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M O Melcon

Publications and source records attributed to M O Melcon.

8 recordsLinked to original sources
PubMed1998

Case ascertainment uncertainties in prevalence surveys of Parkinson's disease.

Using unpublished data from five completed prevalence surveys of Parkinson's disease (PD), we investigated case ascertainment uncertainties that potentially have a direct effect on prevalence. These uncertainties arise from the choice of diagnostic criteria, the choice of screening method, and the amount of information lost because of nonresponse. The surveys were conducted in Argentina, India, China, Italy, and the Netherlands. Our analyses consisted of simple comparisons of prevalence results, positive predictive values (a screening measure), and nonresponse percentages. We found that (a) prevalence comparisons between surveys have diminished value if the surveys used different diagnostic criteria for PD; (b) screening performance may be affected adversely if symptom questions are answered by one family member for the entire family living together rather than by each family member individually; and (c) nonresponse from refusal or unavailability does not necessarily lead to bias, but special caution may be appropriate with prevalence results pertaining to elderly women.

Aged↗
PubMed1997

Prevalence of Parkinson's disease in Junín, Buenos Aires Province, Argentina.

We investigated the prevalence of Parkinson's disease (PD) in a South American city: Junín, Buenos Aires Province, Argentina. At dwellings systematically selected, the case finding involved household screenings and neurological examinations (i.e., a two-phase survey approach). Only persons 40 years of age or older were eligible (N = 7,765). There were 51 cases of PD identified, yielding a crude prevalence of 656.8 per 100,000 population. The age-specific prevalence was consistently higher in men than women, and it increased with advancing age for both sexes. In addition to prevalence figures. we present tallies related to clinical features of PD, as well as tallies related to other subtypes of parkinsonism.

Adult↗
PubMed1997

A population perspective on diagnostic criteria for Parkinson's disease.

For Parkinson's disease (PD), little is known about how the choice of diagnostic criteria affects research results. Using data on PD from three community studies (from Argentina, the Netherlands, Italy), we compared the impact on prevalence of several sets of diagnostic criteria. Each set was based on cardinal signs--resting tremor, bradykinesia, rigidity, impaired postural reflexes--and required that other parkinsonism be excluded. Some sets had additional requirements related to duration of symptoms, asymmetry of signs, or response to medication. In terms of prevalence, much lower estimates were associated with the requirements of asymmetry of signs and response to medication. The assessment of these clinical features may not be practical in community studies. Impaired postural reflexes, as a cardinal sign, seemed superfluous. For community studies of PD, we recommend the following diagnostic criteria: at least two of resting tremor, bradykinesia, or rigidity, in the absence of other apparent causes of parkinsonism.

Age Distribution↗
PubMed1995

Methods for a prevalence survey of neurological disorders in Junín, Buenos Aires, Argentina.

A two-phase prevalence survey of major neurological disorders was conducted in the city of Junín, Buenos Aires, Argentina. In phase 1, a sample of households was screened to identify persons who possibly had a disorder of interest. In phase 2, persons screened as positive in phase 1 were clinically examined by neurologists. This article describes the survey methods used, discusses related methodologic issues (e.g., the problem of false negatives), and presents demographic findings and attrition tallies. A brief account of the pilot investigations is also included as an appendix.

Adolescent↗
PubMed1977

[Neurological complications of Argentinian hemorrhagic fever].

The Argentine hemorrhagic fever (AHF) is an infectious disease, endemo-epidemical, of viral etiology, produced by the Junin virus and limited to the Buenos Aires Province, South of Córdoba, East of La Pampa, and South of Santa Fe. It generally assails rural workers at harvest-time, especially during corn-harvest. The incubation period of the disease does not exceed 12 days. A feverish syndrome with asthenia, adynamia, myalgias, migraine, photophobia, epigastralgia etc., appear. The patient has a facial erythema, petechias on the skin, enantema on the palate, conjunctive micropolyadenopaty injection. The laboratory shows a low erytro, leukopenia with aneosinophilia, thrombopenia and a urine with albuminuria and virous cells. After the fourth day, hemorrhage and a neurological case appears. The laboratory tends to normalize and cast appears in the urine. The most striking neurological signs are the following: muscular hypotonia, proprioceptive hyporreflexia or arreflexia, marinesco reflex, shakings, difficulty to stand and walk, oscillations in consciousness level, and ocular disturbances. The cytochemical test of the C.L. Rachis in the usual ways of the AHF is within its normal characteristics; on the other hand there are modifications in the nervous cases: the total proteins are nearly always increased and the cells augmented with a great predominance of mononuclear cells. The electroencephalogrammes were always abnormal, varying from a brief disorganization up to a diffusive and permanent slowness. The half of which additionally presented paroxisms generalized by slow waves. The pathological anatomy over the central nervous system makes us think that the lesion would not primitively neuronal but that the action of the virus would be indirectly done through the capillar wall. This capillar lesion is produced by multiple focuses. The neuronal destruction with necrosis by microinfarcts is minimum. The symptoms and neurological signs are present in 10% of the clinical cases; the death-rate in the nervous clinical cases having reached 50% of them. The premature treatment allows the death-rate to diminish and the cases that survive have not many after effects.

Adult↗