GIANT FUSIFORM ANEURYSM ARISING FROM FENESTRATED POSTERIOR CEREBRAL ARTERY AND BASILAR TIP VARIATION: CASE REPORT

OBJECTIVE: A giant fusiform aneurysm in the posterior cerebral artery (PCA) is rare, as is fenestration of the PCA and basilar apex variation. We describe the angiographic and surgical findings of a giant fusiform aneurysm in the P1-P2 PCA segment associated with PCA bilateral fenestration and superior cerebellar artery double origin. CLINICAL PRESENTATION: A 26-year-old woman presented with a 2-month history of visual blurring. Digital subtraction angiography showed a giant (2.5 cm) fusiform PCA aneurysm in the right P1-P2 segment. The 3-dimensional view showed a caudal fusion pattern from the upper portion of the basilar artery associated with a bilateral long fenestration of the P1 and P2 segments and superior cerebellar artery double origin. INTERVENTION: Surgical trapping of the right P1 -P2 segment, including the posterior communicating artery, was performed by a pretemporal approach. Angiograms performed 3 and 13 months after surgery showed complete aneurysm exclusion, and the PCA was permeated and filled the PCA territory. Clinical follow-up at 14 months showed the patient with no deficits and a return to normal life. CONCLUSION: To our knowledge, this is the first report of a giant fusiform aneurysm of the PCA associated with P1-P2 segment fenestration and other variations of the basilar apex (bilateral superior cerebellar artery duplication and caudal fusion). Comprehension of the embryology and anatomy of the PCA and its related vessels and branches is fundamental to the decision-making process for a PCA aneurysm, especially when parent vessel occlusion is planned.

GIANT FUSIFORM ANEURYSM ARISING FROM FENESTRATED POSTERIOR CEREBRAL ARTERY and BASILAR TIP VARIATION: CASE REPORT

OBJECTIVE: A giant fusiform aneurysm in the posterior cerebral artery (PCA) is rare, as is fenestration of the PCA and basilar apex variation. We describe the angiographic and surgical findings of a giant fusiform aneurysm in the P1-P2 PCA segment associated with PCA bilateral fenestration and superior cerebellar artery double origin.CLINICAL PRESENTATION: A 26-year-old woman presented with a 2-month history of visual blurring. Digital subtraction angiography showed a giant (2.5 cm) fusiform PCA aneurysm in the right P1-P2 segment. The 3-dimensional view showed a caudal fusion pattern from the upper portion of the basilar artery associated with a bilateral long fenestration of the P1 and P2 segments and superior cerebellar artery double origin.INTERVENTION: Surgical trapping of the right P1 -P2 segment, including the posterior communicating artery, was performed by a pretemporal approach. Angiograms performed 3 and 13 months after surgery showed complete aneurysm exclusion, and the PCA was permeated and filled the PCA territory. Clinical follow-up at 14 months showed the patient with no deficits and a return to normal life.CONCLUSION: To our knowledge, this is the first report of a giant fusiform aneurysm of the PCA associated with P1-P2 segment fenestration and other variations of the basilar apex (bilateral superior cerebellar artery duplication and caudal fusion). Comprehension of the embryology and anatomy of the PCA and its related vessels and branches is fundamental to the decision-making process for a PCA aneurysm, especially when parent vessel occlusion is planned.

Microsurgical Anatomy of the Posterior Cerebral Artery in Three-Dimensional Images

OBJECTIVE: To describe the microsurgical anatomy, branches, and anatomic relationships of the posterior cerebral artery (PCA) represented in three-dimensional images. METHODS: Seventy hemispheres of 35 brain specimens were studied. They were previously injected with red silicone and fixed in 10% formalin for at least 40 days. Four of the studied specimens were frozen at -10 degrees to -15 degrees C for 14 days, and additional dissection was done with the Klingler`s fiber dissection technique at x6 to x40 magnification. Each segment of the artery was measured and photographed to obtain three-dimensional stereoscopic images. RESULTS: The PCA origin was in the interpeduncular cistern at the pontomesencephalic junction level in 23 specimens (65.7%). The PCA was divided into four segments: P1 extends from the PCA origin to its junction with the posterior communicating artery with an average length of 7.7 mm; P2 was divided into an anterior and posterior segment. The P2A segment begins at the posterior communicating artery and ends at the most lateral aspect of the cerebral peduncle, with an average length of 23.6 mm, and the P2P segment extends from the most lateral aspect of the cerebral peduncle to the posterior edge of the lateral surface of the midbrain, with an average length of 16.4 mm; P3 extends from the posterior edge of the lateral surface of the midbrain and ends at the origin of the parieto-occipital sulcus along the calcarine fissure, with an average length of 19.8 mm; and the P4 segment corresponds to the parts of the PCA that run along or inside both the parieto-occipital sulcus and the distal part of the calcarine fissure. CONCLUSIONS: To standardize the neurosurgical practice and knowledge, surgical anatomic classifications should be used uniformly and further modified according to the neurosurgical experience gathered. The PCA classification proposed intends to correlate its anatomic segments with their required microneurosurgical approaches.

Trigeminal neuralgia related to megadolichobasilar artery compression: a prospective series of twenty-nine patients treated with gamma knife surgery, with more than one year of follow-up.

BACKGROUND: Trigeminal neuralgia (TN) secondary to megadolichobasilar artery (MBA) compression is considerably difficult to manage surgically. OBJECTIVE: This study aims to evaluate the safety/efficacy of Gamma Knife surgery (GKS) in this special group of patients. METHODS: Between July 1992 and November 2010, 29 patients with >1 year of follow-up presenting with MBA compression were treated with GKS at Timone University Hospital. Radiosurgery was performed using a Gamma Knife (model B, C or Perfexion). A single 4-mm isocenter was positioned in the cisternal portion of the trigeminal nerve at a median distance of 9.1 mm (range: 6-18.2 mm) from the emergence. RESULTS: The median follow-up period was 46.1 months (range: 12.9-157.9 months). Initially, all patients (100%) were pain free; the average time to complete pain relief was 13.5 days (range: 0-240 days). Their actuarial probability of remaining pain free without medication at 0.5, 1 and 2 years was 93.1, 79.3 and 75.7%, respectively, and remained stable until 13 years after treatment. The actuarial probability of hypoesthesia onset at 6 months was 4.3%; at 1 year it reached 13% and remained stable until 13 years after treatment. CONCLUSIONS: GKS proved to be reasonably safe and effective on a long-term basis as a first- and/or second-line surgical treatment for TN due to MBA compression.

Elevated level of endothelin-1 in cerebrospinal fluid and lack of nitric oxide in basilar arterial plasma associated with cerebral vasospasm after subarachnoid haemorrhage in rabbits

BACKGROUND: The role of endothelin-1 (ET-1) and nitric oxide (NO) as two important mediators in the development of cerebral vasospasm (CVS) after subarachnoid haemorrhage (SAH) is controversial. The objective of this study was to determine whether local levels of ET-1 and NO in cerebral arterial plasma and/or in cerebrospinal fluid (CSF) are associated with the occurrence of CVS after SAH. METHODS: CVS was induced using the one-haemorrhage rabbit model and confirmed by digital subtraction angiography of the rabbits' basilar artery on day 5. Prior to sacrifice, local CSF and basilar arterial plasma samples were obtained by a transclival approach to the basilar artery. Systemic arterial plasma samples were obtained. ET-1 levels were determined by immunometric technique (pg/ml +/- SEM) and total nitrate/nitrite level spectrophotometrically (micromol/l +/- SEM). FINDINGS: Angiographic CVS was documented after SAH induction (n = 12, P < 0.05). The ET-1 level in CSF was significantly elevated by 27.3% to 0.84 +/- 0.08 pg/ml in SAH animals (n = 7) in comparison to controls (0.66 +/- 0.04 pg/ml, n = 7, P < 0.05). There was no significant difference in ET-1 levels in systemic and basilar arterial plasma samples of SAH animals compared to controls. A significant lack of local NO metabolites was documented in basilar arterial plasma after SAH (36.8 +/- 3.1 micromol/l, n = 6) compared to controls (61.8 +/- 6.2 micromol/l, n = 6, P < 0.01). CONCLUSION: This study demonstrates that an elevated ET-1 level in CSF and local lack of NO in the basilar arterial plasma samples are associated with CVS after experimental SAH.

Aortas isolated from sinoaortic-denervated rats exhibit rhythmic contractions that are regulated by pharmacologically distinct calcium sources

Sinoaortic denervation is characterized by arterial pressure lability, without sustained hypertension. Aortas isolated from rats with sinoaortic denervation present rhythmic contractions. We studied the participation of distinct Ca2+ sources in the maintenance of the oscillations. Three days after the surgeries, aortic rings were placed in an organ chamber, and the incidence of aortas presenting rhythmic contractions was measured. Specific drugs were employed to analyse the participation of the Ca2+ released from the sarcoplasmic reticulum [2-APB (diphenylborinic acid 2-aminoethyl ester), thapsigargin and ryanodine] and external Ca2+ entry [Bay K 8644, verapamil and DMB (dimethylbenzyl amiloride)] on the rhythmic contractions. Additionally, we verified the effects of chloride channel blocker NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid] on the maintenance of the rhythmic contractions. Under phenylephrine stimulus, sinoaortic-denervated rat aortas exhibited rhythmic contractions in the frequency of 4.5 +/- 0.50 cycles/min. and an amplitude of 0.465 +/- 0.05 g. 2-APB, thapsigargin and ryanodine inhibited the rhythmic contractions. Bay K 8644 increased the oscillations, reaching maximum values with a concentration of 50 nM (18.5 +/- 2.5 cycles/min.). The rhythmic contractions were inhibiting by verapamil and Ca2+-free solution. DMB and NPPB did not alter the oscillations. In conclusion, we observed that aorta isolated from sinoaortic-denervated rats present rhythmic contractions. Moreover, drugs that impaired intracellular Ca2+ release from sarcoplasmic reticulum interrupted the oscillations. The oscillations also depend on the extracellular Ca2+ entry through L-type Ca2+.

Patterns of neurovascular compression in patients with classic trigeminal neuralgia: A high-resolution MRI-based study.

PURPOSE: To describe the anatomical characteristics and patterns of neurovascular compression in patients suffering classic trigeminal neuralgia (CTN), using high-resolution magnetic resonance imaging (MRI). MATERIALS AND METHODS: The analysis of the anatomy of the trigeminal nerve, brain stem and the vascular structures related to this nerve was made in 100 consecutive patients treated with a Gamma Knife radiosurgery for CTN between December 1999 and September 2004. MRI studies (T1, T1 enhanced and T2-SPIR) with axial, coronal and sagital simultaneous visualization were dynamically assessed using the software GammaPlan?. Three-dimensional reconstructions were also developed in some representative cases. RESULTS: In 93 patients (93%), there were one or several vascular structures in contact, either, with the trigeminal nerve, or close to its origin in the pons. The superior cerebellar artery was involved in 71 cases (76%). Other vessels identified were the antero-inferior cerebellar artery, the basilar artery, the vertebral artery, and some venous structures. Vascular compression was found anywhere along the trigeminal nerve. The mean distance between the nerve compression and the origin of the nerve in the brainstem was 3.76±2.9mm (range 0-9.8mm). In 39 patients (42%), the vascular compression was located proximally and in 42 (45%) the compression was located distally. Nerve dislocation or distortion by the vessel was observed in 30 cases (32%). CONCLUSIONS: The findings of this study are similar to those reported in surgical and autopsy series. This non-invasive MRI-based approach could be useful for diagnostic and therapeutic decisions in CTN, and it could help to understand its pathogenesis.

Improving the Prediction of Spontaneous and Post-thrombolytic Recanalization in Ischemic Stroke Patients.

BACKGROUND: Endovascular treatment for acute ischemic stroke patients was recently shown to improve recanalization rates and clinical outcome in a well-defined study population. Intravenous thrombolysis (IVT) alone is insufficiently effective to recanalize in certain patients or of little value in others. Accordingly, we aimed at identifying predictors of recanalization in patients treated with or without IVT. METHODS: In the observational Acute Stroke Registry and Analysis of Lausanne (ASTRAL) registry, we selected those stroke patients (1) with an arterial occlusion on computed tomography angiography (CTA) imaging, (2) who had an arterial patency assessment at 24 hours (CTA/magnetic resonance angiography/transcranial Doppler), and (3) who were treated with IVT or had no revascularization treatment. Based on 2 separate logistic regression analyses, predictors of spontaneous and post-thrombolytic recanalization were generated. RESULTS: Partial or complete recanalization was achieved in 121 of 210 (58%) thrombolyzed patients. Recanalization was associated with atrial fibrillation (odds ratio , 1.6; 95% confidence interval, 1.2-3.0) and absence of early ischemic changes on CT (1.1, 1.1-1.2) and inversely correlated with the presence of a significant extracranial (EC) stenosis or occlusion (.6, .3-.9). In nonthrombolyzed patients, partial or complete recanalization was significantly less frequent (37%, P < .01). The recanalization was independently associated with a history of hypercholesterolemia (2.6, 1.2-5.6) and the proximal site of the intracranial occlusion (2.5, 1.2-5.4), and inversely correlated with a decreased level of consciousness (.3, .1-.8), and EC (.3, .1-.6) and basilar artery pathology (.1, .0-.6). CONCLUSIONS: Various clinical findings, cardiovascular risk factors, and arterial pathology on acute CTA-based imaging are moderately associated with spontaneous and post-thrombolytic arterial recanalization at 24 hours. If confirmed in other studies, this information may influence patient selection toward the most appropriate revascularization strategy.

A systematic study of the brain base arteries in the turkey (Meleagris gallopavo)

Thirty heads with neck segments of turkeys (Meleagris gallopavo) were dissected for a systematic study of the arteries. The frequency of the arteries found was: Cerebral carotid artery, intercarotid anastomosis and internal ophthalmic artery (100%). Caudal branch of the cerebral carotid artery to the right (R) vestigial artery (70%) and developed (30%) and to the left (L) developed (70%) and vestigial artery (30%). Ventral tectal mesencephalic artery in (70%) to R and (30%) to L was the direct branch of the cerebral carotid artery to L (70%) and to R (30%) collateral branch of the developed caudal branch. Basilar artery to L in (70%) and to R (30%) formed from the developed caudal branch; rostral ventral cerebellar artery present (86.7%) and absent (13.3%) to R and L. Caudal ventral cerebellar artery to R single (73.3%), double (23.3%) and triple (3.3%); caudal ventral cerebellar artery to L single (73.3%) and double (26.7%). Dorsal spinal artery branch of caudal ventral cerebellar artery to R (80%) and to L (73.3%). The rostral branch of cerebral carotid artery showed as collateral branches the single caudal cerebral artery to R (100%) and to L (96.7%) while in (3.3%) it was double. The middle cerebral artery was single to R and L (100%). Cerebroethmoidal artery to R and L (100%) with its collateral branch to single rostral cerebral artery (90%) to R and (86.7%) to L and double (10%) to R and (13.3%) to L. Ethmoidal artery to R and to L (100%) single. The cerebral arterial circle was rostrally and caudally opened, so that the cerebral blood supply was exclusively made by the carotid system.

A systematic study of the brain base arteries in the rabbit (Oryctolagus cuniculus)

The brains of 30 New Zealand rabbits (Oryctolagus cuniculus) were injected with red stained latex. The arteries of the ventral surface of the brain were systematized on the right (R) and on the left (L) side with the respective percentage of appearance: the aortic arch emitted the braquicephalic trunk and the left subclavian artery (83.3%); or the braquicephalic trunk, the left common carotid artery and the left subclavian artery (16.7%). The braquicephalic trunk emitted the right and the left common carotid arteries and the right subclavian artery (83.3%); or the right common carotid artery and the right subclavian artery (16.7%). The common carotid arteries were divided into external and internal carotid arteries (96.7% on the R, 100% on the L.). The internal carotid artery to the R was present (96.7%) and absent (3.3%), and to the L, was present (100%). The rostral choroidal artery to the R was collateral branch of the rostral branch of the internal carotid artery (83.3%), collateral branch of caudal branch of the internal carotid artery (16.7%), and to the L was collateral branch of the rostral branch of the internal carotid artery (93.3%), collateral branch of the caudal branch of the internal carotid artery (6.7%). The middle cerebral artery to the R and to the L was single (80%) and double (20%). The rostral cerebral artery to the R had middle caliber (90%), thin caliber (6.7%) and too thin caliber (3.3%), and to the L had middle caliber (76.7%), thin caliber (16.7%) and too thin caliber (6.7%). The internal ethmoidal artery was absent (73.3%), present and single (26.7%). The caudal cerebral artery to the R was single (66.7%), double (26.7%) and triple (6.7%), and to the L was single (63.3%) and double (36.7%). The terminal branches of the right and left vertebral arteries were present (100%, and formed the basilar artery (100%). The ventral spinal artery was present (100%). The caudal cerebellar artery, to the R was single (43.3%), single with labyrinthic artery isolated (26.7%) and double (30%), and to the L was single (50%), single with labyrinthic artery isolated (6.7%), double (40%) and triple (3.3%). The trigeminal artery to the R and to the L was present (100%). The rostral cerebellar artery to the R was single (53.3%) and double (46,7%), and to the L was single (63.3%) and double (36.7%). The rabbit's cerebral arterial circle was caudally closed (100%) and rostrally closed (93.3%) or opened (6.7%). The brain was supplied by the vertebral-basilar and carotid systems.

Effects of cervical sympathectomy on vasospasm induced by meningeal haemorrhage in rabbits

This study investigates the role of cervical sympathectomy in the prevention of acute vasospasm induced by meningeal haemorrhage in rabbits. Sixteen adult English Norfolk rabbits were divided into 2 experimental groups: bilateral cervical sympathectomy of the superior sympathetic ganglion (SSSG, n=8), and bilateral SSSG and sympathectomy of the inferior sympathetic ganglion (SISG, n=8). Other 24 animals were used as controls. Basilar artery diameter was evaluated by angiography. SSSG protected the animals against developing cerebral vasospasm; SSSG associated with SISG did not increase this effect.

Sudden bilateral deafness from hyperleukocytosis in chronic myeloid leukemia

Sudden-onset bilateral deafness as a clinical manifestation of hyperleukocytosis in chronic myeloid leukemia (CML) is a rare occurrence. We found only 27 clinical descriptions in 16 published papers. In this work, the authors present a review on deafness in CML and describe a new case with prominent hyperleukocytosis, where the neurological findings suggest slowing of the circulation through small blood vessels in the brainstem as the cause of deafness. The evolution was good after treatment. To our knowledge, this is the second case documented with electrical auditory brainstem-evoked potentials and the first with magnetic resonance imaging. Copyright (C) 2000 S. Karger AG, Basel.

Influência do treinamento aeróbico intradialítico no fluxo sanguíneo cerebral e o reflexo sobre a função cognitiva e qualidade de vida em pacientes renais crônicos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mechanical thrombectomy with solitaire stent retrieval for acute ischemic stroke in a Brazilian population

OBJECTIVE: Large vessel occlusion in acute ischemic stroke is associated with low recanalization rates under intravenous thrombolysis. We evaluated the safety and efficacy of the Solitaire AB stent in treating acute ischemic stroke. METHODS: Patients presenting with acute ischemic stroke were prospectively evaluated. The neurological outcomes were assessed using the National Institutes of Health Stroke Scale and the modified Rankin Scale. Time was recorded from the symptom onset to the recanalization and procedure time. Recanalization was assessed using the thrombolysis in cerebral infarction score. RESULTS: Twenty-one patients were evaluated. The mean patient age was 65, and the National Institutes of Health Stroke Scale scores ranged from 7 to 28 (average 17+/-6.36) at presentation. The vessel occlusions occurred in the middle cerebral artery (61.9%), distal internal carotid artery (14.3%), tandem carotid occlusion (14.3%), and basilar artery (9.5%). Primary thrombectomy, rescue treatment and a bridging approach represented 66.6%, 28.6%, and 4.8% of the performed procedures, respectively. The mean time from symptom onset to recanalization was 356.5+/-107.8 minutes (range, 80-586 minutes). The mean procedure time was 60.4+/-58.8 minutes (range, 14-240 minutes). The overall recanalization rate (thrombolysis in cerebral infarction scores of 3 or 2b) was 90.4%, and the symptomatic intracranial hemorrhage rate was 14.2%. The National Institutes of Health Stroke Scale scores at discharge ranged from 0 to 25 (average 6.9+/-7). At three months, 61.9% of the patients had a modified Rankin Scale score of 0 to 2, with an overall mortality rate of 9.5%. CONCLUSIONS: Intra-arterial thrombectomy with the Solitaire AB device appears to be safe and effective. Large randomized trials are necessary to confirm the benefits of this approach in acute ischemic stroke.

An anatomical analysis of the mini-modified orbitozygomatic and supra-orbital approaches

Seven sides of cadaver heads were used to compare the surgical exposures provided by the mini-modified orbitozygomatic (MOz) and supra-orbital (SO) approaches. The Optotrak 3020 computerized tracking system (Northern Digital, Waterloo, ON, Canada) was utilized to evaluate the area of anatomical exposure defined by six points: (1) ipsilateral sphenoid ridge; (2) most distal point of the ipsilateral middle cerebral artery (MCA); (3) most distal point of the ipsilateral posterior cerebral artery (PCA); (4) most distal point of the contralateral PCA; (5) most distal point of the contralateral MCA; and (6) contralateral sphenoid ridge. Additionally, angles of approach for the ipsilateral MCA bifurcation, ipsilateral ICA bifurcation, basilar artery tip, contralateral MCA and ICA bifurcation and anterior communicating artery (AcomA) were evaluated, first for SO and then for MOz. An image guidance system was used to evaluate the limits of surgical exposure. No differences in the area of surgical exposure were noted (p > 0.05). Vertical angles were significantly wider for the ipsilateral and contralateral ICA bifurcation, AcomA, contralateral MCA and basilar tip (p < 0.05) for MOz. No differences in horizontal angles were observed between the approaches for the six targets (p > 0.05). There were no differences in the limits of exposure. MOz affords no additional surgical working space. However, our results demonstrate systematically that vertical exposure is improved. The MOz should be performed while planning an approach to these regions and a wider exposure in the vertical axis is needed. (C) 2012 Elsevier Ltd. All rights reserved.