Detachable balloon embolization: concomitant use of a second safety balloon.

We describe a relatively unusual case of carotid cavernous fistula in association with a persistent trigeminal artery, presumably related to aneurysm rupture near the carotid origin of the vessel. We emphasize the use of a second, nondetachable balloon solely for the purpose of stabilizing placement of the first device at the time of detachment.

Assessment of the efficacy of noninvasive screening for patients with asymptomatic neck bruits.

BACKGROUND AND PURPOSE: Several recent clinical trials have shown that endarterectomy is efficacious in patients with asymptomatic carotid artery stenosis. The purpose of this study was to evaluate the effectiveness of various test strategies for screening and diagnosing carotid artery disease. METHODS: We constructed a model of the natural history of carotid artery disease using literature-based estimates of the prevalence and incidence of carotid artery stenosis and associated morbidity and mortality. Markov cohort simulation was used to estimate the mean quality-adjusted life years and monetary costs associated with various management strategies. RESULTS: Screening is cost-effective in the baseline model. Key parameters affecting the efficacy of screening are prevalence of operable lesions, benefit of surgery, surgical complication rates, quality of life with stroke, rate of stenosis progression, and excess morbidity and mortality. CONCLUSIONS: Asymptomatic patients with carotid bruits may benefit from screening if the prevalence rate is > or = 20%, the benefits and risks associated with surgery are similar to those observed in the Asymptomatic Carotid Atherosclerosis Study, and the quality of life with stroke is considerably lower than the quality of life without stroke. Ultrasound followed by three-dimensional time-of-flight MR angiography, if indicated, is a promising test strategy.

Current implications for the efficacy of noninvasive screening for occult intracranial aneurysms in patients with a family history of aneurysms.

Although the technology exists for accurate noninvasive screening for intracranial aneurysms, the efficacy of screening depends on several key parameters of the natural history of aneurysms. Recent studies suggest that the prevalence of intracranial aneurysms may reach 20% in the subpopulation of patients with a family history of these lesions; other key parameters are less certain. The authors investigated factors that impact the efficacy of screening to establish interim guidelines. Three plausible models for the natural history of aneurysms were constructed. For each model the monetary cost of screening and the average gain in life expectancy were computed for a range of screening ages and prevalence rates. It is shown that the efficacy of screening depends on the pattern of aneurysm rupture. If aneurysms develop and rupture rapidly, then screening has no benefit. On the other hand, if aneurysms remain at risk for some time after formation, then screening may improve average life expectancy depending on when it occurs. The authors recommend that patients with a positive family history of aneurysms who are 30 years of age or younger be screened. This recommendation is based on the belief that the gains attributable to screening, assuming a constant rupture rate, outweigh the losses attributable to screening using a decreasing rupture rate model.

Intracranial hypertension after resection of cerebral arteriovenous malformations. Predisposing factors and management strategy.

BACKGROUND AND PURPOSE: Surgical excision of cerebral arteriovenous malformations (AVMs) may be complicated by postoperative breakthrough edema and hemorrhage and by intracranial hypertension. Embolization, staged resection, and meticulous surgical technique have decreased but not completely eliminated this complication. In this study we prospectively assess the prevalence of intracranial hypertension after excision of cerebral AVMs, examine factors predisposing to this complication, and document the outcome of aggressive monitoring and treatment of elevated intracranial pressure (ICP). METHODS: During a 4-year period at a single institution, 32 consecutive patients with cerebral AVMs underwent surgical excision after staged embolization. All patients underwent postoperative monitoring of ICP and a uniform management protocol of intracranial hypertension. RESULTS: Intractable intracranial hypertension was encountered after resection of 9 of 32 cerebral AVMs, including 3 of 20 (15%) AVMs 6 cm or less in maximum diameter and 6 of 12 (50%) AVMs greater than 6 cm in maximum diameter. This complication occurred in 5 of 10 (50%) lesions located in distal or border-zone locations, in 4 of 9 (44%) AVMs arising directly off proximal cerebral arteries, and in none of 13 AVMs in other locations. Preoperative single-photon emission-computed tomography perfusion scans were performed in 17 patients and demonstrated parenchymal hypoperfusion beyond the AVM nidus in 5 of 10 AVMs 6 cm or less in maximum diameter, none of which manifested postoperative intractable ICP. Hypoperfusion was observed on single-photon emission-computed tomography in 7 of 7 AVMs greater than 6 cm that were studied by this modality, and intractable ICP was observed postoperatively in 5 of these cases despite preoperative staged embolization in every case. Patients with symptomatic intractable ICP were treated with intravenous short-acting barbiturates under a strict critical care protocol. There was no instance of uncontrollable intracranial hypertension or break-through edema while on barbiturate therapy. There was no permanent morbidity related to this treatment and no mortality or new disability morbidity in this series. CONCLUSIONS: We conclude that intractable intracranial hypertension remains a common complication after resection of a subgroup of cerebral AVMs despite preoperative embolization, modern neuroanesthesia and critical care management, and microsurgical technique. A proactive management protocol aimed at ICP control is safe and effective in the management of this complication.

Stereotactic and computer-assisted neurosurgery at the Cleveland Clinic: review of 501 consecutive cases.

BACKGROUND: Stereotactic and computer-assisted techniques have revolutionized the diagnosis and treatment of many disorders of the brain by directing surgical instruments, the surgeon's hands, or focused radiation to an imaged target along predefined routes. METHODS: This report reviews the basic principles and techniques of stereotactic and computer-assisted procedures in 501 consecutive procedures. RESULTS: Procedures performed include biopsy; decompression of cysts, hematomas, ventricles, and abscesses; "point," computer-assisted volumetric, and frameless stereotactic resection of brain lesions; placement of depth electrodes; treatment of movement or pain disorders; implantation of radioactive seeds in malignant tumors; and radiosurgery. CONCLUSIONS: Overall, image-directed stereotactic neurosurgery proved safe, accurate, and versatile.

Pathogenesis of subcortical hyperintense lesions on magnetic resonance imaging of the brain. Observations in patients undergoing controlled therapeutic internal carotid artery occlusion.

BACKGROUND AND PURPOSE: Factors associated with the pathogenesis of subcortical hyperintense lesions on magnetic resonance imaging of the brain are not known. We describe four cases of de novo genesis of subcortical hyperintense lesions in patients undergoing controlled therapeutic internal carotid artery occlusion, and we speculate on associated pathophysiological mechanisms. METHODS: Twelve consecutive patients underwent controlled therapeutic internal carotid artery occlusion for symptomatic giant cerebral aneurysm using the detachable balloon technique under full anticoagulation. Preocclusion (within 2 weeks) and postocclusion (within 6 weeks) magnetic resonance imaging of the brain was performed in eight cases and evaluated for preexisting and new appearance of subcortical hyperintense lesions. RESULTS: There were four instances of de novo genesis of subcortical hyperintense lesions after carotid occlusion. New subcortical hyperintense lesions were ipsilateral to carotid occlusion in every instance and in two cases were associated with ipsilateral hemispheric ischemic symptoms despite anticoagulant therapy. In one instance, there were transient hemispheric symptoms without the appearance of new subcortical hyperintense lesions. Age, vascular risk factors, and preexisting subcortical hyperintense lesions did not appear to predispose patients to de novo genesis of new hyperintensities. CONCLUSIONS: This is the first documentation of de novo genesis of subcortical hyperintense lesions in a controlled setting of hemodynamic ischemic insult. Symptomatic and asymptomatic lesions can be detected in this setting. Anticoagulation does not appear to provide protection from this phenomenon. Careful prospective studies are required to further evaluate risk factors and possible clinical consequences associated with the genesis of new subcortical hyperintense lesions.

Comparison and spacial correlation of interictal HMPAO-SPECT and FDG-PET in intractable temporal lobe epilepsy.

The respective contribution of interictal HMPAO-SPECT and FDG-PET to the imaging of the epileptogenic zone in intractable temporal lobe epilepsy is not known. Ten consecutive patients with drug resistant focal epilepsy of temporal lobe origin were studied with prolonged noninvasive video-EEG monitoring, magnetic resonance imaging, interictal FDG-PET and HMPAO-SPECT. Five patients demonstrated unitemporal and 5 patients bitemporal interictal and/or ictal EEG epileptiform abnormalities. We developed a 3-dimensional semiquantitative method for interpretation and comparison of FDG-PET and HMPAO-SPECT using a 15-compartment model of the temporal lobe. In all 5 patients with unilateral epileptogenicity, interictal hypometabolism and hypoperfusion were recorded on the side of the EEG abnormalities without discrepancy between PET and SPECT. The severity and the extent of focal abnormalities were consistently greater on PET than on SPECT, in agreement with previously well documented better 'sensitivity' of PET. Among the 5 patients with bitemporal epileptogenicity, results of SPECT and PET were convergent in only 2 cases. In this group, SPECT abnormalities appeared more profound but either SPECT or PET were not constantly correlated with the side of predominant EEG epileptogenicity. Abnormalities on PET and SPECT were more frequently limited to mesiobasal structures among cases with unilateral epileptogenicity and tended to involve neocortical structures in bitemporal cases. We conclude that interictal FDG-PET and HMPAO-SPECT provide the same type of information on the side of the epileptogenic zone in cases with clearly unilateral epileptogenicity, with abnormalities more intense and more extensive on PET.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors predisposing to clinical disability in patients with cavernous malformations of the brain.

The factors predisposing to an aggressive clinical course in cavernous malformations of the brain are not known. Disabilities from neurological deficits and from seizures were assessed and graded in 84 patients harboring 100 cavernous malformations and were correlated with patient sex and age, lesion size, lesion location, lesion multiplicity, and previous overt hemorrhage. Univariate analysis showed that female sex, infratentorial lesion location, and previous gross hemorrhage were significantly associated with subsequent neurological disability. Logistic regression analysis showed that infratentorial lesion location and previous gross hemorrhage were independent factors simultaneously and significantly associated with neurological disability. Age less than 40 was the only significant factor predisposing to seizure disability (in both univariate and multivariate analyses). Lesion size, multiplicity, and other factors did not influence clinical disability. This information should assist in management decisions regarding cavernous malformations.

Application of magnetic resonance angiography to neurosurgical practice: a critical review of 150 cases.

The potential role of magnetic resonance angiography (MRA) in clinical neurosurgical practice was evaluated in 150 consecutive patients in an attempt to define clinical situations in which it aided in diagnosis, helped guide treatment options, and/or possibly eliminated the need for conventional catheter angiography. Among patients with nonvascular pathology (n = 42), MRA provided useful clinical information in 55% of cases, and could have effectively replaced catheter angiography in 76% of cases. In this group of patients, MRA provided excellent depiction of tumour and vessel relationships, and in conjunction with conventional imaging modalities reliably ruled out the question of tumour versus aneurysm whenever that question was raised. Among patients with vascular lesions (n = 108), MRA visualized the lesion in 18 of 20 (90%) aneurysms, 11 of 11 (100%) vascular malformations, 31 or 31 (100%) cases with known occlusive vascular disease, and reliably excluded occlusive vascular disease in 19 of 30 (63%) cases. The MRA potentially could have replaced conventional catheter angiography in less than 8% of cases with vascular pathology treated surgically, and in 76% of cases with vascular pathology treated medically or expectantly. Imaging time was relatively short, 10 to 20 minutes for intracranial vessels and 6.5 to 13 minutes for extracranial vessels. Shortcomings included the lack of spacial resolution required for surgical planning and the possible misleading information in the settings of low flow and partial thrombosis. It is concluded that currently available MRA modalities contribute useful information in a wide spectrum of neurosurgical clinical situations including screening and serial follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Alternating sequential intracarotid BCNU and cisplatin in recurrent malignant glioma.

The authors entered 43 patients with recurrent malignant glioma in a trial of alternating sequential intracarotid BCNU and cisplatin. Protocol design was alternating courses of BCNU (2 doses, 300 to 400 mg each) and cisplatin (2 doses, 150 to 200 mg each) each at 4-week to 6-week intervals. Eight of 40 patients (20%) evaluable after the first course of BCNU showed partial or minor response. Only 18 patients were evaluable after the first course of cisplatin, and 5 were evaluable after the second course of BCNU. Median survival was 9 months (range, 2 weeks to 6 years). Cerebral or ocular toxicity unique to this method of chemotherapy administration and failure to show clinical improvement were the most common reasons for removal from study. Because of the high attrition rate, the authors were unable to determine a meaningful response to alternating sequential BCNU and cisplatin or to test the clinical degree of cross-resistance to these agents in human malignant glioma.

Constant infusion of morphine for intractable cancer pain using an implanted pump.

In the past, pain control for chronic pain syndromes using narcotic infusion has been carried out primarily via the intrathecal (subarachnoid) route. This report presents one of the first large series of terminally ill cancer patients with intractable pain treated with continuous epidural morphine infusions by means of implanted pumps and epidural spinal catheters. The purpose of the study was to demonstrate that the epidural route is effective with minimal complications, and that screening with temporary epidural catheter infusions results in a high rate of subsequent pain relief. A multidisciplinary team (neurosurgeon, anesthesiologists, psychiatrists, oncologists, and nurse clinicians) evaluated and treated all of the patients studied. Percutaneous placement of temporary epidural catheters for a trial assessment was performed by the anesthesiologists. Pain evaluations were conducted independently by psychiatrists using both verbal and visual analog scales. From 1982 to 1988, 41 (59.4%) of 69 patients evaluated for eligibility experienced good pain control during trial assessment and were subsequently implanted with Infusaid infusion pumps. Preinfusion pain analog values were 8.6 +/- 0.3 and postimplantation values at 1 month were 3.8 +/- 0.4 (p less than 0.001). Over this same 1-month period. requirements of systemic morphine equivalents decreased by 79.3% with epidural infusions as compared to preinfusion requirements (p less than 0.001). There were no instances of epidural scarring, respiratory depression, epidural infections, meningitis, or catheter blockage. One patient developed apparent drug tolerance and three patients required further catheter manipulations. This series strongly suggests that significant reductions in cancer pain can be obtained with few complications and a low morphine tolerance rate using chronic epidural morphine infusion. Anesthesiology and psychiatry input, along with temporary catheter infusion screening and quantitative pain evaluations using analog scales, are essential.