Papers by Marcelo Placencia
… . Cuidando la Salud …, 1996
Rodriguez Morales, Oswaldo; Placencia, Marcelo; Granja, Luis; López, José; López, Francisco; Romo... more Rodriguez Morales, Oswaldo; Placencia, Marcelo; Granja, Luis; López, José; López, Francisco; Romo, Hugo. ... In: Instituto Ecuatoriano de Seguridad Social. Hospital Carlos Andrade Marín. Memorias. Congreso de Aniversario. Cuidando la Salud de los Trabajadores. ...
Neurologia Neurocirugia Psiquiatria, 1983
A house-to-house surveyof epileptic seizures covering apopulation of72121 persons wascarried outi... more A house-to-house surveyof epileptic seizures covering apopulation of72121 persons wascarried outinaruralareaof northern Ecuador. A cascade systemof diagnosis wasusedtoidentify allcasesof epileptic seizures inthispopulation. 1029 caseswerefound, ofwhom 881wereconsidered tobedefinite casesand148were possible cases. Of the1029cases, 56% hadactive epilepsy. Thelifetime prevalenceratewasfoundtoliebetween12-2 and 19*511000 and theprevalence of active casesbetween6-7and8-0/1000. An annualincidence rateofbetween122/ 100000and 190/100 000wasestimated. Seizure typewasclassified without EEG dataandalmosthalfofthecaseshad partial seizures. In27%ofcasesanaetiologywasproposed onclinical grounds. Thisisoneoffewreported studies ofa population thathasbeenlargely unexposedtoantiepileptic drugs,providing anopportunity tostudythenatural historyoftheuntreated condition. Ithas beensuggested thattreatment innewly developing epilepsy willpreventits development to a chroniccondition. Only37% ofthe1029casesh...
Neuroepidemiology, 1992
215 patients with epilepsy and 125 healthy controls were questioned on the effects of epilepsy on... more 215 patients with epilepsy and 125 healthy controls were questioned on the effects of epilepsy on social functioning as part of a population-based study of epilepsy in Northern Ecuador. 144 of these patients and 98 of the controls were followed, over a period of 1 year during an intervention study and their response to treatment assessed. Economic, intellectual and social functioning were examined. In the patient group, function was affected in important areas, most clearly, work. The low opinion the community had of the intellectual and physical abilities of patients might affect a patient's own view of themselves and sometimes diminish their opportunity for development. At 12 months, as a result of treatment, a significantly lower level of patients reported effects on function in some areas, though control individuals' views of their functional impairment had not shifted to any extent. Moreover, despite improvement, more patients at 12 months acknowledged fear of seizures, especially their unpredictability, as a handicapping factor, particularly in working outside or away from home. This seems to indicate that even when seizures are controlled, for many patients, the uncertainties of the condition remain and continue to affect their view of their capabilities.
Neuroepidemiology, 1995
As part of a population-based study of epilepsy in northern Ecuador, 215 patients with epilepsy a... more As part of a population-based study of epilepsy in northern Ecuador, 215 patients with epilepsy and 125 controls were given a questionnaire designed to elicit the degree of stigma associated with epilepsy. Evidence for stigma was also sought from local medical personnel. 144 patients and 98 controls were questioned again 12 months later at study completion to see whether their perceptions had changed. Both intellectual and physical abilities of people with epilepsy were regarded as low by controls, and this opinion did not change over the study period. Observations by medical personnel also suggested stigmatizing attitudes in the community. The number of patients reporting problems with their marriage or childbearing as a result of their epilepsy did not alter over the 12-month period, unlike their estimates of their own intellectual and physical capacities which had significantly improved. Conversely, although their expectations of employment outside the home had diminished, the reasons stated for this related to continuing epilepsy and not to the objections of fellow workers and employers.
Neuroepidemiology, 1992
The methodology is presented of a large-scale study of epilepsy carried out in a highland area in... more The methodology is presented of a large-scale study of epilepsy carried out in a highland area in northern Ecuador, South America, covering a population of 72,121 people; The study was carried out in two phases, the first, a cross-sectional phase, consisted of a house-to-house survey of all persons in this population, screening for epileptic seizures using a specially designed questionnaire. Possible cases identified in screening were assessed in a cascade diagnostic procedure applied by general doctors and neurologists. Its objectives were: to establish a comprehensive epidemiological profile of epileptic seizures; to describe the clinical phenomenology of this condition in the community; to validate methods for diagnosis and classification of epileptic seizures by a non-specialised team; and to ascertain the community's knowledge, attitudes and practices regarding epilepsy. A sample was selected in this phase in order to study the social aspects of epilepsy in this community. The second phase, which was longitudinal, assessed the ability of non-specialist care in the treatment of epilepsy. It consisted of a prospective clinical trial of antiepileptic therapy in untreated patients using two standard anti-epileptic drugs. Patients were followed for 12 months by a multidisciplinary team consisting of a primary health worker, rural doctor, neurologist, anthropologist, and psychologist. Standardised, reproducible instruments and methods were used. This study was carried out through co-operation between the medical profession, political agencies and the pharmaceutical industry, at an international level. We consider this a model for further large-scale studies of this type.
Epilepsy Research, 1992
Two hundred and fifteen patients with epilepsy and 125 controls were given questions designed to ... more Two hundred and fifteen patients with epilepsy and 125 controls were given questions designed to elicit their help-seeking strategies for the condition. This was part of a large-scale medical intervention study in a rural area of a developing country (the provinces of El Carchi and Imbaburra, northern Ecuador). Local medical personnel were also surveyed. One hundred and forty-four patients and 98 controls were questioned again 12 months after they had been enrolled in the intervention programme to see if their attitudes and practices had changed. Over the study period, belief in medical remedies, particularly those offered by the study, rose significantly among both controls and patients. Control readiness to consult local healers for help and belief in their effectiveness also rose, whereas patient belief in healer help, already significantly less at baseline because of previous negative experiences, had declined still further. Though no patients treated were on antiepileptic treatment at baseline, 71% claimed to have sought the help of allopathic practitioners at some point in the past, 35% 'many times'. Of these only 21% had ever been given antiepileptic drugs; some consultations were not at local health facilities. Thirty-two per cent of patients also claimed to have consulted traditional healers. The high number of patients claiming to visit doctors was not entirely confirmed in the medical evidence. Even this source, however, suggested more consulted doctors than expected from the observation that only 10% were on any kind of treatment at the start of the study (none on antiepileptic drugs). The conclusion was that people with epilepsy were anxious for help and had previously sought and been prepared to pay for treatment. Long-term treatment was not taken up despite the existence of local health facilities. This may be explained by a lack of information regarding treatments available and their nature, and by a failure to offer effective treatment, which itself may be due to the lack of training and experience in the treatment of epilepsy by local medical personnel.
Epilepsy Research, 1993
The results of a prospective assessment of antiepileptic drug treatment carried out over a 12-mon... more The results of a prospective assessment of antiepileptic drug treatment carried out over a 12-month period, in the context of existing community health care in a rural area of a developing country (a highland region of northern Ecuador), are reported. A house to house survey defined all patients in the area with a history of epileptic seizures, and 192 patients with active epilepsy were recruited into the programme. These patients were randomised to treatment with carbamazepine or phenobarbital, and 139 completed the assessment. Treatment was carried out by health visitors and rural doctors, monitored by a team of neurologists, and standard treatment regimens were used. Treatment was effective in controlling seizures, 53% of the patients were rendered entirely seizure free in the second 6 months of therapy, and a further 14% had a 50% or more reduction in seizures. These results were similar to those reported in hospital based studies in developed countries. No significant differences were found between the efficacy and safety of phenobarbital or carbamazepine. Antiepileptic drug levels were monitored during the study, and ranges similar to those found in developed countries were recorded. Compliance was good. In view of the successful treatment in this community control programme, we would recommend that community programmes for the control of epilepsy in rural settings should be given a higher priority in the planning of health care provision than is commonly the case. Finally, the programme afforded the opportunity to study the efficacy of treatment in patients with chronic long-standing epilepsy, who had not been previously treated, and the results of this treatment were good.
Brain, 1992
A large-scale neuro-epidemiological study was carried out in a population of 72,121 inhabitants o... more A large-scale neuro-epidemiological study was carried out in a population of 72,121 inhabitants of a region of Northern Ecuadorian Andean Sierra, to identify prevalence and incidence rates of epileptic seizures and to identify demographic and geographic variations in these rates. Calculations were made using three datasets. First, rates were calculated from all cases identified in the field (raw dataset); secondly, lower rates were calculated based on a further diagnostic and reclassification procedure (minimum estimated dataset); thirdly, higher rates were derived by calculating false negative rates from the screening procedures, and adding these to the cases actually identified (maximum estimated dataset). Lifetime point-prevalence rates between 12.2/1000 and 19.5/1000 were recorded (minimum and maximum estimated rates), and the prevalence of active epileptic seizures was between 6.7/1000 and 8.0/1000 (minimum estimated and raw datasets). Incidence rate ranging between 122/100,000/year and 190/100,000/year were found (minimum, estimated and raw datasets). A marked difference in prevalence rates was found in two subregions of the survey area, and also in urban and rural areas. The reasons for these differences were not identified.
Brain, 1992
A large-scale clinico-epidemiological study of epileptic seizures has been carried out in a highl... more A large-scale clinico-epidemiological study of epileptic seizures has been carried out in a highland area in northern Ecuador, South America. This paper describes the design and the two-staged validation procedures undertaken to authenticate the screening questionnaire, which was used to detect epileptic seizures in the community during this project. An initial questionnaire consisting of 20 questions was devised and then validated in a group of healthy subjects and a group of patients with known epileptic seizures. This questionnaire was found to have a sensitivity of 100% and a specificity of 50.8%. A cluster analysis of the responses rates was undertaken and a set of nine questions which presented a specificity of 92% and sensitivity of 98% were chosen to be used during the survey. The validation of this nine-question instrument was then undertaken by direct application to a general population of 72 121 persons. Positive, negative, false positive and false negative rates were derived. The screening instrument was found to have a sensitivity of 79.3%, a specificity of 92.9%, a positive predictive value of 18.3%, a negative predictive value of 99.6% and a Youden's index of 0.79. The methodology of the study and the instruments developed are recommended for future neuro-epidemiological work in epilepsy. The problems of validation are discussed, and previous epidemiological studies of epilepsy reviewed with special emphasis on the handling of questions of validation.
Journal of Neurology, Neurosurgery & Psychiatry, 1994
A house-to-house survey of epileptic seizures covering a population of 72 121 persons was carried... more A house-to-house survey of epileptic seizures covering a population of 72 121 persons was carried out in a rural area of northern Ecuador. A cascade system of diagnosis was used to identify all cases of epileptic seizures in this population. 1029 cases were found, of whom 881 were considered to be definite cases and 148 were possible cases. Of the 1029 cases, 56% had active epilepsy. The lifetime prevalence rate was found to lie between 12-2 and 19*511000 and the prevalence of
La epilepsia constituye un problema de salud publica tanto po su alta frecuencua como por las rep... more La epilepsia constituye un problema de salud publica tanto po su alta frecuencua como por las repercusiones sociales y economicas en la poblacion. En paises desarrollados la prevalencia de epilepcia de alrededor de 6 por mil habitantes, esta cifra difiere substancialmente de las reportadas en paises subdesarrollados en donde la mayoria de publicaciones mencionan cifras entre 8 a 22 por mil. Durante la decada de los ochenta se realizaron varios trabajos de investigacion epidemiologica de la epilepsia en el Ecuador
Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 1994
ABSTRACT:The complicated pathophysiological and immunological changes in the central nervous syst... more ABSTRACT:The complicated pathophysiological and immunological changes in the central nervous system of patients with neurocysticercosis produce a variety of signs and symptoms, which complicate the clinical and surgical management of this disease. A complete and objective classification is needed, to improve the medical approach as a whole. We studied 336 patients, in whom we classified neurocysticerosis according to criteria of viability and location of the parasite in the CNS: active form (37.2%) when the cysticercus is alive, transitional form (32.8%) when it is in the degenerative phase, and inactive form (30%) when the parasite is dead. This classification establishes the correlation between the different forms of neurocysticerosis and its clinical manifestations, and can be used for planning therapeutic strategies.
Revista Ecuatoriana De Neurologia, 1999
Background: Abnormal involuntary movements have been described in patients with hydrocephalus. Ho... more Background: Abnormal involuntary movements have been described in patients with hydrocephalus. However, the etiophatogenesis of this association has not been clarifed. We study the presence of dyskinesia, as weel as its clinical and demographic characteritics in patients with hydrocephalus. Design and patients: Series of cases studied during a 10 year period in a neurologic service of a third-level reference hospital. Nine subjects, 6 men and 3 women (mean age: 67 years) in whom hydrocephalus proced dyskinesia. Results: Hydrocephalus preced in 2.33 years the appearence of dyskinesia. Dyskinetic symptoms included tremor in 6 patients, parkinsonism in 1, and dystonia in 2. Five of these patients had family history of dyskinesia in parents or siblings. In 4 of them, the placement of a ventriculoperitoneal shunt improved the abdominal movements. Conclusion: Hydrocephalus may trigger dyskinesia (tremor, parkinsonism, and cranial-cervical dystonia) in a group of susceptible patients who a...
Revista Ecuatoriana De Neurologia, 2001
... Dr. Arturo Carpio, 1,2 Dr. Marcelo Placencia, 3,4 Dr. Marcelo Román, 5 Dr. Rafael Aguirre, 6 ... more ... Dr. Arturo Carpio, 1,2 Dr. Marcelo Placencia, 3,4 Dr. Marcelo Román, 5 Dr. Rafael Aguirre, 6 Dra. ... Manejo Comunitario de la Epilepsia (MCE) realizado por Placencia y colaboradores en una población andina de 72.121 habitantes [5], mediante la aplicación puerta-a-puerta de ...
Revista Ecuatoriana De Neurologia, 2001
... Dr. Arturo Carpio, 1,2 Dr. Marcelo Placencia, 3,4 Dr. Marcelo Román, 5 Dr. Rafael Aguirre, 6 ... more ... Dr. Arturo Carpio, 1,2 Dr. Marcelo Placencia, 3,4 Dr. Marcelo Román, 5 Dr. Rafael Aguirre, 6 Dra. ... Manejo Comunitario de la Epilepsia (MCE) realizado por Placencia y colaboradores en una población andina de 72.121 habitantes [5], mediante la aplicación puerta-a-puerta de ...
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Papers by Marcelo Placencia