Dexamethasone significantly attenuates sub-arachnoid hemorrhage-induced elevation in cerebrospinal fluid citrulline and leukocytes.

AIM: Cerebral vasospasm is a leading cause of death and disability following aneurysmal subarachnoid hemorrhage (SAH). Nitric oxide (NO) is a potent mediator of vasodilation, and citrulline is a known contributor to NO production. The leukocytosis inflammatory response can increase vasoconstrictive compounds that may also contribute to vasospasm. Dexamethasone is a glucocorticosteroid commonly administered after SAH, which may alter the production of leukocytes and citrulline. The goal of this project was to study the effects of dexamethasone on leukocytosis, citrulline, and angiographic vasospasm. METHODS: Experimental SAH was induced in 18 New Zealand white rabbits. Intravenous dexamethasone was administered to one group (N.=9) at 2 mg/kg/day. A placebo group (N.=9) was given a saline infusion with otherwise identical procedures. CSF citrulline, leukocytes, protein, and glucose, as well as plasma citrulline were measured at baseline and 3 days post-SAH in a blinded fashion. Basilar artery angiography was performed at baseline and repeated 3 days post-SAH. RESULTS: The change in CSF citrulline from day 0 to day 3 was significantly lower in the dexamethasone group compared to controls (P=0.002). The change in CSF white blood cells was also significantly lower (P=0.005). There was no significant change in plasma citrulline levels or angiographic vasospasm. CONCLUSION: Dexamethasone significantly decreases CSF citrulline and CSF leukocytosis after experimental SAH. It is possible this could lead to a relative vasoconstriction and vasodilation, respectively. These processes could cancel-out opposing effects of dexamethasone on cerebral vasospasm, partially contributing to the recognized, multifactorial, inconsistent effects of glucocorticoids on vasospasm.

Resolution of trigeminal neuralgia after palliative embolization of a cerebellopontine angle arteriovenous malformation.

BACKGROUND: Trigeminal neuralgia (TN) is a syndrome with debilitating paroxysmal facial pain, one cause of which is thought to be vascular compression of the nerve root entry zone causing ephaptic transmission. Arteriovenous malformations (AVM) have been reported to cause TN, including AVMs in the cerebellopontine (CP) angle. These lesions have been successfully treated with endovascular coiling, ethylene-vinyl alcohol copolymer (Onyx) and surgery for decompression. CASE DESCRIPTION: We present a case of TN caused by AVM in the CP angle in a patient who was not a candidate for microsurgery and who did not want radiofrequency treatment or other destructive procedures because he would not tolerate facial numbness. The patient's symptoms were successfully treated by embolization using an ethylene-vinyl alcohol copolymer. After 17 months he had a recurrence of pain which was again treated with palliative embolization and again experienced resolution of his symptoms. CONCLUSION: This case demonstrates that palliative embolization is a safe and effective option for the treatment of trigeminal neuralgia pain in patients for whom surgery of the AVM is not an option.

A grading scale to predict outcomes after intra-arterial thrombolysis for stroke complicated by contrast extravasation.

OBJECTIVE: Contrast extravasation after intra-arterial thrombolysis for stroke occurs frequently and is identifiable on a computed tomographic (CT) scan, but it is often unrecognized or misdiagnosed. Few articles describing this phenomenon have been published. The clinical outcomes of patients after contrast extravasation are poorly understood. We designed a grading system to predict outcomes after contrast extravasation and tested the grading scale prospectively. METHODS: We studied 27 patients who had contrast extravasation exhibited on a CT scan immediately after intra-arterial thrombolysis. The National Institutes of Health Stroke Scale was used to quantify neurological examinations preoperatively, postoperatively, and at follow-up an average of 3 months later. A grading scale from 0 to 10 was developed from a retrospective analysis of the first 18 patients using odds ratios and Fisher's exact test. The grading system was then applied prospectively to the next 9 consecutive patients. RESULTS: Six components of the grading system were weighted approximately proportional to corresponding odds ratios: 1) incomplete recanalization (3 points), 2) prolonged angiographic blush (2 points), 3) hyperdensity greater than 150 Hounsfield units (2 points), 4) lesion volume greater than 50 cc exhibited on a CT scan (1 point), 5) lesion in eloquent parenchyma (1 point), and 6) hypodensity demonstrated on an immediate postoperative CT scan (1 point). The contrast extravasation grades for each outcome category (excellent, fair, poor, died) increased in stepwise fashion. There was a direct linear correlation between the assigned grade and National Institutes of Health Stroke Scale score improvement at follow-up. CONCLUSION: This grading system should prove useful as a preliminary guide for predicting outcomes of patients with contrast extravasation after intra-arterial thrombolysis for stroke. Further analysis in a large cohort of prospective patients is necessary to ensure extensibility.

Carotid artery angioplasty and use of stents in high-risk patients with contralateral occlusions.

OBJECT: The risks associated with carotid endarterectomy (CEA) are increased in the presence of contralateral carotid artery (CA) occlusion. The 30-day stroke and death rate for patients in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) who had contralateral CA occlusion was 14.3%. The authors analyze their experience with angioplasty and/or stent placement in patients with contralateral CA occlusion to determine the safety and efficacy of endoluminal revascularization in this subgroup. METHODS: Twenty-six procedures were evaluated in 23 patients with high-grade CA stenosis and contralateral CA occlusion. The first 15 procedures were evaluated retrospectively, and the next 11 prospectively. All patients had severe medical comorbidities and were considered too high risk for CEA, even without considering the contralateral occlusion. Clinical follow-up review was performed an average of 18 months later (median 15 months). CONCLUSIONS: The average ipsilateral CA stenosis according to NASCET criteria was 78% preprocedure and 5% postprocedure. There were no changes in neurological or functional outcome immediately postoperatively in any patient. The 30-day postoperative stroke and death rates were zero. However, there was one symptomatic femoral hematoma that resolved without surgery. At follow up, there were three patients who had suffered stroke or death. One patient died secondary to respiratory arrest at 2 months; one died secondary to prostate carcinoma at 12 months; and one patient experienced a minor stroke contralateral to the treated artery at 41 months. Despite the substantial preoperative risk factors in patients in this series, the 30-day stroke and death rate for angioplasty and/or stent placement appears to be lower than that of CEA in patients with contralateral occlusions.

Percutaneous transluminal angioplasty and stent placement for recurrent carotid artery stenosis.

OBJECT: Treatment consisting of percutaneous transluminal angioplasty (PTA) and stent placement has recently been proposed as an alternative to surgical reexploration in patients with recurrent carotid artery stenosis following endarterectomy. The authors retrospectively reviewed their experience after performing 25 procedures in 21 patients to assess the safety and efficacy of PTA with or without stent placement for carotid artery restenosis. METHODS: The mean interval between endarterectomy and the endovascular procedures was 57 months (range 8-220 months). Seven arteries in five patients were treated by PTA alone (including bilateral procedures in one patient and repeated angioplasty in the same vessel in another). Early suboptimum results and recurrent stenosis in some of these initial cases prompted the authors to combine PTA with stent placement in the treatment of 18 arteries over the past 3 years. No major periprocedural deficits (neurological or cardiac complications) or death occurred. There was one periprocedural transient neurological event, and in one patient a pseudoaneurysm of the femoral artery (at the access site) required surgical repair. In the 16 patients who each underwent at least 6 months of follow-up review, no neurological events ipsilateral to the treated artery had occurred after a mean follow-up period of 27 months (range 6-57 months). Three of five patients who underwent PTA alone developed significant (>50%) asymptomatic restenoses that required repeated angioplasty in one and PTA with stent placement in two patients. Significant restenosis (55%) was observed in only one of the vessels treated by combined angioplasty and stent placement. CONCLUSIONS: Endovascular PTA and stenting of recurrent carotid artery stenosis is both technically feasible and safe and has a satisfactory midterm patency. This procedure can be considered a viable alternative to surgical reexploration in patients with recurrent carotid artery stenosis.

Stenting and secondary coiling of intracranial internal carotid artery aneurysm: technical case report.

OBJECTIVE AND IMPORTANCE: Endovascular stents have been successfully used in the treatment of fusiform and dissecting aneurysms of the peripheral circulation and extracranial carotid and vertebral arteries. Technical limitations related to the inability to navigate the stent and the delivery system through tortuous vascular segments has limited their application with intracranial lesions. Availability of new flexible and pliable stent systems might overcome these difficulties. CLINICAL PRESENTATION: A 49-year-old woman presented with a dissecting pseudoaneurysm of the horizontal portion of the petrous internal carotid artery that increased in size, as revealed by serial angiographic studies. INTERVENTION: The aneurysm was treated by deploying a new flexible stent across the aneurysm neck and by then packing the aneurysm sac with Guglielmi detachable coils that were delivered by a microcatheter positioned through the stent struts into the aneurysm lumen. CONCLUSION: New flexible stents can be used to treat intracranial internal carotid artery aneurysms in difficult-to-access areas, such as the horizontal petrous segment. The stent may disrupt the aneurysm inflow tract, thereby inducing stasis and facilitating intra-aneurysmal thrombosis. In addition, the stent acts as an endoluminal scaffold to prevent coil herniation into the parent artery, which allows tight packing of even wide-necked and irregularly shaped aneurysms. The stent may also serve as a matrix for endothelial growth. We think this new generation of flexible stents and the use of this described technique will usher in the next era of endovascular management of intracranial aneurysms.

Cavernous sinus syndrome during balloon test occlusion of the cervical internal carotid artery. Report of two cases.

The authors report the occurrence of ipsilateral transient cavernous sinus syndrome during balloon test occlusion (BTO) of the cervical internal carotid artery (ICA) and discuss the involved pathomechanisms. The authors reviewed their series of 129 BTOs of the ICA performed between 1989 and 1996. Two patients developed facial paresthesias and transient palsies of the third through sixth cranial nerves during test occlusion of the cervical ICA. The tests were performed prior to planned permanent carotid artery occlusion for the treatment of a neck sarcoma in one patient and a giant cavernous carotid artery aneurysm in the other. The patients' symptoms resolved with deflation of the balloon. When the balloon was subsequently inflated above the inferior cavernous sinus artery (ICSA), one of the patients complained of mild facial discomfort. There was no contralateral weakness or mental status change during test occlusion in either patient. Angiography demonstrated good filling of the ipsilateral intracranial circulation via collateral vessels of the circle of Willis. In these two cases, the cranial nerves in the cavernous sinus were likely supplied by the ICA via the meningohypophyseal trunk and the ICSA. In each case, there was excellent blood supply to the ipsilateral cerebral hemisphere; however, there was probably inadequate retrograde filling of the cranial nerve collateral vessels located where the meningohypophyseal trunk and ICSA originated. These cases emphasize the importance of a patent external carotid artery-ICA connection for successful cervical carotid artery occlusion. Neurological examination during BTO was critical to interpret the clinical manifestations caused by the hemodynamic changes.

A novel approach to flow quantification in brain arteriovenous malformations prior to enbucrilate embolization: use of insoluble contrast (Ethiodol droplet) angiography.

OBJECT: Successful therapeutic embolization of arteriovenous malformations (AVMs) of the brain with liquid polymers (glues) requires precise knowledge of highly variable AVM structure and flow velocities and transit times of blood through the AVM nidus. The goal of this study was to improve AVM flow measurement and visualization by the substitution of the insoluble Ethiodol (ethiodized oil) contrast agent for the soluble contrast media normally used in angiographic studies. METHODS: Before enbucrilate embolization of 24 AVM feeding pedicles in 13 patients, standard contrast medium was superselectively injected into each target pedicle, followed by infusion of 20 microl of Ethiodol microdroplets. Transport of contrast material was assessed using high-speed biplane pulsed digital subtraction angiography (DSA) operating at 15 frames per second. The mean blood flow transit times through AVMs after administration of Ethiodol were found to be approximately half as long as in those measured after injection of soluble contrast materials (0.22 +/- 0.10 seconds compared with 0.46 +/- 0.19 seconds [mean +/- standard deviation]; p < 0.0001). The discrete Ethiodol microdroplets travel with the core flow, more closely approximating the dynamic behavior of enbucrilate, allowing the AVM structure to be traced with high spatial and temporal resolution. There were no inadvertent vessel occlusions or pulmonary complications related to the use of Ethiodol for DSA. CONCLUSIONS: Because of diffusion and convection, forces that decrease concentration, visualization of the contrast front is reduced, often resulting in deceptively long transit times when soluble contrast materials are used. Overestimation may prove dangerous when planning embolizations. The Ethiodol droplet DSA method provides accurate transit time measurements and precise, detailed, and dynamic AVM visualization. Further development of this method will improve the safety and precision of AVM treatments.

Delayed aneurysm regrowth and recanalization after Guglielmi detachable coil treatment. Case report.

Guglielmi detachable coil (GDC) treatment for complicated cerebral aneurysms is an attractive option that has become widely accepted in recent years. This technique is usually considered only if the patient harbors an aneurysm that is not a good candidate for surgical clipping. However, the definition of "surgical candidate" varies among institutions, and many patients worldwide are being treated with GDCs as primary therapy. Although most centers currently perform follow-up angiography at 6 months to 1 year, others do not routinely perform it after an initially good result. The authors present a case that indicates longer follow up may be necessary and illustrates some of the pitfalls of GDC treatment. This 56-year-old man presented to the emergency room with a Hunt and Hess Grade II subarachnoid hemorrhage and was found to have a wide-necked basilar apex aneurysm. Because of associated medical comorbidities, it was decided to treat the aneurysm with endovascular techniques. The patient did well on follow-up angiography at 1 year postprocedure. However, at approximately 2 years follow up, the aneurysm was demonstrated to have dramatically recanalized and regrown, requiring open surgical intervention. Endovascular coiling was insufficient to treat this aneurysm and complicated definitive surgical management because a large coil mass had been placed in the operative field. It can be inferred from this case that angiographic follow up of these types of lesions may be beneficial up to 2 years after GDC treatment.

Angioplasty and stenting for carotid artery stenosis: indications, techniques, results, and complications.

Following the favorable results obtained in the treatment of coronary artery disease, combined angioplasty and stenting has been advocated for the treatment of carotid artery stenosis as well. Although widespread application of angioplasty and stenting for carotid artery disease is neither indicated nor recommended, it may be a viable alternative therapy for select patients who are high-risk patients for surgery. The results of early series have suggested that endoluminal revascularization in these high-risk patients can be performed with an acceptable degree of safety. Although the incidence of death and major stroke rates following angioplasty and stenting procedures compares favorably with surgery, results of more recent clinical series have suggested that the incidence of perioperative transient neurological events and minor strokes may be higher than suggested by earlier reports, especially in patients with recent neurological symptoms and "unstable" plaques. In this article, the authors review the current potential indications for and preliminary results of angioplasty and stenting and describe their procedural technique. In addition, potential applications of stenting to intracranial thromboocclusive carotid artery disease are reviewed.

Temporary balloon protection as an adjunct to endosaccular coiling of wide-necked cerebral aneurysms: technical note.

OBJECTIVE: We present an endovascular technique for treating wide-necked cerebral aneurysms using Guglielmi detachable coils (Target Therapeutics, Fremont, CA) and simultaneous temporary balloon protection. The temporary balloon serves as a mechanical external force to mold the microcoils away from the parent artery. METHODS: Two illustrative cases of wide-necked cerebral aneurysms treated with Guglielmi detachable coils and a temporary balloon are presented. Emphasis is placed on the technical aspects of the approach, with several variations. The first case involves a left posterior cerebral artery aneurysm at the P1/P2 segment, and the second case involves a left paraclinoid internal carotid artery aneurysm. Both patients suffered from subarachnoid hemorrhage, but neither was a candidate for craniotomy. In each case, the coils, when used alone, protruded into the parent artery and were therefore removed. Then a temporary balloon was inflated for mechanical protection during coil deployment. RESULTS: The use of simultaneous temporary balloon protection allowed more dense intra-aneurysmal coil packing, especially in the neck, without parent artery compromise, than did the use of Guglielmi detachable coils alone. CONCLUSION: Endovascular treatment of wide-necked cerebral aneurysms can be facilitated by simultaneous temporary balloon protection.

Treatment of acute pandysautonomia with intravenous immunoglobulin.

Acute pandysautonomia has been suggested to be an uncommon variant of Guillain-Barre syndrome. Acute pandysautonomia does not seem to have been treated with intravenous immunoglobulin or other therapies proved efficacious in Guillain-Barre syndrome. A patient is reported with severe acute pandysautonomia who responded dramatically to intravenous immunoglobulin. The findings are consistent with a dysimmune pathogenesis for this syndrome and suggest a possible treatment for future cases.

Determination of the lethal dose of dexamethasone for early passage in vitro human glioblastoma cell cultures.

Previous investigators have supported the idea that glucocorticoids may be oncolytic. In this study, the percentage of cell death in two human glioblastoma cell cultures was related to the concentration of dexamethasone that was administered. It was determined that for Cell line 1, the median lethal dose was approximately 500-800 micrograms/ml and the completely lethal dose was about 900-1000 micrograms/ml; the 3H-thymidine uptake to approximate the mitotic rate was 16,607 cpm, and the dexamethasone receptor activity was 228 fmol/mg protein. The median lethal dose and completely lethal dose for Cell line 2 was approximately 500-600 micrograms/ml and 700-1000 micrograms/ml, respectively; the 3H-thymidine uptake was 8402 cpm, and the dexamethasone receptor activity was 137 fmol/mg protein. These lethal concentrations of dexamethasone are probably higher than can be tolerated by systemic delivery. However, it remains to be seen whether the interstitial administration of dexamethasone could achieve local concentrations resulting in the oncolysis of malignant gliomas. The clinical significance of these findings will depend on the local tolerance of normal brain parenchyma to very high doses of dexamethasone. A review of some of the literature is included.

Serum angiotensin converting enzyme in diabetic patients.

Serum angiotensin converting enzyme (ACE) levels are higher in patients with diabetes mellitus than in many others. Techniques are available to grade different degrees of diabetic retinopathy, which can demonstrate a relationship between ACE and diabetic retinopathy. In this study, patients with diabetic retinopathy had higher serum ACE levels (6.3 +/- 0.2) than nondiabetic patients (4.3 +/- 0.5) (p < 0.001). In addition, the mean serum ACE level in diabetic patients with nonproliferative retinopathy (5.55 +/- 0.4) was less than that in diabetic patients with proliferative retinopathy (6.63 +/- 0.25) (p = 0.02). Due to the variability in individual serum ACE levels and the frequent use of ACE inhibitors by hypertensive diabetics, these techniques are not suitable for retinopathy screening programs. However, the graded relationship demonstrated by these data may have relevance for the pathophysiology of diabetic retinopathy.