Biomedical subjects

I Berry

Publications and source records attributed to I Berry.

At least 55 records · Page 3Linked to original sources

PubMed1997

Therapeutic effect of mitoxantrone combined with methylprednisolone in multiple sclerosis: a randomised multicentre study of active disease using MRI and clinical criteria.

OBJECTIVE: To evaluate the efficiency of mitoxantrone in multiple sclerosis. METHODS: Forty two patients with confirmed multiple sclerosis, selected as having a very active disease on clinical and MRI criteria were randomised to receive either mitoxantrone (20 mg intravenously (IV) monthly) and methylprednisolone (1 g iv monthly) or methylprednisolone alone over six months. In the steroid alone group five patients dropped out due to severe exacerbation. RESULTS: Blinded analysis of MRI data showed significantly more patients with no new enhancing lesions in the mitoxantrone group compared with the steroid alone group, (90% v 31%, P < 0.001). In the mitoxantrone group there was a month by month decrease almost to zero in the number of new enhancing lesions, and in the total number of enhancing lesions, whereas both remained high in the steroid alone group. The differences were significant for both indices at all months from 1-6. Unblinded clinical assessments showed a significant improvement in change in EDSS at months 2-6 in the mitoxantrone group, with a final mean improvement of more than one point (-1.1 v + 0.3; P < 0.001). There was a significant reduction in the number of relapses (7 v 31; P < 0.01), and an increase in the number of patients free of exacerbation (14 v 7; P < 0.05). CONCLUSION: In this selected group of patients with multiple sclerosis with very active disease, mitoxantrone combined with methylprednisolone was effective in improving both clinical and MRI indices of disease activity over a period of six months whereas methylprednisolone alone was not. Further double blinded long term studies are needed to properly evaluate the effect of mitoxantrone on progression in disability.

Adjuvants, Immunologic↗

PubMed1997

Motor functional MRI for presurgical evaluation of cerebral tumors.

OBJECTIVE: To evaluate the capabilities and the limitations of motor functional magnetic resonance imaging (fMRI) in the presurgical evaluation of the cerebral tumors located in or near the motor homunculus. To correlate each type of activation with the histologic characteristics of each tumor. MATERIALS AND METHODS: fMRI was performed in 17 patients (14 adults and 3 children), without any motor deficit, presenting with various intracerebral tumors. Three fMRI activation paradigms were used: contralateral to the lesion: ballistic opposition of the fingers, flexion-extension of the foot and click of the tongue. Four patients, without motor deficit, with cerebral tumors far from the motor homunculus were used as control group to look for nonspecific activations. In all cases, the histopathology of the tumor was known accurately. RESULTS: In 11 patients with infiltrating tumors, the activated areas were clearly displaced. They were often intratumoral and scattered in correlation with the degree of infiltration. Two patients with noninfiltrating tumors (meningioma) showed extratumoral shift of the activated areas. Four patients presenting cerebral tumors far from the homunculus motor did not show intratumoral activation. The supplementary motor area and the ipsilateral primary motor cortex were also reproducibly activated during the motor tasks. The task of the tongue was often artifacted, probably because of the head motion. CONCLUSIONS: These preliminary results suggest that the histopathologic characteristics of a tumor, and especially its microscopic structure, play a role in the organization of the motor functional area. In a small number of cases, fMRI could be used intraoperatively with a neuronavigation system.

Adolescent↗

PubMed1996

Contribution of Sinerem used as blood-pool contrast agent: detection of cerebral blood volume changes during apnea in the rabbit.

The authors suggest that ultra-small paramagnetic iron oxide (USPIO) particles used as blood pool contrast agents may increase the sensitivity of midfield MRI (i.e., less than 1.5 Tesla) to physiological variations in cerebral blood volume. This hypothesis was tested on a rabbit model of apnea which increases pCO2 and cerebral blood volume. Using Sinerern as the USPIO at a blood concentration of 60 mumol Iron/kg body weight, an 8% T2*-weighted signal decrease could be observed at 1.0 T with 25-33% increase in pCO2. Comparatively, in the absence of USPIO, T2*-weighted signal dropped only 4% during apnea and after mild hyperoxygenation beforehand, due to increased deoxyhemoglobin content. These preliminary data suggest that USPIOs could play an important role in functional MRI at midfield strength, by sensitizing the signal to cerebral blood volume changes.

Animals↗

PubMed1995

Activation of association auditory cortex demonstrated with functional MRI.

Activations in the temporal lobes previously observed using positron emission tomography and auditory stimuli were partially reproduced with functional MRI and echo-planar imaging at 1.5 T in six volunteers performing tone and phoneme monitoring tasks. Verbal processing compared to a tone recognition task significantly activated a cortical area located in the left anterior temporal region (P < 0.02).

Adult↗

PubMed1995

[Cerebral lesions in AIDS: what can be expected from scintigraphy? Cerebral tomographic scintigraphy using thallium-201: a contribution to the differential diagnosis of lymphomas and infectious lesions].

CT and MRI are not consistently able to differentiate central nervous system (CNS) lymphoma from focal cerebral infection such as toxoplasmosis in the human immunodeficiency virus (HIV) involvement. In this study thallium 201 (and/or technetium-MIBI) SPECT was performed in 6 patients suffering from AIDS and CNS lesions. An index based on the ratio of thallium uptake in the lesion vs the contralateral scalp was calculated. In 4 out of 5 patients with lymphoma (3 confirmed by biopsy, 2 highly suspected on CT and resistance to antitoxoplasmosis treatment) focal lesions showed high uptake of thallium. On the other hand one markedly necrotic lymphoma and all infectious lesions did not take up thallium. This suggests a role for thallium 201 brain SPECT in the workup of focal CNS lesions in AIDS.

AIDS-Related Opportunistic Infections↗

PubMed1995

[Results of magnetic resonance imaging in the acute phase of cerebral infarction].

Brain ischemia is now possible to trace through the multiple facets of MRI, morphological as well as functional. Experimental studies have been conducted for many years and clinical feasibility is reached. Although the initial decrease in blood flow does not influence morphological imaging, this early phase is shown with functional MRI, either with diffusion imaging or with cerebral blood volume imaging. The later is achieved either with the calculation of the integral of the first passage of a bolus of a diffusible paramagnetic agent or with the circulation of positive or negative blood pool contrast agents. This may serve to confirm an early diagnosis before inclusion in therapeutic trials. Immediate metabolic changes are reflected on phosphorus and proton spectroscopy achievable during the same session as imaging. This type of information may at this stage serve as a reference. It allows observation of the turnover of lactate over time in the lesion and the neuronal loss shown by decreased N-acetyl-aspartate. Edema, as a reaction to ischemia, builds up over time and has already been described for long as it modifies T1- and T2- weighted sequences. Similarly the breakdown of the blood-brain barrier is well known on conventional sequences because it produces contrast enhancement.

Acute Disease↗

PubMed1994

Randomised double blind trial of the safety and efficacy of two gadolinium complexes (Gd-DTPA and Gd-DOTA).

The main difference between macrocyclic Gd-DOTA and linear Gd-DTPA complexes is the greater stability of the former which theoretically might reduce biological interactions in man. To evaluate the clinical relevance of this property, 300 unselected neurological patients were included in a randomised double-blind comparison involving five European centres, focused mainly on the tolerance of these two contrast media. Clinical tolerance was assessed immediately after the procedure and 24 h later. Adverse events were found with a similar frequency in the two groups (17.3% for Gd-DOTA and 19.3% for Gd-DTPA). Minor neurological symptoms were the most frequent (48.6%) headache being the most common (29.2% of adverse events). No difference in efficacy was found.

Adult↗

PubMed1994

[Vascular dementias].

The recent development of neuro-imaging technology has altered the classic anatomo-clinical pattern of vascular dementias (VD). However, few correlative studies have emerged and the creation of new eponyms--such as the successful "leuko-araiosis"--did not raise new highlights on the mechanisms involved in VD. The different clinical and radiological aspects of VD are briefly reviewed and the contribution of CT-scan and MRI are discussed.

Aged↗

PubMed1993

Database for serial magnetic resonance imaging in multiple sclerosis.

The unique sensitivity of magnetic resonance imaging (MRI) in detecting disease activity in multiple sclerosis (MS) and the objective nature of the information obtained suggest that MRI will be a useful and reliable way of monitoring treatment trials. There is a need to develop an appropriate database which would provide a standardised means of assessment, not only of MRI, but also of essential clinical information. As part of the program of Concerted Action in Multiple Sclerosis, funded by the Commission of the European Community (CEC), we have developed a database for recording serial brain MRI results. The database consists of core, entry and follow-up sections. Both entry and follow-up parts are subdivided into clinical, MR system and MRI data. We expect that the use of this database will maximise efficiency of MRI monitoring in MS treatment trials, particularly in multicentre studies.

Brain↗

PubMed1993

The Nithsdale schizophrenia surveys. XI: Relatives' expressed emotion. Stability over five years and its relation to relapse.

The level of expressed emotion (EE) in 32 relationships between relatives and schizophrenic patients was assessed on three separate occasions over five years. EE was high on all three occasions in 25% of relatives, low on all three in 38%, and fluctuating in 38%; that is, in the majority of relatives (63%) the level of EE was stable over time. Three relatives who had previously shown high EE had evidence of dementia at the time of the third assessment, and showed low EE. Fourteen patients relapsed at least once over five years; patients who relapsed were evenly spread throughout those living in a home in which EE was consistently high, consistently low, or fluctuating. However, patients living in low-EE homes who did relapse did so significantly less often than those who relapsed and were living in homes in which EE was high or fluctuating. At the time of relapse, EE was not consistently high, and some patients in consistently high-EE homes did not relapse at all over five years.

Adult↗

PubMed1993

[Transmission of neurosurgical medical records through computers. Simple reality, considerable progress].

Tests on the transmission of view data processing images were undertaken for 5 months from two experimental micro-processing sites specialized in medical imagery and linked to the R.N.I.S. network. The aim of the research was to validate the equipment and the software, and to find a way of working with regard problems related to long-distance diagnosis. Using an everyday equipment like Apple Macintosh II fx, 75 files were transferred corresponding in 375 images (1% conventional X-ray, 5% digital angiography, 31% scanner and 63% M.R.I.). It has been found that the transfer of medical data is reliable (the images do not deteriorate), easy (less than 3 hours to be familiar with the program) and above all fast (actual transfer time: 8.72 Ko per second). Neurosurgeon and neuroradiologist writers talk about their experience in this field.

Computer Communication Networks↗

PubMed1993

Magnetic resonance imaging evaluation of lower limb muscles during bed rest--a microgravity simulation model.

Head-down (-6 degrees) bed rest, a microgravity simulation model in humans, leads to muscular atrophy of the lower limbs. Magnetic Resonance Imaging (MRI) at 0.5 tesla was performed at 1 year intervals on the same six volunteers (except one) before and after 1 month bed rest. Three of the six subjects were daily exposed in a lying position to LBNP (lower body negative pressure), a countermeasure to cardiovascular deconditioning (LBNP group). The groups were exchanged the second year. After bed rest, the quadriceps of the thigh lost uniformly 11% of its cross section area (CSA) and the triceps of the leg 10.5%, with 12.8% lost from the deeper soleus versus 8.5% from the gastrocnemius (p < 0.05). LBNP produced no effect on these changes. The MRI signal intensity of muscles exhibited a trend toward higher values after bed rest although without statistical significance. MRI allowing for noninvasive and reliable quantification of muscle fibers of the lower limbs is an excellent procedure for the assessment of muscle disuse and countermeasures.

Adult↗

PubMed1992

Experimental focal cerebral ischaemia assessed with IVIM*-MRI in the acute phase at 0.5 tesla.

Intravoxel incoherent motion (IVIM*)-MRI has been performed on a clinical system at 0.5 tesla with a b gradient factor of 100 s/mm2, in a feline focal model of cerebral ischaemia. Images were obtained in 26 cats from less than 1 hour and up to 7-12 hours after stroke. The apparent diffusion coefficient (ADC) was decreased at the site of injury when compared to the contralateral normal side, by 30% in the first, 33% in 1-2 h and 27% in 2-4 h; it increased at 7-12 h, when vasogenic oedema occurred. IVIM*-MRI demonstrated early changes, due to cytotoxic oedema, during the acute phase of cerebral ischaemia to which conventional T2-weighted spin-echo imaging was not sensitive.

Animals↗

PubMed1991

[New imaging methods by nuclear magnetic resonance in multiple sclerosis].

Magnetic resonance imaging (MRI) has rapidly attained a major position among the examinations used in the diagnostic approach of multiple sclerosis because it is highly sensitive in demonstrating lesions. However, these lesional images may have several meanings, and there is the problem of distinguishing between oedema, which is said to reflect recent lesions, and gliosis which is thought to betray old lesions. The intrinsic MRI parameters studied (i.e. relaxation times) are unable to make this distinction, whereas it is provided by paramagnetic contrast media such as gadolinium. There is no correlation between the changes observed at MRI and the severity of the disease. Another problem is the accuracy of lesion localization, since visualization is predominantly macroscopic. This raises several questions about the demonstration of correlations between clinical signs and site of the lesion(s). At the moment, several teams of neuroradiologists are trying to find the most reliable method to determine the size of the lesion. The possible prognostic value of this size and its changes as time goes by are other parameters to be considered once the basic diagnosis has been made.

Brain↗

PubMed1991

[Cerebral imaging and aphasia].

In the field of aphasiology, cerebral imaging has greatly helped in modifying our concepts concerning the physiopathological mechanisms underlying language. Morphological imaging, and particularly computerized tomography (CT), has provided a critical appraisal of established doctrines as well as evidence that subcortical structures participate in language. A more dynamic and evolutive approach of brain organization for language has been introduced by CT and emission imaging techniques which have shown on one side the existence of age-related modifications in the language area, and on the other side the possibility of recovery by activation of structures other than those classically involved. Finally, magnetic resonance imaging has recently revived interest in the study of strict anatomico-clinical correlations.

Adult↗

PubMed1991

Magnetic resonance imaging in monitoring the treatment of multiple sclerosis: concerted action guidelines.

Serial gadolinium enhanced MRI of the brain detects much clinically silent disease activity in early relapsing-remitting and secondary progressive multiple sclerosis (MS), and thus has an important role in monitoring the effects of therapy. Based on the proceedings of a recent Commission of the European Communities (CEC) workshop and a review of the literature, guidelines are presented for using MRI to monitor treatment trials in MS. The guidelines consider: A) MRI system and techniques; B) patient selection; C) trial design; D) analysis of results. Priorities for future research are also indicated.

Brain↗

PubMed1989

[Cerebral imaging and dementia].

Modern imaging techniques undoubtedly are of value when applied to the study of dementia. This value, however, varies with the technique utilized, and one must distinguish between acquired and potential knowledge. Morphological imaging with computerized tomography or magnetic resonance detects or confirms certain causes of dementia (tumours, lacunae, hydrocephalus with normal CSF pressure), but it is still not sensitive and specific enough to be very useful in primary dementias. Functional imaging (essentially with emission tomography) has already provided interesting data in the study of degenerative dementia (correlations with neuropsychology, subtyping), but what is most promising is its possibilities in the physiopathological approach of the disease.

Dementia↗

PubMed1989

Nicardipine reduces ischemic brain injury. Magnetic resonance imaging/spectroscopy study in cats.

We investigated whether the calcium channel entry blocker nicardipine would reduce ischemic brain damage in barbiturate-anesthetized cats subjected to permanent unilateral occlusion of the middle cerebral artery. The evolution of cerebral injury was assessed in vivo in 24 cats by a combination of proton magnetic resonance imaging and phosphorus-31 magnetic resonance spectroscopy for 5 hours following occlusion. Immediately thereafter, the volume of histochemically ischemic brain tissue was determined planimetrically in triphenyl tetrazolium chloride-stained serial coronal sections. Nicardipine was initially administered as an intravenous bolus injection of 10 mg/kg/hr 15 minutes before or 15 minutes after occlusion, followed by continuous infusion at 8 mg/kg/hr for the 5 hours of the experiment. Compared with untreated controls, cats that received nicardipine before or after occlusion showed a significant reduction in the extent of edema in the ipsilateral cerebral cortex, internal capsule, and basal ganglia. The results of phosphorus-31 magnetic resonance spectroscopy studies suggest that nicardipine may protect against cerebral ischemic damage by an action on cellular metabolic processes that preserve high-energy phosphates during the ischemic period.

Animals↗