PubMed Health⌕ Search

Biomedical subjects

L Parnetti

Publications and source records attributed to L Parnetti.

At least 19 recordsLinked to original sources
PubMed2006

Early admission to stroke unit influences clinical outcome.

An improvement in patient arrival time to stroke unit (SU) is recommended, since earlier stroke management seems to improve 'per se' functional outcome. The objective of this study was to determine if early admission influences the outcome, reduces disability and mortality at discharge and three months later independent of tlirombolytic treatment. Consecutive acute stroke patients admitted to SU between January 1st 2000 and December 31st 2003 were studied in order to analyze the actual role of acute management independent specific pharmacological treatment, we excluded subjects who underwent rt-PA. 35.8% of 2,041 consecutive stroke patients arrived within 3 hours; 62.4% within 6 hours; 37.6% arrived later. Approximately 80% of the <6 hour patients presented a National Institutes of Health Stroke Scale (NIHSS) >4 and modified Rankin Scale (mRS) score >2 in comparison with 60% of the >6 hour patients. In hospital (8.7%) and three-month (7.3%) mortality in <3 hour patients were not significantly different from what observed in >3 hour patients (6.8% and 6.1% respectively) while functional outcome after three months was better in <3 hour patients (NIHSS: 34.6 vs 15.2; mRS: 32.9% vs 16.8%). Old age, history of TIA, cardioembolic etiology, severity of neurological deficit and hemorrhagic stroke type all led to earlier arrival time. Admission within 3 hours 'per se' improves outcome and reduced disability at three months.

Adult↗
PubMed2005

Early detection of dementia in clinical practice.

Early identification of dementia and possible risk factors is a critical issue. The Basic Italian Cognitive Questionnaire (BICQ) is designed as a routine instrument for screening patients with initial cognitive impairment in daily practice. It is devoted to the general physician who needs a tool for deciding whether a subject deserves further diagnostic investigation in specialised centres. The administration of BICQ is easy, fast and does not require any training, since it is composed of 12 simple and ecologic questions referring to daily life. The discriminant analysis, a predictive model that generates a function based on linear combinations of the predictor variables, provided the best discrimination between controls with respect to the group of deteriorated patients. According to the classification function coefficients, the questionnaire score predicted correctly 100% of normal subjects and 85% of patients with cognitive impairment. Moreover, the receiving operating characteristics (ROC) analysis showed that the highest sensitivity and specificity were obtained at the cut-off value of 10. Thus, a <or=10 score was indicative of a possible cognitive impairment requiring further diagnostic work-up. Among 963 randomly selected subjects from the general population over 50 years of age, 130 subjects (13.5%) had a score <or=10. A complete diagnostic assessment was carried out in 103 of them. Forty-one (40%) resulted cognitively normal; 34 (33%) fulfilled the diagnostic criteria for mild cognitive impairment (MCI); 28 (27%) were diagnosed as demented.

Aged↗
PubMed2005

Prestroke dementia in patients with atrial fibrillation. Frequency and associated factors.

BACKGROUND AND PURPOSE: Prestroke dementia is frequent but usually not identified. Non-valvular atrial fibrillation (NVAF) is independently associated with an increased risk for dementia. However, the frequency and determinants of prestroke dementia in patients with NVAF have never been evaluated. OBJECTIVE: The aim of this study was to determine the frequency of prestroke dementia and associated factors in patients with a previously known NVAF. METHODS: This is an ancillary study of Stroke in Atrial Fibrillation Ensemble II (SAFE II), an observational study conducted in patients with a previously known NVAF, consecutively admitted for an acute stroke in French and Italian centers. Prestroke dementia was evaluated by the IQCODE in patients with a reliable informant. Patients were considered as demented before stroke when their IQCODE score was > or = 104. RESULTS: of 204 patients, 39 (19.1%; 95% confidence interval [CI]: 13.7%-24.5%) patients met criteria for prestroke dementia. The only variable independently associated with prestroke dementia was increasing age (adjusted odds ratio for 1 year increase in age: 1.10; 95 % CI: 1.04-1.17), and there was a nonsignificant tendency for previous ischemic stroke or TIA and arterial hypertension. CONCLUSION: One fifth of stroke patients with a previously known NVAF were already demented before stroke. The main determinant of prestroke dementia is increasing age. A large cohort is necessary to identify other determinants.

Age Factors↗
PubMed2005

Atrial fibrillation in patients with first-ever stroke: frequency, antithrombotic treatment before the event and effect on clinical outcome.

BACKGROUND AND PURPOSES: Atrial fibrillation (AF) is an independent risk factor for stroke. The aims of this study were to assess: (i) the frequency of known or unknown AF in patients admitted to the hospital for a first-ever ischemic stroke and whether AF is associated with an adverse outcome at discharge (death or disability); (ii) the rates and determinants for the use of antithrombotic agents before stroke in patients with known AF and the adherence to the current treatment guidelines; and (iii) whether the lack of adherence to the current guidelines is associated with adverse outcome at discharge. METHODS: Consecutive patients with acute first-ever stroke admitted to an individual Stroke Unit between January 2000 to December 2003, were included in the study. Twelve-lead electrocardiogram (ECG) was performed in all patients on admission. Functional outcome was measured at discharge according to modified Rankin Score. RESULTS: A total of 1549 patients were included in the study: 238 patients (15.4%) were known to have AF and 76 (4.9%) were diagnosed with AF (unknown) on ECG performed on admission. At discharge 91 patients (5.9%) had died and 605 patients (39.0%) had died or were functionally dependent. Multivariate analysis showed that AF on admission was correlated with mortality or disability (OR = 1.58, 95% CI 1.09-2.30, P = 0.015). Before stroke, 124 out of 238 patients with known AF (52.1%) were not on antithrombotic therapy, 83 (34.9%) were receiving antiplatelet and 31 (13.0%) anticoagulant treatment. Previous transient ischemic attack, history of ischemic heart disease and hyperlipidemia were associated with the use of antithrombotic therapy. Only 24 out of 114 patients on antithrombotic treatment on admission were adequately treated according to the current guidelines. Of the adequately treated patients, 41.7% died or were disabled at discharge respect to 52.3% of the patients non-adequately treated (RR = 0.80, 95% CI 0.48-1.30). CONCLUSIONS: AF (on history or new diagnosis) was present in 20.3% of the patients with first-ever stroke admitted to a Stroke Unit and it was associated with increased mortality or disability. Only 10% of patients with known AF were previously receiving an adequate antithrombotic treatment according to current guidelines.

Aged↗
PubMed2004

Mild hyperhomocysteinemia is a risk-factor in all etiological subtypes of stroke.

The role of hyperhomocysteinemia as independent risk factor for stroke needs to be confirmed. The aims of our study were to assess (i) the association between risk of stroke and increasing values of plasma homocysteine and (ii) the interaction between mild hyperhomocysteinemia and conventional vascular risk factors. We studied 161 consecutive patients with first-ever ischemic stroke classified using TOAST criteria and 152 neurologically healthy controls. Homocysteine was measured using high performance liquid chromatography (HPLC). Homocysteinemia was elevated in all stroke subtypes: 13.0+/-2.5 micromol/l in patients with cardioembolic disease, 13.9+/-5.4 micromol/l in those with small vessel diseases, 15.5+/-6.8 micromol/l in cases of undetermined stroke, and 17.8+/-13.5 micromol/l in patients with large vessel disease. Mean homocysteinemia was 8.10 micromol/l (SD=2.5) in controls. The logistic regression analysis showed that important independent risk factors for ischemic stroke were hypertension (p<0.0001; OR= 3.205; 95% CI, 1.788-5.742), hyperhomocysteinemia (p<0.0001; OR=1.425; 95% CI, 1.300-1562) and hyperlipidemia (p=0.018; OR=2.243; 95% CI, 1.147-4.385). Hyperhomocyst(e)inemia is an independent risk factor for all stroke subtypes and should be routinely measured and treated in stroke patients.

Aged↗
PubMed2003

Glycosylation of acetylcholinesterase and butyrylcholinesterase changes as a function of the duration of Alzheimer's disease.

The identification of biochemical markers of Alzheimer's disease (AD) may help in the diagnosis of the disease. Previous studies have shown that Abeta(1-42) is decreased, and tau and phospho-tau are increased in AD cerebrospinal fluid (CSF). Our own studies have identified glycosylated isoforms of acetylcholinesterase (Glyc-AChE) and butyrylcholinesterase (Glyc-BuChE) that are increased in AD CSF. Glyc-AChE is increased in APP (SW) Tg2576 transgenic mice prior to amyloid plaque deposition, which suggests that Glyc-AChE may be an early marker of AD. The aim of this study was to determine whether Glyc-AChE or Glyc-BuChE is increased in CSF at early stages of AD and to compare the levels of these markers with those of Abeta(1-42), tau and phospho-tau. Lumbar CSF was obtained ante mortem from 106 non-AD patients, including 15 patients with mild cognitive impairment (MCI), and 102 patients with probable AD. Glyc-AChE, tau and phospho-tau were significantly increased in the CSF of AD patients compared to non-neurological disease (NND) controls. Abeta(1-42) was lower in the AD patients than in NND controls. A positive correlation was found between the levels of Glyc-AChE or Glyc-BuChE and disease duration. However, there was no clear correlation between the levels of tau, phospho-tau or Abeta(1-42) and disease duration. The results suggest that Glyc-AChE and Glyc-BuChE are unlikely to be early markers of AD, although they may have value as markers of disease progression.

Acetylcholinesterase↗
PubMed2003

Cerebrospinal fluid biochemical markers in early detection and in differential diagnosis of dementia disorders in routine clinical practice.

Measurement of total tau and amyloid beta1-42 (Ab42) in cerebrospinal fluid (CSF) improves diagnostic accuracy of Alzheimer's disease (AD). We examined a consecutive patient sample referred to our center for diagnostic assessment of cognitive decline. CSF tau and Abeta42 were assayed each week as routine neurochemical analyses. There were 119 patients investigated. These included 61 with probable AD (35 mild AD, 26 severe AD), 24 with mild cognitive impairment (MCI), 14 with vascular dementia, 11 with Lewy body dementia, and 9 with fronto-temporal dementia. Mild AD showed significantly lower CSF Abeta42 levels and significantly higher CSF tau levels than the other diagnostic groups; 79% of MCI patients had pathological values for both biomarkers. We confirm that these biomarkers have a role in the clinical work-up of patients with cognitive deficits.

Aged↗
PubMed2003

Neurovascular territory involved in different etiological subtypes of ischemic stroke in the Perugia Stroke Registry.

UNLABELLED: We studied the correlation between the potential causes of stroke (TOAST etiological groups) and the involvement of different vascular territories seen on computed tomography (CT) scans in patients with ischemic stroke. Information from consecutive patients with a first-ever stroke have been prospectively coded and entered into a computerized data bank (Perugia Stroke Registry). A population of 1,719 patients were evaluated: 1,284 patients (74.7%) had ischemic stroke. Large artery disease was the main cause of entire middle cerebral artery (MCA) territory infarcts (40.9%), superficial MCA territory infarcts (35.7%), and watershed infarcts (68.2%). The highest presence of emboligenic heart disease was found in the entire MCA territory infarcts (28.8%) or superficial (29.4%) supratentorial infarcts and in cerebellar infarcts (36.8%). Small artery disease was the most common presumed cause of deep MCA infarcts (75.0%) and posterior cerebral artery (PCA) territory infarcts (52.1%). IN CONCLUSION: stroke location could depend on its etiology. Lacunar infarcts are the most prevalent (36.7%), being mostly localized in the deep MCA territory; large artery disease includes more than two-thirds of watershed infarcts; the most prevalent territories involved in cardioembolic stroke are the entire MCA and posterior fossa.

Adult↗
PubMed2002

Cerebrospinal fluid levels of biomarkers and activity of acetylcholinesterase (AChE) and butyrylcholinesterase in AD patients before and after treatment with different AChE inhibitors.

In order to evaluate the biochemical effects of long-term treatment with inhibitors of acetylcholinesterase (AChE) in patients with Alzheimer's disease (AD), we measured the activities of AChE and butyrylcholinesterase (BuChe) and the concentrations of beta-amyloid (1-42), tau and phosphorylated tau proteins in the cerebrospinal fluid (CSF). A total of 91 patients suffering from probable AD of mild to moderate degree were treated for 6 months with donepezil (n=59), galantamine (n=15), rivastigmine (n=10), or placebo (n=7). AChE activity in CSF was significantly increased after treatment with donepezil and galantamine; the opposite was observed in the rivastigmine-treated group. Untreated patients did not show any AChE activity variation. BuChE did not show any change in any of the groups studied. Mean values of beta-amyloid(1-42), total tau and phosphorylated tau also did not vary significantly. We conclude that AChE inhibitors induce different effects on CSF AChE activity, while other CSF biomarkers are not significantly affected by treatment.

Acetylcholinesterase↗
PubMed2002

Stroke related to carotid artery dissection in a young patient with Takayasu arteritis, systemic lupus erythematosus and antiphospholipid antibody syndrome.

Autoimmune diseases are rarely the cause of stroke even in the young age group in association with cervical artery dissection and collagen vascular diseases. Takayasu arteritis is a chronic, idiopathic, inflammatory disease that primarily affects large vessels, such as the aorta and its main branches. Takayasu arteritis rarely coexists with systemic lupus erythematosus, and only few cases have been reported in association with the presence of antiphospholipid antibodies. We describe a young patient with right internal carotid artery dissection and subsequent stroke who presented with all three syndromes. Although this patient met the diagnostic criteria for each syndrome, systemic lupus erythematosus, Takayasu arteritis and the antiphospholipid antibody syndrome, it remains unlikely that the three disorders are not related. We suggest a single disimmune disorder may have led to carotid artery dissection.

Adult↗
PubMed2001

Peripheral blood lymphocytes muscarinic cholinergic receptor subtypes in Alzheimer's disease: a marker of cholinergic dysfunction?

Muscarinic M2-M5 muscarinic cholinergic receptors were investigated in peripheral blood lymphocytes of patients with mild cognitive impairment of the Alzheimer's type (MCIAT), probable Alzheimer's disease (AD) and probable vascular dementia (VaD). [3H]-N-methyl scopolamine (NMS) in the presence of muscarinic antagonists and Mamba venom to occlude different receptor subtypes was used as radioligand. Analysis of [3H]-NMS binding curves without receptor subtype assessment resulted in a slight decrease of receptor density in AD patients. Evaluation of receptor subtypes in MCIAT and AD patients revealed a decrease of M3 receptor by more than 50%, an increase of M4 receptor expression by about 20% and no changes of M2 or M5 receptors. The expression of M2-M5 receptors was unaltered in VaD patients. Strong positive and negative correlations respectively were found between the density of lymphocyte M3 and M4 receptors and MMSE score in both MCIAT (0.78 for M3 receptor and 0.80 for M4 receptor) and AD (0.82 for M3 receptor and 0.83 for M4 receptor) patients. These findings suggest that changes in the expression of peripheral blood lymphocyte M3 and M4 receptors in AD are related to the degree of cognitive impairment. Assessment of lymphocyte muscarinic receptor subtypes may contribute to characterization of cholinergic impairment in AD.

Aged↗
PubMed2001

CSF phosphorylated tau is a possible marker for discriminating Alzheimer's disease from dementia with Lewy bodies. Phospho-Tau International Study Group.

Tau and beta-amyloid (1-42) (Abeta42) are two independent markers for the early diagnosis of Alzheimer's disease (AD). In the present study, biochemical markers were validated as tools for differential diagnosis between AD and dementia with Lewy bodies (DLB). Tau, Abeta42 and phospho-tau (181P) were measured in cerebrospinal fluid (CSF) from controls (n=40) and from patients with AD (n=80) or DLB (n=43) using the HT7-AT270 assay (prototype version). In comparison with AD, in DLB no differences were found for Abeta42 and lower phospho-tau. ROC analysis was used to compare the discriminatory power of total tau with that of phospho-tau. The area under the curve (AUC) amounted to 0.782 +/- 0.048 (mean +/- SE) for tau and to 0.839 +/- 0.042 for phospho-tau (p = 0.039) for differentiation of AD from DLB. The present results indicate that CSF phospho-tau may be a good marker for differentiation between AD and DLB.

Alzheimer Disease↗
PubMed2001

Plasma total homocysteine levels and the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene: a study in an Italian population with dementia.

Hyperhomocysteinemia is a known risk factor for vascular disease and commonly occurs in the elderly. Several studies have shown an association between elevated plasma homocysteine levels and cognitive impairment, indicating that it may play a role in the pathophysiology of dementia. We studied plasma homocysteine, folate, vitamin B12 levels and the MTHFR C677T genotype in an Italian population of patients with dementia. We confirmed that elevated plasma tHcy (>14 micromol/l) is common in elderly subjects with dementia. Although we found a high prevalence of the MTHFR TT genotype (21.2%) the allele frequency is not over-represented relative to the control population. We also observed a high incidence of folate deficiency (38%) in subjects with dementia. Elevated homocysteine was associated with low plasma folate (<5.7 nmol/l) and the MTHFR TT genotype. Moderate to severe hyperhomocysteinemia (>26.1 nmol/l) was associated with a significantly lower MMSE score. Hyperhomocysteinemia may be neurotoxic by several different mechanisms affecting cognitive function. Further studies are needed to fully explore the potential of B vitamin supplementation to lower plasma homocysteine and improve cognitive function.

Aged↗
PubMed2001

Treatment of cognitive dysfunction associated with Alzheimer's disease with cholinergic precursors. Ineffective treatments or inappropriate approaches?

The observations of the loss of cholinergic function in neocortex and hippocampus in Alzheimer's disease (AD) developed the hypothesis that replacement of cholinergic function may be of therapeutic benefit to AD patients. The different approaches proposed or tested included intervention with acetylcholine (ACh) precursors, stimulation of ACh release, use of muscarinic or nicotinic receptor agonists and acetylcholinesterase (AChE) or cholinesterase (ChE) inhibition. Inhibition of endogenous ACh degradation through ChE inhibitors and precursor loading were treatments more largely investigated in clinical trials. Of the numerous compounds in development for the treatment of AD, AChE and ChE inhibitors are the most clinically advanced, although clinical trials conducted to date did not always confirm a significant benefit of these drugs on all symptom domains of AD. The first attempts in the treatment of AD with cholinergic precursors did not confirm a clinical utility of this class of compounds in well controlled clinical trials. However, cholinergic precursors most largely used such as choline and phosphatidylcholine (lecithin) were probably not suitable for enhancing brain levels of ACh. Other phospholipids involved in choline biosynthetic pathways such as CDP-choline, choline alphoscerate and phosphatidylserine clearly enhanced ACh availability or release and provided a modest improvement of cognitive dysfunction in AD, these effects being more pronounced with choline alphoscerate. Although some positive results cannot be generalized due to the small numbers of patients studied, they probably would justify reconsideration of the most promising molecules in larger carefully controlled trials.

Age of Onset↗