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Biomedical subjects

C Pozzilli

Publications and source records attributed to C Pozzilli.

32 records · Page 2Linked to original sources
PubMed1988

Remote effects of subcortical cerebrovascular lesions: a SPECT cerebral perfusion study.

The remote effects of small unilateral cerebrovascular lesions confined to subcortical structures were evaluated by single photon emission computerized tomography (SPECT) and a CBF tracer, I-123 HIPDM. A CBF study was performed in 34 patients presenting with subcortical stroke either in the acute or in the chronic stages. Twenty-one of the 34 patients showed areas of cortical hypoperfusion ipsilateral to the subcortical lesion. In 14 patients, asymmetry of perfusion was also observed at the cerebellar level, perfusion being significantly reduced in the cerebellar hemisphere contralateral to the lesion. There was no correlation between the degree and extension of these remote effects and the type of stroke (ischemic or hemorrhagic), the patency of cerebral arteries, or the size and site of the lesion by transmissive computerized tomography (TCT). Subcortical hematomas showed a correlation between occurrence of remote effects and time interval from the onset of stroke, occurring more frequently in the acute phase. A correlation was observed between cortical and cerebellar remote effects and the severity of clinical presentation. The causes of remote effects are still unclear and have been extensively debated. Our data indicate that there is a relationship of remote effect to the neurological status. It is possible to show, by noninvasive, low-cost methods, remote CBF effects after stroke that may contribute to the assessment of brain functional impairment.

Acute Disease↗
PubMed1988

Calcium antagonists in ischemic stroke.

Clinical neurological examination, computed tomography (CT) scan, cerebral angiography, and cerebral blood flow-single photon emission computerized tomography (CBF-SPECT) study have been performed in 39 patients with acute ischemic stroke within 6 h from the onset of symptoms. Seven of these patients were submitted to a second CBF study after an intravenous infusion of nimodipine. A greater CBF impairment was observed in patients with severe neurological deficit at entry, poor outcome, cerebral arterial occlusion, and large hypodensity on the CT scan performed 1 week after admission. In patients treated with nimodipine, a significant increase of CBF was detected at the periphery of the ischemic zone, indicating a potential action of this Ca antagonist on the "ischemic penumbra."

Adult↗
PubMed1988

Quantitative assessment of blood-brain barrier permeability in multiple sclerosis using 68-Ga-EDTA and positron emission tomography.

Fifteen patients with definite multiple sclerosis were examined with high volume delayed (HVD) CT scan and positron emission tomography (PET) using 68-Ga-EDTA as a tracer. The passage of 68-Ga-EDTA across the blood-brain barrier (BBB) was measured by using multiple graphical analysis. This method permits the simultaneous calculation of a blood to brain influx constant Ki (ml/g-1 min-1) and of the plasma volume Vp (ml/g-1). Focal areas of abnormal CT enhancement and pathological accumulation of 68-Ga-EDTA were visualised in four patients who were all examined during a clinical exacerbation of the disease. The mean Ki value measured in these areas was 12.5, SD 3.4 indicating a moderate but significant increase of BBB permeability compared with the value found in normal tissue (3.2, SD 0.9). No parallel increase in Vp values was found in these pathological areas. Quantitative data obtained with PET seems to provide further insight into the study of BBB function in multiple sclerosis.

Adolescent↗
PubMed1987

Haemodynamics and oxygen metabolism in patients after reversible ischaemic attack or minor ischaemic stroke assessed with positron emission tomography.

Regional cerebral blood flow (CBF), blood volume (CBV) and oxygen metabolic rate (CMRO2) were evaluated and compared among normals, patients with recent reversible ischaemic attacks (RIAs) and patients with chronic minor infarction using positron emission tomography. Average CBF together with CMRO2 significantly decreased in the infarction group in the middle cerebral artery territory of the affected hemisphere while the mean values for RIAs were intermediate between the other two groups. CBV also reduced, however it was more preserved compared to flow as seen in decreased CBF/CBV values. Significant interhemispheric difference was found in CBF/CBV ratio, but it did not clearly correlate with OEF changes. Higher OEF was noted only in the restricted brain regions of RIAs where CBF showed large hemispheric asymmetry. However, in other regions, the coupled decline of blood flow and metabolism was found which suggests tissue damage or neuronal cell loss in the brain with previous RIA symptoms.

Adult↗
PubMed1987

Remote effects of caudate hemorrhage: a clinical and functional study.

Clinical, anatomical and functional findings in two cases of previous caudate nucleus hemorrhage, with good recovery, are presented. CBF data obtained with SPECT and 123 I-HIPDM well correlate with functional residual deficit, despite normal TCT examinations. These observations are suggestive of a partial "wallerian" diaschisis.

Affect↗
PubMed1987

Positron emission tomography in minor ischemic stroke using oxygen-15 steady-state technique.

A study with positron emission tomography (PET) was performed on 10 patients with ischemic stroke and mild disability. The patients underwent cerebral angiography, x-ray computed tomography (CT) scan and regional cerebral measurements of CBF, CMRO2, oxygen extraction ratio (OER), and cerebral blood volume (CBV). Only minor arterial involvement was detected by angiography. In all patients, PET images of functional defects were more extensive than the corresponding CT hypodensity, and there were statistically significant reductions in CBF, CMRO2, and CBF/CBV ratio as compared with control subjects. Half of the regions analyzed in the affected hemisphere demonstrated a disruption of the normal coupling between CBF and CMRO2 as reflected by OER values significantly higher or lower than those of the corresponding region of the contralateral hemisphere. The pathophysiological pattern of high OER combined with a reduction in CBF proportionally greater than the reduction in CMRO2 was particularly indicative of regional chronic hemodynamic compromise in these patients.

Aged↗
PubMed1987

Sequential computed tomography and 123I-HIPDM scans in multiple sclerosis with large plaque. A case report.

We report a case of acute multiple sclerosis in whom computed tomography (CT) scan suggested the presence of a large plaque. The anatomical and functional recovery of the brain tissue was followed by means of repeated CT scan and 123I-HIPDM studies. Single photon emission CT may be successfully employed to monitor the pathophysiological changes associated with the demyelinating process.

Adult↗
PubMed1985

Peripheral white blood cell count in cerebral ischemic infarction.

Peripheral white blood cell (WBC) count was determined in 95 patients with ischemic cerebral infarction 3 days after the onset of the stroke. At this time, higher WBC counts were found in patients with more severe neurological impairment and larger infarct size. A relationship between increase of WBC count and poor clinical outcome was also demonstrated. The elevation of peripheral WBC count observed soon after cerebral infarction reflects the degree of the inflammatory response in the acute hase and seems to have a direct relationship with the extent of the local cerebral damage.

Aged↗
PubMed1985

Effect of unlabeled indium oxine and indium tropolone on the function of isolated human lymphocytes.

The purpose of this study was to compare the effect of indium oxine and indium-tropolone complexes (nonradiolabeled) on the function of isolated human lymphocytes. peripheral lymphocytes were obtained from 15 normal volunteers and incubated with indium oxine or indium tropolone according to the standard techniques currently used when cells are radiolabeled for subsequent in vivo studies. The phytohemagglutinin-induced (PHA) lymphocyte transformation and a more specific lymphocyte functional test (the mixed lymphocyte reaction) were performed following incubation with the indium complexes. The results indicate that PHA transformation is not affected by either indium oxine or indium tropolone, whereas both chelates reduced the mixed lymphocyte reaction. This suggests that these substances have a selective toxic effect only on a functionally distinct lymphocyte subset (i.e., the cytotoxic T cells) and indicates that there is no significant difference between the two indium chelates in terms of their effect on lymphocyte function.

Adult↗
PubMed1985

Homing and circulation of indium-111-labelled leucocytes. A post-mortem study.

The history of a patient with a suspected ischemic brain infarct undergoing an indium-111-tropolone white cell labelled test is reported. The patient, who died 12 h after injection of the labelled cells, suffered of a brain haemorrhage. The post-mortem examination has allowed for the first time the measurement of radioactivity in different organs following the injection of indium-111-labelled leucocytes. High radioactivity was found only in tissues affected by inflammatory processes and in the lymphonodes draining the corresponding areas. This report clearly indicates the importance of this method for the study of white cell localization and circulation to the sites of infections.

Cerebral Hemorrhage↗
PubMedDate not supplied

Simplified, noninvasive PET measurement of blood-brain barrier permeability.

Blood-brain barrier (BBB) permeability to [68Ga]EDTA was measured by positron emission tomography (PET) in four normal volunteers and in 11 patients with brain tumors. A unidirectional transfer constant, Ki, was calculated applying multiple-time graphical analysis (MTGA). This method allows the detection of backflux from brain to blood and, by generalization, the measurement of the constant Kb (brain to blood). Furthermore, the need for an independent measurement of the intravascular tracer is obviated: MTGA itself provides an estimate of the cerebral plasma volume (Vp). In the four normal volunteers the Ki was 3.0 +/- 0.8 X 10(-4) ml g-1 min-1 (mean +/- SD) and the Vp 0.034 +/- 0.007 ml g-1. A net increase in Ki up to a maximum of 121.0 X 10(-4) ml g-1 min-1 (correspondent value of Kb = 0.025 min-1) as well as an increase of Vp was observed in malignant tumors. The input function was calculated using both the [68Ga]EDTA concentration in sequential arterial blood samples and, noninvasively, the activity derived from the superior sagittal sinus image. The values of Ki and Vp from these two calculations were in good agreement. The application of MTGA to PET permits the evaluation of passage of substances across the BBB without making assumptions about the compartments in which the tracer distributes.

Adult↗
PubMedDate not supplied

Imaging of leukocytic infiltration in human cerebral infarcts.

The circulating white blood cells of patients with brain infarction were labelled in vitro with Indium-111 tropolonate; the cells were reinjected to study the inflammatory process by gamma camera imaging. Eight patients with acute cerebral ischemic infarct were studied during the first two weeks after the onset of neurological symptoms. In seven cases a well defined area of increased radioactivity was revealed in the infarcted hemisphere indicating active migration and tracking of labelled leukocytes in cerebral infarct. This method allows monitoring of the cellular inflammatory response in human cerebral infarcts and adds another imaging technique.

Acute Disease↗
PubMedDate not supplied

Relationship between bladder dysfunction and brain MRI in multiple sclerosis.

We studied 70 consecutive patients with definite multiple sclerosis (MS) to examine the relationship between magnetic resonance imaging (MRI) cerebral findings and urinary disturbances. Thirty-two subjects (46%) had urinary symptoms and 38 (54%) were asymptomatic. Patients with urinary symptoms exhibited greater overall functional disability. A significant correlation between the presence of midbrain lesions and urinary dysfunctions was found which may indicate an important role of the mesencephalic formation to preserve continence.

Adolescent↗