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Biomedical subjects

J Reul

Publications and source records attributed to J Reul.

At least 19 recordsLinked to original sources

European carotid PROCAR Trial: prospective multicenter trial to evaluate the safety and performance of the ev3 Protégé stent in the treatment of carotid artery stenosis--1- and 6-month follow-up.

BACKGROUND: The purpose of the European PROCAR Trial was to evaluate the safety and performance of the Protégé stent in the treatment of common and/or internal carotid artery stenoses with adjunctive use of a filter embolic protection device. METHOD: The Protégé GPS stent is a self-expanding Nitinol stent system mounted on a 6 Fr 0.018'' (6-9 mm stent) or 7 Fr 0.035'' (10 mm stent) over-the-wire delivery system. Study patient assessments were conducted at baseline, periprocedure, discharge, and 1 and 6 months postprocedure. A total of 77 patients have been enrolled in the trial. RESULTS: In the 77 lesions treated (31 symptomatic, 46 asymptomatic), the procedure was technically successful in 76 (99%), with an average residual stenosis of less than 30%. One procedure failed because the embolic protection device could not be retrieved and the patient was sent to surgery. Within 30 days, there were four (5.2%) major adverse neurological events (MANEs). Three of the MANEs were major strokes (3.9%), one a minor stroke. The fifth MANE occurred prior to the 6-month follow-up visit; this patient had a major stroke 75 days after the procedure and died 36 days later. One additional death occurred because of urosepsis. CONCLUSIONS: The PROCAR trial shows that the Protégé stent with adjuvant use of a filter embolic protection device satisfies safety and performance criteria for the treatment of carotid artery stenosis. The incidence of MANEs for the Protégé stent is comparable to the incidence of these events in other recent carotid stent studies and standard carotid endarterectomy (CEA).

Aged↗

[Brainstem edema during a hypertensive crisis with vasogenic and cytotoxic concerns].

HISTORY AND ADMISSION FINDINGS: A 66-year-old woman on antihypertensive treatment was urgently admitted to a neurological/neuroradiological unit with signs of a mild brainstem syndrome and possible hypertensive crisis. INVESTIGATIONS: Magnetic resonance imaging (MRI) of the head indicated both intracellular (so-called cytotoxic) and vasogenic edema. TREATMENT AND COURSE: After antihypertensive medication all symptoms disappeared within an hour and the MRI became essentially normal. CONCLUSION: The reversible vasogenic edema was probably caused by an hypertensive encephalopathy, while the signs of focal cerebral ischemia were due to an intracellular, ultimately irreversible, edema. In this case there was evidence of both phenomena having occurred concomitantly.

Aged↗

Intrasubject reproducibility of presurgical language lateralization and mapping using fMRI.

BACKGROUND: fMRI is becoming a standard tool for the presurgical lateralization and mapping of brain areas involved in language processing. However, its within-subject reproducibility has yet to be fully explored. OBJECTIVE: To evaluate within-test and test-retest reliability of language fMRI in consecutive patients undergoing evaluation for epilepsy surgery. METHODS: Thirty-four unselected patients were investigated once (within-test reliability) and 12 patients twice (test-retest reliability). The imaging series consisted of an alternating 25-second synonym judgment condition with a 25-second letter-matching condition repeated 15 times. Reproducibility of activation maps of the first and second half of session 1 or activation maps of sessions 1 and 2 was evaluated by comparing one global and three regional lateralization indexes (Broca's area, remaining prefrontal cortex, temporoparietal area) and on a voxel-by-voxel basis (intraclass correlation coefficient, percentage overlap, correlation of t-values). RESULTS: Global and regional language lateralization was achieved with high reliability within and across sessions. Reproducibility was evenly distributed across both hemispheres but not within each hemisphere. Frontal activations were more reliable than temporoparietal ones. Depending on the statistical threshold chosen, the voxel-by-voxel analysis revealed a mean overlap of activations derived from the first and second investigation of up to 48.9%. CONCLUSION: Language fMRI proved sufficiently reliable for the determination of global and regional lateralization of language representation in individual unselected patients with epilepsy.

Adolescent↗

Hypertrophic olivary degeneration following pontine haemorrhage: hypertensive crisis or cavernous haemangioma bleeding?

The clinical and magnetic resonance (MR) features of hypertrophic olivary degeneration are described, along with a rare but treatable cause of this entity-pontine cavernous haemangioma. Hypertrophic olivary degeneration occurs after focal lesions to the dentato-rubro-olivary pathway, typically following a pontine haemorrhage involving the ipsilateral central tegmental tract, the contralateral superior cerebellar peduncle, or the dentate nucleus. Clinically, there is palatal myoclonus and an uncontrollable tremor, presumably caused by loss of inhibitory control. On MR imaging, hypertrophic olivary degeneration is characterised by a non-enhancing T1 isointense, T2 hyperintense enlargement confined to the olivary nucleus. Typically, haemorrhages following a hypertensive crisis are responsible for hypertrophic olivary degeneration. However, in the three reported cases, imaging findings within the former bleeding cavity suggested a cavernous haemangioma as the source of the haemorrhage.

Cerebral Hemorrhage↗

Language mapping in less than 15 minutes: real-time functional MRI during routine clinical investigation.

Neurosurgical interventions often require the presurgical determination of language dominance or mapping of language areas. Results obtained by fMRI are closely correlated with invasive procedures such as electrical stimulation mapping or the intracarotid amobarbital test. However, language fMRI is not used routinely, because postprocessing is time-consuming. We utilized a real-time analysis software installed directly on the MR console computer and SPM99 as reference postprocessing software. We assessed the reliability of the immediate determination of language dominance based on individual activation maps by comparing the results of the visual analysis of images derived from conventional postprocessing with those produced by the real-time tool. All images were rated independently by six senior neurologists blinded to other data. We validated the robustness of the real-time method statistically by comparing global and regional lateralization indices derived from real-time and postprocessing analysis. Functional MRI was performed with a standard 1.5-T whole-body scanner. Brain activity was contrasted between an alternating semantic judgment and letter matching task. Twelve right-handed, healthy control subjects and 12 consecutive patients with drug-resistant, localization-related epilepsy were investigated. The semantic condition induced almost invariably left hemispheric activations in Broca's area, the premotor cortex, the dorsolateral prefrontal cortex, and the temporoparietal region. Although real-time analysis reduced noise less effectively than SPM99, visual ratings and lateralization indices produced highly concordant results with both methods. In conclusion, real-time fMRI, as used here, allowed reliable language lateralization and mapping in less than 15 min during routine clinical MRI investigation with no need for postprocessing.

Adult↗

Diagnostic and therapeutic management of spinal arachnoid cysts.

BACKGROUND: The wide variety of intraspinal cystic lesions necessitates different elaborate diagnostic procedures to choose the right therapeutic management in symptomatic patients. Based on the case reports of seven patients with symptomatic spinal arachnoid cysts we discuss the aetiology, diagnostic procedures and therapeutic management of extra- and intradural spinal cysts. METHOD: All patients underwent MRI, Myelography and CT-Myelography during diagnostic evaluation. During surgery the cyst was resected and the communication between the cyst and the subarachnoid space was closed. FINDINGS: Two patients were identified with intradural, five with extradural spinal arachnoid cysts. Postoperative outcome was favourable in those patients without preoperative cord damage. INTERPRETATION: MRI is the diagnostic procedure of first choice because of its potential to demonstrate the exact localisation, extent and relationship of the arachnoid cyst to the spinal cord. Cord atrophy secondary to compression can be visualised and used for prediction of neurological outcome. Myelography and CT-Myelography (CTM) are still of diagnostic value since they might demonstrate the communication between the subarachnoid space and the cyst, which is important for surgical planning. The aim of surgical treatment is neural decompression and prevention of refilling of the cyst which is best accomplished by complete resection of the cyst and closure of the communication between cyst and subarachnoid space.

Adult↗

Detectability and detection rate of acute cerebral hemisphere infarcts on CT and diffusion-weighted MRI.

Our purpose was to compare the detectability and detection rate of acute ischaemic cerebral hemisphere infarcts on CT and diffusion-weighted MRI (DWI). We investigated 32 consecutive patients with acute hemisphere stroke with unenhanced CT and DWI within 6 h of stroke onset. The interval between CT and DWI ranged from 15 to 180 min (mean 60 min). Infarct detectability on CT and DWI was determined by comparing the initial CT, DWI and later reference images in a consensus reading of five independent examiners. The "true" detection rate was assessed by analysing all single readings. Two patients had intracerebral haematomas on DWI and CT and were excluded. There were 27 patients with ischaemic infarcts; all were visible on DWI and proven by follow-up. DWI was negative in three patients without a final diagnosis of infarct (100% sensitivity, 100% specificity, chi2 = 30, P < 0.0001). Ischaemic infarcts were visible on 15 and not seen on 12 CT studies (55 % sensitivity, 100% specificity, chi2 = 1.48, P = 0.224). With regard to the single readings (30 examinations x 5 examiners = 150 readings), 63 CT readings were true positive and 72 false negative (sensitivity 47 %, specificity 86%, chi2 = 2.88, P = 0.089). Of the DWI readings 128 were true positive and 7 false negative (sensitivity 95%, specificity 87 %, chi2 = 70.67, P < 0.0001). Interobserver agreement was substantial for CT (chi = 0.72, 95 % confidence interval, 0.6-0.84) and DWI (chi = 0.82, 95 % confidence interval, 0.46-1). Taken together, detectability and detection rate of acute (< 6 h) hemisphere infarcts are significantly higher with DWI than with CT.

Brain↗

Clinical significance of intracranial developmental venous anomalies.

OBJECTIVES: Venous angiomas, or developmental venous anomalies (DVAs), represent the most often occurring cerebral vascular malformation. The clinical significance of a DVA is, however, at present unclear. METHODS: A retrospective analysis was carried out on two series of consecutive cranial MRIs performed between January 1990 and August 1996 in a university department of neuroradiology and in a large radiological private practice. The medical records of all patients in whom a DVA was diagnosed were screened to identify the specific complaint which necessitated the imaging procedure. RESULTS: A total of 67 patients with DVA could be identified. In 12 patients an associated cavernoma was found. The main reason for performing the MRI was the evaluation of seizures or of headaches. In all patients with DVA in whom an intracerebral haemorrhage was diagnosed an associated cavernoma was present at the site of the haemorrhage. None of the 67 patients showed an association between the complaints that led to the MRI and the location of the DVA. CONCLUSIONS: DVAs do not seem to be associated with a specific clinical presentation. In a significant percentage of cases, however, coexisting cavernomas are found which have a defined bleeding potential and should be treated independently of the DVA. This study supports the hypothesis that DVAs are a congenital abnormality of venous drainage without clinical significance.

Adult↗

Determination of cognitive hemispheric lateralization by "functional" transcranial Doppler cross-validated by functional MRI.

BACKGROUND AND PURPOSE: Changes of blood flow velocity in the right and left middle cerebral artery (MCA) induced by cognitive demands are detectable by means of "functional" transcranial Doppler sonography (fTCD). Functional MRI (fMRI) is an alternative method for mapping brain activity. The purpose of this study was to determine whether fTCD can detect hemispheric lateralization and to cross-validate fTCD with fMRI. METHODS: Bilateral continuous MCA monitoring of 14 healthy, right-handed subjects with TCD was performed while the subjects underwent a visuospatial task, and the hemispheric blood flow velocity shift was calculated. Identical stimulus and response patterns were used in fMRI. Blood oxygenation level-dependent fMRI was performed with the use of a gradient-echo echo-planar sequence on a 1.5-T scanner. Statistical maps were computed on a voxel-by-voxel basis, hemispheric ratios for activated pixels were computed, and a group study was performed separately for the male and female subgroups. RESULTS: Statistical analyses (t test) showed a significantly higher mean peak blood flow velocity increase (P<0.05) of the right MCA (111.3+/-7.0%) compared with the left MCA (107.1+/-6.1%). fMRI demonstrated bilateral activation in the superior parietal lobulus (Brodmann area 7) with a right/left ratio of 1.95. Concordant differences between the female and male subgroups could be visualized with both methods. CONCLUSIONS: Both methods succeeded in discriminating a blood flow shift to the right hemisphere induced by a complex cognitive visuospatial task. fMRI cross-validates the findings of fTCD. Our study suggests that fTCD can investigate the close relationship between brain activity and blood flow and lateralize higher cognitive functions reliably.

Adult↗

Agenesis of the internal carotid artery: color Doppler, CT, and MR angiography findings.

Agenesis of the internal carotid artery (ICA) is a rare finding that can lead to the false diagnosis of an ICA occlusion. We present the case of a young woman with agenesis of the left ICA. Diagnosis was made noninvasively by color Doppler imaging (CDI) in combination with high-resolution CT of the base of the skull. Magnetic resonance angiography confirmed the diagnosis. CDI in combination with CT of the base of the skull allows the diagnosis of ICA agenesis without the use of invasive procedures.

Adult↗

Functional magnetic resonance mapping of sensory motor cortex for image-guided neurosurgical intervention.

PURPOSE: This paper describes the potentials of functional magnetic resonance imaging (fMRI) to map sensory motor cortex in patients with mass lesions near primary motor cortex and to guide neurosurgical procedures located close to eloquent brain regions. MATERIAL AND METHODS: 7 patients with mass lesions near the central sulcus and 10 healthy volunteers were studied using a blood oxygenation level dependent 2D multislice multishot T2* weighted gradient echo EPI sequence on a 1.5T Phillips Gyroscan during alternating epochs of rest and motor activation of hand, foot and tongue. Sites of neuronal activation were identified by statistical analysis of the signal time course using Kolmogorov Smirnov statistics. RESULTS: Neuronal activation following motor tasks consistently localised to the contralateral precentral gyrus and the supplementary motor area, even in the presence of local brain pathology. Additionally we could observe activation in primary sensory areas (post-central gyrus) and supplementary motor area (SMA) in some cases. CONCLUSION: fMRI is capable of mapping sensory motor cortex even in the presence of distorting brain lesions. Since this information will provide valuable information to the neurosurgeon during pre-operative planning, we consider this method for neurosurgical navigation a valuable tool in the routine diagnostic of intracerebral interventions.

Adult↗

Endovascular coil embolization of microsurgically produced experimental bifurcation aneurysms in rabbits.

BACKGROUND: Endovascular treatment of cerebral aneurysms is a relatively new method, since only a few animal models and data are available. The present experimental study was performed in order to establish an appropriate aneurysm animal model, to determine the rate of permanent occlusion, and to correlate radiologic and morphologic findings. METHODS: End-to-side anastomoses of both common carotid arteries were performed microsurgically in 53 chinchilla rabbits. Venous pouches were adapted into the newly created bifurcation, resulting in berry-shaped aneurysms comparable to those in humans with regard to size and hemodynamics. Platinum and tungsten coils were used for endovascular embolization. The embolized aneurysms were investigated radiologically and morphologically. RESULTS: Twenty-three carotid bifurcation aneurysms remained for testing endovascular therapeutic approaches. The morphologic examinations of 13 embolized aneurysms revealed in no instance a complete obliteration, even in the three cases that were considered completely embolized according to angiographic criteria. CONCLUSIONS: The present animal model is an optimal tool for endovascular research. Analysis of the results of coil obliteration revealed a considerable discrepancy between radiologic and pathologic findings. The radiologic degree of aneurysm occlusion was overestimated.

Animals↗

Early and late onset manifestations of cerebral vasculitis related to varicella zoster.

Varicella-zoster associated cerebral vasculitis (VZCV) as a cause of cerebral infarction has hitherto been considered a rare condition. Ischemic stroke in previously healthy children has occurred during recovery from chickenpox or has been attributed to virus reactivation among immunosuppressed patients. The clinical, radiologic and immunologic findings in four children with VZCV will be reported. Clinical manifestations included sudden onset of hemiparesis, motor aphasia and disturbed consciousness in previously healthy children. Only one child had a history of chickenpox six weeks prior to the onset of stroke, whereas a latency period of up to four years between chickenpox and the onset of stroke was found in the other three children. Diagnosis of VZCV was confirmed repeatedly by demonstrating intrathecal production of varicella-zoster IgG antibodies in three children or a four-fold increase of varicella-zoster serum IgA-antibodies in one child. Intrathecal production of antibodies against other latent viruses and borreliosis could be excluded. PCR for varicella on CSF, performed in two patients, remained negative. No intrathecal production of varicella-zoster antibodies has been found in a control group of twenty clinically healthy children (age range from 2-18 years) with a previous varicella infection. During follow-up two children recovered completely whereas two children still suffer from serious neurological deficits. Immunological investigations, performed in three children, showed circulating immune-complexes with slightly lowered complement concentrations in two patients. In addition a lowered T-helper/T-suppressor cell ratio of unknown origin was found in three children. These immunological findings will be discussed in the light of the pathophysiology of VZCV.

Adolescent↗

Cerebral tuberculoma 11 years after renal transplantation.

A case of cerebral tuberculoma in a 39-year-old patient who had received a renal graft from a living related donor 11 years previously is reported. The patient had a major seizure, progressive psychiatric signs and fever 5 days prior to admission. The clinical history suggested a neurological cause and rapid diagnosis of a cerebral tuberculoma was made by a computed tomography-guided stereotactic puncture of a space-occupying cerebral lesion. The aspirated pus contained Mycobacterium tuberculosis. Anti-tuberculous therapy with isoniacid, rifampicin, ethambutol and pyracinamide was administered. Transplant function deteriorated and the patient died due to intractable septicemia with multiorgan failure from pulmonary infection dissemination and additional urinary tract infection with atypical mycobacteria. The chance for a benign clinical course necessitates vigorous procedures for an early diagnosis of cerebral infections in renal transplant recipients with neurological/psychiatric signs.

Adult↗

[Neuro-interventional treatment of cerebrovascular malformations].

Cerebral vascular malformations are relatively rare diseases, however, their clinical impact is high. The group of vascular malformations include arterio-venous malformations of the brain and of the dura mater (AVM and DAVM) and arterial aneurysms. The danger coming from these malformations lies in the ruture with following cerebral stroke. Patients may die directly, or suffer from numerous deficits as hemipegia, loss of vision or speech and several severe cognitive deficits. Early diagnosis and early treatment is most important to avoid such complications and to prevent the patients from permanent invalidisation. A therapeutic alternative with increasing impact is given with the minimal invasive endovascular procedures. Alone, or in combination used with Radiosurgery and Neurosurgery, these techniques enable a most optimal and risk-reduced therapy for the patients.

Cerebral Angiography↗

[Solid craniopharyngioma in the 3rd ventricle--differential diagnostic aspects].

We report on a 54-year-old man with a solid craniopharyngioma in the third ventricle. Differentiation from a meningeoma was possible by visualization of a small cystic component in the suprasellar cistern and a central hypodensity/ hypointensity on CT and MRI, respectively. The latter seems to be a rather typical finding. Considering the differential diagnosis of tumors within the third ventricle, it must be emphasized that tumors arising within the ventricle are rare and invasion from primary extraventricular tumors is more common. A craniopharyngioma of the papillary type often has the typical imaging appearance described above.

Cerebral Ventricle Neoplasms↗

[Lipoma of the corpus callosum in a newborn infant: misinterpretation of cranial ultrasound by coincidence with thrombocytopenia].

Among the very rare intracerebral lipomas, those of the corpus callosum are the most frequent. Due to the advanced technology and the frequent use of ultrasonography these lesions are diagnosed more and more often. A female neonate was admitted to our hospital because of a progressive thrombocytopenia. Pregnancy was complicated by an autoimmune thrombocytopenia of the mother. While there were no remarkable findings on clinical presentation, a sonogram of the brain revealed an area of increased echogenicity in the midline which was interpreted as an intracerebral hemorrhage. In absence of any respective clinical signs a magnet-resonance-tomography of the brain was performed leading to the hypothesis of a lipoma of the corpus callosum (LCC) that could be verified by a densitometry in a cranial computer tomography (CT). Obviously, the initially performed sonogram was misinterpreted as an intracerebral hemorrhage due to the coincidence with the thrombocytopenia. At last the discrepancy of clinical and ultrasonographical findings led to the diagnosis by magnet-resonance-tomography and CT scan. Knowledge of the typical sonographic appearance of an LCC may be helpful for the differential diagnosis of this rare lesion even in fetal ultrasound.

Brain Neoplasms↗