Biomedical subjects

R Floris

Publications and source records attributed to R Floris.

At least 73 records · Page 4Linked to original sources

PubMed1987

Computed tomography abnormalities in hanging.

The CT pattern of bilateral and symmetrical round low density areas in the globi pallidi has been observed in a young man who attempted suicide by hanging. These CT abnormalities are similar to those described in other conditions such as carbon monoxide, hydrogen sulfide, cyanide and methanol poisoning, hypoglycaemia, drowning and acute global central nervous system hypoperfusion. The findings appear to be correlated with acute cerebral hypoxia.

Adult↗

PubMed1987

Subacute necrotizing encephalomyelopathy (Leigh's disease): clinical correlations with computerized tomography in the diagnosis of the juvenile and adult forms.

A computerized tomography (CT) scan was performed on 6 surviving patients with a suspected diagnosis of subacute necrotizing encephalomyelopathy of the juvenile and adult forms. Bilateral low density areas were observed in the putamina in all cases. This CT pattern conformed with the characteristic pathological changes of the disease. Once the possibility of Wilson's disease or an earlier episode of acute cerebral hypoxia, syndromes which both display a similar appearance in CT, is excluded, a diagnosis of subacute necrotizing encephalomyelopathy may be considered in cases showing bilateral low density areas in the basal ganglia, especially in the putamina, and with a consistent clinical history.

Adolescent↗

PubMed1986

Pneumocephalus and tension pneumocephalus after posterior fossa surgery in the sitting position: a prospective study.

Thirty patients subjected to posterior fossa surgery in the sitting position were evaluated postoperatively by CT scans in order to assess the true incidence of pneumocephalus and subsequent development, if any, of tension pneumocephalus. This prospective survey shows that the postoperative incidence of intracranial air was 100%, while no progression towards tension pneumocephalus producing severe neurological deterioration was observed. It can thus be claimed that, although the sitting position may favour the development of tension pneumocephalus also other factors contribute to its pathogenesis. Finally, neither nitrous oxide nor temperature play any significant role in the development of this complication.

Adolescent↗

PubMed1985

Computerized tomography in CO poisoning.

In a case of CO poisoning CT scanning revealed bilateral low density areas in the globi pallidi, associated with diffuse hypodensity of the white matter of the cerebral hemispheres. Serial scanning threw some light on the possible mechanism involved and appears to support the hypothesis of necrotic damage of vascular origin following brain edema. An attempt is made to correlate the pattern of CT abnormalities with clinical evolution.

Basal Ganglia↗

PubMed1985

AK and ADA polymorphisms in South Sardinia.

A sample of the South Sardinia population was studied with respect to adenylate kinase (AK) and adenosine deaminase (ADA) enzymes. The gene frequencies were: AK1 0.975 and ADA1 = 0.933. The results were compared with those of other Italian populations.

Adenosine Deaminase↗

PubMed1984

Prognostic evaluation of brainstem hematomas: the role of CT scan and brainstem auditory evoked potentials.

6 cases of brainstem hematoma were studied utilizing CT scan and brainstem auditory evoked potential (BAEP) recordings. CT scan did not contribute to an early discrimination between primary and secondary hematomas. Size of the hematoma and the presence of blood in the CSF did not represent evident signs in differentiating benign from unfavourable brainstem hematomas or hemorrhages. BAEP recordings showed the presence of electrophysiological anomalies at the level of the lesion, demonstrating that bleeding as well as tumor in the brainstem can provoke a focal damage.

Adult↗

PubMed1984

6PGD and PGM1 polymorphisms in south Sardinia.

A sample of unrelated individuals, born and living in South Sardinia, was studied with respect to the enzymes 6PGD and PGM1. The gene frequencies were: PGDA 0.989 and PGM1 0.790. The results were compared with those of other Italian populations.

Gene Frequency↗

PubMed1983

Subjective posttraumatic syndrome. A comparison of visual and brain stem auditory evoked responses.

Evoked responses testing including pattern visual evoked potentials (VEPs) and brain stem auditory evoked potentials (BAEPs) were performed in 57 subjects suffering from subjective posttraumatic syndrome (SPTS). 36 of them had loss of consciousness after head injury. Abnormalities were found in 12 subjects out of 57 (21%). In addition, the pathological findings by percentage were: 25% in subjects who had loss of consciousness after head injury (9 cases out of 36) and 14% in subjects without loss of consciousness (3 cases out of 21). Evoked response alterations were more frequent in subjects with frontal and/or occipital trauma; BAEP abnormalities were found to be more frequent than VEPs. Our findings suggest that evoked responses testing could be a useful noninvasive technique to evidence an organic dysfunction of CNS in some subjects with SPTS.

Adult↗

PubMedDate not supplied

Pattern of anesthetic diffusion during peribulbar infiltration: a CT evaluation.

PURPOSE: The aim of this study was to evaluate the changes undergone by orbital structures during peribulbar anesthesia. METHODS: CT-thin slices were acquired and 8-9 ml of anesthetic, with a small part of low-density non-ionic water-soluble contrast medium were injected under CT guide once to follow extraconal spreading and diffusion to intraconal structures and above all, the surgically important structures such as recti muscles, orbicular and optic nerve sheath. Conjunctival sack involvement was assessed and conjunctival chemosis was rated. Induced ptosis was evaluated, verifying change before and after eyepressure. RESULTS: The results help in optimizing anesthetic technique, above all concerning the site, materials and quantity, and suggest the amount of anesthesia could be reduced. CONCLUSIONS: The peribulbar anesthetic technique proved effective and safe for patients.

Aged↗

PubMedDate not supplied

[Non-invasive assessment of epiaortic vessels. Comparison of magnetic resonance angiography with gadolinium, spiral computerized tomography angiography, and digital angiography].

PURPOSE: The aim of the study was to compare gadolinium-enhanced MRA (Gd-MRA), Computed Tomography angiography (CTA) and digital subtraction angiography (DSA) in the evaluation of carotid stenosis. MATERIAL AND METHODS: Thirty patients with US-proven internal carotid artery stenosis over 50%, underwent Gd-MRA, CTA and DSA. Gd-MRA was acquired using the keyhole technique. RESULTS: The overall agreement was 90% for Gd-MRA and 93% for CTA. Gd-MRA and CTA overestimated 5 and 4 cases of mild stenosis and 1 case each of moderate stenosis, respectively. Gd-MRA better delineated ulcerated plaques, tandem lesions and pseudo-occlusions. DISCUSSION AND CONCLUSIONS: Because of the high speed acquisition breath-hold is no longer necessary for Gd-MRA and more delayed phases were analysed when necessary. The main limitation of Gd-MRA was represented by insufficient volume coverage that allowed the visualisation of supraaortic vessels from the arch only in 57% of the cases. Calcified plaques were very well detected by CTA and not by Gd-MRA. In our experience Gd-MRA represents the second step non invasive tool in patients with US-proven carotid stenosis. This leads to avoid conventional angiography in most cases.

Angiography, Digital Subtraction↗

PubMedDate not supplied

Diffusion and perfusion MR imaging in cases of Alzheimer's disease: correlations with cortical atrophy and lesion load.

BACKGROUND AND PURPOSE: Perfusion and diffusion-weighted MR imaging are powerful new imaging techniques for evaluating tissue pathophysiology in association with many neurologic disorders, such as neurodegenerative diseases. The purpose of our study was to evaluate the sensitivity and specificity of dynamic susceptibility contrast-enhanced MR imaging and diffusion-weighted MR imaging in cases of Alzheimer's disease and to assess the role of atrophy in the quantification of cortical perfusion. METHODS: Thirty-nine participants were studied: 18 patients with moderate cognitive impairment with probable Alzheimer's disease, 16 patients with mild impairment with possible or probable Alzheimer's disease, and 15 group-matched elderly healthy comparison volunteers. Relative values of temporoparietal, sensorimotor, and hippocampal regional cerebral blood volume (rCBV) were measured as a percentage of cerebellar rCBV, and group classification was assessed with logistic regression. Brain atrophy was used as a covariate to assess its role in rCBV quantification. Regions of interest placed on orientation-independent apparent diffusion coefficient maps allowed the calculation of apparent diffusion coefficient values and relative anisotropic indices of the head of the caudate nuclei, thalamus, parietal, frontal, and hippocampal cortices bilaterally, genu and splenium of corpus callosum, and anterior and posterior white matter in patients with Alzheimer's disease and in control volunteers. RESULTS: Temporoparietal rCBV ratios were reduced bilaterally in the patients with Alzheimer's disease. Sensitivity was 91% in moderately affected patients with Alzheimer's disease and 90% in patients with mild cases. Specificity was 87% in healthy comparison volunteers. Lower values of sensitivity and specificity were obtained for sensorimotor (73%, 50%, and 67%, respectively) and hippocampal cortices (80%, 80%, and 65%, respectively). Using brain atrophy as a covariate, patients with Alzheimer's disease still showed a statistically significant reduction of rCBV compared with control volunteers. Diffusion-weighted MR imaging analysis only showed a trend, with no statistic significance, of reduction of anisotropy in posterior white matter. CONCLUSION: Dynamic susceptibility contrast-enhanced MR imaging of rCBV may be an alternative to nuclear medicine imaging for the evaluation of patients with Alzheimer's disease. When brain atrophy is used as a covariate, differences in rCBV still persist between patients with Alzheimer's disease and control volunteers, suggesting that perfusion impairment is unrelated to atrophy. No significant results for either white or gray matter were obtained using diffusion-weighted MR imaging.

Aged↗

PubMedDate not supplied

Cerebral hemodynamics in asymptomatic patients with internal carotid artery occlusion: a dynamic susceptibility contrast MR and transcranial Doppler study.

BACKGROUND AND PURPOSE: Perfusion imaging with dynamic susceptibility contrast MR imaging (DSC-MRI) has been used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. The aim of the present study was to determine the hemodynamic changes occurring in asymptomatic patients with unilateral internal carotid artery (ICA) occlusion by use of DSC-MRI with transcranial Doppler (TCD) measurement of the breath-holding index (BHI). METHODS: Nine patients with asymptomatic unilateral ICA occlusion underwent DSC-MRI and TCD examination. One patient was excluded from final analysis because of severe movement artifacts. On a separate workstation, regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional mean time to peak (rMTT) were calculated on the basis of signal decay rate during the passage of gadolinium bolus through the sampled volume in the territory of the middle cerebral artery. TCD-BHI was calculated in all patients. Six healthy subjects underwent the same MR protocol as the patients. RESULTS: Compared with control subjects, patients with unilateral ICA occlusions had hemodynamic changes in the ipsilateral hemisphere: rCBF was significantly lower than in controls (P <.01), and r MTT was significantly increased in both white (WM) and gray matter (GM) in the affected side (WM: P <.01; GM: P <.05). No statistically significant difference in rCBV was found in the group of patients (occluded versus contralateral, P <.1) or between the patient and control groups (occluded side versus controls, P <.1). The correlation of rCBV and BHI showed a strong relation of the two variables, showing a decrease of the latter when the former increased. CONCLUSION: DSC-MRI is a valuable tool for measuring hemodynamic changes in the presence of carotid disease with hemodynamic impairment. In our opinion, hemodynamic changes and efficiency of collateral pathways can be evaluated in occlusive carotid disease by using paired measurement of BHI and DSC-MRI. In the patient group, MR-determined rCBV and TCD-determined BHI showed a significant inverse correlation, suggesting similar significance of the two indices.

Angiography, Digital Subtraction↗

PubMedDate not supplied

Extra-foraminal prolapsed lumbar disc: a possible cause of recurrent sciatica in failed low-back surgery patient. Case report.

The present report describes the case of a 48 year-old woman who had undergone two separate lumbar laminectomies for a L4-L5 disc. She was admitted for a recurrent sciatica of 6-months duration, which failed to respond to conservative treatment. Myelogram on admission was negative. However CT showed a far laterally placed bulging L4-L5 disc. The patient was successfully reoperated on using a paramedian posterolateral approach on the side of the lesion. The rationale for this approach is discussed.

Cicatrix↗

PubMedDate not supplied

Collet-Sicard syndrome caused by a coiling of the internal carotid artery.

A Collet-Sicard syndrome was observed in a 53-year-old patient with a coiling of the left internal carotid artery just below the skull base. Although impairment of cranial nerves by tortuous vessel compression has frequently been reported, a combined palsy of the last four cranial nerves related to such a mechanism has never been described before.

Carotid Artery, Internal↗

PubMedDate not supplied

[A case of cerebral stroke caused by a spontaneous dissection of the internal carotid with rapid resolution].

We describe a case of acute stroke due to a spontaneous carotid dissection. Doppler sonography performed 12 hours after stroke and repeated in the following days suggested a dissection of the right internal carotid artery, then confirmed by angiography. The dissection could be unrecognized because of a complete normalization of the flow within the fifth day. This case shows the importance of performing an early ultrasonic examination in stroke patients.

Aortic Dissection↗

PubMedDate not supplied

[NMR of phakomatoses].

23 patients affected by phakomatoses were studied with NMR, including tuberous sclerosis (11 cases), Sturge-Weber's disease and Von Recklinghausen's neurofibromatosis (6 cases). SE sequence was used performing T1-WIs with TR = 350-750 ms and TE = 20-30 ms and T2-WIs with TR = 1500-2100 ms and TE = 50-100 ms. Tuberous sclerosis was characterized in each case by the presence of hiperintense areas in T2-WIOs, associated in 9 cases to subependimal microcalcifications. Sturge-Weber-disease showed: cerebral or lobar emiatrophia, abnormal vascularization and cortical calcifications. Cerebral neurofibromatosis was characterized by extra-assial tumors, associated in 4 cases to gliomas of the optical pathways. The AA. conclude that NMR is the choice examination in the evaluation of phakomatoses.

Adolescent↗

PubMedDate not supplied

[Boundary cerebral infarct in a case of essential thrombocythemia].

We describe a case of essential thrombocythemia in a patient with a mild heart failure. The only clinical manifestation consisted of neurologic symptoms. Cerebral CT was able to show boundary zone infarcts. A possible pathogenetic mechanism for the unusual clinical and radiological finding is proposed.

Aged↗

PubMedDate not supplied

[Nuclear magnetic resonance in pathology of the central nervous system in children].

The following study aims to establish the role of MRI in investigation of the CNS in children. 300 patients are examined, 220 affected by CNS disease. The examinations were performed using SE sequence (T1-weighted images TR = 350-700 ms TE = 30-60 ms; T2-weighted images TR = 1500-2000 ms TE = 50-200 ms). In most of the patients general anesthesia or sedation was necessary. Patients are divided into groups based on pathology and the advantages and shortcomings of MRI are discussed. In conclusion, MRI should be the technique of choice in the evaluation of malformative affections, white matter and inflammatory disease; it should be complementary to CT and angiography in tumors and vascular pathology.

Adolescent↗