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Biomedical subjects

H Pétursson

Publications and source records attributed to H Pétursson.

12 recordsLinked to original sources
PubMed2000

Familial aggregation of Parkinson's disease in Iceland.

BACKGROUND: The role of genetics in early-onset Parkinson's disease has been established, but whether there is a genetic contribution to the more common, late-onset form remains uncertain. METHODS: We reviewed the medical records and confirmed the diagnosis of Parkinson's disease in 772 living and deceased patients in whom the disease had been diagnosed during the previous 50 years in Iceland. With the use of an extensive computerized data base containing genealogic information on 610,920 people in Iceland during the past 11 centuries, several analyses were conducted to determine whether the patients were more related to each other than random members of the population (control subjects). RESULTS: Patients with Parkinson's disease, including a subgroup of 560 patients with late-onset disease (onset at >50 years of age), were significantly more related to each other than were subjects in matched groups of controls, and this relatedness extended beyond the nuclear family. The risk ratio for Parkinson's disease was 6.7 (95 percent confidence interval, 4.3 to 9.6) for siblings, 3.2 (95 percent confidence interval, 1.2 to 7.8) for offspring, and 2.7 (95 percent confidence interval, 1.6 to 3.9) for nephews and nieces of patients with late-onset Parkinson's disease. CONCLUSIONS: Late-onset Parkinson's disease has a genetic component as well as an environmental component.

Age of Onset↗
PubMed1995

Studies of reversible and selective inhibitors of monoamine oxidase A in dysthymia.

Dysthymia is a relatively common disorder and is frequently associated with other mental conditions such as major depression and anxiety. A number of controlled and uncontrolled studies have indicated that conventional as well as more recent antidepressants such as moclobemide, a selective, reversible inhibitor of monoamine oxidase (MAOI), may be effective in dysthymia and dysthymia-like disorders. However, assessment of the results of previous studies is confounded by the relative lack of standards in diagnostic criteria, outcome measures, dosage and duration of treatment. Applying DSM-III-R criteria, the efficacy of moclobemide in dysthymia has been confirmed in a significant study from South America, and other comparable studies are under way. The potential role of selective, reversible MAOIs such as moclobemide can be more firmly established when results of additional investigations have become available.

Benzamides↗
PubMed1994

The benzodiazepine withdrawal syndrome.

Physiological dependence on benzodiazepines is accompanied by a withdrawal syndrome which is typically characterized by sleep disturbance, irritability, increased tension and anxiety, panic attacks, hand tremor, sweating, difficulty in concentration, dry wretching and nausea, some weight loss, palpitations, headache, muscular pain and stiffness and a host of perceptual changes. Instances are also reported within the high-dosage category of more serious developments such as seizures and psychotic reactions. Withdrawal from normal dosage benzodiazepine treatment can result in a number of symptomatic patterns. The most common is a short-lived "rebound" anxiety and insomnia, coming on within 1-4 days of discontinuation, depending on the half-life of the particular drug. The second pattern is the full-blown withdrawal syndrome, usually lasting 10-14 days; finally, a third pattern may represent the return of anxiety symptoms which then persist until some form of treatment is instituted. Physiological dependence on benzodiazepines can occur following prolonged treatment with therapeutic doses, but it is not clear what proportion of patients are likely to experience a withdrawal syndrome. It is also unknown to what extent the risk of physiological dependence is dependent upon a minimum duration of exposure or dosage of these drugs. Withdrawal phenomena appear to be more severe following withdrawal from high doses or short-acting benzodiazepines. Dependence on alcohol or other sedatives may increase the risk of benzodiazepine dependence, but it has proved difficult to demonstrate unequivocally differences in the relative abuse potential of individual benzodiazepines.

Animals↗
PubMed1991

Dementia and depression in old age: psychophysiological aspects.

This study describes the psychophysiological results of a larger investigation of the clinical, morphological, psychometric and psychophysiological aspects of dementia of the Alzheimer type and depression in elderly patients. Healthy volunteers provided a further measure of control. It was found that widely used clinical rating scales delineated the 3 groups of subjects to a significant degree. The average frequency of the electroencephalogram (EEG), the P2-N2 peak-to-peak amplitude and P3 latency of the auditory evoked potential and a characteristic downward shift of the EEG power spectrum differed significantly between demented patients, depressive patients and normal controls. The higher total power in the EEG of the dementia group did not prove statistically significant, probably because of the small numbers. Other psychophysiological measures such as skin conductance level (SCL) and skin temperature (ST) did not reveal statistically significant differences between the groups. Thus, certain psychophysiological measurements may become valuable in the differential diagnosis of these disorders.

Aged↗
PubMed1990

Homicide in the Nordic countries.

This article reviews and assesses previous studies of homicide in the Nordic countries and compares the main findings with those from other countries. In spite of the relative sparsity of data, the nature of the available information allows a reasonably reliable comparison to be made between different Nordic countries. Although findings from separate studies vary somewhat, some general trends have been noticed and seem to apply to most of the countries in question: in particular, changes that have occurred over the last 2 decades. Thus, all the Nordic countries have experienced an increase in homicide incidence during this period, and with some notable exceptions, this increase has been quite drastic. Certain other trends have been observed, such as the prominent role of alcoholism and drug abuse in homicide offences, as well as the relative increase in nondomestic offences. Homicide followed by suicide has decreased proportionately among males, whereas this trend has not occurred to the same extent among females, who are more frequently involved in domestic homicide. Methods of homicide have also varied somewhat during the last few decades. The case of homicide in Greenland is discussed separately in view of its special circumstances. Studies dealing with the various psychiatric and mental health problems related to homicide in the Nordic countries are discussed and a hypothesis is offered about possible sociocultural factors, in particular alcohol and drug abuse, that seem to be important.

Alcoholism↗
PubMed1989

Psychiatric evidence: a study of psychological issues.

This article discusses the nature of psychiatric evidence in Icelandic criminal proceedings and presents findings from an investigation of the role of amnesia, malingering and overcontrolled hostility among different types of offenders. Amnesia was most common in homicide cases, and was almost invariably associated with alcohol intoxication. An unexpectedly high rate of overcontrolled hostility was found among sex offenders, which may have important theoretical and clinical implications. The results indicate that deliberate faking of an intellectual deficit on psychometric tests occurs rarely in a forensic context.

Adolescent↗
PubMed1989

Moclobemide and clomipramine in endogenous depression. A randomized clinical trial.

The purpose of this study was to compare moclobemide and clomipramine in endogenous depression according to the Newcastle II classification. Sixty-two patients were allocated to either 300 mg moclobemide or 150 mg clomipramine, both given in 3 daily doses. Improvements occurred over time but differences between treatments were never statistically significant. Dizziness, tremor and anticholinergic symptoms were significantly more frequent with clomipramine.

Adult↗
PubMed1988

Electroencephalographic correlates of electroconvulsive therapy.

The aim of this investigation was to study the detailed profile and persistence of electroconvulsive therapy (ECT)-induced EEG correlates. Subjects were submitted to a detailed clinical evaluation as well as automated, computerized EEG recordings. Analysis was performed of different frequency bands, mean frequency and total power as well as a detailed study of cortical auditory-evoked responses. Age and sex-matched control subjects comprised a group of comparable patients, none of whom had received ECT, a second control group of healthy volunteers and a third group of amitriptyline-treated patients. No statistically significant EEG changes were found among patients who had been treated with ECT from several months to several years prior to the investigation. During ECT, highly significant cumulative effects were observed in most of the EEG measures, particularly increased slow-wave activity and a corresponding reduction in fast-wave activity. Predictably, significant changes also occurred in mean EEG frequency and total power. No significant changes were observed in the cortical-evoked responses. EEG abnormalities were still significant one week following the completion of a course of ECT, but reverted to baseline levels within four weeks.

Cerebral Cortex↗
PubMed1986

Computed tomographic scans in ECT-patients.

Although the safety and efficacy of electroconvulsive therapy (ECT) is acknowledged by most, concern has repeatedly been expressed that the treatment may have some lasting effects on the brain. To study potential morphological changes, 22 patients with a history of ECT were submitted to a detailed clinical evaluation and a brain CT scan examination. Age- and sex-matched control subjects comprised a group of comparable patients, none of whom had received ECT, and a second control group of healthy volunteers. Patients had larger ventricle/brain ratios and cortical "atrophy" scores than normal controls, but no association was found between these radiological measures and a previous history of ECT. Hence, the present data are consistent with recent reports that affective disorders may be associated with enlarged brain ventricles, although the clinical significance of such findings remains unclear. In line with previous investigations age correlated significantly with cortical "atrophy" scores and ventricle/brain ratios for all subjects. Statistical tests of correlations between duration of illness, previous psychotropic drug exposure and CT scan appearances were mainly inconclusive.

Adult↗
PubMed1981

Psychiatric aspects of homicide.

Homicide is frequently associated with mental illness and suicide. The present study is an investigation of all known homicide incidents in Iceland during the past 80 years (1900-1979). There were 45 homicide incidents, involving 52 victims and 47 offenders. One-third of the perpetrators were either psychotic, mentally subnormal, or committed suicide. A further one-third were diagnosed as personality disordered, alcoholic, drug dependent or neurotic. A substantial proportion of the offenders suffered from fairly marked physical disabilities, and the mentally ill were significantly more frequently afflicted by such defects. Over 60% of the offenders and 50% of the victims were under the influence of alcohol at the material time. The findings are generally consistent with those of previous psychiatric studies of homicide.

Adult↗
PubMedDate not supplied

The attribution of blame and type of crime committed: transcultural validation.

This study examines the relationship between type of offence and the attributions offenders make about their criminal act. The subjects were 98 Icelandic criminals who had completed the Gudjónsson Blame Attribution Inventory. Significant differences in attribution were found between offender groups. Sex offenders and those who had committed acts of interpersonal violence reported most guilt about their offence and they attributed cause for their offence more to mental factors (eg, loss of self-control) than other types of offender. Violent offenders had the highest external attribution and sex offenders the lowest. The findings with regard to the three attributions are remarkably similar to those found previously for British offenders.

Adult↗