9 patients. Two patientsdied of acute, postoperative complications within a monthof implantation, so no information regarding tumor controlis available for them. Late complications included abone flap infection in one patient and aCSF leak in another; both were treated withoutfurther sequelae.These results demonstrate that permanent ¹²⁵I implants canresult in good survival and quality of life,and occasionally can yield long-term survival. Potentially, itis a cost-effective treatment in that a separateprocedure for stereotactic implantation or radiosurgery is notneeded, as is the case with the useof temporary high-activity seeds. The permanent implantation itselfadds less than 10 minutes to the craniotomy,and the risk of symptomatic radiation necrosis islow. We recommend consideration of this procedure inpatients harboring large, recurrent metastatic tumors that requirefurther surgery.     

Incidence studies of primary and secondary intracranial tumors: A systematic review of their methodology and results

We reviewed the incidence studies of intracranial tumors to compare their methodology and identify whether there was evidence of true differences in incidence by time, place, age, or sex. Studies were identified from Medline (1966–95), bibliographies of relevant articles, and personal knowledge. For each study, various methodological details were recorded, along with the age-standardized incidence of all primary tumors and the crude and age/sex-specific incidences of different types of intracranial tumor. Methodological factors which significantly influenced the reported incidence were identified and the results of different studies were compared and combined in a meta-analysis if appropriate. Twenty studies (over 20,000 primary tumors) were included. Higher incidences of primary tumors were found in studies that: used many methods to identify cases (odds ratio [OR] 1.92); included a high percentage of asymptomatic patients (OR 2.03); did not require histologic confirmation of the diagnosis (OR 1.69). Studies from the 1980's reported higher incidences than in previous decades (OR 1.51), probably because of improved methodology. Comparable studies from the 1980's gave widely different incidence rates for all primary tumors (7.1–18.6 per 100,000 per year). In all studies, the incidence of neuroepithelial and meningeal tumors increased dramatically with age. Neuroepithelial tumors were 40% more common in men, whilst meningeal and cranial nerve tumors were about 80% and 40% more common in women, respectively. Further incidence studies are required to establish geographical and secular variations in the incidence of primary intracranial tumors but these must use comparable methodologies. Provisional guidelines for future studies are given.     

Intracranial chondroma of the occipital lobe

A case report of an intracranial chondroma is discussed with emphasis on magnetic resonance imaging.