Frequency and clinical features of Lewy body dementia in Italian memory clinics.

BACKGROUND: The latest developments in Lewy Body Dementia (DLB) raise some controversies on clinical features, neuroimaging and therapy. The aim of our study is to determine clinical, neuropsychological, neuroimaging and EEG profile of DLB through retrospective and prospective data of 102 patients. METHODS: data were collected with an analytical form that was developed by an expertise of neurologists. RESULTS: DLB represented 4.8% of the dementia population, with no sex difference. Family history of dementia was common (24.5%), while familiarity for parkinsonism was rare (4.9%). Cognitive disturbances were the predominant clinical presentation at onset (49%), followed by behavioral symptoms (29.4%) and parkinsonism (21.6%). Clinical features at consultation were: memory disturbances (almost all cases), symmetrical (68.6%) or asymmetrical (18.6%) parkinsonism, cognitive fluctuations (49%), visuospatial deficits (53.9%), and visual hallucinations (44.1%). Autonomic signs were present in a third of the cases, while sleep disorders were present in 44.1%. Some clinical response to antiparkinsonian drugs was evident in half of the cases. MRI, SPET, EEG and Neuropsychiatric Inventory data were available in a subgroup of patients. CONCLUSIONS: Most of our data were in accordance with the previous literature. However, some data underline the relationship between DLB, Alzheimer's and Parkinson's disease.

Molecular phylogeography of the asp viper Vipera aspis (Linnaeus, 1758) in Italy: evidence for introgressive hybridization and mitochondrial DNA capture.

Owing to its temperature dependence and low vagility, the asp viper (Vipera aspis) is an interesting model species to study the effects of Pleistocene climatic fluctuations on vertebrate genomes. We genotyped 102 specimens from the whole Italian distribution range at three mitochondrial DNA regions (2278 characters, total) and six microsatellite DNA loci (Short Tandem Repeats, STR). The molecular phylogeny was constructed according to Bayesian, Neighbour Joining, Maximum Parsimony and Maximum Likelihood procedures. All methods grouped individuals of the three morphological subspecies (V. a. aspis, V. a. francisciredi, V. a. hugyi) into five different haploclades. Specimens assigned to hugyi clustered in two highly differentiated clades, one being sister group to the complex comprising the second clade of hugyi (i.e., a paraphyletic status), plus two clades of francisciredi. The Bayesian clustering of the STR variability disclosed only two groups, the first including aspis and francisciredi, the second all hugyi. Introgressive hybridization and capture of francisciredi-like lineages in the hugyi mitochondrial genome were suggested to explain the discordance between mitochondrial and nuclear data. The phylogeographic pattern was compatible with population contractions in three glacial refuges. Plausibility of derived hypothesis was checked using coalescence simulations as post hoc tests. Long-term drift and serial founder effects, rather than selection, appeared the main factors affecting the genetic make-up of the Italian asp viper.

White matter damage in Alzheimer's disease assessed in vivo using diffusion tensor magnetic resonance imaging.

OBJECTIVE: To investigate the extent and the nature of white matter tissue damage of patients with Alzheimer's disease using diffusion tensor magnetic resonance imaging (DT-MRI). BACKGROUND: Although Alzheimer's disease pathology mainly affects cortical grey matter, previous pathological and MRI studies showed that also the brain white matter of patients is damaged. However, the nature of Alzheimer's disease associated white matter damage is still unclear. METHODS: Conventional and DT-MRI scans were obtained from 16 patients with Alzheimer's disease and 10 sex and age matched healthy volunteers. The mean diffusivity (D), fractional anisotropy (FA), and inter-voxel coherence (C) of several white matter regions were measured. RESULTS: D was higher and FA lower in the corpus callosum, as well as in the white matter of the frontal, temporal, and parietal lobes from patients with Alzheimer's disease than in the corresponding regions from healthy controls. D and FA of the white matter of the occipital lobe and internal capsule were not different between patients and controls. C values were also not different between patients and controls for any of the regions studied. Strong correlations were found between the mini mental state examination score and the average overall white matter D (r=0.92, p<0.001) and FA (r=0.78; p<0.001). CONCLUSIONS: White matter changes in patients with Alzheimer's disease are likely to be secondary to wallerian degeneration of fibre tracts due to neuronal loss in cortical associative areas.

Primary progressive aphasia: a patient with stress assignment impairment in reading aloud.

Surface dyslexia is a pattern of reading impairment which has been seldom described in Italian native speakers. We report the case of a female Italian patient, RM, suffering from primary progressive aphasia (PPA) of the fluent type, who presented stress assignment errors in reading aloud. In Italian these errors are considered to be strongly suggestive of surface dyslexia. We studied RM's reading performance in light of existing cognitive models on reading. Since the first assessment, she presented multi-level impairment involving pre-semantic, lexical-semantic and post-semantic stages. Her stress assignment errors have been interpreted as a generalisation of the most frequent tendency in Italian language: namely to assign stress to the penultimate syllable. In agreement with previous studies, our case suggests that surface dyslexia in PPA is not a monolithic entity but, on the contrary, that it may arise from impairment at various stages of the reading process.

Degenerative dementia of the frontal type. Clinical evidence from 9 cases.

The retrospective neurological, neuroradiological and neuropsychological observation of 9 cases of dementia with frontal symptoms is reported. Aim of this paper is to contribute to the clinical corpus of data related to the frontal features of the frontotemporal dementia (FTD) syndrome, so as to support clinicians' awareness and widen the information available for the diagnostic approach to the dementias. FTD is a clinical diagnosis which does not imply a single underlying pathology, since more than one condition can induce the syndrome. Inertia and behavioural symptoms were the traits characterizing both the onset and the progression of the disease in our patients. Progression brought to the surface behavioural and neuropsychological patterns generically traced back to frontal dysfunction. Social inadequacy was the most salient trait. From a clinical point of view frontal dementias may be regarded as a conceptually different type of dementia with respect to Alzheimer's disease, i.e., a 'behavioural' as opposed to a 'cognitive' progressive disorder.

Cognitive modelling of face processing: evidence from Alzheimer patients.

This is a prospective neuropsychological study on face processing in Alzheimer's disease (AD). The aim was to assess the prevalence and the nature of face processing disorders in AD, and at investigating possible inter-test dissociations within the framework of currently used face processing models. A standardized four-test battery of unknown face discrimination and familiar face recognition was given to 30 mildly deteriorated patients with AD. Half of the patients performed below the cut-off in at least one of the tests. Deficits in familiar face recognition tests were more frequently observed than deficits in unknown face discrimination tests. There was no correlation between impairment of face processing and overall cognitive impairment or visual disorders. A multiple single case approach allowed us to elicit statistically warranted double dissociations between tasks assessing unknown face discrimination and tasks assessing familiar face recognition. Moreover, the ability to decide whether or not a stimulus is a face or a non-face has proven to be a non-mandatory step to further process the face stimuli. All together, these findings support the hypothesis that distinct pathways are involved in the processing of unknown and familiar faces, as posited by Bruce and Young [Br. J. Psychol. 77, 305-327, 1986].

A neuropsychological instrument adding to the description of patients with suspected cortical dementia: the Milan overall dementia assessment.

A new, short, neuropsychologically oriented test for dementia assessment--the Milan Overall Dementia Assessment (MODA)--is described. Age and education adjusted norms based on 217 healthy controls are given. A validation study on 312 outpatients suspected of dementia (121 with probable Alzheimer's disease) showed that the MODA differentiated patients with cognitive impairment from normal subjects more effectively than did the DSM III-R. The correlation between the MODA and the mini mental state examination was 0.63 in controls and 0.84 in patients with Alzheimer's dementia. The MODA test-retest reliability was 0.83. The test proved to be well suited to longitudinal studies.