Radek Ptacek | Charles University, Prague (original) (raw)

Papers by Radek Ptacek

European Neuropsychopharmacology, 2003

European Psychiatry, 2011

Stress in medical practice has always been a topical issue. This is partly because medical servic... more Stress in medical practice has always been a topical issue. This is partly because medical service involves taking care of other peoples´ lives and mistakes or errors could be costly and sometimes irreversible. It is thus expected that the medical doctor himself must be in a perfect state of mind devoid of morbid worries and anxieties. This is however not usually the case, because the doctor apart from being affected by the same variables that impose stress on the general population, is also prone to stress because of the peculiarities of his work situation and the expectation of the society at large. We have conducted an extensive research to determine the level of stress load and occurrence of burnout syndrome between Czech medical doctors comparing to general professions. Group of medical doctor (n=500) was compared to group of on medical professions (n=500) using questionnaires for evaluation of stress load and burnout syndrome. The results of the study confirmed that occurrence of high stress load and burnout syndrome is substantially higher than in non-medical professions (p< 0.01) and further several specific factors influencing occurrence of stress and burnout syndrome was identified (i.e. age, length of medical practice etc). The study supports the hypothesis that medical professions represent serious factor in stress load and thus persons in medical professions should be subject to special care. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-201.

European Psychiatry, 2011

Current studies show that individuals who were in foster or institutional care experience higher ... more Current studies show that individuals who were in foster or institutional care experience higher rates of physical and psychiatric morbidity than the general population. Children in foster care have a higher probability of having Attention Deficit Hyperactivity Disorder, and deficits in executive functioning, anxiety as well other developmental problems. These children experience higher degrees of incarceration, poverty, homelessness, and suicide. Recent studies show alarming occurrence of trauma and high stress load in children in institutional but as well as foster care. We have conducted an extensive study (n=360) monitoring occurrence of trauma in history of children in foster care (n=120), in institutional care (n=120) and in functional biological families (n=120). We have also evaluated levels of social emotional development and occurrence of child psychopathology. The results of the presented study showed that children in institutional and foster care show substantially higher occurrence of trauma in their history, higher incidence of reactive psychopathology (i.e. depression) and their level of social emotional development is substantially lower comparing to children from functional biological families (p< 0.01). The study proposes that children in foster and institutional care require substantial psychosocial support and attention. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-202.

European Psychiatry, 2011

Loneliness affects both psychical and physical health and among geriatric patients can be serious... more Loneliness affects both psychical and physical health and among geriatric patients can be serious. Social loneliness, anxiety-related personality traits, risk of developing depression, alcoholism or suicidal behavior could be associated with a functional variant in the serotonin transporter. Serotonin transporter gene length polymorphism (5-HTTLPR) is associated with changes of serotonin transporter activity and is one of the major factors which contribute to the etiology of many psychiatric disorders. The aim of the study was to found possible differences in distribution of variants in two groups of geriatric patients (average age 80 years). Group of 300 probands were examined for 5-HTTLPR variants. Blood samples were randomly collected from 150 elderly males and 150 elderly females. The elderly individuals were not related and lived in the same geographic region as the control newborns and the young adults. Two groups were defined -ambulatory (apparently healthy, 65 males and 70 females) and non-ambulatory (have no people who could take care about them, having chronic diseases and depend on geriatric care, 85 males and 80 females) people. Bialelic and trialelic dividing of 5-HTTLPR was considered. Length polymorphism was analyzed (L or S variant) and single nucleotide polymorphism was detected (L A or L G variant). A significant difference was found in allele distribution of 5-HTTLPR in two groups of patients. Ambulatory group of patients had higher occurrence of L allele and also L A allele. The results of the study suggest that social loneliness may have some personality predictors that may have its genetical correlates.

European Psychiatry, 2011

Assessment medicine represents an individual area of expertise that requires special skills and k... more Assessment medicine represents an individual area of expertise that requires special skills and knowledge and it also put specific stress load on the assessment doctors. Different responsibility and the style of work, including special kind of contact with clients make this profession to different from other fields of clinical medicine. The specific work load may bring different stressors and cause specific mental load. We have conducted an extensive research to determine the level of stress load and occurrence of possible signs of depression and other reactive mental illnesses among Czech assessment doctors. The research group consisted of all assessment doctors in the Czech Republic (n=403) and a control group consisting of other medical and non medical professions (m=403). The groups were compared on the basis of questionnaires evaluating levels of stress, depression and occurrence of other possible mental illnesses. General personality traits were evaluated too. The results of the study: Assessment medicine doctors show higher incidence of stress related phenomenon as depression, burnout syndrome and other reactive psychiatrical signs comparing to other medical and non-medical professions (p< 0.01). This may be connected to specificity of the profession bringing specific stress load. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-201.

European Psychiatry, 2011

Social and emotional loneliness represent a serious factor in etiology of psychiatric and somatic... more Social and emotional loneliness represent a serious factor in etiology of psychiatric and somatic disorders. Current studies show that individuals suffering from severe social and emotional loneliness in their childhood may show substantial deficits in cognitive as well as in emotional development. It is supposed that children in foster care or institutional care may be exposed to higher level of social or emotional loneliness and thus show changes in cognitive and emotional development, that may play role in further life as well as in etiology of mental illnesses. We have conducted an extensive study (n=360) monitoring occurrence of social and emotional loneliness in children in foster care (n=120), in institutional care (n=120) and in functional biological families (n=120). We have also evaluated the stage of cognitive and emotional development. The results of the presented study showed that children in institutional and foster care show substantially higher occurrence of serious level of social and emotional developmentcomparing to children from biological families (p, 0.01). The intensity of social and emotional loneliness is in negative correlation with cognitive (r=0, 6; p< 0.01) as well as with emotional development (r=0, 7; p< 0.01). The results of study propose that children in foster and institutional care require substantial psychosocial support and attention especially in the area of social and emotional development. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-202

European Psychiatry, 2011

According to current studies and clinical practice ADHD children show probable changes in growth ... more According to current studies and clinical practice ADHD children show probable changes in growth and development, mainly in signs of nutrition. ADHD can be associated with higher predisposition to obesity, higher values of signs of nutrition, as body mass index or higher value of fat. Growth and weight changes in ADHD children are usually described in connection to stimulants use, the most common medication of the disorder. However, present research confirmed that these changes could be more typical for the disorder than for the treatment. These characteristics are considered to be directly connected with the disorder. The presented study compared anthropometric characteristics -mainly signs of nutritionskin folds, abdominal circumference, in medicated and non-medicated ADHD boys (n=104, age 4-16 years) with the normal non-clinical population. The results of the presented study showed significant differences between children with ADHD and those without the diagnosis. The differences found to be statistically significant (p< 0.01) being signs of nutrition (percentage of fat, abdominal circumference) and also growth suppression (lower body height). Differences between the medicated and non-medicated groups corresponded only to a lower value of body fat in the medicated children. ADHD can higher values of nutrition signs (percentage of fat, abdominal circumference, BMI, weight) in comparison to normal population. It could be caused by specific feeding customs which should be monitored in further studies.

Medical science monitor: …, Jan 1, 2011

ANS: The Journal for Neurocognitive …, Jan 1, 2009

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed childhood p... more Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed childhood psychiatric disorders manifested in almost every part of children's behavior. The most common treatment of ADHD is medication with stimulants, by specific amphetamine and methylphenidate. It is known that the treatment by stimulants may be accompanied by side effects from among decrease of appetite or changes in development as growth suppression and loss of weight which may present very serious phenomenon. Although many studies have monitored changes in growth and weight during medication, they did not provide definite results that the growth and weight suppression are caused by medication or not. According to many studies the height deficit is approximately amounted to 1 cm/year during the first 3 years of the treatment and can be clinically serious. Contrary to these findings some authors reported that the growth or weight changes can be a natural symptom of ADHD and not just a consequence of medication. The present article reviews key studies monitoring changes in parameters of growth in medicated children with ADHD, compares their results and suggest methodology improvements for further studies.

Medical science …, Jan 1, 2009

This comparative and comprehensive study builds on a previous study comparing the P300 wave of im... more This comparative and comprehensive study builds on a previous study comparing the P300 wave of impulsively violent delinquents and a non-impulsive non-delinquent group. The purpose was to investigate changes in P300 cognitive evoked potentials, especially the amplitude and latency at the Pz electrode site. The P300 parameters of perpetrators of various types of criminal offences and those of a control group matched for age, gender, and educational status were compared (N=80). There were 20 subjects with impulsively aggressive delinquent behavior. The observed parameters were compared with the neuropsychophysiological correlates of a group of 20 subjects with deliberately (i.e. non-impulsive) violent behavior, a group of 20 delinquents sentenced for property crimes (theft), and 20 non-delinquent non-impulsive nonviolent persons. To differentiate these groups, Eysenck&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s IVE questionnaire and a structured interview according to DSM IV criteria conducted by a certified forensic psychiatrist were used. The results showed a significantly lower P300 wave amplitude in the impulsively aggressive individuals than in the other groups. No significant differences were found in terms of latency. The results confirm the results of previous studies. The results suggest the possibility of a neuropsychophysiological correlate of impulsively aggressive individuals behaving in a socially dangerous way. This opens a discussion on the subject of expert evaluation of criminal acts within the context of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;uncontrolled affect&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;.

Chronobiology …, Jan 1, 2011

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral disorder of ch... more Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral disorder of childhood. Problems with sleep structure, efficiency, and timing have been reported in some, but not all, studies on ADHD children. As the sleep-wake cycle belongs to circadian rhythms, the timekeeping circadian system might be involved in ADHD. To assess whether the circadian system of ADHD children differs from that of controls, the rhythm of the pineal hormone melatonin was used as a reliable marker of the system. Saliva from 34 ADHD and 43 control 6-to 12-yr-old children was sampled at 2-h intervals throughout the entire 24-h cycle, and the melatonin profiles of the ADHD and control children were compared. The nocturnal melatonin peaks of the ADHD and control group did not differ significantly. The high nocturnal interindividual variability of the peaks seen in adulthood was present already in the studied children. The 24-h melatonin profiles of all the ADHD subjects did not differ significantly from those of the control subjects. Categorization of subjects according to age, into groups of 6-to 7-yr-old (9 ADHD, 5 control), 8-to 9-yr-old (16 ADHD, 26 control), and 10-to 12-yr-old (9 ADHD, 12 control) children, revealed significant differences between the ADHD and control group in the melatonin rhythm waveform, but not in nocturnal melatonin peaks; the peaks were about the same in both groups and did not change significantly with increasing age. In the oldest, but not in the younger, children, the melatonin signal duration in the ADHD group was shorter than in the control group. The difference might be due to the fact that whereas in the control group both the evening melatonin onset and the morning offset phase delayed in the oldest children relative to those in the youngest children, in the ADHD group only the onset, but not the offset, phase delayed with increasing age. The data may indicate subtle differences between the circadian system of ADHD and control children during development.

Neuro endocrinology …, Jan 1, 2008

Event-Related potentials are a simple non-invasive neurophysiological method enabling to comprehe... more Event-Related potentials are a simple non-invasive neurophysiological method enabling to comprehend certain aspects of the cognitive processing of information in humans. The best-known component of Event-Related Potentials is the so-called P3 wave. Alterations in the parameters of P300 wave have been discovered in certain personality disorders and in persons with impulsively aggressive behaviour. The purpose of this study is to investigate the changes of these parameters, especially an amplitude and latency in the place of Pz electrode. We examined 15 persons with the impulsive aggressive behaviour and compared them to a population comparable of normal age, gender and approximate degree of education. We used P300 auditory and a neuropsychological Eysenck IVE battery. The results showed that significantly lower amplitudes had been found in the aggressive impulsive subjects as compared to the control group. No statistically significant differences have been discovered in the latency. These results seem to confirm previous studies.

Neuro endocrinology …, Jan 1, 2007

Dissociation is often defined as partial or total disconnection between memories of the past, awa... more Dissociation is often defined as partial or total disconnection between memories of the past, awareness of identity and of immediate sensations, and control of bodily movements, often resulting from traumatic experiences, intolerable problems, or disturbed relationships. This type of reaction to a psychological and/or physical trauma has often various neurobiological consequences and its clinical assessment has received enormous interest in recent psychological and neuroscience research. Psychometric parameters of the Czech version of the Dissociative Experiences Scale were tested from the viewpoints of internal consistency, validity and factor structure, using data from a sample of n=783 adults, divided into three groups (epilepsy n=243, depression n=357, norm n=183), average age 39 years, SD=13.5. Findings of this study demonstrated that reliability, validity and factor structure of the Czech version of the Dissociative Experiences Scale correspond to those of the original English version. The Czech version of the questionnaire may be considered a suitable tool for estimating subjectively experienced dissociative symptoms.

Neuro endocrinology …, Jan 1, 2009

The aim of the study is to compare complex anthropometric characteristics in non medicated boys w... more The aim of the study is to compare complex anthropometric characteristics in non medicated boys with ADHD and normal population. METHODS: Complex anthropometric examination of non-medicated ADHD boys (n=46, average age 11.03 years), statistical and clinical comparison to the actual population growth norm. In contrast to the most of the previous studies, which analyzed mostly only BMI or basic signs of growth as height and weight, the presented study operates with a complex anthropometrical measurement and comparison with actual population norm.

Sleep Medicine, Jan 1, 2010

Objective: To evaluate sleep macrostructure, sleep disorders incidence and daytime sleepiness in ... more Objective: To evaluate sleep macrostructure, sleep disorders incidence and daytime sleepiness in attention-deficit/hyperactivity disorder (ADHD) affected children compared with controls. Methods: Thirty-one patients (26 boys, 5 girls, mean age 9.3 ± 1.7, age range 6-12 years) with ADHD diagnosed according to DSM-IV criteria, without comorbid psychiatric or other disorders, as never before pharmacologically treated for ADHD. The controls were 26 age-and sex-matched children (22 boys, 4 girls, age range 6-12 years, mean age 9.2 ± 1.5). Nocturnal polysomnography (PSG) was performed for two nights followed by the multiple sleep latency test (MSLT). Results: No differences between the two groups comparing both nights were found in the basic sleep macrostructure parameters or in the time (duration) of sleep onset. A first-night effect on sleep variables was apparent in the ADHD group. Occurrence of sleep disorders (sleep-disordered breathing [SDB], periodic limb movements in sleep [PLMS], parasomnias) did not show any significant differences between the investigated groups. A statistically significant difference (p = 0.015) was found in the trend of the periodic limb movement index (PLMI) between two nights (a decrease of PLMI in the ADHD group and an increase of PLMI in the control group during the second night). While the mean sleep latency in the MSLT was comparable in both groups, children with ADHD showed significant (sleep latency) inter-test differences (between tests 1 and 2, 1 and 4, 1 and 5, p < 0.01). Conclusion: After the inclusion of adaptation night and exclusion of psychiatric comorbidities, PSG showed no changes in basic sleep parameters or sleep timing, or in the frequency of sleep disorders (SDB, PLMS) in children with ADHD compared with controls, thus not supporting the hypothesis that specific changes in the sleep macrostructure and sleep disturbances are connected with ADHD. A first-night effect on sleep variables was apparent only in the ADHD group. Though we found no proof of increased daytime sleepiness in children with ADHD against the controls, we did find significant vigilance variability during MSLT in the ADHD group, possibly a sign of dysregulated arousal.

… medical journal of …, Jan 1, 2009

AHDH children can show changes in growth and development. Many studies describe these changes as ... more AHDH children can show changes in growth and development. Many studies describe these changes as a side effect of stimulant medication. However, changes in somatic development can also appear n non-medicated children. This suggests that the changes could be a manifestation of the disorder itself and not just a side effect of the treatment.

European Neuropsychopharmacology, 2003

European Psychiatry, 2011

Stress in medical practice has always been a topical issue. This is partly because medical servic... more Stress in medical practice has always been a topical issue. This is partly because medical service involves taking care of other peoples´ lives and mistakes or errors could be costly and sometimes irreversible. It is thus expected that the medical doctor himself must be in a perfect state of mind devoid of morbid worries and anxieties. This is however not usually the case, because the doctor apart from being affected by the same variables that impose stress on the general population, is also prone to stress because of the peculiarities of his work situation and the expectation of the society at large. We have conducted an extensive research to determine the level of stress load and occurrence of burnout syndrome between Czech medical doctors comparing to general professions. Group of medical doctor (n=500) was compared to group of on medical professions (n=500) using questionnaires for evaluation of stress load and burnout syndrome. The results of the study confirmed that occurrence of high stress load and burnout syndrome is substantially higher than in non-medical professions (p< 0.01) and further several specific factors influencing occurrence of stress and burnout syndrome was identified (i.e. age, length of medical practice etc). The study supports the hypothesis that medical professions represent serious factor in stress load and thus persons in medical professions should be subject to special care. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-201.

European Psychiatry, 2011

Current studies show that individuals who were in foster or institutional care experience higher ... more Current studies show that individuals who were in foster or institutional care experience higher rates of physical and psychiatric morbidity than the general population. Children in foster care have a higher probability of having Attention Deficit Hyperactivity Disorder, and deficits in executive functioning, anxiety as well other developmental problems. These children experience higher degrees of incarceration, poverty, homelessness, and suicide. Recent studies show alarming occurrence of trauma and high stress load in children in institutional but as well as foster care. We have conducted an extensive study (n=360) monitoring occurrence of trauma in history of children in foster care (n=120), in institutional care (n=120) and in functional biological families (n=120). We have also evaluated levels of social emotional development and occurrence of child psychopathology. The results of the presented study showed that children in institutional and foster care show substantially higher occurrence of trauma in their history, higher incidence of reactive psychopathology (i.e. depression) and their level of social emotional development is substantially lower comparing to children from functional biological families (p< 0.01). The study proposes that children in foster and institutional care require substantial psychosocial support and attention. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-202.

European Psychiatry, 2011

Loneliness affects both psychical and physical health and among geriatric patients can be serious... more Loneliness affects both psychical and physical health and among geriatric patients can be serious. Social loneliness, anxiety-related personality traits, risk of developing depression, alcoholism or suicidal behavior could be associated with a functional variant in the serotonin transporter. Serotonin transporter gene length polymorphism (5-HTTLPR) is associated with changes of serotonin transporter activity and is one of the major factors which contribute to the etiology of many psychiatric disorders. The aim of the study was to found possible differences in distribution of variants in two groups of geriatric patients (average age 80 years). Group of 300 probands were examined for 5-HTTLPR variants. Blood samples were randomly collected from 150 elderly males and 150 elderly females. The elderly individuals were not related and lived in the same geographic region as the control newborns and the young adults. Two groups were defined -ambulatory (apparently healthy, 65 males and 70 females) and non-ambulatory (have no people who could take care about them, having chronic diseases and depend on geriatric care, 85 males and 80 females) people. Bialelic and trialelic dividing of 5-HTTLPR was considered. Length polymorphism was analyzed (L or S variant) and single nucleotide polymorphism was detected (L A or L G variant). A significant difference was found in allele distribution of 5-HTTLPR in two groups of patients. Ambulatory group of patients had higher occurrence of L allele and also L A allele. The results of the study suggest that social loneliness may have some personality predictors that may have its genetical correlates.

European Psychiatry, 2011

Assessment medicine represents an individual area of expertise that requires special skills and k... more Assessment medicine represents an individual area of expertise that requires special skills and knowledge and it also put specific stress load on the assessment doctors. Different responsibility and the style of work, including special kind of contact with clients make this profession to different from other fields of clinical medicine. The specific work load may bring different stressors and cause specific mental load. We have conducted an extensive research to determine the level of stress load and occurrence of possible signs of depression and other reactive mental illnesses among Czech assessment doctors. The research group consisted of all assessment doctors in the Czech Republic (n=403) and a control group consisting of other medical and non medical professions (m=403). The groups were compared on the basis of questionnaires evaluating levels of stress, depression and occurrence of other possible mental illnesses. General personality traits were evaluated too. The results of the study: Assessment medicine doctors show higher incidence of stress related phenomenon as depression, burnout syndrome and other reactive psychiatrical signs comparing to other medical and non-medical professions (p< 0.01). This may be connected to specificity of the profession bringing specific stress load. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-201.

European Psychiatry, 2011

Social and emotional loneliness represent a serious factor in etiology of psychiatric and somatic... more Social and emotional loneliness represent a serious factor in etiology of psychiatric and somatic disorders. Current studies show that individuals suffering from severe social and emotional loneliness in their childhood may show substantial deficits in cognitive as well as in emotional development. It is supposed that children in foster care or institutional care may be exposed to higher level of social or emotional loneliness and thus show changes in cognitive and emotional development, that may play role in further life as well as in etiology of mental illnesses. We have conducted an extensive study (n=360) monitoring occurrence of social and emotional loneliness in children in foster care (n=120), in institutional care (n=120) and in functional biological families (n=120). We have also evaluated the stage of cognitive and emotional development. The results of the presented study showed that children in institutional and foster care show substantially higher occurrence of serious level of social and emotional developmentcomparing to children from biological families (p, 0.01). The intensity of social and emotional loneliness is in negative correlation with cognitive (r=0, 6; p< 0.01) as well as with emotional development (r=0, 7; p< 0.01). The results of study propose that children in foster and institutional care require substantial psychosocial support and attention especially in the area of social and emotional development. SUPPORTED BY THE RESEARCH GRANT GK MPSV-01-202

European Psychiatry, 2011

According to current studies and clinical practice ADHD children show probable changes in growth ... more According to current studies and clinical practice ADHD children show probable changes in growth and development, mainly in signs of nutrition. ADHD can be associated with higher predisposition to obesity, higher values of signs of nutrition, as body mass index or higher value of fat. Growth and weight changes in ADHD children are usually described in connection to stimulants use, the most common medication of the disorder. However, present research confirmed that these changes could be more typical for the disorder than for the treatment. These characteristics are considered to be directly connected with the disorder. The presented study compared anthropometric characteristics -mainly signs of nutritionskin folds, abdominal circumference, in medicated and non-medicated ADHD boys (n=104, age 4-16 years) with the normal non-clinical population. The results of the presented study showed significant differences between children with ADHD and those without the diagnosis. The differences found to be statistically significant (p< 0.01) being signs of nutrition (percentage of fat, abdominal circumference) and also growth suppression (lower body height). Differences between the medicated and non-medicated groups corresponded only to a lower value of body fat in the medicated children. ADHD can higher values of nutrition signs (percentage of fat, abdominal circumference, BMI, weight) in comparison to normal population. It could be caused by specific feeding customs which should be monitored in further studies.

Medical science monitor: …, Jan 1, 2011

ANS: The Journal for Neurocognitive …, Jan 1, 2009

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed childhood p... more Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed childhood psychiatric disorders manifested in almost every part of children's behavior. The most common treatment of ADHD is medication with stimulants, by specific amphetamine and methylphenidate. It is known that the treatment by stimulants may be accompanied by side effects from among decrease of appetite or changes in development as growth suppression and loss of weight which may present very serious phenomenon. Although many studies have monitored changes in growth and weight during medication, they did not provide definite results that the growth and weight suppression are caused by medication or not. According to many studies the height deficit is approximately amounted to 1 cm/year during the first 3 years of the treatment and can be clinically serious. Contrary to these findings some authors reported that the growth or weight changes can be a natural symptom of ADHD and not just a consequence of medication. The present article reviews key studies monitoring changes in parameters of growth in medicated children with ADHD, compares their results and suggest methodology improvements for further studies.

Medical science …, Jan 1, 2009

This comparative and comprehensive study builds on a previous study comparing the P300 wave of im... more This comparative and comprehensive study builds on a previous study comparing the P300 wave of impulsively violent delinquents and a non-impulsive non-delinquent group. The purpose was to investigate changes in P300 cognitive evoked potentials, especially the amplitude and latency at the Pz electrode site. The P300 parameters of perpetrators of various types of criminal offences and those of a control group matched for age, gender, and educational status were compared (N=80). There were 20 subjects with impulsively aggressive delinquent behavior. The observed parameters were compared with the neuropsychophysiological correlates of a group of 20 subjects with deliberately (i.e. non-impulsive) violent behavior, a group of 20 delinquents sentenced for property crimes (theft), and 20 non-delinquent non-impulsive nonviolent persons. To differentiate these groups, Eysenck&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s IVE questionnaire and a structured interview according to DSM IV criteria conducted by a certified forensic psychiatrist were used. The results showed a significantly lower P300 wave amplitude in the impulsively aggressive individuals than in the other groups. No significant differences were found in terms of latency. The results confirm the results of previous studies. The results suggest the possibility of a neuropsychophysiological correlate of impulsively aggressive individuals behaving in a socially dangerous way. This opens a discussion on the subject of expert evaluation of criminal acts within the context of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;uncontrolled affect&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;.

Chronobiology …, Jan 1, 2011

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral disorder of ch... more Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral disorder of childhood. Problems with sleep structure, efficiency, and timing have been reported in some, but not all, studies on ADHD children. As the sleep-wake cycle belongs to circadian rhythms, the timekeeping circadian system might be involved in ADHD. To assess whether the circadian system of ADHD children differs from that of controls, the rhythm of the pineal hormone melatonin was used as a reliable marker of the system. Saliva from 34 ADHD and 43 control 6-to 12-yr-old children was sampled at 2-h intervals throughout the entire 24-h cycle, and the melatonin profiles of the ADHD and control children were compared. The nocturnal melatonin peaks of the ADHD and control group did not differ significantly. The high nocturnal interindividual variability of the peaks seen in adulthood was present already in the studied children. The 24-h melatonin profiles of all the ADHD subjects did not differ significantly from those of the control subjects. Categorization of subjects according to age, into groups of 6-to 7-yr-old (9 ADHD, 5 control), 8-to 9-yr-old (16 ADHD, 26 control), and 10-to 12-yr-old (9 ADHD, 12 control) children, revealed significant differences between the ADHD and control group in the melatonin rhythm waveform, but not in nocturnal melatonin peaks; the peaks were about the same in both groups and did not change significantly with increasing age. In the oldest, but not in the younger, children, the melatonin signal duration in the ADHD group was shorter than in the control group. The difference might be due to the fact that whereas in the control group both the evening melatonin onset and the morning offset phase delayed in the oldest children relative to those in the youngest children, in the ADHD group only the onset, but not the offset, phase delayed with increasing age. The data may indicate subtle differences between the circadian system of ADHD and control children during development.

Neuro endocrinology …, Jan 1, 2008

Event-Related potentials are a simple non-invasive neurophysiological method enabling to comprehe... more Event-Related potentials are a simple non-invasive neurophysiological method enabling to comprehend certain aspects of the cognitive processing of information in humans. The best-known component of Event-Related Potentials is the so-called P3 wave. Alterations in the parameters of P300 wave have been discovered in certain personality disorders and in persons with impulsively aggressive behaviour. The purpose of this study is to investigate the changes of these parameters, especially an amplitude and latency in the place of Pz electrode. We examined 15 persons with the impulsive aggressive behaviour and compared them to a population comparable of normal age, gender and approximate degree of education. We used P300 auditory and a neuropsychological Eysenck IVE battery. The results showed that significantly lower amplitudes had been found in the aggressive impulsive subjects as compared to the control group. No statistically significant differences have been discovered in the latency. These results seem to confirm previous studies.

Neuro endocrinology …, Jan 1, 2007

Dissociation is often defined as partial or total disconnection between memories of the past, awa... more Dissociation is often defined as partial or total disconnection between memories of the past, awareness of identity and of immediate sensations, and control of bodily movements, often resulting from traumatic experiences, intolerable problems, or disturbed relationships. This type of reaction to a psychological and/or physical trauma has often various neurobiological consequences and its clinical assessment has received enormous interest in recent psychological and neuroscience research. Psychometric parameters of the Czech version of the Dissociative Experiences Scale were tested from the viewpoints of internal consistency, validity and factor structure, using data from a sample of n=783 adults, divided into three groups (epilepsy n=243, depression n=357, norm n=183), average age 39 years, SD=13.5. Findings of this study demonstrated that reliability, validity and factor structure of the Czech version of the Dissociative Experiences Scale correspond to those of the original English version. The Czech version of the questionnaire may be considered a suitable tool for estimating subjectively experienced dissociative symptoms.

Neuro endocrinology …, Jan 1, 2009

The aim of the study is to compare complex anthropometric characteristics in non medicated boys w... more The aim of the study is to compare complex anthropometric characteristics in non medicated boys with ADHD and normal population. METHODS: Complex anthropometric examination of non-medicated ADHD boys (n=46, average age 11.03 years), statistical and clinical comparison to the actual population growth norm. In contrast to the most of the previous studies, which analyzed mostly only BMI or basic signs of growth as height and weight, the presented study operates with a complex anthropometrical measurement and comparison with actual population norm.

Sleep Medicine, Jan 1, 2010

Objective: To evaluate sleep macrostructure, sleep disorders incidence and daytime sleepiness in ... more Objective: To evaluate sleep macrostructure, sleep disorders incidence and daytime sleepiness in attention-deficit/hyperactivity disorder (ADHD) affected children compared with controls. Methods: Thirty-one patients (26 boys, 5 girls, mean age 9.3 ± 1.7, age range 6-12 years) with ADHD diagnosed according to DSM-IV criteria, without comorbid psychiatric or other disorders, as never before pharmacologically treated for ADHD. The controls were 26 age-and sex-matched children (22 boys, 4 girls, age range 6-12 years, mean age 9.2 ± 1.5). Nocturnal polysomnography (PSG) was performed for two nights followed by the multiple sleep latency test (MSLT). Results: No differences between the two groups comparing both nights were found in the basic sleep macrostructure parameters or in the time (duration) of sleep onset. A first-night effect on sleep variables was apparent in the ADHD group. Occurrence of sleep disorders (sleep-disordered breathing [SDB], periodic limb movements in sleep [PLMS], parasomnias) did not show any significant differences between the investigated groups. A statistically significant difference (p = 0.015) was found in the trend of the periodic limb movement index (PLMI) between two nights (a decrease of PLMI in the ADHD group and an increase of PLMI in the control group during the second night). While the mean sleep latency in the MSLT was comparable in both groups, children with ADHD showed significant (sleep latency) inter-test differences (between tests 1 and 2, 1 and 4, 1 and 5, p < 0.01). Conclusion: After the inclusion of adaptation night and exclusion of psychiatric comorbidities, PSG showed no changes in basic sleep parameters or sleep timing, or in the frequency of sleep disorders (SDB, PLMS) in children with ADHD compared with controls, thus not supporting the hypothesis that specific changes in the sleep macrostructure and sleep disturbances are connected with ADHD. A first-night effect on sleep variables was apparent only in the ADHD group. Though we found no proof of increased daytime sleepiness in children with ADHD against the controls, we did find significant vigilance variability during MSLT in the ADHD group, possibly a sign of dysregulated arousal.

… medical journal of …, Jan 1, 2009

AHDH children can show changes in growth and development. Many studies describe these changes as ... more AHDH children can show changes in growth and development. Many studies describe these changes as a side effect of stimulant medication. However, changes in somatic development can also appear n non-medicated children. This suggests that the changes could be a manifestation of the disorder itself and not just a side effect of the treatment.