Recollection of public events in healthy people: a latent-variable stochastic approach to disentangling retrieval and storage.

Recollection of media-mediated past events was examined in 96 healthy participants to investigate the interaction between the age of the subject and the "age" of memories. The results provided evidence that people older than 75 years recall recent events significantly worse than remote ones. Younger participants (47-60 years old) showed the reverse pattern.

Amyotrophic lateral sclerosis: prognostic indicators of survival.

Amyotrophic lateral sclerosis (ALS) has a fatal outcome in about three years, but survival is known to vary considerably, making it difficult to predict disease duration in individual cases. The aim of this study was to investigate possible early prognostic factors of ALS survival. We included 123 probable or definite cases of ALS, with disease onset between 1989 and 1998, and with a follow-up of at least one year.

Hemisphere asymmetry for imitation of hand and finger movements, Goldenberg's hypothesis reworked.

Goldenberg and co-workers put forward the hypothesis that coding of hand gestures with respect to body parts depends upon the functioning of the left hemisphere while the right hemisphere would be involved in imitation of finger postures. They supported this claim with experimental evidence from lesion studies, however, they failed to back it up with functional neuroimaging data. To verify Goldenberg's hypothesis on hemisphere asymmetries for hand/finger postures imitation, the performance of 35 patients with left hemisphere lesion (L/pts), of 24 patients with right hemisphere lesion (R/pts) and that of 41 matched controls was assessed in two imitation tasks, respectively, taxing hand or finger postures.

Time ordering in frontal lobe patients: a stochastic model approach.

Frontal lobe patients reproduced a sequence of capital letters or abstract shapes. Immediate and delayed reproduction trials allowed the analysis of short- and long-term memory for time order by means of suitable Markov chain stochastic models. Patients were as proficient as healthy subjects on the immediate reproduction trial, thus showing spared encoding and short-term memory.

Spontaneous recovery from acalculia.

A topic much considered in research on acalculia was its relationship with aphasia. Far less attention has been given to the natural course of acalculia. In this retrospective study, we examined the relationship between aphasia and acalculia in an unselected series of 98 left-brain-damaged patients and the spontaneous recovery from acalculia in 92 acalculic patients with follow-up.

Is serum neopterin level a marker of responsiveness to interferon beta-1a therapy in multiple sclerosis?

Background: Interferon beta (INFbeta) may induce the expression of several proteins, including neopterin, considered a biological marker of INFbeta activity.

Objectives: The aim of this study was to determine the serum neopterin concentration at the beginning of, and during, IFNbeta-1a therapy in relapsing-remitting multiple sclerosis (r-r MS) patients, and to look for a possible correlation between protein synthesis and the clinical course of the disease.

Methods: Thirteen r-r MS patients were treated with INFbeta-1a (i.

The epidemiology of ALS in Modena, Italy.

Objective: To determine the incidence, prevalence, and mortality rates of ALS in the province of Modena, Northern Italy, from 1990 through 1999.

Methods: A retrospective epidemiologic study was conducted, ascertaining cases from all neurologic centers and hospitals of the province, death certificates, and the Italian ALS Association, section of Modena. All clinical records were reviewed, and only patients fulfilling the El Escorial revised diagnostic criteria were included.

Verbal learning strategies in Parkinson's disease.

Word-list learning was studied in patients with Parkinson's disease (PD) and normal control (NC) participants by means of the selective-reminding procedure of H. Buschke and P. A.

Verbal learning strategies in patients with multiple sclerosis.

Word list learning was studied in patients with a definite diagnosis of Multiple Sclerosis and in Normal Control subjects by means of the selective reminding procedure of Buschke and Fuld in two learning conditions: (1) using unrelated items and (2) paired-associate items. The Multiple Sclerosis patients displayed poor learning in both conditions. To identify the functional locus of their deficit, stochastic Markov chain analyses were performed, which allowed individual measurements of encoding, automatic and intentional retrieval abilities.

Learning and forgetting processes in Parkinson's disease: a model-based approach to disentangling storage, retention and retrieval contributions.

Learning and forgetting a prose passage was studied in 20 patients with Parkinson's disease and in 20 normal control subjects by means of stochastic models, with the aim of identifying the learning and retaining abilities that are affected by Parkinson's disease. Results suggested that Parkinson's disease patients are impaired in developing automatic processing both during learning and retaining, while functions that require active attention are spared. The automatic/intentional dissociation, which is the hallmark of motor disturbance in Parkinson's disease, extends to memory abilities, and, on the grounds of neuroanatomical, neurochemical and neurophysiological correlates, suggests that the memory deficit in Parkinson's disease may be contingent on a dysfunction of the medial prefrontal-cingulate cortex.

Parkinson's disease affects automatic and spares intentional verbal learning. A stochastic approach to explicit learning processes.

We studied word list and paired associates learning in patients with idiopathic Parkinson's disease and normal controls by means of a two-stage stochastic model, which allows independent measurements of encoding, storage and retrieval abilities. We preliminarily ascertained that the model components were both sufficient and necessary to account for the overall performance of the subjects, and then compared the learning abilities between the two groups. Parkinson's disease patients were selectively impaired in identifying well-known engrams, for which learning is superfluous, and in automatic retrieval, namely in abilities that do not need attentional effort.

How to differentiate retrieval from storage deficit: a stochastic approach to semantic memory modeling.

Some of the methods currently used to differentiate retrieval from storage deficits in brain damaged patients are revisited. Indices based on association or agreement measures among the responses given by the subject on repeated trials, as well as direct estimates of storage and retrieval abilities based on crude percentages, are open to criticism. A simple Markov chain stochastic approach, which is free of the drawbacks of the other methods and which distinguishes storage from retrieval deficits more reliably and powerfully, is proposed.

Newest human herpesvirus (HHV-6) in the Guillain-Barré syndrome and other neurological diseases.

To investigate the presence of human herpesvirus-6 (HHV-6) in patients affected by Guillain-Barré syndrome (GBS) and by other neurological diseases (OND), we examined by indirect immunofluorescence analysis (IFA) the sera and cerebrospinal fluid (CSF) from 28 GBS and 63 OND. Moreover, we tested 150 blood donors (BD) to appreciate the diffusion of HHV-6 infection in the Italian adult healthy population. We found a significantly higher titre of antibody to HHV-6 in the GBS patients compared with OND and BD, although the pathogenicity of the virus is not known.

A model-based study of learning and memory following transient global amnesia attacks.

Verbal learning and forgetting were studied in patients one month after an episode of Transient Global Amnesia and in normal control subjects by means of a two-stage stochastic model, which allows independent measurements of encoding, storage and forgetting. We preliminarily ascertained both the necessity and the sufficiency of the model to account for several performance scores of the two experimental groups, and then compared the learning and forgetting functions between groups. In spite of the analytical power of the statistical method adopted.

Natural killer cells and lymphocyte subsets in active MS and acute inflammation of the CNS.

Cerebrospinal fluid (CSF) and peripheral blood (PB) lymphocyte subsets were determined by flow cytometry (FCM) in 15 patients with active multiple sclerosis (MS) and 15 patients with acute inflammatory diseases (ID) of the central nervous system (CNS) in order to establish correlations between the two groups of diseases, as well as between the CSF and PB subsets distribution. A panel of monoclonal antibodies was applied to all the samples: Leu3 (CD4), Leu4 (CD3), Leu2 (CD8), Anti-HLA-DR, Leu11 (CD16). Statistical analysis did not show differences in CD3+ nor in CD3+ DR+ T-cells both in the CSF and PB in the two groups of patients.

Apperceptive and associative forms of prosopagnosia.

Three prosopagnosic patients were given four face tests, two perceptual (an unknown face identification test and an age estimation test) and two also implying memory (a familiarity check test and a famous face recognition test). The patients' performance was assessed with reference to the score distribution of the normal population. A patient was found to fail both perceptual and mnestic tests, without any noticeable difference between them.

Space exploration with and without the aid of vision in hemisphere-damaged patients.

Space exploration carried out under visual control and in its absence (blindfolded condition) was investigated in 20 RBD patients, 10 LBD patients and 20 normal controls with a modified version of Chedru's test (pressing the keys of a keyboard). Conventional tests for visual hemi-inattention permitted to classify RBD patients in a group with visual neglect (RBD VN+) and a group without visual neglect (RBD VN-). On the visual version of the test both RBD groups showed a preference for pressing the keys ipsilateral to the lesion side, but this tendency was more marked in the RBD VN+ group than in any other brain-damaged group.

Diagnostic investigations in MS: which is the most sensitive?

In an attempt to establish the efficacy of the different diagnostic tests, 41 multiple sclerosis (MS) patients at different stages of the disease were studied by means of visual evoked potential (VEP) recording, T-lymphocyte subset determination cerebrospinal fluid (CSF) analysis and magnetic resonance (MR) imaging. MR and CSF oligoclonal bands (OB) were the most sensitive techniques for the diagnosis of MS, being positive in 88% of patients, while VEP and helper/suppressor (H/S) T-cell ratio were altered in 54% and 46% of patients respectively. Low significant agreement coefficient were found among the 4 tests and the major value, even though "fairly" significant, was between MR and OB.

Skull asymmetries bear no relation to the occurrence of apraxia. A clinical and CT-scan study in patients with unilateral brain damage.

This study aimed at assessing whether there was a relation between presence or absence of apraxia following a parietal and/or frontal left hemisphere lesion and "typical" skull asymmetries, evidenced by CT scan (prevalence of the left over the right occipital length and width and of the right over the left frontal length and width). Skull asymmetries were measured in a sample of 160 brain-damaged patients and their prevalence was found to agree with those reported by the literature in normal subjects. A subgroup of 72 patients with lesions restricted to the parietal and/or frontal lobe were given a movement imitation test and diagnosed as apraxic, borderline or normal making reference to the performance of 150 control subjects.

Attentional shift towards the rightmost stimuli in patients with left visual neglect.

In a search task where four letters were displayed to the right of a central fixation point, right brain-damaged patients with visual neglect showed the fastest response when the target was at the rightmost position and progressively slower responses as it moved towards the center of the display. This finding confirms Kinsbourne's claim that in visual neglect an important role is played by the magnetic attraction that the extreme end of the right structured space exerts on the patient's attention.

DNA repair, sensitivity to gamma radiation and to heat shock in lymphocytes from acute, untreated multiple sclerosis patients.

Increases in spontaneous sister chromatid exchange (SCE) and gamma radiation-induced chromosome aberrations have been reported in peripheral blood lymphocytes (PBL) from multiple sclerosis (MS) patients, suggesting the presence of an abnormality in repair in this disease. We tested this hypothesis by measuring the ability to repair DNA and survival, after exposure to low (2-12 Gy) and high (100 Gy) gamma ray doses or to a high temperature (37-45 degrees C), of freshly isolated PBL from 15 patients affected by definite MS and 15 healthy subjects. The MS patients were untreated and in the acute phase of the disease.

[Risk factors and short-term prognosis in ischemic and hemorrhagic attacks: review of 503 patients admitted to the Neurologic Clinic of Modena].

Cerebrovascular risk factors, characteristics of the lesion (ischaemia or haemorrhage in the carotid or vertebro-basilar area) and mortality in the acute phase were studied in 503 patients admitted for first stroke. Seventy-five per cent of the patients had an ischaemic lesion and 25% a hemorrhagic one. Most of the ischaemic lesions occurred in patients aged 71-80 years, while haemorrhagic strokes hit subjects aged 61-70 years.

Right posterior brain-damaged patients are poor at assessing the age of a face.

The ability to order unknown faces by age was investigated in right and left brain-damaged patients, divided into posterior and non-posterior groups on the basis of CT scan findings. A face recognition test and a figure ground discrimination test were also given. All three tests were affected by brain damage, but their sensitivity to the locus and side of lesion varied.

Frequency and recognition judgement by young and elderly adults.

The aim of this study was to compare the performance of young and elderly subjects at two different memory tasks (frequency judgement and word recognition) under two retrieval conditions (forced and unforced choice) in order to determine the source of any incidental age-related memory deficit. Fifty young subjects (aged from 15 to 35 yr) and 50 elderly subjects (aged from 60 to 85) participated in this study. The results showed a significant difference between age groups at word recognition independent of retrieval condition, while frequency judgement was found significantly impaired in elderly as compared with young subjects only when an unforced choice procedure was required.

Neurophysiological and CSF immunological study of 19 patients affected by acute idiopatic optic neuritis.

We studied 19 patients affected by acute idiopatic optic neuritis (ON), with neurophysiological tests: visual (VEP), somatosensory (SSEP), acoustic (ABR) evoked potentials and study of the blink reflex (BR), and with cerebrospinal fluid (CSF) examination, in order to detect "silent" lesions in the central nervous system (CNS) and/or immunological alterations, suggestive of multiple sclerosis (MS). The percentage of cases with at least one altered CSF IgG parameter (IgG index, IgG synthesis/day and IgG oligoclonal bands) has been higher than that of cases with one or more altered neurophysiological tests, regardless of the apparently intact eye VEP. If we also included this last test, the 2 percentages become identical.