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Biomedical subjects

Giovanni B Frisoni

Publications and source records attributed to Giovanni B Frisoni.

At least 19 recordsLinked to original sources
PubMed2003

Computer-assisted imaging to assess brain structure in healthy and diseased brains.

Neuroanatomical structures may be profoundly or subtly affected by the interplay of genetic and environmental factors, age, and disease. Such effects are particularly true in healthy ageing individuals and in those who have neurodegenerative diseases. The ability to use imaging to identify structural brain changes associated with different neurodegenerative disease states would be useful for diagnosis and treatment. However, early in the progression of such diseases, neuroanatomical changes may be too mild, diffuse, or topologically complex to be detected by simple visual inspection or manually traced measurements of regions of interest. Computerised methods are being developed that can capture the extraordinary morphological variability of the human brain. These methods use mathematical models sensitive to subtle changes in the size, position, shape, and tissue characteristics of brain structures affected by neurodegenerative diseases. Neuroanatomical features can be compared within and between groups of individuals, taking into account age, sex, genetic background, and disease state, to assess the structural basis of normality and disease. In this review, we describe the strengths and limitations of algorithms of existing computer-assisted tools at the most advanced stage of development, together with available and foreseeable evidence of their usefulness at the clinical and research level.

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PubMed2003

Mild cognitive deterioration with subcortical features: prevalence, clinical characteristics, and association with cardiovascular risk factors in community-dwelling older persons (The InCHIANTI Study).

OBJECTIVES: To identify subjects with minimal or mild nonamnestic cognitive impairment with parkinsonian stance and gait and investigate vascular correlates of this condition. DESIGN: First wave of an epidemiological longitudinal study (InCHIANTI) on factors predicting loss of mobility in older persons. SETTING: The Chianti geographic area (Tuscany, Italy). PARTICIPANTS: Five hundred fifty-six subjects aged 70 to 90 with Mini-Mental State Examination (MMSE) scores greater than 23 of 30, of the 1,260 persons aged 65 and older randomly selected from the population registry of Greve in Chianti and Bagno a Ripoli, two small towns near Florence. METHODS: Low cognitive performance (LCP) was defined as an age- and education-adjusted MMSE below the 50th percentile for the InCHIANTI population. Subcortical features were plastic rigidity on neurological examination (parkinsonism), gait disturbance (small-step gait or parkinsonian gait), and dysexecutive features. Two hundred forty-three participants had high cognitive performance, 166 had LCP without subcortical features, and 75 had LCP with subcortical features. Vascular risk factors were hypertension, atrial fibrillation or pathological findings on electrocardiogram (ECG), low serum high-density lipoprotein (HDL) or high low-density lipoprotein cholesterol, diabetes mellitus, obesity, and heavy smoking. RESULTS: Three main vascular risk factors were significantly more prevalent in LCP with subcortical features: hypertension (P =.02), atrial fibrillation or ECG changes (P =.04), and low HDL cholesterol (P =.001). LCP with subcortical features was significantly associated with cerebrovascular risk factors (P =.001). CONCLUSION: Gait disturbance and nonamnestic cognitive symptoms might be the consequence of subcortical vascular damage.

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PubMed2003

Validation study of a CT-based weighted rating scale for subcortical ischemic vascular disease in patients with mild cognitive deterioration.

OBJECTIVES: Subcortical ischemic vascular disease (SIVD) is frequently associated with cognitive impairment. Rating scales to grade cerebrovascular disease are available, but their sensitivity to the clinical features of mild SIVD is unclear. The aim of the study is to devise and validate a computed tomography (CT)-based visual rating scale sensitive to SIVD in patients with mild cognitive deterioration. METHODS: Subjects were 122 consecutive outpatients of a memory clinic (mean age +/- SD 77 +/- 8 years, 71% females, mean +/- SD score of mental state exam 22 +/- 3, 61% with clinical dementia rating of 0.5 and 39% of 1). Diffuse leukoaraiosis, fuzzy and patchy lesions, and lacunes were assessed on ordinary CT films and weights were computed based on clinical indicators of SIVD. A continuous score and an ordinal class (0-3) with higher values indicating higher vascular damage were derived. RESULTS: Intraclass correlation coefficients for intra- and interrater reliability of the subcortical vascular score and class ranged from 0.84 to 0.88. Convergent validity versus the scale of Wahlund et al. was good (Spearman's correlation coefficient between 0.53 and 0.73, p < 0.0005). Known-group validity was assessed versus clinical diagnoses of degenerative (mild cognitive impairment determined by Petersen et al. and NINCDS-ADRDA probable Alzheimer's disease; n = 58), mixed (possible Alzheimer's disease with cerebrovascular disease; n = 21), and vascular cognitive impairment (criteria of Erkinjuntti et al. for subcortical vascular dementia and cognitive impairment; n = 43). Patients with degenerative cognitive impairment were more often in the lower subcortical vascular classes (43% in class 0, 43% in class 1, 14% in class 2, and 0% in class 3), while patients with mixed (0, 24, 24, and 52%) and vascular cognitive impairment were in increasingly higher subcortical vascular classes (0, 12, 35, 53%; p < 0.00005). Criterion-related validity was assessed versus clinical indicators of cerebrovascular disease. Hypertension, platelet aggregation inhibitor use, balance, gait, and bradykinesia increased linearly with increasing subcortical vascular class (p for trend <0.02). CONCLUSIONS: This rating scale is valid and sensitive to capture different degrees of SIVD associated with mild cognitive deterioration.

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PubMed2002

Development of a CT-based weighted rating scale for subcortical cerebrovascular disease sensitive to mild clinical symptoms.

OBJECTIVE: To devise and validate a CT-based visual rating scale sensitive to subcortical cerebrovascular disease (sCVD) in patients with cognitive impairment. METHODS: Three types of vascular lesions were rated separately in 16 brain regions. A unique vascular score was computed weighing the regression coefficients of the three scores in linear models. Thereafter, subcortical vascular classes (SVC) of increasing severity (0-3) were created. Known-group and convergent validity of the SVC was tested in 122 cognitively impaired patients with MMSE of 18 and higher. These patients were grouped according to clinical diagnosis in degenerative, mixed, and vascular. RESULTS: Intraclass correlation coefficients were between 0.86 and 0.94. The subcortical vascular score was 8.0+/-9.4 in the degenerative, 33.0+/-17.2 in the mixed, and 36.8+/-14.8 in the vascular patients (p=0.0001). In particular, none of the degenerative patients had SVC=3, and only 14% had SVC=2. On the contrary, none of the mixed and vascular patients had SVC=0, while about 50% had SVC=3 in both groups. The prevalence of hypertension was increasing with increasing SVC (p for trend=0.02). The performance on tasks evaluating balance, gait, and bradykinesia decreased with increasing SVC severity (p for trend=0.006, 0.01, 0.001, respectively). CONCLUSION: The scale is a valid tool to estimate the vascular component in patients with cognitive impairment.

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PubMed2002

Clinical characteristics of frontotemporal patients with symmetric brain atrophy.

In this paper we explored patterns of frontal and temporal asymmetry in frontotemporal dementia (FTD) and tried to isolate clinical correlates associated with asymmetry or lack thereof. Volumes of frontal and temporal lobes, hippocampus and entorhinal cortex were measured using magnetic resonance imaging (MRI) in 10 patients with FTD. Age- and cranial size-specific values were computed through linear regression analysis (W-scores). A subgroup of 3 patients with symmetric frontal and temporal atrophy was identified. When compared to patients with asymmetric atrophy, the former had younger age at onset of the disease (p = 0.02), greater overall frontotemporal (p = 0.02) and greater entorhinal atrophy (p < 0.04). Two of the three patients were apolipoprotein E epsilon4 carriers versus none of the asymmetric patients (p = 0.02). The lack of asymmetry in this small sample of FTD patients was associated with greater brain atrophy, younger age at onset, and presence of the epsilon4 allele of apolipoprotein E. The presence of the epsilon4 allele is consistent with the hypothesis of greater vulnerability of the brain in epsilon4 carriers.

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PubMed2002

Mild cognitive impairment with subcortical vascular features: clinical characteristics and outcome.

OBJECTIVES: To identify non-demented individuals with cognitive impairment due to a cerebrovascular etiology among those coming to observation of a memory clinic and to describe their clinical features and outcome. METHODS: Patients were enrolled in a prospective study on early cognitive impairment carried out in a Memory Clinic. Mild cognitive impairment of the vascular type (MCI-V) was defined based on modified criteria for subcortical vascular dementia (SVD) by Erkinjuntti and colleagues. Twenty-nine patients with MCI-V (age 78 +/- 7, Mini Mental State Exam (MMSE) 24 +/- 3) were compared with 14 with mild cognitive impairment of degenerative etiology (MCI) based on the Mayo Clinic criteria (age 72 +/- 9, MMSE 25 +/- 2), and to 21 patients with frank SVD (age 80 +/- 6, MMSE 21 +/- 3). Patients were followed over time for 32 +/- 8 months. RESULTS: MCI-V patients had a neuropsychological profile characterized by poor performance on frontal tests (Wisconsin card sorting and word fluency) and neurological features of parkinsonism without tremor (impairment of balance and gait). Of those followed for at least 40 months, 50 % of patients with MCI-V and SVD had died, while all MCI patients were still alive ( P = 0.03). Of those alive, 68 % of the MCI-V, 52 % of the SVD, and 17 % of the MCI patients had reached one of the following outcomes at 40 months: nursing home placement, functional loss, and cognitive deterioration ( P = 0.02). CONCLUSIONS: Patients with MCI-V have a distinctive clinical picture and can be identified in a clinical setting. Because of the high frequency of adverse outcomes, very early preventive measures need to be devised.

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PubMed2002

Regional brain atrophy in patients with mild Alzheimer's disease and delusions.

BACKGROUND AND OBJECTIVE: The pathophysiology and the neurobiology of the behavioral disturbances in Alzheimer's disease (AD) are far from understood. The aim of the study was to assess whether delusional AD patients have a specific pattern of regional brain atrophy. METHODS: The setting of the study was the outpatient facility of a memory clinic. Subjects were 41 AD patients with mild dementia severity (Mini-Mental State Exam score of 22 +/- 3, range 18 to 27). Delusions were assessed with the pertinent subscale of the UCLA Neuropsychiatric Inventory (NPI). Nondelusional (n = 22) AD and delusional (n = 19) AD were defined on the basis of absence (NPI delusions subscale = 0) or presence (NPI delusions subscale = 1 or higher) of delusions. Thirteen (68%) of the delusional patients had isolated theft delusions, and 6 (32%) had theft associated with another paranoid delusion (of jealousy or persecution). None of the patients had misidentifications or other delusions of nonparanoid content. Temporal lobe and frontal lobe atrophy were assessed with linear measures (radial width of the temporal horn, rWTH, and frontal index, FI) taken from computed tomographic films. Temporal and frontal asymmetries were computed as right/left ratio of the rWTH and FI. RESULTS: AD patients without delusions had symmetrical enlargement of both temporal (8.1 +/- 3.9 vs. 8.5 +/- 4.5) and frontal horns (35.8 +/- 4.8 vs. 35.9 +/- 4.6). On the contrary, AD with delusions showed temporal horns larger to the right (9.1 +/- 3.3 vs. 7.7 +/- 3.1, p = .06) and the frontal horn to the left (35.7 +/- 4.3 vs. 37.5 +/- 4.2, p = .02). This different pattern was confirmed with a gender-adjusted repeated measures analysis of variance model interaction term between asymmetry and group: F1,38 = 5.5, p = .03). DISCUSSION: AD patients with delusions are characterized by a specific pattern of frontal and temporal asymmetry of brain atrophy, whereas nondelusional patients are symmetric. Because the asymmetry pattern of the delusional patients is similar to the physiological pattern of asymmetry of individuals without dementia, the data indicate that the absence of theft delusions in the mild stage of AD rather than their presence is associated with an abnormal asymmetry pattern.

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PubMed2002

Predictors of cognitive improvement after reality orientation in Alzheimer's disease.

BACKGROUND: there is increasing evidence to support the efficacy of reality orientation in cognitive deficits in patients with Alzheimer's disease. The clinical characteristics of patients who respond to reality orientation are poorly understood; this knowledge could be important, given that the provision of reality orientation therapy is labour-intensive and may provoke emotional distress. AIM: to evaluate retrospectively which demographic and clinical characteristics of Alzheimer's patients predict cognitive outcomes. METHOD: we analysed 38 mild-to-moderately demented outpatients who regularly attended a one-month formal reality orientation programme. The mini mental state examination score changes from baseline-and immediately after-reality orientation were correlated with demographic and pre-treatment clinical characteristics by a linear regression analysis. RESULTS: short-term responsiveness to reality orientation was significantly predicted by a lower level of cognitive functioning (as measured by the mini mental state examination) at baseline and by the absence of euphoria, accounting together for 57.6% of variance. CONCLUSION: a lower mini mental state examination and the absence of euphoric behaviour in patients with mild-to-moderate Alzheimer's disease may predict a good cognitive outcome of reality orientation therapy.

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PubMed2002

Geriatric Index of Comorbidity: validation and comparison with other measures of comorbidity.

BACKGROUND: the debate about measures of chronic comorbidity in the elderly is mainly due to the lack of consensus on pathogenetic models. OBJECTIVE: the aim of the present study was to compare the concurrent validity of a number of measures of chronic comorbidity assuming different pathogenic models, versus disability in elderly patients. SETTING: the Geriatric Evaluation and Rehabilitation Unit for subacute and disabled patients. PARTICIPANTS: 493 new and consecutive elderly patients (mean age 79 years, 71% females) admitted to the Geriatric Evaluation and Rehabilitation Unit. MEASUREMENTS: we evaluated age, gender, cognitive status, depressive symptoms, functional status, somatic health, and nutritional status on admission. Functional status was assessed by the self- or proxy reported Katz's BADL scale and by the performance-based Reuben's Physical Performance Test. Somatic health was assessed as presence and severity of diseases according to standardized criteria. Comorbidity was measured as number of diseases, sum of disease severity, and with a composite score (Geriatric Index of Comorbidity) which takes into account both number of diseases and occurrence of very severe diseases. Mortality was assessed after 12 months. RESULTS: specific diseases and their severity were found to be associated with disability measures. All measures of comorbidity were significantly correlated with disability, but only the Geriatric Index of Comorbidity was independently associated after adjustment for severity of individual diseases. In addition, increasing severity of comorbidity as defined by Geriatric Index of Comorbidity was associated with greater disability while this was not true for the other comorbidity measures (F statistics for the regression model including the Geriatric Index of Comorbidity=19.9). The Geriatric Index of Comorbidity, but not the other comorbidity measures, predicted mortality (relative risk of death 2.3, 95% confidence interval 1.7-3.1). CONCLUSION: the Geriatric Index of Comorbidity, a measure of comorbidity assuming that both number of diseases and occurrence of very severe diseases are determinants of health, has the greatest concurrent validity with disability and is the best predictor of mortality.

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PubMed2002

The radial width of the temporal horn in mild cognitive impairment.

BACKGROUND AND PURPOSE: The diagnosis of preclinical Alzheimer's disease (AD) (or mild cognitive impairment [MCI]) is loaded with a high degree of uncertainty. The aim was to test the accuracy of a computed tomography-based (CT-based) marker of medial temporal lobe atrophy, the radial width of the temporal horn (rWTH), in MCI. METHODS: Ten MCI and 42 AD patients and 29 nondemented controls underwent brain CT on the temporal lobe plane (slice thickness = 2 mm). The rWTH was taken on CT films with a precision caliper placed at the tip of the temporal horn radial to the curvature of the hippocampal head region. RESULTS: When specificity was fixed at 95%, the sensitivity for the detection of AD was 39/42 (93%) and that for the detection of MCI was 8/10 (80%). CONCLUSION: The rWTH is a measure sensitive to the regional brain atrophy common in early AD.

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PubMed2002

Hashimoto's encephalopathy in the elderly: relationship to cognitive impairment.

Hashimoto's encephalopathy (HE) is a steroid-responsive encephalopathy associated with high titers of antithyroid antibodies. To date, 57 pediatric-, adult-, and elderly-onset cases have been described in the literature. The clinical picture is pleomorphic, and cognitive impairment is a frequently reported symptom. We report the case of a patient with slowly progressive cognitive impairment possibly caused by HE. The issue of the differential diagnosis with primary dementia is discussed. A review of cases of HE showing cognitive deterioration is also presented, and factors possibly related to characteristics of cognitive impairment and outcome after therapy are considered.

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