Endovascular management of vertebral artery dissecting aneurysms: review of 25 patients.

AIM: Management of Vertebral Artery (VA) dissections remains controversial. The clinical and angiographic variables of VA dissections were evaluated to demonstrate the safety and efficacy of endovascular intervention in treatment of VA dissecting aneurysms. MATERIAL AND METHODS: 25 patients with 27 VAdissecting aneurysms were treated with endovascular intervention during the last 10 years.17 patients were admitted with subarachnoid hemorrhage. 23 aneurysms treated using destructive endovascular trapping, while reconstructive techniques were used in 3 aneurysms treated with stent-assisted coiling and one aneurysm treated with false lumen embolization. RESULTS: The right VA was involved in 14 patients, the left VA in 9 patients, while 2 patients had bilateral VA dissection. The pearl and string sign was the commonest angiographic sign in 12 aneurysms. Perioperative complications included; rebleeding in one patient, symptomatic brain stem infarction in two patients and silent cerebellar ischemic lesion in one patient. Afavorable outcome was evident more in patients with unruptured VA dissection (100%) versus (76.5%) in patients presented with SAH. CONCLUSION: The endovascular technique should be individualized according to the clinical status of the patient, angiographic variables, condition of the posterior circulation and the available supplies.

Microarray profile of seizure damage-refractory hippocampal CA3 in a mouse model of epileptic preconditioning.

A neuroprotected state can be acquired by preconditioning brain with a stimulus that is subthreshold for damage (tolerance). Acquisition of tolerance involves coordinate, bi-directional changes to gene expression levels and the re-programmed phenotype is determined by the preconditioning stimulus. While best studied in ischemic brain there is evidence brief seizures can confer tolerance against prolonged seizures (status epilepticus). Presently, we developed a model of epileptic preconditioning in mice and used microarrays to gain insight into the transcriptional phenotype within the target hippocampus at the time tolerance had been acquired. Epileptic tolerance was induced by an episode of non-damaging seizures in adult C57Bl/6 mice using a systemic injection of kainic acid. Neuron and DNA damage-positive cell counts 24 h after status epilepticus induced by intraamygdala microinjection of kainic acid revealed preconditioning given 24 h prior reduced CA3 neuronal death by approximately 45% compared with non-tolerant seizure mice. Microarray analysis of over 39,000 transcripts (Affymetrix 430 2.0 chip) from microdissected CA3 subfields was undertaken at the point at which tolerance was acquired. Results revealed a unique profile of small numbers of equivalently up- and down-regulated genes with biological functions that included transport and localization, ubiquitin metabolism, apoptosis and cell cycle control. Select microarray findings were validated post hoc by real-time polymerase chain reaction and Western blotting. The present study defines a paradigm for inducing epileptic preconditioning in mice and first insight into the global transcriptome of the seizure-damage refractory brain.

Percutaneous angioplasty and stenting of subclavian arteries before surgical coronary revascularization in a patient with an aberrant right subclavian artery.

An aberrant right subclavian artery occurs in less than 2% of the population. An associated stenosis of the subclavian artery carries a risk of subclavian-coronary steal in patients who undergo coronary revascularization. We report on the case of a 54-year-old man admitted to our hospital for a coronary artery bypass graft (CABG). Angiographic examination revealed bilateral subclavian-artery stenosis with an aberrant right subclavian artery, anomalous origin of the right vertebral artery from the right common carotid artery, and left vertebral-artery occlusion. The patient underwent successful bilateral subclavian angioplasty and stenting.

Apparent diffusion coefficient of pituitary macroadenoma evaluated with line-scan diffusion-weighted imaging.

OBJECTIVE: The goal of this study was to evaluate the consistency of pituitary macroadenoma using apparent diffusion coefficient (ADC) with line-scan diffusion-weighted imaging (LSDWI). METHODS: Patients with pituitary macroadenoma (n=19) were studied prospectively. The LSDWI was performed using a maximum b factor of 1000 s/mm2. The consistency of macroadenoma was rated as soft, intermediate or hard at transsphenoidal surgery. The ADC values of tumors were compared with the tumor-consistency ratings. RESULTS: A soft consistency was found at surgery in 13 patients (mean ADC: 0.84+/-0.1x10(-3) mm2/s); an intermediate consistency was observed in six patients (mean ADC: 0.81+/-0.16x10(-3) mm2/s). No tumors of hard consistency were found. There was no significant difference in ADC values between tumors of soft consistency compared with tumors of intermediate consistency (P=0.37). CONCLUSIONS: A relationship between tumor consistency and the ADCs of soft and intermediate macroadenomas was not shown in this study using LSDWI.

Diffusion-weighted MR imaging in carotid angioplasty and stenting with protection by the reversed carotid arterial flow.

BACKGROUND AND PURPOSE: Distal embolism during carotid angioplasty with stent (CAS) can be protected by a flow-reversal device. Diffusion-weighted MR imaging was used to evaluate this protective procedure and perform a comparison with the control. METHODS: Cases of CAS with protection procedures were included in this study. Sixty-five men (68 procedures) and 5 women (5 procedures), with an average age of 68.8 years, having severe carotid stenosis were treated in our department between 2002 and 2004. Eleven cases were treated with the Parodi Anti-Emboli System, with which the internal carotid blood flow is reversed by simultaneous occlusion of the proximal common carotid artery and external carotid artery. Diffusion-weighted MR imaging was performed within 1-3 days after CAS. As controls, data from diffusion-weighted MR imaging in 26 patients who had diagnostic angiography were included. RESULTS: Diffusion-weighted MR imaging in diagnostic angiography showed 11.5% appearance of ischemic spots after procedures. In the Parodi Anti-Emboli System, this value was 18.2%. In the CAS group, ischemic lesions appeared only in the hemisphere ipsilateral to carotid stenosis. There were no ischemic lesions in the opposite carotid or vertebrobasilar territory. The appearance rate of new ischemic spots was not significantly different between the control group and the group of CAS with Parodi Anti-Emboli System (chi2 test, P = .6227, Fisher exact method). CONCLUSIONS: Protection results obtained with the Parodi system were excellent and comparable with conventional angiography.

Nonconvulsive focal inhibitory seizure: subdural recording from motor cortex.

The authors obtained an ictal electrocorticogram with chronically implanted subdural electrodes from a 30-year-old man with a low grade glioma in the right postcentral gyrus who had a focal inhibitory seizure of the left arm. During the ictal paresis, the authors observed epileptic discharges in the positive arm motor area of the right precentral gyrus and in its rostral area, but not in the negative motor area. The epileptic activity probably inhibited the spinal motoneuron pool without eliciting excitatory activity in the corticospinal pathway.

Survival-promoting activity of IL-7 on IL-2-dependent cytotoxic T lymphocyte clones: resultant induction of G1 arrest.

Interleukin-7 (IL-7) is essential for both T cell and B cell development. Recent studies have suggested that IL-7 also functions as a survival-promoting factor for resting and activated T cells. In this study we examined the effects of IL-7 on survival and cytotoxicity of tumor-specific CD8(+) cytotoxic T lymphocyte (CTL) clones established and maintained either with IL-2 alone or with a combination of IL-2 and IL-7. While the CTL clones cultured in IL-2 alone died around day 10, the CTL clones cultured in the presence of IL-2 and IL-7 survived for more than 4 weeks after seeding. The long-term survival of the latter was correlated with the presence of IL-7 in the medium. In addition, IL-7 alone prolonged survival of other IL-2-dependent CTL clones after the removal of IL-2. IL-7 maintained the CTLs in G1 arrest after a slight proliferation during the initial phase during which low-level but sustained DNA synthesis was observed. However, there was no direct correlation between DNA synthesis and enhancement of long-term survival by IL-7 as demonstrated by the inhibiting proliferation of the CTL clones with the protein kinase inhibitor genistein. During long-term survival in the presence of IL-7, the cytotoxic activities of the CTL clones decreased gradually to background levels although they were restored soon after the next passage. These results suggested that IL-7 had the ability to set machinery in motion against apoptosis in the IL-2-dependent CTL clones. Such an effect of IL-7 might play a role in vivo in the process leading activated T cells to the resting, that is, memory state.

ProNectin F-grafted-ethylene vinyl alcohol copolymer (EVAL) as a liquid type material for treating cerebral aneurysm--an in vivo and in vitro study.

The authors aimed to develop a liquid material for embolization of aneurysms. In vitro and in vivo performances of the new embolic material were examined by cell culture and using an aneurysm model made in common carotid arteries (CCAs) of adult rats. Engineered protein ProNectin F (PnF), which contains 13 sites of an arginine-glycine-aspartic acid (RGD), was grafted onto ethylene vinyl alcohol copolymer (EVAL-g-PnF). The liquid material, EVAL-g-PnF dissolved in DMSO, was infused into an aneurysm model. The blood segments were harvested 2, 5, and 14 days and examined histologically. A number of bovine coronary artery endothelial cells became able to attach to and form cobblestone-like islands on the EVAL by incorporating PnF. The aneurysm model infused with the EVAL-g-PnF solution revealed that the aneurysm lumen was filled with proliferated fibroblasts and macrophages. On the other hand, the aneurysm model treated with unmodified EVAL showed that the cavity was almost filled with EVAL mass and that fibroblasts and macrophages filled a narrow space between the EVAL mass and the cavity wall. The results indicate that EVAL-g-PnF could be more suitable for reorganizing the cavity of an aneurysm than native EVAL.

Solidifying liquid with novel initiation system for detachable balloon catheters.

In endovascular surgery, to permanently hinder blood inflow into an aneurysm for example, a catheter is percutaneously introduced into an artery and the balloon is positioned and inflated by a solidifying liquid and then released into the diseased part. A novel solidifying liquid for the inflated balloon curable under the continuous feeding of oxygen through the wall of the balloon is described here. Glucose oxidase which oxidizes glucose producing hydrogen peroxide was used for polymerization of the solidifying liquid. This solidifying liquid cured even in the presence of oxygen and water. It was radiopaque when mixed with the iodinated X-ray contrast chemical iopamidol. In addition, the solidified liquid had appropriate mechanical properties. The endovascular surgery could be carried out safely using it.

Non-adhesive cyanoacrylate as an embolic material for endovascular neurosurgery.

Endovascular neurosurgery is now becoming available as one of strategies for the treatment of cerebro-spinal arterio-venous malformations and aneurysms. For this treatment, a microcatheter is advanced into or close to a lesion and then an embolic material is administered through it to obliterate the lesion. N-butyl-2-cyanoacrylate (NBCA) has preferentially been used as an embolic material in Europe and America. However, its exceptionally strong adhesive force sometimes causes adhesion between the tip of the microcatheter and the artery. In this study, a new non-adhesive cyanoacrylate, isostearyl-2-cyanoacrylate (ISCA), was developed. It carries a long hydrophobic side isostearyl group with lower reactivity and adhesion than other cyanoacrylates. Its polymerization rate is, however, too low to obliterate a vascular lesion with a rapid blood flow. To increase the polymerization rate. ISCA was mixed with NBCA. As a result, the adhesive force of the mixture became extremely low, compared with that of NBCA. The viscosity of the mixture was low enough to allow its' use as an embolic material. Tissue reactions against the mixture was milder than those against NBCA. Radio-angiography became possible by mixing further with Lipiodol. The evaluation of this new embolic material with a rabbit renal artery showed that the obliteration effect of the mixture of ISCA and NBCA was excellent to use as an embolic material for clinical applications.

Somesthetic function of supplementary motor area during voluntary movements.

To clarify the somesthetic functions of the supplementary motor area (SMA), we recorded the cortical potentials following the median nerve electric stimulation directly from the SMA and investigated the modulation caused by voluntary movements in two patients with intractable SMA seizures. The evoked potentials over the SMA consisted of positive (61.5ms) and negative (100.0 ms) peaks, which were enlarged by voluntary movements of the stimulated hand. The present finding is in strong contrast with the attenuation (gating) of the response at the primary sensorimotor area (SM1) and suggests that the voluntary movements differently modulate the somatosensory functions of SMA and SM1.

Ischemic tolerance due to the induction of HSP70 in a rat ischemic recirculation model.

Various studies have demonstrated an increase in heat shock protein 70 (HSP70) synthesis in the brain following transiently induced ischemia, suggesting a protective role for HSP70 against ischemic insult. In this study, we determined the time course of HSP70 mRNA and protein induction in rat hippocampus following ischemia using Pulsinelli's four-vessel occlusion model, and suggested a protective role for HSP70 induction in limiting ischemic damage to neurons and delayed neuronal death. In Northern blotting analysis using human HSP70 DNA as a probe, the accumulation of HSP70 mRNA after 5 min ischemia became evident at 4 h, and continued until 16 h, while after 30 min ischemia, HSP70 mRNA appeared at 2 h, and continued above control level until 24 h after treatment. In immunoblot analysis using anti-HSP70 antibody, induction of HSP70 protein appeared 24 h and reached a maximum 48 h after 5 min ischemia. In immunohistochemical analysis using anti-HSP70 antibody, staining was not detected in CA1 neurons until 16 h after 5 min ischemia, but staining in CA1 gradually increased 1 day after ischemia and reached a maximum level 2 days after ischemia. Similar time profiles in the staining pattern of HSP70 protein were observed in CA3 and CA4 neuronal cells following 30 min ischemia. When rats pretreated with 5 min ischemia (non-lethal for CA1 pyramidal neurons) were exposed to a 30 min, lethal period of ischemia, 2 days after pretreatment, considerable staining of HSP70 was observed. Pretreated rats had much less neuronal damage in the CA1 sector than did rats subjected to lethal, 30 min ischemia alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary somatosensory cortex is actively involved in pain processing in human.

We recorded somatosensory evoked magnetic fields (SEFs) by a whole head magnetometer to elucidate cortical receptive areas involved in pain processing, focusing on the primary somatosensory cortex (SI), following painful CO(2) laser stimulation of the dorsum of the left hand in 12 healthy human subjects. In seven subjects, three spatially segregated cortical areas (contralateral SI and bilateral second (SII) somatosensory cortices) were simultaneously activated at around 210 ms after the stimulus, suggesting parallel processing of pain information in SI and SII. Equivalent current dipole (ECD) in SI pointed anteriorly in three subjects whereas posteriorly in the remaining four. We also recorded SEFs following electric stimulation of the left median nerve at wrist in three subjects. ECD of CO(2) laser stimulation was located medial-superior to that of electric stimulation in all three subjects. In addition, by direct recording of somatosensory evoked potentials (SEPs) from peri-Rolandic cortex by subdural electrodes in an epilepsy patient, we identified a response to the laser stimulation over the contralateral SI with the peak latency of 220 ms. Its distribution was similar to, but slightly wider than, that of P25 of electric SEPs. Taken together, it is postulated that the pain impulse is received in the crown of the postcentral gyrus in human.

Krypton-81m single photon emission tomography and the collateral circulation in carotid occlusion: the role of the circle of Willis and leptomeningeal anastomosis.

Cerebral perfusion images were investigated in patients with carotid artery occlusion, using single photon emission computed tomography with the infusion of krypton-81m into the internal, common carotid and vertebral arteries. The contribution of the circle of Willis and cerebral cortical anastomoses to the maintenance of adequate blood supply into the involved hemisphere was analysed. It was concluded that the cerebral perfusion image is superior to angiography in evaluating collateral circulation, and in the case of carotid occlusion, the circle of Willis is important in preventing infarction in the territory of the perforating arteries, while the cerebral cortex mainly receives its blood supply through the cortical leptomeningeal anastomoses, illustrating the major role of the leptomeningeal anastomosis as a collateral channel.

Electrocorticogram-electromyogram coherence during isometric contraction of hand muscle in human.

OBJECTIVE: To clarify how the primary sensorimotor and supplementary motor areas are involved in the generation of the rhythmicity of electromyogram (EMG) activity during continuous muscle contraction. METHOD: We analyzed the coherence between subdurally recorded cortical electroencephalograms (EEG) and EMGs of the contralateral wrist extensor muscle during continuous isometric contraction in 8 patients with medically intractable epilepsy. RESULTS: In all subjects, a significant coherence between the primary motor area (M1) and EMG was observed at the peak frequency of 15+/-3 Hz (means+/-SD). In the primary somatosensory area (S1) of 7 subjects and the supplementary motor area proper (SMA proper) of 4 subjects, significant coherence with EMG was observed at 12+/-5 and 15+/-4 Hz, respectively. The time lags revealed by cross-correlogram were 10+/-3, 7+/-1 and 22+/-8 ms in the M1, S1 and SMA proper, respectively, with the EMG lagging in all areas. CONCLUSION: These findings suggest that the rhythmic activity in the SMA proper, as well as in the S1 and M1, is related to the generation of the rhythmicity of EMG activity.

Human supplementary motor area is active in preparation for both voluntary muscle relaxation and contraction: subdural recording of Bereitschaftspotential.

Bereitschaftspotentials (BPs) preceding muscle relaxation and contraction were compared by using subdural electrodes which were implanted onto the right medial frontal surface in two patients with supplementary motor area (SMA) seizure. The applied movement paradigm (muscle relaxation and contraction tasks) was completely the same as employed in our previous study [Terada, K., Ikeda, A., Nagamine, T. and Shibasaki, H., Electroenceph. clin. Neurophysiol., 95 (1995) 335-345]. In both patients, either negative or positive BPs were observed in the SMA-proper and supplementary negative motor area (SNMA) starting at 1.2-1.8 prior to both movements. In one patient, BP was more widespread in the relaxation task whereas more restricted to the hand area in the contraction task. In the other patient, the BPs were observed in the cortical area rostral to SNMA (pre-SMA), in addition to the SMA-proper, in both tasks. It is concluded that SMA-proper and SNMA, and probably pre-SMA as well, in humans are similarly active in preparation for both voluntary muscle contraction and relaxation.

Scalp vein detected using internal carotid angiography that did not result in venous sinus compromise.

We present an unusual case of a scalp vein detected by using angiography of the internal carotid artery. The vein arose from the superior sagittal sinus and drained into the deep posterior cervical vein via the parietal emissary vein. This scalp vein may be a collateral pathway for venous sinuses; however, the patient had no evidence of venous sinus occlusive disease or intracranial hypertension.

Treatment of a spontaneous carotid cavernous fistula using an electrodetachable microcoil.

The authors detail their use of a modified version of an electrolysis coil currently manufactured in the United States. They connect a platinum wire to a stainless steel wire via a copper segment, and apply low voltage current to induce thrombosis while electrolysis of the copper effects separation of the platinum coil. Their technique shows potential for treatment of complicated carotid cavernous fistulas.

Characteristics of ethylene vinyl alcohol copolymer (EVAL) mixtures.

PURPOSE: To determine physical characteristics of mixtures of ethylene vinyl alcohol copolymer (EVAL) and metrizamide dissolved in dimethyl sulfoxide, liquid materials developed for embolization of arteriovenous malformations. METHODS: EVAL and dimethyl sulfoxide were mixed in various proportions and sterilized. The viscosity and density of each mixture was measured. Precipitation times were determined by dropping the mixtures into saline or human blood. The mixtures were filtered and the filtrates weighed. RESULTS: Densities and viscosities of the various mixtures differed significantly, proportionally to the concentration of EVAL. Precipitation times also differed significantly, in inverse proportion to the concentration of EVAL. Temperature and aqueous solution did not affect precipitation times significantly. The weight of the filtrate significantly increased with time but was constant for each precipitation time. Temperature significantly affected filtrate weight; aqueous solution did not. CONCLUSIONS: Because of their different physical properties, the various EVAL mixtures are suited to embolizing different types of arteriovenous malformations.

A new liquid material for embolization of arteriovenous malformations.

We have developed a liquid material for embolization of arteriovenous malformations that is a mixture of ethylene vinyl alcohol copolymer and metrizamide dissolved in dimethyl sulfoxide. Upon contact with blood, dimethyl sulfoxide rapidly diffuses into the blood and forms an ethylene vinyl alcohol copolymer elastic soft sponge that obstructs both the feeder and the nidus. The material, which is not adhesive, was used for embolization of three left cerebral arteriovenous malformations with satisfactory results.