Irreversible total blindness in multiple sclerosis.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
C Pozzilli
Publications and source records attributed to C Pozzilli.
Anterior corpus callosum atrophy and verbal fluency in multiple sclerosis.
To determine whether different portions of the corpus callosum (CC) are responsible for transferring the information of specific cognitive modalities, eighteen females with relapsing-remitting Multiple Sclerosis (MS) were studied using neuropsychological procedures and Magnetic Resonance Imaging (MRI). Measures of both anterior and posterior CC areas were obtained in patients with MS as well as in eighteen age and sex matched healthy controls. MRI scans were additionally analyzed for each patient in order to evaluate the extent of demyelinating lesions in both periventricular and subcortical areas. Patients with MS exhibited a significant decrease in both the anterior and posterior CC areas compared with normal subjects. The results of statistical analysis showed that, even when the effect of demyelinating lesions was taken into account within a regression equation, the atrophy of anterior CC area strongly affected the performance on verbal fluency task. These data emphasize the importance of the anterior CC area for the interhemispheric transfer of cognitive information associated with verbal fluency.
Adult↗
Quantitative assessment of cerebral blood flow in partial epilepsy using Xe-133 inhalation and SPECT.
The Xe-133 inhalation method was used to study rCBF in 12 patients with partial epilepsy during the interictal phase. SPECT images evidenced a focal CBF defect in 10 out of 12 patients, while quantitative analysis showed CBF abnormalities in all the patients. The focal CBF defect corresponded to the site of EEG abnormalities in nine patients. Additional low-flow areas beyond the EEG focus were found. Five patients presented a significant CBF decrease in the cerebellar hemisphere contralateral to the EEG focus. In five patients with unilateral EEG abnormalities, a CBF reduction was found in the contralateral cerebral hemisphere, mirror to the EEG focus. Finally, a widespread CBF decrease involving one or both cerebral hemispheres was observed in seven patients. Global and rCBF values were not correlated with age, duration of disease, frequency of seizures, secondary generalization, or specific therapy. SPECT may be useful in evaluating EEG epileptic foci, and quantitative SPECT allows the detection of functional effects of the epileptic focus on anatomically connected remote areas, probably due to the decrease of afferent inputs (diaschisis phenomenon).
Administration, Inhalation↗
SPECT, MRI and cognitive functions in multiple sclerosis.
Seventeen patients with relapsing remitting multiple sclerosis (MS) and mild physical disability had neuropsychological testing, magnetic resonance imaging (MRI) and single photon emission computerised tomography (SPECT) using technetium 99m (99mTc) hexamethyl-propyleneamine oxime (HMPAO). Performance in verbal fluency, naming and memory testing appeared to be impaired in MS patients compared with 17 age-sex and education matched normal controls. Weighted periventricular and confluent lesion scores and the width of the third ventricle, proved to be the most sensitive MRI measures in differentiating more cognitively impaired patients from those who were relatively unimpaired. Ratios of regional to whole brain activity, measured by SPECT, showed significant reduction in the frontal lobes and in the left temporal lobe of MS patients. A relationship was found between left temporal abnormality in 99mTc-HMPAO uptake and deficit in verbal fluency and verbal memory. Finally, asymmetrical lobar activity indicated a predominant left rather than right temporo-parietal involvement.
Brain↗
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↗
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↗
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↗
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↗
Facts and trends in cerebral blood flow and metabolism: synopsis of brain '89.
Explore the source record for details and available documents.
Animals↗
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↗
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↗
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↗
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↗
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↗
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↗
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↗
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↗
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↗