Clinical and angiographic risk factors for stroke and death within 30 days after carotid endarterectomy and stent-protected angioplasty: a subanalysis of the SPACE study.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are used to prevent ischaemic stroke in patients with stenosis of the internal carotid artery. Better knowledge of risk factors could improve assignment of patients to these procedures and reduce overall risk. We aimed to assess the risk of stroke or death associated with CEA and CAS in patients with different risk factors. METHODS: We analysed data from 1196 patients randomised to CAS or CEA in the Stent-Protected Angioplasty versus Carotid Endarterectomy in Symptomatic Patients (SPACE) trial. The primary outcome event was death or ipsilateral stroke (ischaemic or haemorrhagic) with symptoms that lasted more than 24 h between randomisation and 30 days after therapy. Six predefined variables were assessed as potential risk factors for this outcome: age, sex, type of qualifying event, side of intervention, degree of stenosis, and presence of high-grade contralateral stenosis or occlusion. The SPACE trial is registered at Current Controlled Trials, with the international standard randomised controlled trial number ISRCTN57874028. FINDINGS: Risk of ipsilateral stroke or death increased significantly with age in the CAS group (p=0.001) but not in the CEA group (p=0.534). Classification and regression tree analysis showed that the age that gave the greatest separation between high-risk and low-risk populations who had CAS was 68 years: the rate of primary outcome events was 2.7% (8/293) in patients who were 68 years old or younger and 10.8% (34/314) in older patients. Other variables did not differ between the CEA and CAS groups. INTERPRETATION: Of the predefined covariates, only age was significantly associated with the risk of stroke and death. The lower risk after CAS versus CEA in patients up to 68 years of age was not detectable in older patients. This finding should be interpreted with caution because of the drawbacks of post-hoc analyses.

30 day results from the SPACE trial of stent-protected angioplasty versus carotid endarterectomy in symptomatic patients: a randomised non-inferiority trial.

BACKGROUND: Carotid endarterectomy is effective in stroke prevention for patients with severe symptomatic carotid-artery stenosis, and carotid-artery stenting has been widely used as alternative treatment. Since equivalence or superiority has not been convincingly shown for either treatment, we aimed to compare the two. METHODS: 1200 patients with symptomatic carotid-artery stenosis were randomly assigned within 180 days of transient ischaemic attack or moderate stroke (modified Rankin scale score of < or =3) carotid-artery stenting (n=605) or carotid endarterectomy (n=595). The primary endpoint of this hospital-based study was ipsilateral ischaemic stroke or death from time of randomisation to 30 days after the procedure. The non-inferiority margin was defined as less than 2.5% on the basis of an expected event rate of 5%. Analyses were on an intention-to-treat basis. This trial is registered at Current Controlled Trials with the international standard randomised controlled trial number ISRCTN57874028. FINDINGS: 1183 patients were included in the analysis. The rate of death or ipsilateral ischaemic stroke from randomisation to 30 days after the procedure was 6.84% with carotid-artery stenting and 6.34% with carotid endarterectomy (absolute difference 0.51%, 90% CI -1.89% to 2.91%). The one-sided p value for non-inferiority is 0.09. INTERPRETATION: SPACE failed to prove non-inferiority of carotid-artery stenting compared with carotid endarterectomy for the periprocedural complication rate. The results of this trial do not justify the widespread use in the short-term of carotid-artery stenting for treatment of carotid-artery stenoses. Results at 6-24 months are awaited.

[Neuroradiological imaging in patients with sensorineural hearing loss prior to cochlear implantation]. / Neuroradiologische Diagnostik bei Patienten mit sensorineuralem Hörverlust vor Cochlea-Implantation.

Cochlear implantation (CI) is an established technique for enabling speech perception in patients suffering from severe bilateral sensorineural hearing loss (SNHL). Thorough preoperative radiological assessment is essential for correctly evaluating the indication for surgery and safely performing cochlear implantation. CT and conventional and functional MRI are available for radiological assessment. Therefore, knowledge of the most frequent congenital syndromal, non-syndromal, and acquired malformations of inner ear structures is fundamental. This article provides information about imaging techniques prior to CI and relevant malformations of the inner ear. Safety aspects for patients with a cochlear implant undergoing MR imaging are also discussed.

Cerecyte coils in the treatment of intracranial aneurysms: a preliminary clinical study.

BACKGROUND AND PURPOSE: Recanalization remains a major drawback in the endovascular treatment of intracranial aneurysms. Here, we report on our preliminary clinical experience with a new bioactive coil. PATIENTS AND METHODS: In a prospective study, 25 aneurysms were treated in 24 patients. Endovascular occlusion of the aneurysm was performed by using a novel polyglycol acid-loaded coil (Cerecyte). Mean aneurysm volume was 114.7 mm(3), with a mean dome height of 5.2 mm and a neck width of 2.8 mm. The primary goal of this study was to assess the safety of this new polymer-loaded coil in terms of periprocedural, technical, or angiographic complications. The secondary scope was to evaluate treatment efficacy regarding primary aneurysm occlusion, packing attenuation, and recanalization at follow-up angiography at 6 months. RESULTS: There were no major technical or angiographic complications resulting in permanent morbidity. Complete initial occlusion of the aneurysm was accomplished in 17 patients, and a neck remnant was present in 8 patients. All aneurysms with complete initial occlusion remained stable at 6 months. Progression of a neck remnant without need for retreatment was noted in 2 patients, whereas 5 neck remnants turned to complete occlusion. Thus, complete occlusion rate at 6 months was 88%. CONCLUSION: In this preliminary study the use of Cerecyte coils was safe, with an incidence of procedural complications comparable with that of bare platinum coils. Although most of the aneurysms in this study were small, the immediate and 6-month follow-up angiographic results are encouraging so that in our opinion, a larger clinical trial is warranted.

Fatal recurrent subarachnoid hemorrhage after complete endovascular aneurysm occlusion.

Endovascular treatment of aneurysms has become an alternative to the neurosurgical approach. Here, we describe a patient presenting with a subarachnoid hemorrhage (SAH) due to a basilar tip aneurysm, which was completely occluded with coils. Fourteen days later the patient died due to massive recurrent SAH. Histologic evaluation showed aneurysm rerupture with coil dislocation in the subarachnoid space. This is a rare histologically documented case of fatal recurrent hemorrhage early after coil embolization of cerebral aneurysms.

Presence and removal of arteriovenous malformation: Impact of regional cerebral blood flow, as assessed with xenon/CT.

In 26 patients with supratentorial AVMs and 1 patient with a dural arteriovenous fistula, the regional cerebral blood flow (rCBF) was assessed by means of xenon-enhanced computed tomography (Xe/CT) before and after complete resective surgery. Each assessment comprised an acetazolamide challenge in order to check the cerebrovascular reserve capacity. While scanning through the AVM was purposely avoided, a single brain slice at the level of the basal ganglia was examined. Five regions of interest (ROIs) in gray matter of the AVM-bearing hemisphere were compared to the contralateral ROIs and categorized into 7 CBF groups. Interhemispherical differences exceeding 20% of the contralateral value in either direction were considered to the significant. AVM-related (AVM-R) and AVM-non-related (AVM-NR) ROIs were looked at separately. Before surgery, all possible rCBF patterns were found, including a normal rCBF as well as a reduced or an increased rCBF, either in AVM-R, AVM-NR, or both. After AVM removal, a rCBF increase in AVM-R is relatively rare, whereas a rCBF decrease is twice as frequent. A rCBF drop to a level of impaired reserve capacity correlates with the occurrence of post-operative neurological deficit.

Spinal canal stenosis in L-2-hydroxyglutaric aciduria.

We describe 2 brothers with L-2-hydroxyglutaric aciduria who developed severe spastic tetraparesis in their 30s. They also had an underlying condition of high-grade cervical spinal canal stenosis diagnosed by magnetic resonance imaging. They were operated on to decompress the spine, and the preexisting gait disturbances slowly diminished after the decompression. Since most people with L-2-hydroxyglutaric aciduria show spastic signs in their legs and arms, we conclude that cervical spinal canal stenosis may be the underlying reason and may be linked to this rare metabolic disorder.

Measurement of the midbrain diameter on routine magnetic resonance imaging: a simple and accurate method of differentiating between Parkinson disease and progressive supranuclear palsy.

Anteroposterior diameters of the suprapontine midbrain, the pons, and the collicular plate were measured in 50 patients with various parkinsonian syndromes (Parkinson disease [PD] [n = 20], progressive supranuclear palsy [PSP] [n = 16], and multiple-system atrophy of striatonigral type [n = 14]) and 12 age-matched healthy control subjects by means of axial T2-weighted magnetic resonance images. While no differences in midbrain diameter were found between patients with PD (mean, 18.5 mm) and control subjects (mean, 18.2 mm), patients with PSP had significantly lower midbrain diameters (mean, 13.4 mm) than patients with PD and control subjects (P<.001), without any overlap between these 2 groups. However, midbrain diameters of patients with multiple-system atrophy were also significantly lower than those of control subjects and patients with PD, with individual values showing overlap with the PSP, PD, and control groups. Pontine and collicular plate diameters did not contribute additional information. We therefore conclude that measurement of anteroposterior diameter of the midbrain on axial T2-weighted magnetic resonance images is a reliable means to differentiate patients with PSP from those with PD and should be incorporated into the diagnostic criteria for PSP.

Peroneal nerve palsy caused by thrombosis of crural veins.

Acute palsies of the peroneal nerve may have a variety of causes. In many patients, the cause remains undetermined. The authors report a patient with a thrombosis of a crural vein causing an acute peroneal nerve palsy. If the clinical history of patients with an acute peroneal nerve lesion is suggestive of venous thrombosis an appropriate diagnostic workup should be considered.

Cerebral activation patterns in patients with writer's cramp: a functional magnetic resonance imaging study.

Functional MRI (fMRI), visualizing changes in cerebral blood oxygenation, has to date not been performed either in patients with writer's cramp or in healthy subjects during writing. We compared the cerebral and cerebellar activation pattern of 12 patients with writer's cramp during writing with a group of 10 healthy subjects performing the same tasks over 30-s periods of rest or writing. Sixty echo planar imaging multislice datasets were analysed using SPM96 software. Data were analysed for each subject individually and groupwise for patients vs. controls. Healthy subjects showed a significant activation of the ipsilateral dentate nucleus, contralateral cerebellar hemisphere, contralateral primary sensorimotor cortex, and contralateral precentral gyrus during writing. Patients with writer's cramp showed significantly greater activation of the ipsilateral cerebellar hemisphere than controls. Also the activation in the primary sensorimotor cortex extended further caudally and anteriorly towards the premotor association area. Activation was observed in the thalamus during writing only among the patients. Our results indicate an increased basal ganglia output via the thalamus to the motor and premotor cortical areas in dystonia patients and support the notion of disinhibition of the motor cortex leading to cocontractions and dystonic postures.

Confirmation of CT criteria to distinguish pathophysiologic subtypes of cerebral infarction.

PURPOSE: To determine whether cerebral infarctions classified as embolic or hemodynamic by their appearance on CT scans reflect distinct pathophysiologic entities. METHODS: Cerebral infarctions were retrospectively classified into two groups according to their morphologic appearance on CT scans: territorial infarctions and watershed, or terminal supply area, infarctions. Specific CO2 reactivity for both groups of patients was determined with the xenon-133 method and 32 stationary detectors. Twenty-one patients with unilateral, supratentorial, ischemic cerebral infarctions were selected. CT findings were highly suggestive of a territorial infarction in 14 patients (mean age, 56 years) and of a watershed infarction in seven patients (mean age, 52 years). RESULTS: The initial slope index of the territorial and watershed infarction groups during CO2 inhalation was 55.1 +/- 2.4 sec-1 and 52.0 +/- 1.9 sec-1, respectively, in the infarcted hemispheres and 58.3 +/- 2.3 sec-1 and 55.1 +/- 1.5 sec-1, respectively, in the noninfarcted hemispheres. CO2 reactivity of the unaffected detectors was 1.75 +/- 0.3 sec-1 mm Hg-1 and 1.51 +/- 0.2 sec-1 mm Hg-1 for the territorial and watershed infarction groups, respectively. CO2 reactivity of the affected detectors was 1.75 +/- 0.3 sec-1 mm Hg-1 and 1.27 +/- 0.2 sec-1 mm Hg-1 for the two groups, respectively. The CO2 reactivity difference between affected detectors of the hemodynamic group and age-matched healthy control subjects was significant. CONCLUSIONS: The difference in CO2 reactivity between the two groups supports the concept that CT criteria can identify two pathophysiologic entities. In addition, we conclude that during the chronic stage, lower CO2 reactivity of the watershed infarction indicates that the global hemodynamic situation in these infarcts is more severely compromised than in territorial infarctions.

Phase-contrast MR imaging of the cervical CSF and spinal cord: volumetric motion analysis in patients with Chiari I malformation.

BACKGROUND AND PURPOSE: Most previous MR studies of the dynamics of Chiari I malformation have been confined to sagittal images and operator-dependent measurement points in the midline. To obtain a deeper insight into the pathophysiology of the Chiari I malformation, we performed a prospective study using axial slices at the level of C2 to analyze volumetric motion data of the spinal cord and CSF over the whole cross-sectional area. METHODS: Eighteen patients with Chiari I malformation and 18 healthy control subjects underwent cardiac-gated phase-contrast imaging. Cross-sectional area measurements and volumetric flow/motion data calculations were made for the following compartments: the entire intradural space, the spinal cord, and the anterior and posterior subarachnoid space. RESULTS: The most striking feature was an increased early systolic caudal and diastolic cranial motion of the spinal cord in the patients. CSF pulsations in the anterior subarachnoid space were unchanged at systole but showed an impaired diastolic upward flow. In the posterior compartment, the CSF systole was slightly shortened, with an impairment of diastolic upward flow. Fourteen of the 18 patients had associated syringeal cavities. This subgroup showed an increased systolic downward displacement of the cord as compared with patients without a syrinx. CONCLUSION: Obstruction of the foramen magnum in patients with Chiari I malformation causes an abrupt systolic downward displacement of the spinal cord and impairs the recoil of CSF during diastole.

Uncommon morphologic characteristics in Leigh's disease.

We describe a 4-month-old male patient with severe developmental delay and elevated lactate in blood and CSF. The MR images showed abnormalities differing from the typical pattern found in association with Leigh's disease. The examination of fibroblast cultures showed diminished activity of mitochondrial complexes I and III. The patient died at the age of 9 months.

Extracerebral intracranial glioneural hamartoma with extension into the parapharyngeal space.

A newborn had an extracerebral, intracranial mass extending from the right middle cranial fossa through the base of the skull to the parapharyngeal space. The mass was predominantly composed of immature brain tissue. It was enclosed by its own leptomeninges and dura and was classified as a glioneural hamartoma.

Cerebral MR in ophthalmoplegia plus.

PURPOSE: To evaluate MR patterns in ophthalmoplegia plus and correlate them with clinical symptoms. METHODS: MR was performed on a 1.5-T whole-body scanner with T2-weighted gradient-echo and spin-echo images. The retrospective analysis included 19 patients with clinically established diagnoses of ophthalmoplegia plus. RESULTS: Two types of cerebral MR abnormalities were found in ophthalmoplegia plus: brain atrophy and hyperintensities restricted to the white matter and basal ganglia, which appeared as either focal or diffuse areas of high signal intensity and were of strictly supratentorial location. No specific distribution was found. These findings differ markedly from infarction-like lesions found in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. CONCLUSIONS: MR is sensitive for the detection of central nervous system involvement in ophthalmoplegia plus, but findings are nonspecific. However, cerebral MR in ophthalmoplegia plus is different from other mitochondrial encephalomyopathies and underlines the clinical differentiation of mitochondrial encephalomyopathies.

MR imaging- and MR spectroscopy-revealed changes in meningiomas for which embolization was performed without subsequent surgery.

We describe our experience with follow-up MR imaging and MR spectroscopy in two patients after embolization of meningiomas without subsequent surgery. In both patients there was a marked reduction in tumor size and a decrease in contrast enhancement associated with spectroscopic signs of fatty degeneration. We did not observe regrowth; however, in one patient with incomplete angiographic devascularization, residual vital tumor tissue was seen at follow-up examinations.

Efficacy of trisacryl gelatin microspheres versus polyvinyl alcohol particles in the preoperative embolization of meningiomas.

BACKGROUND AND PURPOSE: Trisacryl gelatin microspheres are a new, commercially available nonabsorbable embolic agent. The purpose of this study was to evaluate their efficacy in the preoperative embolization of meningiomas as compared with polyvinyl alcohol (PVA) particles of various sizes. METHODS: In 30 consecutive patients, trisacryl gelatin microspheres (150-300 microm) were used for the preoperative superselective embolization of meningiomas (group 1). Thirty other consecutive patients had embolization with PVA particles of 45 to 150 microm (n = 15, group 2) and of 150 to 250 microm (n = 15, group 3). Extent of devascularization, intraoperative blood loss, blood transfusion, and hemostasis at the time of surgery were recorded for every patient. The inflammatory reaction, the extent of necrotic areas, and the most distal intravascular location of the embolic agent (arterial, arteriolar, precapillary, capillary) were recorded. RESULTS: There was no significant difference in the extent of angiographic devascularization among the groups. Intraoperative blood loss differed significantly between groups 1 and 2 and groups 1 and 3, but not between groups 2 and 3. The trisacryl gelatin microspheres were located more distally in tumor vessels than were the PVA particles of either size. The extent of intratumoral necrosis was not significantly different between the two embolic agents. In all groups there was a mild inflammatory tissue reaction in the vicinity of the embolic agent. CONCLUSION: Trisacryl gelatin microspheres may be effective in the preoperative embolization of meningiomas, producing significantly less blood loss at surgery than seen with PVA particles of either size, possibly because of the significantly more distal vascular penetration of the microspheres.

MR spectroscopy in gliomatosis cerebri.

BACKGROUND AND PURPOSE: The diagnosis of gliomatosis cerebri with MR imaging is known to be difficult. We report on the value of MR spectroscopy in the diagnosis, grading, and biopsy planing in eight patients with histopathologically proved gliomatosis cerebri. METHODS: Patients underwent MR imaging and MR spectroscopy (single-voxel point-resolved spectroscopy [PRESS] at 1500/135, and chemical-shift imaging [CSI] PRESS at 1500/135) before open (n = 4) or stereotactic (n = 4) biopsy. In six patients who underwent CSI, biopsy samples were taken from regions of maximally elevated levels of choline/N-acetylaspartate (Cho/NAA). RESULTS: All patients showed elevated Cho/creatine (Cr) and Cho/NAA levels as well as varying degrees of decreased NAA/Cr ratios, which were most pronounced in the anaplastic lesions. In low-grade lesions, there was a maximum Cho/NAA ratio of 1.3, whereas in anaplastic tumors, the maximum Cho/NAA level was at least 2.5. Spectra in two patients with grade III lesions revealed a lactate peak; lactate and lipid signals were seen in two patients with grade IV lesions. Biopsy specimens from regions with maximally elevated levels of Cho/NAA showed dense infiltration of tumor cells. CONCLUSION: MR spectroscopy might be used to classify gliomatosis cerebri as a stable or a progressive disease indicating its potential therapeutic relevance.

Dysembryoplastic neuroepithelial tumors: MR and CT evaluation.

PURPOSE: To evaluate dysembryoplastic neuroepithelial tumors (DNTs) on MR and CT studies and to compare DNT with other frequently encountered epileptogenic glioneuronal lesions. METHODS: We analyzed the MR images and CT scans of 16 patients who had complex partial epilepsy and DNT with respect to tumor location, size, CT density, MR signal intensity, mass effect, contrast enhancement, and heterogeneity, and compared these features with CT and MR findings in 51 cases of ganglioglioma and 33 cases of glioneuronal malformation. RESULTS: DNTs were located in the temporal lobe in 14 patients and in the frontal lobe in 2 patients. The cortex was involved in all cases and the subcortical white matter in 10 cases. Fifty percent of the tumors had poorly defined contours. On MR images, 14 DNTs had multiple cysts and 2 had single cysts. Contrast enhancement was observed in 6 DNTs, and mass effect was present in 9. CT scans disclosed moderately hypodense lesions in 7 patients and markedly hypodense cystic lesions in 6 patients. Two DNTs were calcified. Tumor hemorrhage with perifocal edema was observed in 1 case. Contrary to previous reports, slow but definite tumor growth was present during a 13-year period in 2 of 6 patients in whom serial CT or MR studies were obtained. CONCLUSION: A multicystic appearance on MR images is a characteristic feature of DNT and corresponds to its myxoid matrix and multinodular architecture. This feature is rare in gangliogliomas and glioneuronal malformations, and, as such, may help differentiate DNTs from these disorders.

A report of the clinical use of the detach-18 mechanical detachable platinum coil in 41 patients.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the safety and reliability of the mechanical detachment system of a new platinum coil, Detach-18, when used as a vascular occlusive device for neurovascular disease. METHODS: Forty-one patients (nine male and 32 female patients; age range, 26-75 years; mean age, 54.4 years) underwent treatment at seven centers. Twenty-two patients had dural arteriovenous fistulae of the transverse sinus treated by a transvenous route. Fourteen patients underwent internal carotid artery occlusion in the treatment of aneurysms, meningioma, facial tumor, or carotid injury. One patient underwent occlusion of the basilar artery and one patient underwent occlusion of the vertebral artery for treatment of aneurysms. In two patients, coils were used as part of the treatment of their arteriovenous malformations. In all cases, the Detach-18 coils were delivered through a microcatheter with two distal markers. Two types of coils, a 0.015-inch-diameter "regular" coil and a 0.014-inch-diameter "soft" coil, were used. RESULTS: A total of 569 coils were used, 541 of which were detached. The number of coils in ranged from four to 53 (average number of coils, 14). The coils passed easily through the microcatheter. The detachment maneuver occurred within 10 to 25 s with 20 turns of the introducing wire. No premature coil detachment occurred. Complete occlusion of the vessel lumen was achieved in 35 cases. In three cases, 80% to 90% occlusion was achieved. In two cases, 70% to 80% occlusion was achieved. There were no device-related complications. CONCLUSION: The detachment system was safe, reliable, consistent, and fast. This is a useful system for coil embolization in neurovascular applications.