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Biomedical subjects

T Paiva

Publications and source records attributed to T Paiva.

At least 19 recordsLinked to original sources
PubMed2002

Prevalence of narcolepsy symptomatology and diagnosis in the European general population.

OBJECTIVE: To determine the prevalence of narcolepsy in the general population of five European countries (target population 205,890,882 inhabitants). METHODS: Overall, 18,980 randomly selected subjects were interviewed (participation rate 80.4%). These subjects were representative of the general population of the UK, Germany, Italy, Portugal, and Spain. They were interviewed by telephone using the Sleep-EVAL expert system, which provided narcolepsy diagnosis according to the International Classification of Sleep Disorders (ICSD). RESULTS: Excessive daytime sleepiness was reported by 15% of the sample, with a higher prevalence in the UK and Germany. Napping two times or more in the same day was reported by 1.6% of the sample, with a significantly higher rate in Germany. Cataplexy (episodes of loss of muscle function related to a strong emotion), a cardinal symptom of narcolepsy, was found in 1.6% of the sample. An ICSD narcolepsy diagnosis was found in 0.047% of the sample: The narcolepsy was severe for 0.026% of the sample and moderate in 0.021%. CONCLUSION: This is the first epidemiologic study that estimates the prevalence of narcolepsy in the general population of these five European countries. The disorder affects 47 individuals/100,000 inhabitants.

Adolescent↗
PubMed2001

Neurological teleconsultation for general practitioners.

A neurology teleconsulting network was implemented between a university hospital in Lisbon and five nearby health centres. PCs equipped for videoconferencing were installed, connected by ISDN lines at 128 kbit/s. Fifty-three general practitioners (GPs) were surveyed. The survey showed that the GPs had difficulties in using computers, but they had definite intentions to use teleconsultation for neurology cases and 83% of the respondents stated that they would probably use the technique. During the study, 90 neurology teleconsultations took place over 55 weeks. The average consultation rate was 1.6 teleconsultations per week (SD 1.3, range 0-6). The conferences lasted 10-45 min. Longer teleconsultations were mainly due to technical difficulties in using computers on the part of users with a low level of computer literacy. The patients were 42 males and 46 females, with a mean age of 38 years (SD 20, range 1-84); two patients were discussed twice. The benefits consisted mainly of advice on patient medication, diagnosis and the prevention of unnecessary specialist consultations or laboratory examinations. Doctor-doctor teleconsultation allows the rapid resolution of queries which otherwise cause stress to patients and increase the cost and complexity of care.

Adolescent↗
PubMed2000

Multimedia education in headache: the European Neurological Network.

The European Neurological Network is a European Economic Community supported project. The purpose of the project was to develop a multimedia educational tool for general practitioners in order to improve their management of sleep disorders, epilepsy and headache. The project involves approximately one hundred engineers and physicians from Belgium, Denmark, England, Finland, France, Germany, Italy, Portugal and Spain. This paper concerns the multimedia educational tool on headache. The system consists of five different modules, i.e. classification, clinical data, headache tutorial, diagnostic headache diary and nomenclature. It is possible to move between the modules both vertically and horizontally. The headache classification of the International Headache Society is provided in full text as a work of reference. This classification is used world wide and has been adopted by International Classification of Diseases 10 Neurological Adaptation (ICD-10 NA) and the World Health Organisation. The clinical data concentrate on migraine and tension-type headache, the two most common headache disorders, but data on familial hemiplegic migraine, cluster headache, drug-induced headache and secondary headaches are also available. The headache tutorial consists of case records that the user can test their diagnostic abilities on. The diagnostic headache diary is an expert system on headache diagnostics. It can be filled in during a consultation in order to provide the headache diagnosis or it can be printed and used by the headache patient to record headache attacks and medicine consumption. The nomenclature module provides an explanation of words and expressions used in the system.

Education, Medical, Continuing↗
PubMed2000

Nocturnal sleep quality and circadian blood pressure variation.

OBJECTIVE: To verify whether non-dipper behavior is associated with poor nocturnal sleep quality and a higher rate of obstructive sleep apnea than dipper behavior. METHODS: A sample of 36 subjects older than 50 years (mean age = 70 +/- 6.49 years), 8 males and 28 females, 27 (75%) hypertensive and 9 (25%) normotensive, was studied. Nocturnal polysomnography was carried out in the patients' homes. 24-hour ambulatory blood pressure was studied with Spacelabs 90,207 device. The statistical tests used were Student's t test, Pearson's correlation and the Chi-square test. RESULTS: In the overall sample, higher rates of apnea, higher rates of arousal and shorter duration of the REM (rapid eye movement) phase were linked to high levels of nocturnal diastolic blood pressure, with statistical significance (p < 0.01, p < 0.01, p < 0.05 respectively). Sleep fragmentation was associated with the lowest percentages of variation in daytime to nighttime systolic blood pressure (p < 0.03). Apnea rates were significantly higher in the hypertensive group compared to the normal blood pressure population (p = 0.04). We also observed that higher rates of nocturnal apnea corresponded to lower variations in daytime to nighttime systolic blood pressure (p = 0.015) and to a lower dipper index (p < 0.05). Higher indexes of arousal and lower REM latency were associated with higher nocturnal blood pressure, both systolic (p = 0.039 and p = 0.008, respectively) and diastolic (p = 0.003 and p = 0.029, respectively). Sleep efficiency was also negatively correlated with mean levels of nocturnal diastolic blood pressure (p = 0.038). CONCLUSIONS: The quality of nocturnal sleep seems to play an important role in blood pressure levels, particularly in the nocturnal blood pressure profile. A poor quality of nocturnal sleep and the rate of obstructive sleep apnea were associated with non-dipper behavior in the hypertensive population. Sleep evaluation is particularly useful in non-dipper subjects with hypertension.

Aged↗
PubMed2000

PSG-EXPERT. An expert system for the diagnosis of sleep disorders.

This paper describes PSG-EXPERT, an expert system in the domain of sleep disorders exploring polysomnographic data. The developed software tool is addressed from two points of view: (1)--as an integrated environment for the development of diagnosis-oriented expert systems; (2)--as an auxiliary diagnosis tool in the particular domain of sleep disorders. Developed over a Windows platform, this software tool extends one of the most popular shells--CLIPS (C Language Integrated Production System) with the following features: backward chaining engine; graph-based explanation facilities; knowledge editor including a fuzzy fact editor and a rules editor, with facts-rules integrity checking; belief revision mechanism; built-in case generator and validation module. It therefore provides graphical support for knowledge acquisition, edition, explanation and validation. From an application domain point of view, PSG-Expert is an auxiliary diagnosis system for sleep disorders based on polysomnographic data, that aims at assisting the medical expert in his diagnosis task by providing automatic analysis of polysomnographic data, summarising the results of this analysis in terms of a report of major findings and possible diagnosis consistent with the polysomnographic data. Sleep disorders classification follows the International Classification of Sleep Disorders. Major features of the system include: browsing on patients data records; structured navigation on Sleep Disorders descriptions according to ASDA definitions; internet links to related pages; diagnosis consistent with polysomnographic data; graphical user-interface including graph-based explanatory facilities; uncertainty modelling and belief revision; production of reports; connection to remote databases.

Computer Systems↗
PubMed2000

The sleep tutorial.

A multimedia Sleep tutorial for General Practitioners was implemented from scratch. The implementation had into account the following features: 1) Specific needs of GPs evaluated in 3 different countries, related with Tutorial contents and technical features; 2) Multinational authorship from European experts; 3) Multilingual possibilities; 4) User friendliness and easy navigation. The tutorial was implemented and tested and its gama version is now available for commercialization.

Adolescent↗
PubMed2000

Headache tutorial.

The headache multimedia educational tool for the general practitioners, consists of five different modules, i.e. classification, clinical data, headache tutorial, diagnostic headache diary and nomenclature. It is possible to move between the modules both vertically and horizontally. This paper concerns the headache tutorial. It consist of case records that the user can test his diagnostic abilities on. Each case record is subdivided into an interview by the physician, physical and neurological examination, laboratory test, sum of positive diagnostic elements, suggestions of diagnoses and management. A total of 12 case records are provided. The system will be available on a CD-ROM.

Adult↗
PubMed2000

General practitioners and neurotelemedicine.

Predicting attitudes towards teleconsultation systems and intentions of use is crucial at the beginning of the implementation phase, due to the critical role of human factors in its acceptance and continuous utilisation. The main objective of this study was to assess and understand GP's attitudes and intentions towards using the teleconsultation system in Neurology, implemented in Lisbon, between Hospital de Santa Maria/Neurology Outpatient Clinic and the Health Care Centers of its Health Unit. The final aim is the promotion of a wide acceptance and utilisation of the system, through the development of adequate communication strategies. A predictive model "Theory of Reasoned Action" was chosen as method. It was operated with the application of a questionnaire to a sample of 53 GP's, developed from the results of a content analysis of 10 interviews. A total of 44 GP's stated that, probably they will use the system, 5 were neutral and 4 probably will not use it. The responses were submitted to factor and multiple regression analysis. Attitude was determined by only one factor "Accessibility and Quality" (b = 0.486; p = 0.007) from the 5 factors obtained. The intention variance was explained in 26.9% by the attitude and subjective norm. However, only the attitudinal factor (b = 0.469; p = 0.002) contributes significantly to its explanation with no significant influence from the subjective norm. GP's intentions towards using the system are very positive. Nevertheless, there are significant differences between the centers that are participating and not participating in the project. Communication strategies envisaging dissemination and generalised acceptance and utilisation should focus on accessibility and quality of care aspects.

Adult↗
PubMed1999

Respiratory disorders in ALS: sleep and exercise studies.

Sleep disruption in ALS/MND is related to hypoventilation and nocturnal O(2) saturation. Maximal inspiratory pressure (PI(max)) proved sensitive in predicting nocturnal O(2) saturation. However, PI(max) is highly dependent on patient collaboration; on the other hand Mouth Occlusion Pressure (MOP) is a reliable, non-volitional parameter index of central respiratory drive. Since exercise testing (ET) is also part of the assessment of ventilatory regulation the authors aimed to determine whether MOP and ET are sensitive and reliable parameters predictive of nocturnal O(2) saturation and clinical evolution. We conducted a Polysomnographic (PSG) study in two groups of 14 patients, selected according to their MOP level. Patients performed at admission an ET, Respiratory Function tests (RFT) and clinical evaluation with Norris spinal and bulbar scores (SNS and BNS). All patients in Group I (Low MOP) had decreased O(2) saturation during ET (P<0.001). Correlation study showed correlation between ET and MOP (R=0.6); PI(max) slope and PE(max) slope correlated with ET (R=-0.4; -0.6), respectively. ET also correlated with nocturnal O(2) saturation and SNS slope (R=0.8; -0.5), respectively. SNS and BNS slopes correlated with nocturnal O(2) saturation (R=-0.4; -0.7), respectively. The best correlations found were between MOP slope and BNS slope and SNS slope (R=0.8; 0.7), respectively. The high predictive values of MOP and ET at admission to nocturnal O(2) saturation (predicted value=80%) suggested the need of nocturnal pulse oximetry as a standard procedure. MOP and ET should also be used in evaluation protocols of ALS/MND.

Adult↗
PubMed1997

An international study on sleep disorders in the general population: methodological aspects of the use of the Sleep-EVAL system.

The comparability among epidemiological surveys of sleep disorders has been encumbered because of the array of methodologies used from study to study. The present international initiative addresses this limitation. Many such studies using the exact same methodology are being completed in six European countries (France, the United Kingdom, Germany, Italy, Portugal, and Spain), two Canadian cities (metropolitan areas of Montreal and Toronto), New York State, and the city of San Francisco. These surveys have been undertaken with the aim of documenting the prevalence of sleep disorders in the general population according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) and the International Classification of Sleep Disorders (ICSD-90). Data are gathered over the telephone by lay interviewers using the Sleep-EVAL expert system. This paper describes the methodology involved in the realization of these studies. Sample design and selection procedures are discussed.

Adolescent↗
PubMed1996

The sleep of non-depressed patients with panic disorder: a comparison with normal controls.

All-night sleep EEG recordings were performed in non-depressed patients with panic disorder, agoraphobia, and a group of age- and sex-matched normal controls. Patients were selected according to DSM-IV and all subjects were studied under drug-free conditions. In addition to sleep continuity disturbances, patients with panic disorder have a reduced percentage of slow wave sleep, mainly due to diminished amounts of stage 4. REM sleep characteristics are identical in the two groups. When depressive co-morbidity and non-specific causes of insomnia are excluded, the sleep EEG of panic patients seems to be characterized by modest changes in sleep continuity and sleep architecture. These findings favour the existence of a neurophysiological frontier between anxiety disorders and depressive illness.

Adult↗
PubMed1996

[Sleep disturbances in elderly hypertensive patients].

OBJECTIVE: To investigate the subjective and objective perturbations in the elderly hypertensive patients. SAMPLE: 32 individuals were studied with ages > or = 65 years, 14 men and 18 women, with controlled idiopathic high blood pressure, diagnosed over a year ago, and able to lead autonomous lives. METHODS: These outpatients were asked to answer sleep questionnaires adapted from Stanford's questionnaire, and a nocturnal sleep polygraphic register was kept. RESULTS AND CONCLUSIONS: This group of elderly hypertensive outpatients slept badly but never consulted a doctor due to sleeping problems. The most frequent complaints were fatigue, body pains, frequent interruptions of sleep during the night and sleepiness during the day. In the polysonographic register, we highlight insomnia, snoring, obstructive apnea and the periodic movements during sleep. These findings could explain the patient's complaints. Research must be continued on sleep apnea in the elderly hypertensive patients particularly in those with snoring.

Aged↗
PubMed1995

EEG monitoring during endovascular embolization of cerebral arteriovenous malformations.

Arteriovenous malformations (AVMs) may have a bad prognosis. Endovascular embolization with cyanocrylate represents nowadays an important initial step in a staged treatment, that later may include surgery or radiotherapy. Embolization may induce significant changes in the dynamics of the cerebral circulation, some of which may provoke neurological sequelae. Therefore assessment of potential complications is usually done by using a superselective amytal test, during which small doses of amytal are injected directly in the pedicle that is going to be embolized. In spite of an extensive use of the EEG during endovascular embolization its evaluation in terms of benefits and limitations is not available. Such evaluation is therefore the aim of this work. EEG monitoring was performed during endovascular embolization of 19 patients; a large majority of patients presented large AVMs, with Spetzler indexes around IV or V. The main results were as follows: (1) EEG changes at baseline were significantly correlated with the AVM size and the Spetzler index but were unable to predict the difficulties in the embolization; (2) during amytal tests EEG positivity reached 35% and consisted mainly in ipsilateral slow focal activity; (3) in some cases embolization was performed in spite of transient EEG changes. It was found that focal or diffuse abnormalities in the lower frequency range, even when slight, could be followed by clinical hazards (3 out of 11 cases); (4) EEG monitoring was important in the prediction, evaluation and prognosis of clinical complications.

Adolescent↗
PubMed1995

EEG sleep characteristics in dysthymia and major depressive disorder.

All night EEG sleep recordings were compared in patients with dysthymia and major depressive disorder. Subjects were selected according to DSM-IV and underwent 2 weeks of treatment with placebo before the sleep evaluations. All patients with major depressive disorder were classified as nonmelancholic and belonged to the recurrent subtype, without full interepisode recovery. Patients with major depressive disorder have a shorter duration of total sleep time, a longer sleep latency and a lower sleep efficiency. However, similar sleep architecture and REM sleep characteristics were found in the two groups. These EEG sleep data seem to favor the existence of a biological overlap between the two forms of nonmelancholic unipolar depression. The validity of dysthymia is still unclear and therefore the nosological implications of our observations are discussed.

Adult↗