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Biomedical subjects

Tarja Porkka-Heiskanen

Publications and source records attributed to Tarja Porkka-Heiskanen.

At least 19 recordsLinked to original sources
PubMed2006

Preliminary findings of proton magnetic resonance spectroscopy in occipital cortex during sleep deprivation.

Proton magnetic resonance spectroscopy ((1)H MRS) has revealed biochemical alterations in various psychiatric disorders. Changes in brain metabolites may be caused not only by the disease's progression or response to treatment, but also by physiological variability. The aim of this study was to use (1)H MRS to assess the effects of specific short-term physiological states on major metabolites. Eight healthy women underwent (1)H MRS at the beginning and end of a 40-h period of sleep deprivation. The ratios of N-acetyl-aspartate (NAA), total creatine (tCr), and choline-containing compounds (Cho) to water (H(2)O) were determined from the occipital cortex during both baseline and photic stimulation conditions. During sleep deprivation, NAA/H(2)O decreased by 7% and Cho/H(2)O by 12%. Photic stimulation had no effect on the measured metabolites in the alert state, but in the sleep-deprived state the level of Cho/H(2)O increased during neuronal activation. The results suggest that NAA/H(2)O and Cho/H(2)O may depend on the state of alertness.

Adult↗
PubMed2006

Localization of equilibrative nucleoside transporters in the rat brain.

Adenosine is a recognized inhibitory neuromodulator and neuroprotective agent in the central nervous system. It is produced both intra- and extracellularly and transported across the cell membrane. Nucleoside transporters thus have a major impact on the extracellular adenosine levels, and consequently adenosine signalling. We have raised and characterized polyclonal antibodies against both the equilibrative nucleoside transporters 1 and 2, and report for the first time their distribution in rat brain at the cellular level. Double staining studies were performed to assess the localization of the transporters in neural and glial cells. Both transporters were present in practically all neurons. Some astrocytes showed equilibrative nucleoside transporter 1 staining, while equilibrative nucleoside transporter 2 staining on astrocytes was observed only sporadically.

Animals↗
PubMed2006

Clinical neurological abnormalities in young adults with Asperger syndrome.

Children with Asperger syndrome (AS), a neurodevelopmental disorder falling in the autism spectrum disorders, have an increased rate of neurological abnormalities, especially in motor coordination. While AS is a lifelong condition, little is known about the persistence of neurological abnormalities in adulthood. Twenty young adults with AS were compared with 10 healthy controls using a structured clinical neurological rating scale. The score for neurological abnormalities was higher in the AS group. In addition, a subscore for neurological soft signs indicating defective functioning of the central nervous system with a non-localizing value was significantly higher in the AS subjects. This preliminary study indicates that neurological abnormalities, soft signs in particular, represent a non-specific vulnerability factor for AS. Consistent with other features of AS, neurological abnormalities seem to persist into adulthood.

Adult↗
PubMed2005

Childhood inattention and hyperactivity symptoms self-reported by adults with Asperger syndrome.

BACKGROUND: Increasing public awareness of the adult manifestations of developmental neuropsychiatric disorders, like Asperger syndrome and attention deficit hyperactivity disorder (ADHD), has provoked an increasing number of persons to seek assessment for the first time in adulthood. As these disorders have their origin in childhood, instruments for retrospective evaluation of childhood behavior are needed. SAMPLING AND METHODS: In this preliminary study, 20 adults with Asperger syndrome filled in the Wender-Utah Rating Scale for ADHD to describe retrospectively their childhood behavior. RESULTS: Fourteen out of 20 adults with Asperger syndrome self-rated above the cut-off limit for ADHD. The median total score was also higher than that reported in normal populations in previous studies. When compared with 10 controls, patients with Asperger syndrome scored higher in almost all individual items. CONCLUSIONS: A high score on the Wender-Utah rating Scale for ADHD in this patient group might be a sign of true comorbidity with ADHD, an indication of overlapping features typical of both disorders, or a result of other psychiatric comorbidity originating already in childhood. Moreover, there are no data about the proper cut-off limit for ADHD in these subjects. Therefore, one should be cautious when applying this scale beyond its original context of comparison between adults with ADHD, unipolar depression and healthy controls.

Adolescent↗
PubMed2005

Quantitative electroencephalographic measures in homicidal men with antisocial personality disorder.

Many symptoms of antisocial personality disorder have been proposed to be related to decreased daytime vigilance. To explore this hypothesis, quantitative analyses were conducted of the electroencephalographic (EEG) activity of drug-free and detoxified homicidal male offenders with antisocial personality disorder as the primary diagnosis. Subjects comprised 16 men recruited from a forensic psychiatric examination in a special ward of a university psychiatric hospital. Fifteen healthy age- and gender-matched controls with no criminal record or history of physical violence consisted of hospital staff and students. An overall reduction of alpha power was observed in the waking EEG of offenders. A bilateral increase in occipital delta and theta power was also found in these individuals. This study provides further support to the growing evidence of brain dysfunction in severe aggressive behavior. Homicidal offenders with antisocial personality disorder seem to have difficulties in maintaining normal daytime arousal. Decreased vigilance, together with social and psychological variables, may explain their aberrant behavior in everyday life. New studies are, however, needed to specify the vigilance problems of this patient group.

Adult↗
PubMed2005

Women's sleep in health and disease.

A huge amount of knowledge about sleep has accumulated during the last 5 decades following the discovery of rapid eye movement (REM) sleep. Nevertheless, there are numerous areas of considerable ignorance. One of these concerns the particularities of sleep in women. Most basic and clinical studies have been performed in male subjects, and only very recently research groups around the world have addressed women's sleep in health and disease. In this review, we summarize the present knowledge on the influence of oestrogens on the brain and on the distinctive changes of sleep across the menstrual cycle, during pregnancy and menopause. In addition, studies in female rodents are reviewed as well as the knowledge on female peculiarities regarding the interactions between sleep regulation and age-related changes in circadian rhythms. We also address specific aspects of sleep loss and sleep disorders in women. Finally, very recent studies on the sociology of sleep are summarized and future directions in the field are discussed.

Adult↗
PubMed2005

Higher plasma ACTH levels in adults with Asperger syndrome.

OBJECTIVE: The aim of this preliminary study was to characterize the levels of plasma adrenocorticotropic hormone (ACTH) and cortisol in adult patients with Asperger syndrome (AS). METHODS: Twenty medication-free individuals with high-functioning AS were recruited from a clinic specialized in autism spectrum disorders. Ten age-matched healthy persons (hospital staff or students) with no neuropsychiatric disorders served as controls. Blood samples for the assessment were collected at 8:00 a.m. RESULTS: The patients with AS had significantly higher plasma-ACTH values than did the healthy controls. Plasma-cortisol levels were similar in both groups. CONCLUSION: Increased plasma-ACTH levels are associated with AS. Future studies are needed to clarify whether this finding is a biological consequence of chronic anxiety and elevated stress, or a sign of facilitated response to an acute novel stressor.

Adolescent↗
PubMed2005

Actigraphic assessment of sleep in young adults with Asperger syndrome.

A high prevalence of subjective insomnia in adults with Asperger syndrome has been reported. In the present study the sleep quality of these patients was studied using wrist actigraphy. Nineteen adults with Asperger syndrome and frequent feelings of insomnia were compared with 10 controls devoid of neuropsychiatric disorders and subjective sleep problems during six consecutive nights. The patients had similar actigraphic sleep profile to the controls. The subjective low sleep quality in patients was not reflected in actigraphic assessment of sleep. This finding suggests that pervasive anxiety inherent in persons with Asperger syndrome predisposes them to insomnia complaints.

Adult↗
PubMed2004

Adenosine A1 receptor-dependent G-protein activity in the rat brain during prolonged wakefulness.

Adenosine accumulates in the basal forebrain during prolonged wakefulness and induces sleep. There is abundant evidence showing that the sleep-inducing effects are mediated locally in the basal forebrain through the adenosine A1 receptor. In previous studies an increase in the mRNA expression but no apparent change in the ligand binding of the A1 receptors have been found. In the present study we used [(35)S]GTPgammaS autoradiography to assess regional A1 receptor dependent G-protein activity in rat brain during prolonged wakefulness and recovery sleep. We found that the G-protein activity was increased in the cortex but not in the basal forebrain during the first hours of sleep deprivation, suggesting different A1 receptor mediated responses to increasing adenosine concentrations in different brain areas.

Animals↗
PubMed2004

Lower limb motor restlessness in Asperger's disorder, measured using actometry.

The movement disturbances and brain imaging findings in Asperger's disorder (AD) suggest a dopaminergic deficit in movement regulation. Movement disorders of different etiologies have been quantified and specified with actometry. We compared 10 AD patients with 10 healthy controls, measuring their rest-activities by actometry. The lower limb motor activity was significantly higher in the AD group. They also displayed a rhythmic, periodic movement pattern similar to akathisia. These findings suggest a hypothesis of idiopathic akathisia and a special sensitivity to adverse effects of neuroleptic drugs.

Adolescent↗
PubMed2004

Neurological soft signs in homicidal men with antisocial personality disorder.

Neurological soft signs (NSS) are characterized by abnormalities in motor, sensory, and integrative functions. NSS have been regarded as a result of neurodevelopmental dysfunction, and as evidence of a central nervous system defect, resulting in considerable sociopsychological dysfunction. During the last decade there has been growing evidence of brain dysfunction in severe aggressive behavior. As a symptom, aggression overlaps a number of psychiatric disorders, but it is commonly associated with antisocial personality disorder. The aim of the present study was to examine NSS in an adult criminal population using the scale by Rossi et al. [29]. Subjects comprised 14 homicidal men with antisocial personality disorder recruited from a forensic psychiatric examination. Ten age- and gender-matched healthy volunteers as well as eight patients with schizophrenia, but no history of physical aggression, served as controls. The NSS scores of antisocial offenders were significantly increased compared with those of the healthy controls, whereas no significant differences were observed between the scores of offenders and those of patients with schizophrenia. It can be speculated that NSS indicate a nonspecific vulnerability factor in several psychiatric syndromes, which are further influenced by a variety of genetic and environmental components. One of these syndromes may be antisocial personality disorder with severe aggression.

Adult↗
PubMed2004

The effect of age on prepro-orexin gene expression and contents of orexin A and B in the rat brain.

Orexin A and B (hypocretin 1 and 2) are hypothalamic peptides, which are synthesized in the lateral hypothalamus. Orexins participate in the regulation energy balance, food intake, vigilance and several endocrine and autonomic functions. The widespread projections of the orexin neurons suggest that they may have a role in coordination of different brain activities. The effects of ageing on the orexin system have not been studied previously. Prepro-orexin gene expression in the lateral hypothalamus, and the contents of orexin A and B peptides in the lateral hypothalamus and hypothalamus were measured in young, middle-aged and old (3, 12 and 24 months) rats. In the course of ageing, the expression of the prepro-orexin gene and the levels of orexin A and B decreased; the main decrease occurred by 12 months. Sleep deprivation for 6h increased slightly the expression of prepro-orexin gene in young rats. Deterioration of the orexin system may play a role in the phenomenon associated with aging, e.g. decreased consolidation of vigilance states, endocrine changes and dysfunctions of autonomic nervous system.

Aging↗
PubMed2004

Stimulus-induced brain lactate: effects of aging and prolonged wakefulness.

Both aging and sleep deprivation disturb the functions of the frontal lobes. Deficits in brain energy metabolism have been reported in these conditions. Neurons use not only glucose but also lactate as their energy substrate. The physiological response to elevated neuronal activity is a transient increase in lactate concentrations in the stimulated area. We have previously shown that cognitive stimulation increases brain lactate. To study the effect of prolonged wakefulness on the lactate response we designed an experiment to assess brain lactate levels during a 40-h sleep deprivation period in young (19-24 years old; n = 13) and in aged (60-68 years old; n = 12) healthy female volunteers. Brain lactate levels were assessed with proton MR-spectroscopy ((1)H MRS) during the performance of a silent word generation task. The (1)H MRS voxel location was individually selected, using functional magnetic resonance imaging, to cover the activated area in the left frontal lobe. The degree of sleepiness was verified using vigilance tests and self-rating scales. In the young alert subjects, the silent word generation test induced a 40% increase in lactate, but during the prolonged wakefulness period this response disappeared. In the aged subjects, the lactate response could not be detected even in the alert state. We propose that the absence of the lactate response may be a sign of malfunctioning of normal brain energy metabolism. The behavioral effects of prolonged wakefulness and aging may arise from this dysfunction.

Adult↗
PubMed2004

Asperger syndrome, alexithymia and perception of sleep.

Two research traditions, the one on Asperger syndrome (AS) and the other on alexithymia, have produced similar findings independently of each other indicating a possible association between these two phenomena. Both conditions are also associated with impaired initiation and continuity of sleep. Twenty AS adults were compared with 10 healthy controls using the Toronto Alexithymia Scale and the Basic Nordic Sleep Questionnaire. AS subjects were significantly more alexithymic and reported lower sleep quality as compared with controls. AS and alexithymia are associated although the mediating factors are unknown. It is possible that alexithymic traits predispose to anxiety, which in turn lowers the sleep quality in AS adults. Alternatively, low sleep quality might be due to AS itself.

Adult↗
PubMed2004

ADHD and sleep in homicidal men with antisocial personality disorder.

A history of attention deficit hyperactivity disorder (ADHD) is commonly found in subjects with antisocial personality disorder (ASP). Besides ASP, childhood ADHD also predicts drug abuse disorders and criminal activity in adulthood. Childhood ADHD and ASP appear to be the only psychiatric disorders reported to be associated with an increase in deep sleep. The aims of the present study were to retrospectively measure the childhood ADHD of habitually violent men with ASP and Cloninger type 2 alcoholism, and to characterize the possible relationship between childhood ADHD and sleep architecture in these men. The subjects of the study consisted of 14 homicidal offenders recruited from a forensic psychiatric examination. Ten age- and gender-matched healthy volunteers served as controls. Childhood ADHD symptoms were measured using the Wender-Utah Rating Scale (WURS). The main findings were that violent offenders with ASP had significantly higher mean WURS scores compared with controls, and both the absolute and percentage amount of stage 4 sleep as well as delta and theta powers in this sleep stage were positively correlated with the WURS scores. The present study supports the idea that childhood ADHD is associated with the abnormal sleep architecture in habitually violent men with ASP. These two disorders seem to share, at least partly, the same central nervous system deficit.

Adolescent↗
PubMed2004

Sleep in young adults with Asperger syndrome.

Asperger syndrome (AS) is a neurodevelopmental disorder belonging to autism spectrum disorders. Both children and adults with AS have subjective impairment in the initiation and continuity of sleep, and studies using objective assessment are sparse. Twenty young AS adults with frequent complaints of low sleep quality were compared to 10 age-, gender- and education-matched controls without sleep complaints using polysomnography and spectral power analysis of slow-wave sleep. AS subjects displayed a similar polysomnographic profile as compared with controls. In spectral power analysis, a statistically nonsignificant trend towards decreased relative delta power and increased theta power in slow-wave sleep was found in the AS group. It seems that nonorganic insomnia, due to anxiety inherent in AS, is responsible for the low sleep quality in these subjects.

Adult↗