Spontaneous K-complexes in chronic psychophysiological insomnia

Objective

Spontaneous K-complexes are electroencephalographic features unique to non-rapid eye movement sleep. It has been suggested that this phasic event is a sleep-protective mechanism. Because insomnia sufferers report poor sleep quantity and quality, the objective of this study was to document the occurrence of spontaneous K-complexes in Stage 2 sleep of individuals with chronic insomnia. Specifically, the number and density of spontaneous K-complexes were studied in psychophysiological insomnia sufferers.

Setting

This study took place in a sleep and event-related potentials laboratory.

Design

Spontaneous K-complexes were scored during Stage 2 sleep on the second and third nights of a four-consecutive-nights protocol of polysomnographic recordings.

Participants

The sample included 14 participants suffering from psychophysiological insomnia (INS group; mean age=44.1 years) and 14 good sleepers (mean age=38.1 years). Participants underwent sleep and psychological evaluations. INS group participants met the diagnostic criteria for primary psychophysiological insomnia (mean duration of insomnia=9.6 years).

Intervention

Not applicable.

Results

The total number of spontaneous K-complexes and the density according to the total time spent in Stage 2 sleep (spontaneous K-complexes per minute) were compiled. Repeated-measures analyses of variance showed no significant difference in the number and density of spontaneous K-complexes between the INS group (313.98 and 2.66) and the GS group (361.10 and 2.88), respectively.

Conclusion

These results suggest no deficiency in the sleep-protective mechanism of psychophysiological insomnia sufferers in comparison with good sleepers, as measured by the spontaneous K-complexes' number and density.     

EEG coherence during hemispheric activation in schizophrenics

Summary We studied the change of EEG alpha-band coherence between resting and motor performance (reactivity of EEG coherence) in 18 chronic schizophrenics and 30 normal controls, examining differences between left and right hemisphere tasks. Three coherences were examined for each hemisphere. The central-parietal coherence in normals increased on the left for left hemisphere tasks, and decreased on the right for right hemisphere tasks, whereas the patients showed a decrease of both measures, more on the left side. Thus, the interhemispheric difference of central-parietal coherence reactivity was reversed for the schizophrenics (P<0.06) and suggested a left-sided deviation. The lateral-precentral and precentral-central coherences showed no left-right deviations of reactivity in the patients. Since coherence increase is considered to be a sign of the coupled function between the studied regions, our findings suggest a defective coordination of left central-parietal regions during a task in schizophrenics.     

Computer-based model of epidural motor cortex stimulation: Effects of electrode position and geometry on activation of cortical neurons

Objective

The aim of this study was to determine the effects of electrode placement, geometry, and polarity during epidural cortical stimulation (ECS) on thresholds for direct activation of cortical neurons.

Methods

We used a computational model of epidural electrical stimulation of the motor cortex coupled to compartmental models of cortical neurons.

Results

Thresholds varied with stimulation polarity and neuron position, and neurons deep within the sulci had much larger thresholds than those on the crowns or lips of the gyri. Axons were more excitable than cell bodies or dendrites. Delivering stimulation with the lead placed above or perpendicular to the sulci resulted in substantial stimulation of the gyri adjacent to the target gyrus. Electrode diameter and inter-electrode spacing influenced thresholds and affected the spread of activation in the cortex.

Conclusions

Electrode placement, geometry, and polarity during ECS influence excitation properties of cortical neurons substantially.

Significance

Epidural leads have varying geometries, and in clinical studies of ECS the placement of the lead has been inconsistent. These results provide an improved understanding of the effects of electrode placement, geometry, and polarity on the outcome of ECS and can facilitate the rational implantation and programming of ECS systems.     

Normative values for the Hospital Anxiety and Depression Scale (HADS) in the general German population

Objective

The aim of this study was to present normative values for the Hospital Anxiety and Depression Scale (HADS).

Methods

A representative sample of the German general population (N=4410) was tested with the HADS.

Results

Females are more anxious than males, and older subjects are more depressed than younger subjects. The mean scores for anxiety / depression are 4.4 / 4.8 (males) and 5.0 / 4.7 (females). Using the cut-off 8+, the percentages of elevated anxiety and depression in the total sample are 21 % and 23 %, respectively. Regression analyses proved a linear but not a curvilinear age trend of anxiety and depression. Percentile rank norms are given for anxiety, depression, and the HADS total score.

Conclusion

The regression coefficients allow the calculation of expected mean scores for each age and gender distribution of any sample of patients. HADS mean scores are better suited to describe the degree of anxiety and depression in patient samples compared to percentages of subjects with elevated values.     

Disturbed functional connectivity within brain networks subserving domain-specific subcomponents of working memory in schizophrenia: Relation to performance and clinical symptoms

Introduction

Disturbed interregional functional connectivity has been hypothesized to be a promising marker of schizophrenia. The relationship between working memory (WM) impairment, disturbed functional connectivity, and the characteristic symptoms of schizophrenia, however, remains elusive.

Methods

We used functional MRI (fMRI) to investigate in patients with schizophrenia and matched controls the patterns of functional connectivity during the performance of different tasks selectively engaging subcomponent processes of working memory.

Results

Compared with controls, patients showed reduced connectivity of the prefrontal cortex with the intraparietal cortex and the hippocampus and abnormal negative interactions between the ventrolateral and dorsolateral prefrontal cortex during the non-articulatory maintenance of phonological information. During the maintenance of visuospatial information, patients presented reduced connectivity between regions in the superior parietal and occipital cortex, as well as enhanced positive connectivity of the frontal eye field with visual processing areas.

Discussion

Our findings suggest complex dysregulations within the networks supporting working memory functions in schizophrenia, which manifest as decreased positive and abnormal negative interactions. Correlations between the connection strength and WM performance suggest that these dysregulations may be neurofunctional correlates of the WM deficits seen in schizophrenia. Altered prefronto-hippocampal and parieto-occipital connectivity was further found to be associated with higher positive symptoms, providing a possible explanation for the development of delusions and disorganization symptoms.

Conclusion

The present findings can help to better understand the relationship between altered patterns of synchronized brain activity and the cognitive and clinical symptoms of schizophrenia.     

Atypical alpha asymmetry in adults with ADHD

Introduction

A growing body of literature suggests atypical cerebral asymmetry and interhemispheric interaction in ADHD. A common means of assessing lateralized brain function in clinical populations has been to examine the relative proportion of EEG alpha activity (8-12 Hz) in each hemisphere (i.e., alpha asymmetry). Increased rightward alpha asymmetry has been associated with ADHD-like traits such as reduced reward responsiveness, a lack of inhibition toward aversive experience, and increased approach behaviors, and previous work has indicated increased rightward alpha asymmetry in children with ADHD. The current study explores whether increased rightward alpha asymmetry is also evident in adults with ADHD.

Method

We assessed low (8-10 Hz) and high (10-12 Hz) alpha asymmetry in adults with ADHD (n = 29) versus controls (n = 62) during baseline and cognitive activation conditions for nine homologous electrode pairs along the anterior-posterior axis. Result: Seven results emerged (p < .05) showing increased rightward alpha asymmetry in adults with ADHD. This occurred in three specific electrode pairs across two testing conditions, and five of six results occurred in the lower alpha band. Finally, post hoc analysis indicated that increased rightward alpha asymmetry was generally associated with greater numbers of ADHD symptoms—with a possible parietal association for inattentive and a fronto-temporal association for hyperactivity symptoms.

Conclusions

Increased rightward alpha asymmetry previously observed in children with ADHD appears to be a developmentally persistent feature of ADHD.     

L’enfance des schizophrènes : revue de la littérature

Introduction

Pre-morbid antecedents in schizophrenia have been studied for some time now more particularly as potential markers of vulnerability. What are the tell-tale signs in some of the patient's childhood? The authors suggest a non-exhaustive review of the literature on this subject.

Method

The authors reviewed the literature (English and French) of prospective and retrospective studies.

Results

Many fields appear to be impaired during the childhood of some schizophrenic patients, fields such as: developmental abnormalities, speech impairments, social interactions, behaviour, cognitive functioning. The authors also noticed the presence of neurological soft signs and para-clinical abnormalities.

Discussion

The authors suggest a critical and synthetic review of existing data: what can be retained of this data? The authors also discuss the evolution of these signs and their interaction with the evolution of the disease itself.

Conclusion

Many of these signs were noticed in several children who later developed schizophrenia. For many authors, the more important these signs are, the more severe the disease will be. These pre-morbid antecedents give rise to theoretical questions and open perspectives concerning an early diagnosis of schizophrenia.     

Reduced functional connectivity in visual evoked potentials in children with autism spectrum disorder

Objective

An analysis of EEG synchrony between homologous early visual areas tested the hypothesis that interhemispheric functional connectivity during visual stimulation is reduced in children with autism compared to controls.

Methods

EEG power and coherence within and between two homologous regions of the occipital cortex were measured during long latency flash visual evoked potentials. Measures were compared between two groups of children (5.5–8.5 years), one with autism spectrum disorders and the other with typical development.

Results

In and below the theta band, interhemispheric synchrony was reduced in autistic subjects compared to typical controls by as much as 50%. Above the theta band interhemispheric synchrony in autistic children became indistinguishable from what would occur for uncorrelated cortical activity. Interhemispheric synchrony in autistic subjects was decreased in spite of bilaterally increased power. Wavelet power showed autistic children had a more rapid initial response to stimulation, a slower recovery, and more modulation at longer latencies.

Conclusions

Results suggest that the sensory cortices of autistic children are hypersensitive to stimulation with concurrent diminished functional connectivity between hemispheres.

Significance

Simultaneously increased intrahemispheric power and decreased interhemispheric synchronization of elemental visual information suggests either that power increases cause poor interhemispheric connectivity or that processes, such as thalamocortical regulation, impact power and coherence independently.     

Abnormal interhemispheric connectivity in male psychopathic offenders

Background

Psychopathic offenders inevitably violate interpersonal norms and frequently resort to aggressive and criminal behaviour. The affective and cognitive deficits underlying these behaviours have been linked to abnormalities in functional interhemispheric connectivity. However, direct neurophysiological evidence for dysfunctional connectivity in psychopathic offenders is lacking.

Methods

We used transcranial magnetic stimulation combined with electroencephalography to examine interhemispheric connectivity in the dorsolateral and motor cortex in a sample of psychopathic offenders and healthy controls. We also measured intracortical inhibition and facilitation over the left and right motor cortex to investigate the effects of local cortical processes on interhemispheric connectivity.

Results

We enrolled 17 psychopathic offenders and 14 controls in our study. Global abnormalities in right to left functional connectivity were observed in psychopathic offenders compared with controls. Furthermore, in contrast to controls, psychopathic offenders showed increased intracortical inhibition in the right, but not the left, hemisphere.

Limitations

The relatively small sample size limited the sensitivity to show that the abnormalities in interhemispheric connectivity were specifically related to the dorsolateral prefrontal cortex in psychopathic offenders.

Conclusion

To our knowledge, this study provides the first neurophysiological evidence for abnormal interhemispheric connectivity in psychopathic offenders and may further our understanding of the disruptive antisocial behaviour of these offenders.     

Positive impact of a family practice-based depression case management on patient's self-management

Objective

Family practice-based depression case management improves depression symptoms and adherence to medication. The aim of this study was to explore the long-term effects of practice-based depression case management on patient depression-related self-management knowledge and activities.

Methods

This long-term follow-up of a randomized controlled trial study took place 12 months after the end of the 1-year case management intervention. We used a modified version of the depression-specific self-management questionnaire described in Ludman et al. [Psychol Med, 33 (2003) 1061-1070]. Analyses of self-management knowledge and activities used a linear mixed model accounting for practice cluster effects and treatment group.

Results

Of the 626 patients included at baseline, 439 (70.1%) participated 24 months later in this follow-up study, i.e., 12 months after the end of the intervention. Compared to control recipients, intervention recipients presented statistically significant increased knowledge of medication side-effects and felt more able to avoid situations that may trigger depression. They also tried more often to undertake enjoyable activities and set more time aside for these activities.

Conclusion

This study suggests that case management improves depression-related self-management knowledge and activities in depressed primary care patients 12 months after the end of the intervention.

Practice implications

Clinicians may consider introducing practice-based case management for improving patients' self-management activities and knowledge.     

H-MR-spectroscopy of cerebellum in adult attention deficit/hyperactivity disorder

Introduction

Neurobiological research has implicated the cerebellum as one possible site of neurophysiological dysfunction in ADHD. Latest theoretical conceptualizations of the cerebellum as core site of the brain to model motor as well as cognitive behavior puts further weight to the assumption that it might play a key role in ADHD pathophysiology.

Methods

30 medication free adult ADHD patients and 30 group matched (gender, age and education) healthy controls were investigated using the method of chemical shift imaging (CSI) of the cerebellum. The vermis, left and right cerebellar hemispheres were processed separately.

Results

We found significantly increased glutamate-glutamine (Glx) to creatine (Cre) ratios in the left cerebellar hemisphere. No other differences in measured metabolite concentrations were observed.

Discussion

To our knowledge this is the first evidence for neurochemical alterations in cerebellar neurochemistry in adult ADHD. They relate well to recent hypotheses that the cerebellum might control mental activities by internal models.     

Topography of syllable change-detection electrophysiological indices in children and adults with reading disabilities

Introduction

Developmental dyslexia (DD) is a frequent language-based learning disorder. The predominant etiological view postulates that reading problems originate from a phonological impairment.

Method

We studied mismatch negativity (MMN) and Late Discriminative Negativity (LDN) to syllables change in both children (n = 12; 8-12 years) and young adults (n = 15; 14-23 years) with DD compared with controls.

Results/discussion

The present study confirmed abnormal automatic discrimination of syllable changes in both children and adults with developmental dyslexia. MMN topographic, amplitude and latency group differences were evidenced, suggesting different brain mechanisms involved in elementary auditory stimulus change-detection in DD, especially in the left hemisphere. The LDN results demonstrated that the auditory disorder of temporal processing in DD children becomes more serious at late stages of information processing and that the apparent cerebral hypo reactivity to speech changes in DD actually may correspond to additional processes. The age-related differences observed in both MMN and LDN topographies, amplitudes and latency between subjects with DD and controls could indicate different developmental courses in the neural representation of basic speech sounds in good and poor readers, with a tendency to normalization with increasing age.

Conclusion

Our results showing atypical electrophysiological concomitants of speech auditory perception in DD strongly support the hypothesis of deviant cortical organization in DD.     

Single-prolonged stress induces apoptosis in the amygdala in a rat model of post-traumatic stress disorder

Objective

To detect the apoptosis-related Bax and Bcl-2 gene expression and apoptotic cell death in the amygdala region in the single-prolonged stress (SPS) rats.

Methods

A total of 100 male Wistar rats were randomly divided into a normal control group and SPS groups of 1d, 4d, 7d, and 14d. The expression of Bax and Bcl-2 was detected using immunohistochemistry and Western Blotting; TUNEL-staining and double-labeled flow cytometry (FCM) were employed for the detection and quantification of the apoptotic cells in the amygdala; morphological change of the subcellular structure in amygdala was observed by using the transmission electron microscopy (TEM).

Results

The ratio of Bax/Bcl-2 peaked at SPS 4d and then gradually decreased. The apoptosis peaked at SPS 4d. The TUNEL-positive cells were found in each SPS group and the TUNEL-positive cells rate peaked at SPS 4d. The morphological change of amygdala cells in each SPS group bears typical apoptotic characteristics.

Conclusions

In the SPS rat brain, we found apoptotic process in the amygdala region which may relate to the pathogenesis of amygdala abnormal function in PTSD.     

Affect recognition as an independent social function determinant in schizophrenia

Introduction

Facial affect recognition deficits may represent specific deficits and contribute to social dysfunction in patients with schizophrenia. Whether their impacts on social dysfunction are independent to those caused by deficits in basic neurocognition and clinical symptoms needs to be further delineated.

Method

Association patterns between affect recognition and basic neurocognitive abilities in 40 acute and 33 stable patients with schizophrenia were compared to explore whether their interrelationships changed across clinical stages. The independent contribution of affect recognition deficits to social dysfunction was explored by multivariate models controlling for general intellectual ability, basic neurocognition, and clinical symptoms.

Results

Affect recognition deficits were associated with social role performances, self-care, and contributed independently to global social functioning in stable patients but not in acute patients. Conversely, affect recognition deficits were associated with impaired basic neurocognitions in acute patients but not in stable patients.

Conclusion

In stabilized community patients with schizophrenia, affect recognition deficits were relatively independent to basic neurocognition and had significant social functional consequences.     

Medication management of depression: the impact of comorbid chronic medical conditions

Objective

This paper addresses the following question: Does quality of care for depression differ between depressed persons with and without chronic medical conditions (CMCs)?

Methods

We used a population-based mental health survey to identify respondents aged 18 to 64 with the diagnosis of major depression in the past year (N=278). In our model, the dependent variable was guideline-level medication management of depression. Determinants for guideline-level care were modeled using multivariate logistic regression.

Results

Depressed persons with CMCs were significantly more likely to receive guideline-level care for depression than were the depressed persons without CMCs (OR=1.46; 95% C.I.=1.12-1.90). This increased likelihood did not persist when the sample excluded persons seeing physicians at more than eight visits per year (OR=0.81; 95% CI=0.35-1.90). Previous psychiatric hospitalization was the only other significant determinant of guideline-level care.

Conclusion

Depressed persons with comorbid CMCs are more likely to receive guideline-level care for depression than are depressed persons without comorbid CMCs. However, the association did not persist once we excluded respondents who were high utilizers. This finding implies that further understanding of the interaction between depression care and comorbid CMCs will require a longitudinal focus on repeated physician-patient interactions.     

Personality dimensions in bulimia nervosa, binge eating disorder, and obesity

Objective

The purpose of this investigation was to examine differences in personality dimensions among individuals with bulimia nervosa, binge eating disorder, non-binge eating obesity, and a normal-weight comparison group as well as to determine the extent to which these differences were independent of self-reported depressive symptoms.

Method

Personality dimensions were assessed using the Multidimensional Personality Questionnaire in 36 patients with bulimia nervosa, 54 patients with binge eating disorder, 30 obese individuals who did not binge eat, and 77 normal-weight comparison participants.

Results

Participants with bulimia nervosa reported higher scores on measures of stress reaction and negative emotionality compared to the other 3 groups and lower well-being scores compared to the normal-weight comparison and the obese samples. Patients with binge eating disorder scored lower on well-being and higher on harm avoidance than the normal-weight comparison group. In addition, the bulimia nervosa and binge eating disorder groups scored lower than the normal-weight group on positive emotionality. When personality dimensions were reanalyzed using depression as a covariate, only stress reaction remained higher in the bulimia nervosa group compared to the other 3 groups and harm avoidance remained higher in the binge eating disorder than the normal-weight comparison group.

Conclusions

The higher levels of stress reaction in the bulimia nervosa sample and harm avoidance in the binge eating disorder sample after controlling for depression indicate that these personality dimensions are potentially important in the etiology, maintenance, and treatment of these eating disorders. Although the extent to which observed group differences in well-being, positive emotionality, and negative emotionality reflect personality traits, mood disorders, or both, is unclear, these features clearly warrant further examination in understanding and treating bulimia nervosa and binge eating disorder.     

Purification, biochemical properties and antithrombotic effect of a novel Streptomyces enzyme on carrageenan-induced mice tail thrombosis model

Introduction

The prevalence of cardiovascular diseases, one of the major causes of worldwide mortality, is being increasingly reported. Safer, more effective, and less expensive thrombolytic drugs can possibly overcome the underlying problems associate with current thrombolytic drugs.

Methods

A thrombolytic enzyme was purified and characterized from a Streptomyces strain. Carrageenan induced tail-thrombosis mice model was used to evaluate in vivo antithrombotic effect of the enzyme.

Results

First 15 N-terminal amino acids of the purified enzyme were IAGGQAIYAGGGRRS, which are significantly different from the reported fibrinolytic enzymes. The enzyme exhibited 14.3 ± 2.3-fold stronger thrombolytic activity than that of plasmin. In carrageenan induced tail-thrombosis model, the enzyme caused reduction in frequency of thrombus. Tail-thrombus of the enzyme treated group was significantly shorter than the physiological saline treated group and the thrombus decrement was correlated with the enzyme dose.

Conclusions

The enzyme purified from the Streptomyces strain can be a potential candidate for the treatment of thrombosis.     

Sources of social support as determinants of psychiatric morbidity after severe life events: prospective cohort study of female employees

Objective

The aim of this study was to study prospectively the associations between sources of social support, life events, and psychiatric morbidity, as explicated in the chronic strain and the stress-buffering hypotheses.

Methods

Psychiatric morbidity and sources of social support were assessed at Time 1 and 3 years later at Time 2 among 4250 female municipal employees. At Time 2, the participants were also asked about their preceding life events during the year.

Results

After adjustment for baseline characteristics, low support from one's partner, coworkers, and supervisor at Times 1 and 2 was positively associated with psychiatric morbidity at Time 2 (OR=1.1-1.6). The support of friends at Time 1 lowered the risk of psychiatric morbidity after death or severe illness in the family and after interpersonal conflict. High postevent network heterogeneity also lowered the risk of psychiatric morbidity after financial difficulty. For the remaining 33 combinations between different sources of social support and life events, no corresponding interactions were found.

Conclusion

The observed associations support the chronic strain hypothesis, but the support for the stress-buffering hypothesis was limited.     

Hemispherectomy sustained before adulthood does not cause persistent hemispatial neglect

Introduction

Hemispatial neglect has been well established in adults following acute ischemic stroke, but has rarely been investigated in children and young adults following brain injury. It is known that young brains have a tremendous potential for reorganization; however, there is controversy as to whether functions are assumed by the opposite hemisphere, or perilesional areas in the same hemisphere. Patients with intractable epilepsy who undergo hemispherectomy for treatment are missing the entire cortex on one side following surgery. In these patients, only the opposite hemisphere is available to assume function. Therefore, they provide the unique opportunity to determine in what cases the left or right hemisphere can take over the spatial attention functions of the opposite hemisphere following damage. The objective of this study was to determine the incidence and types of hemispatial neglect in children and young adults following both right- and left-sided hemispherectomy; which types of spatial attention functions can be assumed by the opposite hemisphere; and whether factors like their age at time of surgery, handedness, or gender influence recovery.

Methods

Thirty-two children and young adults who had previously undergone hemispherectomy were administered two tests to evaluate for two types of hemispatial neglect: a gap detection test and a line cancellation test. Egocentric neglect was defined as significantly more omissions of targets on the contralesional versus ipsilesional side of the page (by chi square analysis; p < .05). Allocentric neglect was defined as significantly more errors in detecting contralesional versus ipsilesional gaps in circles.

Results

Only one of the patients displayed statistically significant hemispatial egocentric neglect on the line cancellation test, and none of the patients displayed statistically significant egocentric or allocentric neglect on the gap detection test.

Conclusions

These results imply that reorganization to the contralateral hemisphere occurs peri-hemispherectomy, as there are no perilesional areas to assume function.