Search PubMed⌕ Search

Biomedical subjects

C Manelfe

Publications and source records attributed to C Manelfe.

At least 55 records · Page 3Linked to original sources
PubMed1998

Intracranial vascular involvement of brain pathologies and venous occlusions.

In this paper, the authors present the contribution of CT and MRI to the diagnosis of acute stroke caused by arterial or venous occlusion. The term "early" used in this context means within 6 h of the onset of symptoms. Signs of early ischemic edema are subtle and sometimes difficult to detect by CT or MRI. The purpose of this presentation is to familiarize the clinician and the radiologist with the subtle brain parenchymal changes seen within the first 6 h after onset of symptoms, in order to improve detection of early ischemic infarction and to improve patient care.

Acute Disease↗
PubMed1998

[Pituitary stalk transection syndrome].

BACKGROUND: Pituitary stalk transection is a non-negligible cause of growth hormone (GH) deficiency. POPULATION AND METHODS: We studied 22 children (13 boys, nine girls) aged at the first clinical manifestations from 2 days to 10 years (average = 5.33 +/- 2 years). Pituitary stalk transection was assessed by the means of magnetic resonance imaging (MRI). The children's past history showed fetal distress in 12 cases (54.5%), cranial trauma in three (13%) and a midline anomaly in three (13%). The first clinical manifestations were neonatal hypoglycemia (two cases), decreased growth velocity (18 cases) and diabetes insipidus (two cases). RESULTS: GH deficiency was complete, present from the onset in 19 of 22 cases and isolated in four. Fifteen of 22 cases had adreno-corticotrophic hormone (ACTH) and thyroid stimulating hormone (TSH) deficiency. Diabetes insipidus was present in six cases and revealed the syndrome in two. All children older than normal age of puberty (n = 10) had gonadotropin deficiency. In our study, these hormonal anomalies progressed from isolated GH deficiency to multiple hormonal deficiencies. CONCLUSION: The recently described stalk transection syndrome is relatively frequent and should be suspected after cranial trauma or fetal distress syndrome. The outcome is progressive evolution towards panhypopituitarism and these patients require regular clinical survey and hormonal controls.

Adrenocorticotropic Hormone↗
PubMed1998

Mucoceles of the paranasal sinuses: uncommon location.

Mucoceles are the most common lesions causing expansion of the paranasal sinuses. The sinuses most commonly involved are, in decreasing order of frequency, frontal sinus, ethmoid sinuses, maxillary sinus and sphenoid sinus. We reviewed 46 cases of surgically proven mucoceles and the purpose of this study was to report five cases of mucoceles in an uncommon location.

Adult↗
PubMed1998

Diffusion and perfusion MRI, measurements of acute stroke events and outcome: present practice and future hope.

The morphological, metabolic and functional changes of brain ischaemia can be studied using various MRI methods. These are readily available should the early visualisation of affected territories be needed. Morphological changes include the depiction of oedema on T1- and T2-weighted images, and metabolic changes are reflected on magnetic resonance spectroscopy. Functional changes reflect haemodynamic failure seen on diffusion- and perfusion-weighted imaging. Modelling of behaviour of T2 and diffusion changes could predict the histological outcome of affected tissue regarding cell recovery on necrosis. In addition, the combination of diffusion and perfusion MRI offers a potential prognostic value.

Acute Disease↗
PubMed1998

[Presurgical evaluation of cerebral tumors with functional MRI].

PURPOSE: To evaluate the capabilities and the limitations of motor functional magnetic resonance imaging (FMRI) in the presurgical planning of the cerebral tumors located in or near the motor homunculus and 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 motor deficit, presenting with various intra cerebral tumors. Three FMRI activation paradigms were used, controlateral 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 non specific 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 non infiltrating 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 sometimes 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 plays a role, with others factors, on the motor functional area organization. In a small number of cases, the data obtained from the FMRI could be used intraoperatively, with a neuronavigation system.

Adolescent↗
PubMed1998

[MRI visualization of multiple sclerosis lesions].

Magnetic resonance imaging represents voxels (volume elements) of the body placed in a magnet, by their magnetization determined under various acquisition conditions weighting the contrast of the image by the density of free water protons and their relaxation times T1 and T2. Thus, the sensitivity in depicting lesions is high but pathological specificity is poor. Efforts are made to increase the diagnosis powerfulness of M.R.I. in multiple sclerosis: a careful correlation with the clinical presentation and the use of better M.R.I. criteria increase the specificity of the conventional T2 sequences. New sequences such as fast spin echo (F.S.E.), turbo spin echo (T.S.E.) or derived from inversion recovery (F.L.A.I.R.: fluid attenuated inversion recovery) improve the detection of lesions. Under specific conditions M.R.I. can be used to monitor the evolution of M.S. Acute phase monitoring focuses on changes in disease activity, new, recurring, enlarging, gadolinium (Gd) enhancing lesions, and chronic phase monitoring appreciate the burden of the disease. However M.R.I. is always considered as a secondary outcome in the phase III trials because insufficient correlations with the clinical disability. In the neurological daily practice conventional M.R.I. is of poor interest in the follow up of individual M.S. patients considering the weakness of prognosis value and the problems in the measurement of the lesions load which is emphasized in the methodology of the clinical trials. Nevertheless, there is a continuing search for techniques which correlate better with clinical measures of the disease such as the quantification of "black holes" on T1 w images or the cerebral and spinal atrophy. New techniques allow to weight the signal by the movement (diffusion imaging), by the complexity of the molecular architecture (magnetization transfer imaging), by the chemical shift (chemical shift imaging) or by the local status of oxygenation (functional M.R.I.). The basic aspects of the pathological lesions in M.S., edema, membrane disruption, demyelination, gliosis, cellular infiltration and axonal loss can be studied more precisely by these new M.R. techniques which should better describe the actual clinical impact of the destructive process. In the last year the importance of axonal loss has simultaneously been confirmed by M. R. spectroscopy and pathological findings. However, magnetization transfer imaging, M.R. diffusion imaging and functional M.R.I. are intensively under investigation for a better analysis of these different factors conditioning the reversibility of the patient disability.

Contrast Media↗
PubMed1997

Magnetization transfer with echo planar imaging.

The aim of magnetization transfer is to saturate the protons of the macromolecule pool with a radiofrequency (RF) pulse leading to differences in free water pool signal. Magnetization transfer (MT) contrast is difficult to achieve with the echo planar imaging (EPI) technique, although its short acquisition time would be most beneficial. Indeed, the RF saturation pulses can only be applied once before sampling the whole k-space in a single-short sequence. A possible solution to improve the sensitivity of EPI to magnetization transfer consists in applying a train of several saturation RF pulses before image acquisition. The different parameters of a RF pulse train and their influence on the MT rate have been tested to optimize an EPI clinical sequence. Our experimental procedure makes it possible to obtain a MT map in about 1 second. The technique is evaluated by multiple sclerosis lesion characterization.

Adult↗
PubMed1997

MRI of intramedullary sarcoidosis: follow-up of a case.

Intramedullary lesions are infrequently the first manifestation of sarcoidosis. We present clinical and radiological follow-up of spinal cord sarcoidosis in a 68-year-old woman, mimicking an intramedullary tumour. MRI revealed an unusual area of low signal intensity on T2-weighted spin-echo images at the core of the lesion, consistent with calcification. Clinical and MRI follow-up showed progressive resolution of the intraspinal lesion, except for the calcification, with oral steroid therapy.

Aged↗
PubMed1997

Acute stroke: usefulness of early CT findings before thrombolytic therapy.

PURPOSE: To determine whether the extent of subtle parenchymal hypoattenuation detected on computed tomographic (CT) scans obtained within 6 hours of ischemic stroke is a factor in predicting patients' response to thrombolytic treatment. MATERIALS AND METHODS: The baseline CT scans of 620 patients, who received either recombinant tissue plasminogen activator (rt-PA) or a placebo, in a double-blind, randomized multicenter trial were prospectively evaluated and assigned to one of three categories according to the extent of parenchymal hypoattenuation: none, 33% or less (small), or more than 33% (large) of the middle cerebral artery territory. The association between the extent of hypoattenuation on the baseline CT scans and the clinical outcome in the placebo-treated and the rt-PA-treated groups after 3 months was analyzed. RESULTS: In 215 patients with a small hypoattenuating area, treatment increased the chance of good outcome. In 336 patients with a normal CT scan and in 52 patients with a large hypoattenuating area, rt-PA had no beneficial effect but increased the risk for fatal brain hemorrhage. CONCLUSION: The response to rt-PA in patients with ischemic stroke can be predicted on the basis of initial CT findings of the extent of parenchymal hypoattenuation in the territory of the middle cerebral artery.

Acute Disease↗
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↗
PubMed1997

Fou rire prodromique heralding a left internal carotid artery occlusion.

BACKGROUND: Four rire prodromique, described as pathological laughter preceding the onset of an apoplectic attack, is a rare phenomenon. CASE DESCRIPTION: A 61-year-old man manifested pathological laughter before a sudden right hemiplegia. MRI showed a left lenticular and caudate nucleus infarct with involvement of the external capsule and prerolandic area. MRA revealed a left internal carotid and middle cerebral artery occlusion. CONCLUSIONS: The clinicoanatomic correlates of this phenomenon are discussed.

Arterial Occlusive Diseases↗
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↗
PubMed1996

Recurrent right hemiplegia associated with progressive ipsilateral carotid artery stenosis.

BACKGROUND: Ipsilateral sensory motor symptoms associated with carotid artery stenosis are rare, and few reports are available in the literature. CASE DESCRIPTION: We report the case of a 50-year-old man who presented with right hemiplegia that recurred 14 months later. A left hemisphere watershed infarction was detected. Repeated angiograms showed a left internal carotid occlusion and a right internal carotid stenosis that initially measured 50% and worsened to 80% after the second stroke. CONCLUSIONS: Repeated quantitative measurements of cerebrovascular reserve demonstrated the hemodynamic mechanism of the strokes and the role of a right internal carotid lesion in causing the recurrence of right hemiplegia.

Brain↗
PubMed1996

[Multiple cerebral telangiectasias. Apropos of an anatoma-radioclinical case].

UNLABELLED: Telangiectasias are vascular malformations corresponding to dilated capillary separated by nervous parenchyma. They are generally asymptomatic and discovered during autopsy. CASE REPORT: We describe the case of a 2-year-old girl who was admitted for drowsiness and vomitings with craniomegaly and right hemiparesis. The cerebral imaging demonstrated large amounts of calcium in the region of pons and left thalamus with a contrast enhancement throughout these calcifications. The thalamic lesion was cystic with obstruction of the third ventricle and hydrocephalus. There were multiple calcifications scattered throughout the basal ganglia and the white matter. The latter had a low density on CT and high signal intensity on MRI (T2). The cerebral angiographic study showed a blush in the pons and the thalamus. Clinical course was fluctuating or intermittently progressive. Finally, in spite of radiotherapy and oral corticosteroid treatment, the child became quadriparesic with oculomotor palsy. She suddenly died at age 4 years and 6 months from a hemorrhage of the pons. Neuropathological study showed two clusters of telangiectasias with calcifications in the pons and the thalamus. Other calcified vascular malformations were seen in the white matter and the basal ganglia. Near the lesions, astrocytar gliosis and edema were observed. The white matter was malacic with isolated calcifications. CONCLUSION: Cerebral telangiectasias may be multiple and may produce severe neurologic disorders, occurring in infancy with fluctuating clinical course. Arteriography may show these usually cryptic vascular malformations. This diagnostic should be kept in mind in view to the neuroradiological aspect we report here.

Basal Ganglia↗
PubMed1996

[Dissection of the intracranial arteries. Apropos of 10 cases].

Ten cases of spontaneous dissection of the cerebral arteries are reported. 3 males and 7 females aged 6 to 60 years (mean age 30 years) were investigated in the Department of Neuroradiology of Toulouse between 1989 and 1994 with CT, angiography and MRI. In 5 cases the dissection involved the carotid artery, in 5 cases the vertebro-basilar system. The clinical presentation was of two types: ischaemic stroke (7 cases) or subarachnoid haemorrhage (3 cases). Their evolution is never lethal, contrary to the classical descriptions of the literature. In all cases an initial angiography then follow up has been performed showing an irregular located arterial stenosis. The diagnosis of intracranial dissection is sometimes made in front of a dissequant aneurysm. In case of doubt, magnetic resonance (MR) imaging is helpful showing a linear hypersignal parallel to an arterial segmental stenosis, and angiography MR an irregular aspect and stenosis of the endoluminal artery.

Adolescent↗
PubMed1996

[The contribution of "time-of-flight" MRI-angiography in the study of neurovascular interactions (hemifacial spasm and trigeminal neuralgia)].

The purpose of this study was to investigate capabilities of Magnetic Resonance Angiography (MRA) in delineating neurovascular compression which has emerged as the most frequent etiology in cases of Hemi-Facial Spasm and Trigeminal Neuralgia. MR investigations were carried out at 1.5 t unit (Magnetom Vision, Siemens). The examination consisted of 3D time-of-flight MRA (3d TOF) protocol, with a FISP sequence (Fast Imaging Steady Precession) and magnetization transfer. Imaging parameters were; TR 39 ms, TE 7 ms; MX 256-512; FOV 210-210 mm. Time acquisition is 10 mm 30 s. The axially acquired angiographic slices were reformatted with a multiplanar reconstruction program (MPR) along and across the plane of facial and trigeminal nerves. Then millimetric raw data images were postprocessed with a maximum intensity projection (MIP) technique. 58 patients presented either with hemifacial spasm (36 cases, 16 women, 20 men, mean age: 58.5 y) or trigeminal neuralgia (22 cases, 13 women, 8 men, mean age: 51 y) were compared with 17 patients (9 women, 8 men, mean age: 57.5 y) as references. MRA with MIP and MPR techniques reliably demonstrates neurovascular compression at the root entry zone (REZ), and allows recognition of the implicated vascular loop in 34 the cases of hemifacial spasm investigated. Raw data were post-processed in an axially oblique plane parallel to the acoustico-facial bundle and secondarily reconstructed in coronally obliques views. These reconstructed images clearly delineate the cross-compression of the emerging facial nerve. The neurovascular conflict was related to an arterial loop from the postero-inferior cerebellar artery (PICA, 21 cases, 61%) and the antero-inferior cerebellar artery (AICA, 8 cases, 23%). Vertebral artery is implicated in conflicts in 5 cases. In 2 cases MRA exploration was negative. In HFS group distance between Vth nerve emergency and neuro vascular contact was measured and compared with control group; there is a significative difference (p < 0.01). In case of trigeminal neuralgia, MRA demonstrates neurovascular compression at the root entry zone of the Vth nerve of 16 patients. In theses cases, oblique and coronally reconstructed images are crucial in demonstrating neurovascular contacts. The vessel implicated in conflict is always the superior cerebellar artery (SCA). A supero-medial loop of the superior cerebellar artery was depicted in these 16 cases. Although 3 patients had negative MRA and MR studies, a case of compression of the origin of the Vth nerve by a enlarged draining vein in a case of brainstem arterio-venous malformation, a petrous apex meningioma was incidentally discovered and thoroughly investigated with gadolinium T1 weighted sequences and 1 demyelinating plaques located along the intraaxial course of the Vth nerve were noticed. In control group on 34 explanations only there are only 4 contacts between Vth nerve and SCA. MRA with a 3D-TOF FISP sequence allows recognition of neurovascular conflicts in case of hemifacial spasm and trigeminal neuralgia while MIP helps to characterize the implicated vessel. Sources images need to be carefully assessed in order to depict unsuspected pathology.

Adolescent↗
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↗