Nonlinear analysis of electroencephalogram at rest and during cognitive tasks in patients with schizophrenia.

BACKGROUND: In spite of the large number of studies on schizophrenia, a full understanding of its core pathology still eludes us. The application of the nonlinear theory of electroencephalography (EEG) analysis provides an interesting tool to differentiate between physiologic conditions (e.g., resting state and mathematical task) and normal and pathologic brain activities. The aim of the present study was to investigate nonlinear EEG activity in patients with schizophrenia. METHODS: We recorded 19-lead EEGs in patients with stable schizophrenia and healthy controls under 4 different conditions: eyes closed, eyes open, forward counting and backward counting. A nonlinear measure of complexity was calculated by means of correlation dimension (D2). RESULTS: We included 17 patients and 17 controls in our analysis. Comparing the 2 populations, we observed greater D2 values in the patient group. In controls, increased D2 values were observed during active states (eyes open and the 2 cognitive tasks) compared with baseline conditions. This increase of brain complexity, which can be interpreted as an increase of information processing and integration, was not preserved in the patient population. LIMITATIONS: Patients with schizophrenia were taking antipsychotic medications, so the presence of medication effects cannot be excluded. CONCLUSION: Our results suggest that patients with schizophrenia present changes in brain activity compared with healthy controls, and this pathologic alteration can be successfully studied with nonlinear EEG analysis.

Relative contributions of psychotic symptoms and insight to quality of life in stable schizophrenia.

The purpose of this study was to examine the relative contributions of psychotic symptomatology such as delusions and hallucinations, and insight to quality of life (QOL) in a sample of outpatients with stable schizophrenia. Eighty-three consecutive outpatients with stable schizophrenia were enrolled in a cross-sectional study. We performed a path analysis using a multiple regression technique to assess the specific effect of psychotic symptomatology on QOL and the possible mediating role of insight. Our findings suggested that (i) psychotic symptomatology was negatively correlated to both QOL and the two dimensions of insight we considered (awareness of symptoms and attribution of symptoms); (ii) the impact of insight on QOL was not uniform as attribution of symptoms positively predicted QOL, while the effect of symptom awareness was negative; (iii) when the mediation effect of insight was taken into account, psychotic symptomatology was no longer a significant predictor of QOL on its own. These results suggested a complex pattern of relationships between different dimensions of insight, QOL and psychotic symptomatology. Different dimensions of insight could be related to different aspects of outcome, and this would need to be reflected in rehabilitation programs.

Personality profiles and subjective perception of pain in head pain patients.

Little or no information is available regarding the effect of the personality characteristics of headache sufferers on the quality of pain perception. The aim of this study is to investigate, in head pain sufferers, the relationship between the personality profile, assessed by the MMPI, and the different dimensions of pain (sensory, affective and evaluative), as assessed by the MPQ. Three hundred and seventeen patients with Migraine and/or tension-type headache (episodic or chronic) and myogenic facial pain were included. The Italian versions of the MMPI-2 and MPQ were administered, and the pain level was measured by the VAS. Cluster analysis based on the clinical scales of MMPI identified four personality profiles closely corresponding to the MMPI profiles obtained by the previous researchers: "depressive" (Dep.), "emotionally overwhelmed" (Emot.), "conversive" (Conv.) and "Coper". Differences in MPQ scales between personality profiles were investigated by means of a general linear model (GLM), adjusting for sex, age and pain level and type. Results of GLM analysis showed that the affective dimension was significantly higher in cluster Emot. than in Dep. (p=0.027), Conv. (p=0.002) and Coper (p=0.003). Total PRI was significantly higher in Emot. than in Conv. (p=0.010). The findings of the present study suggest that a specific personality profile (Emot.), characterized by a heavy emotional burden, may increase the affective dimension of pain with respect to a depressive profile (Dep.), a conversive profile (Conv.) or a normal profile (Coper), independent of sex, age and pain level and type.

Exploring the role of face processing in facial emotion recognition in schizophrenia.

OBJECTIVE: Impairment in emotion perception represents a fundamental feature of schizophrenia with important consequences in social functioning. A fundamental unresolved issue is the relationship between emotion perception and face perception. The aim of the present study was to examine whether facial identity recognition (Identity Discrimination) is a factor predicting facial emotion recognition in the context of the other factors, known as contributing to emotion perception, such as cognitive functions and symptoms. METHODS: We enrolled 58 stable schizophrenic out-patients and 47 healthy subjects. Facial identity recognition and emotion perception were assessed with the Comprehensive Affect Testing System. Different multiple regression models with backward elimination were performed in order to discover the relation of each significant variable with emotion perception. RESULTS: In a regression including the six significant variables (age, positive symptomatology, Identity Discrimination, attentive functions, verbal memory-learning, executive functions) versus emotion processing, only attentive functions (standardised ß = 0.264, p = 0.038) and Identity Discrimination (standardised ß = 0.279, p = 0.029) reached a significant level. Two partial regressions were performed including five variables, one excluding attentive functions and the other excluding Identity Discrimination. When we excluded attentive functions, the only significant variable was Identity Discrimination (standardised ß = 0.278, p = 0.032). When we excluded Identity Discrimination, both verbal memory-learning (standardised ß = 0.261, p = 0.042) and executive functions (standardised ß = 0.253, p = 0.048) were significant. CONCLUSIONS: Our results emphasised the role of face perception and attentional abilities on affect perception in schizophrenia. We additionally found a role of verbal memory-learning and executive functions on emotion perception. The relationship between those above-mentioned variables and emotion processing could have implications for cognitive rehabilitation.

Correlations of attitudes toward antipsychotic drugs with insight and objective psychopathology in schizophrenia.

OBJECTIVE: The aim of this cross-sectional study was to examine the relationships between attitudes toward antipsychotics, insight, and other clinical variables in stable schizophrenia. METHODS: Fifty Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision-(DSM-IV-TR)-diagnosed schizophrenic outpatients were evaluated through a psychiatric assessment. Drug attitudes were measured using the Drug Attitude Inventory and insight using the Scale for the Assessment of Unawareness of Mental Disorder. Differences between patients taking first- or second-generation antipsychotics were investigated. RESULTS: Lack of insight, more severe scores on the positive and general psychopathology subscales of the Positive and Negative Syndrome Scale (PANSS), and later age at onset of schizophrenia correlated with worse global medication attitude. The multiple regression analysis revealed that unawareness of the need of treatment predicted poorer drug global attitude (R(2) = 0.312). Patients taking second-generation antipsychotics showed lower negative attitudes and better global drug attitudes than patients treated with neuroleptics. CONCLUSION: The impact of the awareness of the need for treatment on global medication attitude needs to be a main focus of interventions targeting compliance.

Accompanying symptoms and psychiatric comorbidity in migraine and tension-type headache patients.

OBJECTIVE: Our objective was to assess the prevalence of accompanying symptoms of migraine and tension-type headache in patients with such conditions (both episodic and chronic) and in headache-free controls, and their relationship with depression and anxiety. METHOD: A psychological assessment (Axis I, DSM-IV) was performed, and 21 accompanying symptoms were investigated in 506 patients with episodic migraine (231), chronic migraine (102), episodic tension-type headache (83), and chronic tension-type headache (90) and in 80 controls. The relationship between symptoms, headache type, and psychiatric comorbidity was analyzed. RESULTS: The mean number of symptoms was significantly higher in patients (n=10.3) than in controls (n=3.4). Most symptoms were significantly associated with depression and anxiety, while only some of them were significantly associated with headache, with no relevant difference among groups. CONCLUSION: In headache patients, psychiatric comorbidity (compared with headache type or chronicity) seems to be more strictly associated with an increased burden of accompanying symptoms.

Frontal lobe dysfunction in patients with chronic migraine: a clinical-neuropsychological study.

Neuropsychological tests have demonstrated a frontal lobe dysfunction in several psychiatric and neurological disorders. Our purpose was to examine whether similar functional differences would be found in patients with chronic migraine. The Gambling Task (GT), the Tower of Hanoi-3 (TOH-3) and the Object Alternation Test (OAT) were administered to 23 female patients previously treated for chronic migraine and to 23 healthy women who were similar to the patients in age and educational level, and the mean test scores of the two groups were compared (Student's t and Pearson correlation coefficient). The patient group scored significantly higher than the controls on the TOH-3 and, especially, the OAT. In the patients, no significant relationship was found between the neuropsychological test scores and those for the Minnesota Multiple Personality Inventory (MMPI), the Spielberg State-Trait Anxiety Inventory (STAI), and the Beck Depression Inventory (BDI). In conclusion, the data suggest a relation between chronic headache and dorsolateral function (as tested by the TOH-3) and orbitofrontal function (as tested by the OAT). The decision-making function related to ventromedial prefrontal cortex (tested by the GT) did not show a statistically significant difference between patients and controls. These neuropsychological findings seem to be partly independent of the patient's psychological traits and psychiatric disorders.

Muscle tenderness in different headache types and its relation to anxiety and depression.

To assess in patients with migraine and tension type headache, both episodic and chronic, the extent to which muscle tenderness may relate to anxiety and depression, 459 patients with Episodic Migraine (EM, 125), Chronic Migraine (CM, 97), Episodic Tension Type Headache (ETTH, 82), Chronic Tension Type Headache (CTTH, 83), and EM+ETTH (72) were enrolled. For each patient, a psychological assessment on the Axis 1 of the DSM-IV and muscle palpation of pericranial and cervical muscles were carried out. A Pericranial Muscle Tenderness Score (PTS) and a Cervical Muscle Tenderness Score (CTS) were calculated (range 0-3). Logistic and linear regression analyses were employed to assess relations between muscle tenderness, the demographic variables and psychiatric disorders in the different patient groups. Odds ratio for 'male gender' was higher in groups with tension type headache. Only EM patients showed a positive association with increasing age. Anxiety and depression were significantly associated to CM. A significant negative correlation of PTS and CTS was observed in EM patients. In relation to male gender, the PTS was significantly lower in EM, ETTH and CTTH; CTS was significantly lower in EM, CM, and CTTH. Anxiety and, even more, anxiety and depression combined were positively associated to higher PTS and CTS in EM patients. Anxiety and depression were also positively associated to higher CTS in patients with EM+ETTH. In CTTH patients, PTS only was positively associated to anxiety and depression. We conclude that in patients with EM, the presence of anxiety or anxiety and depression combined considerably increases the level of muscle tenderness in the head and, even more, in the neck, and might facilitate the evolution into CM.

Confirmation of the distinction between chronic migraine and chronic tension-type headache by the McGill Pain Questionnaire.

OBJECTIVE: To investigate if the McGill Pain Questionnaire confirms the distinction between chronic migraine and chronic tension-type headache. BACKGROUND: It has been suggested that different categories of chronic daily headache should be distinguished; in particular, chronic migraine and chronic tension-type headache. METHODS: The McGill Pain Questionnaire and a visual analog scale were administered to 40 patients with chronic daily headache, 85 patients with migraine, and 47 patients with episodic tension-type headache. The patients with chronic daily headache were subdivided, according to criteria described by other authors, into those with chronic migraine (n=29) and those with chronic tension-type headache (n=11). Weighted McGill Pain Questionnaire item scores, subscales, total pain rating indexes, and choice frequency of the descriptors were calculated. The data of chronic migraine and chronic tension-type headache were compared and tested for significant differences (Student t test). The same was done for migraine and episodic tension-type headache. Data were also processed through the Self-organizing Map, a system based on a counter-propagation neural network. RESULTS: In the chronic migraine group, compared with the chronic tension-type headache group, scores were higher in 17 of 20 McGill Pain Questionnaire items (significantly in 5) and for the sensory and affective subscales (significantly). In the migraine group, compared with the episodic tension-type headache group, scores were higher for 18 McGill Pain Questionnaire items (significantly in 7), and for the sensory, affective, and mixed affective-evaluative subscales, total pain-rating index, and visual analog scale (all significantly). The coincidence of descriptors of first choice was low between chronic migraine and chronic tension-type headache, but it was high between chronic migraine and migraine and between chronic tension-type headache and episodic tension-type headache. After Self-organizing Map analysis, chronic migraine and chronic tension-type headache were prevalently distributed in 2 different areas of the map. CONCLUSIONS: In the disorders characterized by a daily and near-daily headache, the McGill Pain Questionnaire consistently can discriminate between those evolving from migraine and those evolving from tension-type headache, indirectly confirming the validity of a distinction between these 2 clinical conditions. The differences are similar to those observed between patients with migraine and patients with episodic tension-type headache. This seems to be independent of the pain level since the difference of the total pain-rating index and the visual analog scale between chronic migraine and chronic tension-type headache was not statistically significant.