摘要:

THE CLINICAL RELEVANCE of any scheme for classification of vascular malformations of the brain remains controversial. Widely accepted pathologic classifications include discrete venous, arteriovenous, capillary, and cavernous malformations. Of 280 cases of possible vascular malformations evaluated by a single cerebrovascular service during a 5-year period, 14 were instances of mixed vascular malformations including definite features of more than one pathologically discrete type of malformation within the same lesion. There were six instances of mixed cavernous and venous malformations in the same lesion; in all instances, the cavernous malformation accounted for the clinical presentation. There were three cases of mixed venous and arteriovenous malformations (arterialized venous malformations), presenting with the typical histoarchitectural appearance of a venous malformation, but with arteriovenous shunting; all cases were symptomatic, two with hemorrhage and one with focal neurological symptoms. There were five cases of predominantly cavernous malformations with features of arteriovenous malformation or capillary telangiectasia in the same lesion. These five cases presented clinically as angiographically occult lesions indistinguishable from a cavernous malformation. Lesions including a venous malformation were recognizable preoperatively because of characteristic imaging features of the venous malformation. Other mixed vascular malformations were indistinguishable on diagnostic studies from pure cavernous malformations. Of the 14 mixed vascular malformations, 11 included a cavernous malformation that was usually responsible for the symptomatic presentation. In the other three cases, manifestations of clinical lesions were due to arteriovenous shunting within a venous malformation. We conclude that mixed vascular malformations of the brain are rare entities with distinct clinical, radiological, and pathological profiles. Their identification generates several hypotheses about common pathogenesis or causation-evolution among different types of lesions.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

THE AUTHORS REPORT their experience with 25 patients (mean age, 44.3 ± 12.1 years) with an intracerebral hematoma (ICH) from a ruptured aneurysm who were emergently operated on without angiography. Instead, preoperative high-resolution infusion computed tomography (CT) scans were used to identify the aneurysm causing the hemorrhage. In all patients, the preoperative Glasgow Coma Scale score was <5 and brain stem compression was evident. ICH was present in the frontal or temporal lobe and was often associated with intraventricular hemorrhage (n = 17) and significant (>1 cm) midline shift (n = 18). Infusion CT scans correctly identified the aneurysm in all patients (middle cerebral artery, 18; posterior communicating artery, 2; carotid bifurcation, 3; anterior communicating artery, 2). Partial evacuation of the hematoma guided by infusion CT scan was usually required first to clip the aneurysm definitively using standard microvascular techniques. Intraoperative rupture occurred twice, and temporary clips were used on four occasions. Lobectomy (n = 8), decompressive craniotomy (n = 15), and ventriculostomy (n = 8) were required to control cerebral swelling. All patients underwent postoperative angiography to confirm aneurysm obliteration. Eleven unruptured aneurysms were subsequently identified. Nine had been predicted by infusion scan. Twelve patients survived, eight of whom were only moderately disabled and were independent at 6-months' follow-up. Of the 13 patients who died, all except one died within 4 days of admission. The authors conclude that although angiographic verification before aneurysm surgery is preferable, in the moribund patient with intracerebral hemorrhage, infusion CT scanning provides sufficient information concerning vascular anatomy to allow rational emergency craniotomy and aneurysm clipping.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

A SUBGROUP OF growth hormone (GH)-secreting pituitary tumors carries somatic mutations within the gene coding for the α subunit of the stimulatory heterotrimeric guanosine 5′-triphosphate-binding protein, Gsα. These so-calledgspmutations result in constitutively activated Gsα and the signal transduction cascade downstream of it, with eventual markedly and continuously elevated cyclic adenosine monophosphate levels as a result of constitutive adenylyl cyclase activity. It is this elevation of intracellular cyclic adenosine monophosphate that is thought to be the cause of excessive GH secretion and somatotroph proliferation. We examined the clinical and biochemical characteristics of acromegalics harboringgsp-positive andgsp-negative pituitary tumors. Of 19 tumors studied, 8 (42%) weregsppositive. There was a slight tendency for basal GH levels in serum to be lower and to be further reduced by an oral glucose tolerance test ingsp-positive patients. However, there was no difference between the two groups in terms of clinical features, tumor size, mitotic activity (as assessed by cytosolic deoxyribonucleic acid polymerase and KI-67 staining), and in vitro GH response to GH releasing factor. We conclude that there is, in general, little difference in the clinical and biochemical characteristics betweengsp-positive andgsp-negative human pituitary GH-secreting tumors.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

THE PATHOPHYSIOLOGICAL MECHANISMS to explain peritumoral edema have not been clarified. Multiple aspects of brain edema secondary to supratentorial meningiomas were prospectively investigated in a group of 29 patients who underwent surgery consecutively. Sixty-nine tumor samples were analyzed for prostanoid levels. Levels of 6-keto-PGF1α, the stable metabolite of prostacycline, were found to correlate well with the extent of edema (r= 0.51,P< 0.01). The ratio, 6-keto-PGF1α × PGE2/TXB2, was found to have the best correlation with edema index (extension/tumor volume) (r= 0.69,P< 0.005). A case of a hemangiopericytic meningioma with the largest edema extent within the study group also exhibited the highest level of 6-keto-PGF1α (2420 pg/mg protein). Steroid treatment (dosage, duration of therapy, and their product) did not correlate with prostaglandin levels. These finding may explain the inconsistent clinical effects of steroids on meningioma-induced edema. Possible explanations for this phenomenon are discussed. Otherwise, histology, pathological features of tumor aggressiveness, or mechanical parameters, such as its volume, location, and insertion site, did not correlate well with edema parameters or with prostaglandin levels. Similarly, tumor water content, imaging parameters in computed tomography and magnetic resonance, and operative findings (including dissection plane, vascularity, and tumor firmness) did not correlate well with edema parameters. Although a direct cause-effect relationship between prostaglandins and peritumoral edema is not conclusively established, the circumstantial evidence of the ability of prostaglandins to induce vasogenic brain edema and the robust association with peritumoral edema is persuasive. Our finding supports the hypothesis that it is the balance among various prostanoids with opposing vasoactive influence that determines the net peritumoral vascular physiology. Pharmacological treatment designed to influence this balance should be tested in future experimental and clinical trials.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

SIXTY-ONE MENINGIOMAS FROM 60 patients were screened for estrogen receptors and progesterone receptors (PgR) with monoclonal antibodies in an immunohistochemical assay. In addition, 43 of the cases were evaluated for tumor size and peritumoral edema, as seen on computed tomographic scans and magnetic resonance images. Sixty-one percent of the tumors contained significant amounts of PgR, whereas no estrogen receptor-positive tumor was observed. Thirteen percent of all tumors were classified as nonbenign variants (atypical and anaplastic meningiomas) and were more frequently found in male patients (P< 0.05). Nonbenign tumors more frequently showed an absence of PgR (P< 0.05), and there was a tendency for PgR-negative tumors to be larger than PgR-positive ones. No correlation was found between PgR status and edema. It is concluded that PgR status in meningiomas is related to tumor differentiation and may be of prognostic value with regard to biological behavior and clinical outcome.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

BRAIN INVOLVEMENT IN hydatid disease occurs in 1 to 2% of allEchinococcus granulosusinfections. Fifty to 75% of intracranial hydatid cysts are seen in children. This study included 19 children who underwent surgery for intracranial hydatid cysts between January 1979 and September 1992. There were 12 boys and 7 girls, ages 3 to 16 years (mean, 8.1 yr). Headache and vomiting were the predominant symptoms. Papilledema was present in 16 patients, and 2 patients had secondary optic atrophy. A round, cystic lesion without perifocal edema and rim enhancement was detected on the computed tomographic scans of 13 patients. The cystic lesions with rim enhancement and perifocal edema were noted on the computed tomographic scans of 3 patients. Of these three patients, two subsequently had a recurrence. Total removal of the cyst without rupture was achieved in 12 patients. Only a 3-year-old boy in whom the cyst ruptured at surgery died. Seven patients in whom either the hydatid cyst ruptured at surgery or there was systemic hydatid disease received mebendazole therapy. Mebendazole seems to be effective in hydatid disease. Cerebral hydatid cysts should be removed in toto without rupture. The preoperative diagnosis is very important in planning surgery. When a cystic lesion is detected on computed tomographic scan, hydatid disease should be taken into consideration in countries where hydatid disease is endemic.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

CHRONIC INTRATHECAL DRUG infusion for the treatment of neurological diseases, such as spasticity and chronic pain, has become an accepted method of therapy in recent years. Concurrent pharmacokinetic studies have shown that the cisternal cerebrospinal fluid (CSF) drug level is considerably lower than the lumbar CSF level during continuous infusion into the lumbar subarachnoid space. One factor that makes analysis of this decline in drug level difficult to quantify is that it is only feasible to sample CSF at the two extremes of the spinal subarachnoid space. Using a radionuclide technique, we have examined the distribution along the spinal canal of a hydrophilic compound, indium-111 diethylenetriamine pentaacetic acid, that was delivered over 72 hours into the lumbar subarachnoid space in five patients with implanted drug pumps. Over a 20-cm distance of the thoracic cord, radionuclide counts decreased gradually so that the indium-111 diethylenetriamine pentaacetic acid concentration surrounding the cord at the T2 vertebral level was 43% of that at the T12 level in four patients. Therefore, it appears that even with a hydrophilic compound, which minimizes spinal cord capillary losses, there is still a considerable reduction of CSF drug concentration along the spinal canal. The clinical implication of this gradual decline in drug level is that for intrathecal infusion of relatively hydrophilic compounds there may not be any advantage in placing the catheter tip at more rostral locations, such as at the midthoracic or cervical cord.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

RETINAL HEMORRHAGE AND intracranial hemorrhage in a child with little external evidence of trauma and with a poorly documented history are considered pathognomonic child abuse. The mechanism and magnitude of force required to produce the injuries are seldom witnessed or known. This study was designed to determine the incidence of retinal hemorrhage in pediatric head injuries under known accidental circumstances, in association with forces sufficient to cause skull fracture and/or intracranial hemorrhage. Of 525 consecutive hospital admissions for head injuries, 200 children filled these criteria. Thirty children were excluded because of suspected child abuse or gunshot wounds. Of the remaining 170, 140 were evaluated by an ophthalmologist for retinal hemorrhage. Two children, who were both involved in side-impact car accidents, had retinal hemorrhages in associated with severe head injury. Retinal hemorrhage occurs rarely in accidental head injury and is associated with extraordinary force.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

WE SUCCESSFULLY MANAGED 11 patients with aqueductal stenosis of adult or adolescent onset, with no mortality or significant morbidity, by using a flexible ventriculoscope to perform either a third ventriculostomy or an aqueductal plasty. A flexible fiberoptic ventriculoscope and its accessories were newly developed, and surgical techniques were improved. For all patients, cinemagnetic resonance imaging was a critical part of the preoperative and postoperative evaluation of cerebrospinal fluid flow in the third ventricle and in the aqueduct of Sylvius. All of the 11 patients showed patency to cerebrospinal fluid flow at the aqueduct of Sylvius and the floor of the third ventricle. Only one patient subsequently required a lumboperitoneal shunt. Flexible endoneurosurgical management is simple and safe and allows in situ observation and the ability to perform biopsies. Therefore, flexible endoneurosurgical third ventriculostomy and aqueductal plasty are now considered our treatment of choice for aqueductal stenosis in adults and adolescents.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

A TECHNIQUE FOR achieving a combined pterional (subfrontal) and anterior temporal exposure for aneurysms of the upper basilar complex is described. The technique is not new, but it does involve several modifications not previously described. A standard pterional skin incision that extends below the zygoma just anterior to the tragus is used. The skin flap is separated from the temporal fascia down to the fat pad over the zygoma; at this point, the superficial layer of the temporalis fascia is incorporated and retracted with the skin flap to expose the zygomaticofrontal process and the zygomatic arch. The muscle is cut anteriorly and inferiorly and is retracted posteriorly over the ear. The bone flap includes the anterior temporal squama down to the temporal floor anteriorly. The pterion and the sphenoidal wings are drilled so as to expose completely the dura over the anterior temporal pole. After opening the dura on a flap centered on the sylvian fissure, the medial cisterns are opened widely and the fissure is opened all the way to the middle cerebral bifurcation. Posterolateral temporal retraction and, when necessary, subpial resection of the anteromedial portion of the uncus enhance the exposure posterolateral to the oculomotor nerve. The advantages of this combined approach are as follows: it combines the more anterior angle of vision offered by the pterional approach with the lateral line of vision offered by the subtemporal approach; it eliminates the need for temporal lobe elevation and it allows simultaneous clipping of other aneurysms of the ipsilateral anterior circle of Willis; and it also reduces the frequency and severity of oculomotor palsy, when compared with the subtemporal approach.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID