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Biomedical subjects

F Nicoli

Publications and source records attributed to F Nicoli.

At least 37 records · Page 2Linked to original sources
PubMed1995

Localised proton magnetic resonance spectroscopy in X-linked adrenoleukodystrophy.

We have performed localised proton magnetic resonance spectroscopy (MRS) of the brain on four patients with X-linked adrenoleukodystrophy (X-ALD). The spectrum is characterised at the beginning of the disease by a decrease in N-acetylaspartate and phosphocreatine-creatine content. Choline is strongly increased, and lactate can be detected in some cases. A proton signal from the CH2 groups borne by free intracellular very long chain fatty acids can also be observed. Later in the disease, the levels of all metabolites, in particular NAA, decrease significantly. The progression of neurometabolism documented by MRS correlates well with MRI and clinical progression on follow-up study. In one case, the metabolic profile recorded by proton MRS was abnormal before any change occurred on MRI. Proton MRS of the brain might be the method of choice for monitoring patients with X-ALD, to screen presumed cases and to study the effects of treatment.

Adolescent↗
PubMed1994

[Marchiafava-Bignami disease: interhemispheric disconnection, Balint syndrome, spontaneously favourable outcome].

We report a new case of Marchiafava-Bignami disease with favourable outcome. This case is particular on several scores. The interhemispheric disconnection syndrome was associated with Balint's syndrome, and this had apparently never been reported in this context previously. Despite the intensity and diffusion of white matter lesions in both hemispheres, and in the absence of vitamin treatment, the clinical and neuroradiological (CT, MRI) improvement occurred early and rapidly. This course, similar to that of toxic drug withdrawal, suggested that this was not a process of vitamin deficiency. Data from the literature indicate that a wide extension of corpus callosum lesions to the semi-ovale centre has a poor vital and functional prognosis. Our case shows that this is not always correct and that the appearance of intralesional necrosis and cavitation is not the rule. We consider that the most reliable factor of poor prognosis seems to be an initial coma.

Adult↗
PubMed1994

Localized brain proton MRS metabolic patterns in HIV-related encephalopathies.

We have examined 9 healthy volunteers and 63 HIV-patients (16 asymptomatic patients and 47 patients with clinical AIDS-dementia complex, ADC) by magnetic resonance spectroscopy (MRS) and imaging (MRI) on a Siemens Magnetom SP63 (1.5 T). Proton MRS of the brain was performed at 63 MHz using the PRESS sequence (echo time = 135 ms, TR = 1.6 s). Four main results have been found: (1) HIV-related encephalopathy induces significant modifications of brain metabolism analyzed by MRS and the most sensitive metabolic parameter is the N-acetyl-aspartate/Choline ratio, (2) the correlation between MRS and MRI is good in 75% of patients, (3) in 4 of the 16 neuro-asymptomatic patients (i.e. 25%) a metabolic encephalopathy was found while MRI was still normal, and (4) MR spectra describe 3 different pathological metabolic patterns in the brain of HIV patients. Two patterns might correspond to the two entities of HIV-induced lesions i.e. HIV encephalitis and HIV-related progressive leukoencephalopathy.

AIDS Dementia Complex↗
PubMed1993

CSF and serum metabolic profile of patients with Huntington's chorea: a study by high resolution proton NMR spectroscopy and HPLC.

We studied both cerebrospinal fluid (CSF) and serum of 11 patients suffering from Huntington's disease (HD) and 12 control subjects by combining high resolution proton NMR spectroscopy and HPLC. NMR spectroscopy analysis of the CSF shows a significant increase (60%) in pyruvate concentration in HD patients. No unexpected molecules were detected. Glutamate, glutamine, aspartate, proline and GABA levels were found unchanged in the CSF of HD patients, using HPLC analysis. Conversely, a significant increase (30%) in the CSF level of glycine was detected. These observations are in agreement with the metabolic hypothesis of HD physiopathogenesis. In addition, the protocol combining NMR spectroscopy and HPLC provides a straightforward evaluation of brain metabolic status and blood-brain-barrier function.

Amino Acids↗
PubMed1993

A multiparametric data analysis showing the potential of localized proton MR spectroscopy of the brain in the metabolic characterization of neurological diseases.

We conducted an extended clinical evaluation of localized proton magnetic resonance spectroscopy (MRS) of the brain, performed on various brain diseases using short stimulated echo times. Pathologies studied were mainly multiple sclerosis, stroke, leukoaraiosis, AIDS-related leukoencephalopathies and glial tumors. Other miscellaneous pathologies were also studied. Magnetic resonance examination of the brain was conducted on a Siemens Magnetom SP63 (equipped with a 1.5 T magnet). Localized proton MRS was performed on a routine basis immediately after imaging, using the STEAM (stimulated echo acquisition mode) with a short echo time (20 ms) combined with a CHESS (chemical shift selective excitation) sequence. One or two VOI (8 ml) were examined. Data on 125 spectra were processed by principal component analysis (PCA) and conventional variance analysis. The following metabolite resonances were studied: inositol-glycine, taurine-scyllo-inositol, choline derivatives, phosphocreatine-creatine, aspartate, glutamine glutamate, N-acetylaspartate, acetate and lactate. PCA demonstrates that the different metabolic variables are independent. The analysis of groups of spectra clearly demonstrates that the metabolic profiles detected by localized MRS in various pathologies (i) differ significantly from controls, and (ii) allow a metabolic discrimination between groups of pathologies. Results of PCA are confirmed by variance analysis. Strokes are characterized by an increase in lactate concentration and leukoaraiosis by a decrease in inositol-glycine resonance. AIDS-related leukodystrophies are characterized by increases in lactate and choline concentrations. Reduction in N-acetylaspartate which is observed in most pathologies is not significant in the small lesions of white matter. Lactate has often been found in MS plaques, but no variation in the choline/phosphocreatine ratio was observed. GABA was tentatively assigned in the spectrum of a patient with epilepsy under sodium valproate treatment. This study illustrates the clinical feasibility of the technique, the value of a multiparametric data analysis in the definition of the pertinent variables characterizing the metabolic impairment, and the impact of localized proton MR spectroscopy of the brain in the assessment of cerebral suffering.

AIDS Dementia Complex↗
PubMed1992

[Ischemic cerebral vascular stroke after heroin sniffing. A new case].

Three hours after sniffing a dose of heroin, a 30-year old man developed right hemiplegia with aphasia. Magnetic resonance imaging of the brain showed an infarct in the territory of the left anterior choroid artery. Cerebral vascular accidents occurring as complications of heroin addiction are rare: a review of the literature yielded only 13 documented cases. The main characteristics of these strokes are analysed and their pathogenetic mechanisms (immuno-allergic vasculitis, vascular spasm) are discussed.

Administration, Inhalation↗
PubMed1992

[Hemichorea-hemiballismus and toxoplasmosis in AIDS].

The authors report two cases of hemichorea-hemiballism revealing a toxoplasmic abscess in the subthalamic nucleus during AIDS. Despite the great frequency of this opportunistic infection such cases are exceptional. This rarity seems to be explained by the frequent association of other lesions of the basal ganglia which may prevent the movement disorders. Nevertheless an hemichorea-hemiballism in young people must suggest a cerebral toxoplasmosis. Finally a symptomatic treatment is often necessary; in these cases the use of sodium valproate must be considered, this drug being able to induce a clinical improvement.

AIDS-Related Opportunistic Infections↗
PubMed1992

Metabolic characterization of neurological diseases by proton localized NMR spectroscopy of the human brain.

Proton localized Magnetic Resonance Spectroscopy (MRS) of the brain allows the non invasive detection of intracellular cerebral metabolites. Localized MRS has been performed using short stimulated-echo times in various neurological diseases including stroke, multiple sclerosis, and AIDS-related leukoencephalopathies. Principal component analysis (PCA) was used to determine the critical parameters defining the metabolic profile of normal and diseased brain. PCA clearly differentiates the demyelinating processes from ischaemic lesions and leukoencephalopathies. Localized MRS of the brain appears growingly as a tool of choice to discriminate, quantitate and assess cerebral metabolic damage in patients with neurological disorders.

AIDS Dementia Complex↗
PubMed1992

[Paralytic pontine exotropia disclosing endocarditis].

A case of bacterial endocarditis complicated by paralytic pontine exotropia is reported. Magnetic resonance imaging clearly showed a rostral lesion of the paramedial pontine reticular formation and the medial longitudinal fasciculus. The occurrence of paralytic pontine exotropia is suggestive of ischaemia, and patients with this so-called "one-and-a-half syndrome" associated with signs of infection should be investigated for endocarditis.

Brain Ischemia↗
PubMed1991

[High resolution NMR spectroscopy of CSF: methodological issues and perspective clinical applications].

High resolution proton nuclear magnetic resonance (NMR) spectroscopy is a new analytical technique which allows to readily identify and quantitate a variety of key metabolites in cerebrospinal fluid (CSF) in relation to normal and pathological brain activity. Proton NMR spectroscopy can be performed on native CSF, with or without addition of exchange reagent (NH4Cl). The analysis of native CSF provides qualitative information (identification) of metabolites or xenobiotics present in the fluid. Alternately, CSF can be lyophilized and dissolved in deuterated water. This concentration offers 2 advantages: additional compounds are detected and a precise quantification of all CSF metabolites can be obtained. Both protocols require a very small volume of CFS (1-2 ml). The high informational content available on the NMR spectra of CSF, the ease-of-use of NMR spectroscopy and its cost effectiveness concur to predict that this analytical approach will keep developing to completement the array of existing tests which are already routinely performed on CSF.

Central Nervous System Diseases↗
PubMed1990

[Chronic subdural hematoma and transient neurologic deficits].

Three cases of chronic subdural hematoma (CSDH) revealed by transient neurological accidents are reported. Although well-known this condition is rare: 1 to 9 p. 100 of CSDHs. Questioning may bring out a history of cranial injury and headache, even minor ones, which are unusual in transient ischemic accidents (TIA). Transient phenomena, such as motor aphasia or speech interruption, point to the diagnosis, especially in male patients over 60 years of age. The finding at electroencephalography of a delta activity more than 48 hours after a TND should exclude the diagnosis of TIA until a CT scan is performed. Since the causes of neurological deficits regressing within less than 24 hours may be ischemia as well a hemorrhage or tumour, the term of transient neurological accident (TNA) should preferably be used, and an emergency CT scan should be performed for diagnostic and therapeutic purposes. Owing to the possibility of another concomitant cause of TNA, the finding of a subdural haematoma should not deter from pursuing cardiovascular examinations. The mechanism of TNA probably involves a vascular factor, as suggested by I-123 IMP cerebral SPECT which shows an intercritical decrease in cerebral blood flow and/or an epileptic factor.

Aged↗
PubMed1989

[Abnormal postural movements: transient ischemic episodes of the carotid?].

Following post-operative occlusion of the right internal carotid artery, a 65-year old man developed abnormal left involuntary movements which appeared in upright position or at exercise and disappeared in sitting or supine positions. The clinical and electroencephalographic features of these movements could have been epileptic. However, this case together with data from the literature suggest that transient ischemic episodes in the carotid territory may be expressed as involuntary movements occurring in certain positions, betraying a severe and abrupt fall in cerebral blood flow.

Aged↗