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Biomedical subjects

V Di Piero

Publications and source records attributed to V Di Piero.

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

Prolonged muscular flaccidity after stroke. Morphological and functional brain alterations.

Patients with a motor deficit due to ischaemic stroke usually develop muscular spasticity, but in some cases they may remain with a prolonged muscular flaccidity which impairs their recovery. Little is known about the causes of these two different functional outcomes. We correlated CT/MRI and 99mTc HM-PAO SPECT with clinical findings in 42 patients at a mean time interval of 3 months after stroke. The patients were divided into two cohorts with either flaccid (prolonged muscular flaccidity) or spastic (muscular spasticity) hemiparesis. Although patients with prolonged muscular flaccidity had a greater motor deficit, the mean structural volume of the ischaemic lesion was similar to that of the muscular spasticity cohort. There was a significantly higher prevalence of structural involvement of the lentiform nucleus in prolonged muscular flaccidity cases. Relative perfusion in the lentiform nucleus, thalamus and contralateral cerebellar hemisphere was significantly lower in prolonged muscular flaccidity than in muscular spasticity patients. A subgroup with only subcortical structural lesions also showed significantly lower relative perfusion in the ipsilateral frontal association areas. A primary involvement of the lentiform nucleus by the structural lesion seems to be crucial for the persistence of flaccidity after stroke. However, cerebral blood flow (CBF) changes in other structurally intact regions indicate their additional role. It is likely that both subcortical-cortical loops involved in motor control, i.e. cortex-basal ganglia-thalamus-cortex and cortex-pons-cerebellum-thalamus-cortex, are more widely and more severely affected in patients with prolonged muscular flaccidity.

Adult↗
PubMed1995

Patterns of neuropsychological impairment in mild dementia: a comparison between Alzheimer's disease and multi-infarct dementia.

The objective was to investigate the clinical and psychometric differences between patients with dementia of Alzheimer type (DAT) and patients with multi-infarct dementia (MID), matched for age, sex, education, and severity. Sixteen patients with DAT, 16 patients with MID, and 30 healthy individuals, were drawn from a longitudinal study on aging and dementia. Subjects with medical or previous mental disorders were excluded. DAT and controls with focal brain abnormalities on magnetic resonance imaging (MRI) were excluded. Diagnosis of dementia was carried out according to DSM-III-R criteria. Dementia severity was staged using the Clinical Dementia Rating (CDR) scale, and only patients with a score of 0.5-1 on CDR were studied. The main outcome measures were quantitative clinical scales of the assessment of global mental status, depression and anxiety, as well as a wide battery of neuropsychological tests for the evaluation of executive/conceptual functions and memory, as well as attention verbal ability, and visuospatial skill functions. The performance of demented patients compared to normal controls was affected on all measurements except for depression and anxiety. DAT patients showed compared to MID patients a greater extent of impairment on tasks assessing verbal comprehension and memory while MID patients were more significantly impaired on measures of frontal lobe functioning. Clinically matched DAT and MID patients show a differential pattern of neuropsychological impairment when studied in an early stage of dementia and with a mild degree of severity. Such patterns might be of value for the development of clinical diagnostic criteria.

Aged↗
PubMed1994

Sjögren's syndrome presenting as ischemic stroke.

BACKGROUND: We describe a young woman who presented with minor stroke as a first clinical symptom of Sjögren's syndrome (SS) in the absence of well-known risk factors for cerebrovascular disease. CASE DESCRIPTION: The medical history included recurrent miscarriages and sun rashes, which directed the diagnosis toward immunologic disorders such as systemic lupus erythematosus and antiphospholipid antibody syndrome, which are often associated with stroke. Only complete laboratory testing, including SSB antibody studies, and ophthalmologic and salivary gland evaluation revealed the correct diagnosis. CONCLUSIONS: Sjögren's syndrome should be considered among the causes of stroke, especially in a young female patient.

Adult↗
PubMed1993

Motor activation by single-photon emission computed tomography. A comparison of xenon-133 and technetium-99m HM-PAO "split-dose" methods.

Single-photon emission computed tomography (SPECT) was used to investigate the feasibility of the technetium 99m-hexamethylpropyleneamineoxime ( 99mTc HM-PAO) split-dose method to evidence changes in regional cerebral blood flow during a motor activation task, in comparison with a quantitative method using the inhalatory xenon-133. Four subjects were studied twice with both methods, at rest and during finger opposition movements. On the activated cerebral hemisphere, a significant increase in regional cerebral blood flow was observed over the motor cortical areas. The average increases were +28.1 +/- 5.6% for the xenon-133 method and +12.3 +/- 5.2% for the 99mTc HM-PAO method. By using the linearization algorithm for the 99mTc HM-PAO method, a mean increase of +22.5 +/- 8.9% was calculated. This study demonstrated that the split-dose method allows the motor activation SPECT studies with 99mTc HM-PAO to be done in a single session.

Analysis of Variance↗
PubMed1992

Motor stimulation response by technetium-99m hexamethylpropylene amine oxime split-dose method and single photon emission tomography.

We applied the technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) split-dose method in order to evaluate the feasibility of assessing cerebral blood flow (CBF) changes with single photon emission tomography (SPET) during a motor activation task. Eleven normal subjects were studied using the Tomomatic 564 (Medimatic, DK). Five subjects were studied twice at rest and 6 subjects at rest and during a motor task performance (finger opposition movements). A total of 28 mCi of 99mTc-HMPAO was injected in 2 doses with a 1:3 ratio. The first scan was obtained after injection of 7 mCi at rest in all subjects. The second scan was obtained a few minutes later, after injection of the remaining dose (21 mCi), under similar resting conditions or during a motor task performance. The mean brain uptake was proportional to the amount of tracer injected and to the acquisition time for both the first scan (5263 +/- 1266 counts x mCi x min) and the second (5034.4 +/- 966 counts x mCi x min). The grey/white matter ratio was 1.67 +/- 0.019 and 1.67 +/- 0.097 for the two scans, respectively. A three-way analysis of variance (ANOVA) for repeated measure showed no significant effects of side, slice and region of interest (ROI) on the CBF in the 5 subjects studied twice at rest, and the mean regional CBF change was -0.2% +/- 5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1992

Reversed laterality of cerebral functions in a non-right-hander: neuropsychological and spect findings in a case of 'atypical' dominance.

A 54-year-old non-right-handed man with positive familial sinistrality showed a pure right hemisphere syndrome following a left hemisphere stroke. Severe right side hemineglect, transcortical motor dysprosodia, spatial dysgraphia and visuo-constructive impairments were observed. At no time were the expected left hemisphere abnormalities such as aphasia, alexia, right-left disorientation or finger agnosia noted. A left fronto-temporal subcortical lesion was documented on CT scan. A Tc-99m HM-PAO SPECT study revealed no cerebral blood flow changes in the right hemisphere while in the left hemisphere a fronto-temporo-parietal cerebral blood flow reduction was evident. This case of a complete reversed laterality of cognitive functions argues for a distinction to be made between 'anomalous' cerebral dominance and 'atypical' cerebral dominance.

Brain↗
PubMed1992

Depression in the early phase of MS: influence of functional disability, cognitive impairment and brain abnormalities.

This study investigated the relationship between depression, physical disability, cognitive deficit and brain abnormalities on magnetic resonance imaging (MRI) in patients with early MS. Eighteen relapsing-remitting MS patients were evaluated: depression was diagnosed according to DSM-III R and measured by the MMPI depression subscale, physical disability was assessed by using the Kurtzke Expanded Disability Status Scale (EDSS) and cognitive functions by means of an extensive neuropsychological test battery. A neuroradiologist blinded to clinical findings quantified cerebral lesion on MRI. Weighted brain area lesion score were developed according to number and size of cerebral lesions. On the basis of DSM-III criteria, six patients were classified as having major depression, seven patients had minor depression and five patients were without depressive symptoms. No significant differences were found among the three groups on both neuropsychological performances and weighted MRI lesion scores. However patients with major depression exhibit greater physical disability than the other MS subgroups. A significant correlation was found between MMPI depression subscale and physical disability. This study suggests that at least in the early phase of MS, depression appears more related to the physical disability than to the severity of pathological brain involvement.

Activities of Daily Living↗
PubMed1992

Motor recovery after acute ischaemic stroke: a metabolic study.

The metabolic changes occurring after ischaemic stroke were measured to investigate the functional anatomy of clinical motor recovery. Positron emission tomography (PET) and the steady-state 15O technique was used to compare resting relative metabolic distributions at the onset of functional deficit with those following recovery. Ten patients were studied with repeat scans. Motor recovery was associated in some patients with an increase of relative oxygen metabolism in anatomical structures normally involved in motor function in the affected hemisphere, particularly in the cortical motor areas. In those patients without such metabolic changes in the cortex of the diseased hemisphere, relative increases in cortical metabolism in the contralateral hemisphere were associated with better motor recovery than in patients with no relative cortical metabolic increase in either hemisphere. There was no correlation between the degree of improvement in motor function and the severity of motor deficit at onset, the size and site of the lesion and the metabolic changes in the infarcted zone. No particular pattern of global metabolic changes was observed after recovery. Thus different relative patterns of metabolic recovery were seen in patients with different lesions and evidence was found for the participation of contralateral structures in the recovery process in some patients.

Acute Disease↗
PubMed1992

Pattern of CBF in the rehabilitation of visuospatial neglect.

The CBF was assessed in seven patients before and after rehabilitation for visuospatial neglect. Two months of treatment produced an increased perfusion both in the right posterior and left anterior areas of the brain. However, only the left anterior CBF increase was correlated with the neglect disorders. The left anterior improvement in CBF was inversely correlated with right-left cerebellum asymmetry in pre- and post-treatment. The present data suggest the role of the frontal eye-fields in the mechanism of recovery of visual exploration in patients with severe neglect.

Adult↗
PubMed1991

Chronic pain: a PET study of the central effects of percutaneous high cervical cordotomy.

We have studied 5 patients with unilateral, severe chronic pain due to cancer before and after percutaneous, ventrolateral cervical cordotomy to investigate the central effects of the procedure. The aim was to identify the functional anatomical correlates of abolishing unilateral nociceptive input to the brain. Patients were investigated by positron emission tomography using C15O2 to evaluate cerebral blood flow. Comparisons were made between the patients with unilateral pain before cordotomy and normal volunteers. These demonstrated significantly less blood flow in 3 out of 4 of the individual quadrants of the hemithalamus contralateral to the side of pain (P less than 0.01-0.05). These differences were abolished by cordotomy. Comparison of the patients before and after cordotomy showed a significant decrease in blood flow in the dorsal anterior quadrant of the thalamus contralateral to the side of pain (P less than 0.05) which was normalised after cordotomy. There were no significant changes in the prefrontal or primary somatosensory cortex. We conclude that chronic pain results in a decrease of synaptic activity at thalamic level either from decreased activity in neurones projecting to that region and/or attenuated local neuronal firing. We have demonstrated no secondary remote effects in cortex, indicating the importance of subcortical mechanisms in central responses to chronic pain.

Aged↗
PubMed1991

[Brain protection in heart surgery].

We investigated the effect of CDP-choline on brain protection during extra-corporeal circulation (ECC) in patients submitted to open-heart surgery. We studied forty patients, using neurological, neuropsychological, neuroradiological (CT scan), and CBF evaluations. All the patients were evaluated two weeks before (T1), two weeks (T2), one month (T3) and six months after surgery (T4). Patients were randomly divided into two groups: subjects of the first group were treated with 2000 mg/die e.v. from two weeks before surgery to ten days after surgery, and then with 1000 mg/die i.m., 15 days per month, for the following 6 months (Group A), while subjects of the second group were treated with 100 mg/die, from two weeks before surgery to six months after surgery (Group B). After surgery, neither neurological symptoms nor morphostructural lesions were observed in the two groups. However, in the Group A, 75% (15 out of 20) of the patients evidenced reduced performances on neuropsychological tests at T2, compared to T1. At T4 only 66% (10 out of 15) of the impaired patients showed a persistence of the deficit. In the Group B 70% (14 out of 20) of the patients displayed reduced performances at T2. At T4, almost all of the patients, namely 86% (12 out of 14), showed a persistence of neuropsychological deficits. CBF data showed hypoperfusion areas in 9 patients in Group A (1.7 +/- 4.15 mean areas per patient), and in 10 patients in Group B (3.33 +/- 1.3 mean areas per patient), at T2. In 2.2+ off

Adult↗
PubMed1991

How to assess acute cerebral ischemia.

There are different approaches to the assessment of acute stroke. Its causes, its severity, and/or its final prognosis may be investigated. The traditional approach is anatomoclinical. It is basically limited to finding out if the lesion is a hemorrhage or an ischemia, and its location. This approach is derived from and supported by the fact that acute stroke is still without a valid therapy. In our opinion, not stroke but individual patients presenting with stroke should be treated. The pathophysiology of the individual stroke should be investigated by means of new techniques: magnetic resonance, emission tomography, and transcranial Doppler. These new techniques will be important in the future, making it possible to create effective therapeutic strategies, designed for treating a particular subgroup of patients, as in the case of fibrinolytic agents. The main aspects of these new techniques for evaluating acute ischemic stroke have been reviewed in this article.

Acute Disease↗
PubMed1990

Cerebrotendinous xanthomatosis: clinical and MRI study (a case report).

We report a patient with cerebrotendinous xanthomatosis (CTX) presenting with dementia, spastic tetraparesis and an unreported akinetic-rigid syndrome. Computed tomography (CT) showed only cerebellar abnormalities while magnetic resonance imaging (MRI) detected additional pallidal and mesencephalic focal alterations. MRI findings, but not CT, correlated with the clinical picture.

Achilles Tendon↗
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

The functional nature of cerebellar diaschisis.

We report a patient who presented with transient clumsiness of his right hand due to a small hemorrhage in the left globus pallidus. Ten days later, positron emission tomography performed at rest showed decreased oxygen metabolism and blood flow at the site of the anatomic lesion and in remote areas such as the ipsilateral frontotemporoparietal cortex and the contralateral cerebellar hemisphere. Cerebellar hypometabolism has been ascribed to functional disconnection of the contralateral hemisphere from the cerebral cortex and has been termed crossed cerebellar diaschisis. One month later, positron emission tomography performed during unilateral motor activation (finger opposition) showed increased blood flow in the sensorimotor and supplementary motor areas contralateral to the hand engaged in the motor task. An at-rest study at this time showed resolution of the crossed cerebellar diaschisis observed acutely, but cerebellar asymmetry was demonstrated during performance of the motor task with the normal as well as with the previously paretic hand. Our activation study demonstrated cerebellar asymmetry in the chronic phase during a motor task, even though resting cerebellar blood flow was symmetrical. This observation reveals the dynamic, functional nature of crossed cerebellar diaschisis and may partially explain the lack of any clinical counterpart in functional studies of the cerebellum performed with the patient at rest.

Brain↗
PubMed1990

Pathophysiology of ischemic brain disease.

In this article, we review and discuss the pathophysiology of brain ischemia, focusing on requirements of cerebral metabolism, biochemical characterization of the energy reserve, and autoradiographic and tomographic methods for in vivo evaluation of cerebral blood flow and metabolism. We propose new therapeutic strategies for the management of the acute phase of stroke, based on diagnostic protocols that include clinical evaluation, noninvasive study of neck and intracranial arteries, brain computed tomography, and single-photon emission computed tomography. The ideal therapeutic trial should combine early thrombolysis and active brain protection against those biochemical mechanisms leading to irreversible neuronal damage.

Animals↗
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↗