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Biomedical subjects

C Pozzilli

Publications and source records attributed to C Pozzilli.

At least 127 records · Page 7Linked to original sources
PubMed1990

Predictive value of brain perfusion single-photon emission computed tomography in acute ischemic stroke.

We investigated 32 patients with completed ischemic stroke less than or equal to 6 hours after the onset of symptoms by means of computed tomography, cerebral angiography, and technetium-99m-labeled hexamethylpropyleneamine oxime single-photon emission computed tomography to study cerebral blood flow. Follow-up computed tomography and cerebral blood flow studies were performed 1 week and 1 month after admission. Poor outcome at 1 month was evident in 18 (78%) of the 23 patients with severe neurologic deficit on admission and in 11 (92%) of the 12 patients with severe hypoperfusion in the affected hemisphere on admission. All 10 patients with severe impairment of both neurologic status and cerebral blood flow had a poor outcome at 1 month. We detected severe hypoperfusion in patients with large lesions on computed tomograms or cerebral artery occlusions on angiograms. Cerebral blood flow had increased at the 1-week follow-up despite different clinical outcomes. Our data provide evidence that early evaluation of cerebral blood flow with single-photon emission computed tomography is useful to detect subgroups of patients with different clinical outcomes during the acute phase of ischemic stroke.

Brain Ischemia↗
PubMed1990

Serial study of gadolinium-DTPA MRI enhancement in multiple sclerosis.

We performed serial baseline and gadolinium (Gd)-DTPA-enhanced MRI in 4 patients with definite multiple sclerosis. Studies were performed every month for a total of 4 scans. We obtained short TR/short TE sequences at 10 and 60 minutes after Gd-DTPA injection. All patients had multiple hyperintense lesions seen on baseline MRI with long TR/short and long TE. There was Gd-DTPA enhancement in new, enlarging, and preexisting lesions that were unchanged in size. The enhancing lesions were always seen on T2-weighted images. There was no difference in enhancement between the 10- and 60-minute studies. Six of 85 preexisting lesions enhanced whereas all new or enlarging lesions enhanced. Enhancement persisted in only 1/3 of the new or enlarging lesions, suggesting that MR enhancement is a transient phenomenon due to local temporary blood-brain barrier breakdown. Our data indicate that Gd-DTPA enhancement monitoring is more sensitive than unenhanced MRI for detecting disease activity in MS.

Adult↗
PubMed1989

Systemic hypertension as a treatable risk factor for cerebrovascular disease.

It has long been established that hypertension is the major risk factor for stroke. Three Italian studies have been reviewed in order to examine different aspects of the problem. In the first study, the role played by the systolic, diastolic and systodiastolic components of hypertension in causing atherosclerotic damage of extracerebral and intracerebral arteries was examined. At the extracranial level, a significant correlation between systolic hypertension and atherosclerotic lesions was evident. The second study evaluated the risk of major stroke, myocardial infarction and death in patients with transient ischemic attacks and reversible ischemic neurologic deficits. Possible prognostic predictors of these events were thoroughly considered: Cumulative survival with the multivariate Kaplan-Meier analysis was significantly lower in hypertensive than in normotensive subjects, particularly for cerebral deaths and for all deaths. The third study was aimed at assessing the risk factors for transient ischemic attacks and stroke in young adults. Again, hypertension emerged as a fundamental risk factor, significantly more frequent in the subgroup of older patients than in the younger subgroup.

Age Factors↗
PubMed1989

Influence of nimodipine on cerebral blood flow in human cerebral ischaemia.

Cerebral blood flow (CBF) was measured by xenon-133 inhalation and single photon emission computerized tomography (SPECT) in 7 patients with acute cerebral ischaemia prior to and 30 min after intravenous infusion of nimodipine (1 mg). Neurological examination, CT and CBF study were performed no later than 6 h after the onset of symptoms. Regional perfusion abnormalities were seen in all patients when the CT scan was still normal. Follow-up CT revealed low-density areas roughly corresponding to the core of the perfusion defect. Nimodipine infusion significantly decreased the mean arterial blood pressure (P less than 0.01), while PaCO2 and clinical symptoms remained unchanged. A significant CBF improvement (P less than 0.05) after nimodipine was seen in the border zone of the ischaemic infarct but not in the core of the lesion or in the unaffected contralateral hemisphere.

Adult↗
PubMed1989

Acetazolamide effects on cerebral blood flow in acute reversible ischemia.

Cerebral blood flow (CBF) was studied in 4 patients with acute reversible ischemia (RIND). To test the ischemic areas' vasoreactivity, CBF was measured by the Xenon-133 inhalation method, before and after acetazolamide injected intravenously. At the baseline CBF study, 3 patients presented hypoperfused areas while one patient had increased CBF over the affected hemisphere. The acetazolamide test, showed in this latter case a "steal phenomenon" while in the other 3 an increase of perfusion was evidenced, in areas of normal flow, as well as in areas with reduced flow. These results suggest that in the acute phase of patients with RIND, when brain regions of hypoperfusion and neurological signs are still present, the vasomotor response may be preserved.

Acetazolamide↗
PubMed1988

Positron CT imaging of an impending stroke.

We present PET findings of a case of a transient ischemic attack which later progressed to cerebral infarction. Cerebral blood flow at the stroke focus in the right parietal cortex measured after a TIA attack and before stroke was as low as 24 ml/100 g/min with some increase in oxygen extraction fraction and blood volume. The condition was compatible with "misery perfusion". This case may be an example suggestive that the "misery perfusion sign" is a warning of impending stroke and its poor prognosis if left without appropriate treatments.

Aged↗
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↗