Ascertainment bias in dementias: a secondary to tertiary centre analysis in Central Italy and conceptual review.

BACKGROUND AND AIMS: Ascertainment bias (AB) indicates a bias of an evaluation centre in estimating the prevalence/incidence of a disease due to the specific expertise of the centre. The aim of our study was to evaluate classification of different types of dementia in new cases appearing in secondary and tertiary centres, in order to evidence possible occurrence of AB in the various (secondary to tertiary) dementia centres. METHODS: To assess the mechanism of AB, the rates of new cases of the different forms of dementia reported by different centres were compared. The centres involved in the study were 11 hospital-based centres including a tertiary centre, located in the University Department of Clinical Neurology. The tertiary centre is endowed with state-of-the-art diagnostic facilities and its scientific production is prominently focused on dementia with Lewy bodies (DLB) thus suggesting the possible occurrence of a bias. Four main categories of dementia were identified: Alzheimer's disease (AD), DLB, fronto-temporal dementia (FTD), vascular dementia (VaD), with other forms in a category apart. The classification rate of new cases of dementia in the tertiary centre was compared with rates reported by secondary centres and rates of recoding were calculated during a follow-up of 2 years. RESULTS: The study classified 2,042 newly diagnosed cases of dementia in a population of 1,370,000 inhabitants of which 315,000 were older than 65. AD was categorized in 48-52 % of cases, DLB in 25-28 %, FTD in 2-4 % and VaD in 17-28 %. During the 2-year follow-up the diagnosis was re-classified in 40 patients (3 %). The rate of recoding was 5 % in the tertiary centre, 2-8 % in referrals from secondary to tertiary centre, 2-10 % in recodings performed in secondary centres and addressed to tertiary centre. Recoding or percentages of new cases of AD or DLB were not different in the comparison between secondary or between secondary and tertiary centres. FTD and VaD were instead significantly recoded. CONCLUSION: The results of the study suggest that in a homogeneous area, AB is not interfering with diagnosis of AD or DLB.

Neurophysiological studies of L-acetylcarnitine administration in man.

Systemic administration of L-acetylcarnitine HCl (LAC) increases in human subjects the amplitude of visual evoked potentials (VEPs) obtained with patterned elements of 7.5 min of visual angle, of steady-state VEPs obtained with intermittent luminous stimulation, of EEG theta, alpha and beta bands. The latency of the "cognitive" P300 potential obtained with an auditory "oddball" paradigm was also reduced by LAC injection, while the amplitude of this potential was increased. These results were obtained in control volunteers and in patients affected by different forms of dementias. The modifications induced by LAC appear 10-15 min after the i.v. injection and last for 50-90 min. These results parallel previously described findings of animal experiments and suggest an effect of LAC on cholinergic neurotransmission.

[Subacute cerebellar degeneration in cystadenopapillary carcinoma of the ovaries]. / Degenerazione cerebellare subacuta in corso di carcinoma cistoadenopapillifero delle ovaie.

A subacute cerebellar degeneration-like paraneoplastic syndrome is reported in a woman with cystoadenopapillar carcinoma involving both ovaries. This syndrome, characterized by remarkable cerebellar ataxia, is an exceptional disorder which pathogenesis is still unknown although there is a hypothesis of a viral infection and autoimmunitary unchaining.

[Westphal-Strumpell disease. Description of a clinical case]. / La malattia di Westphal Strumpell. Descrizione di un caso clinico.

A case of hepatolenticular degeneration with the clinical pattern of Westphal-Strumpell disease is described. Diagnosis was based on clinical pattern, absence of hepatic impairment, typical biochemical abnormalities of copper metabolism and response (clinical and biochemical) to D-penicillamine.

[Comparative study of preparations of sodium and magnesium valproate (VPA) in treatment of patients with epileptic seizures]. / Studio comparativo di preparazioni di valproato (VPA) di sodio e di magnesio nel trattamento di pazienti affetti da crisi epilettiche.

A double blind cross over trial of Sodium Valproate (Na VPA) vs Magnesium Valproate (Mg VPA) was performed in 122 patients affected by focal or generalized epilepsies. Only modest differences resulted from the comparison between the two drugs: retention was 8% superior in patients treated with Mg VPA, the number of critic episodes and the quantification of interictal events was significantly lower in patients affected by focal epilepsy treated with Mg VPA. The incidence of side effects was the same for the two drugs.