Proprioception and Motor Control in Parkinson's Disease

ABSTRACT

Parkinson's disease (PD) is a neurodegenerative disorder that leads to a progressive decline in motor function. Growing evidence indicates that PD patients also experience an array of sensory problems that negatively impact motor function. This is especially true for proprioceptive deficits, which profoundly degrade motor performance. This review specifically address the relation between proprioception and motor impairments in PD. It is structured around 4 themes: (a) It examines whether the sensitivity of kinaesthetic perception, which is based on proprioceptive inputs, is actually altered in PD. (b) It discusses whether failed processes of proprioceptive-motor integration are central to the motor problems in PD. (c) It presents recent findings focusing on the link between the proprioception and the balance problems in PD. And (d) it discusses the current state of knowledge of how levodopa medication and deep brain stimulation affect proprioceptive and motor function in PD. The authors conclude that a failure to evaluate and to map proprioceptive information onto voluntary and reflexive motor commands is an integral part of the observed motor symptoms in PD.     

Somatoform dissociation in eating-disordered patients

This study investigated the role of somatoform dissociation in eating disorders and pathological eating behaviour, relative to the established association of eating pathology with psychological dissociation. The participants were 131 women with DSM-IV diagnoses of anorexic or bulimic disorders and 75 women who had no such disorder. Each woman completed measures of psychological and somatoform dissociation, as well as a measure of bulimic attitudes. The current presence or absence of specific bulimic behaviours was identified during the clinical interview. Levels of both forms of dissociation were higher in the women who had diagnoses of disorders with a bulimic component (bulimia nervosa; anorexia nervosa of the binge/purge subtype) than in the non-clinical or restrictive anorexic women. Somatoform dissociation showed particularly strong links with the presence of bulimic behavioural features (excessive exercise, laxative abuse, diet pill abuse, diuretic abuse) and with bulimic attitudes. The formulation and treatment of cases where there are bulimic features is likely to be enhanced by the assessment of somatoform dissociation.     

Self-esteem in patients with borderline and avoidant personality disorders

This study compared self-esteem in patients with avoidant personality disorder (APD) and borderline personality disorder (BPD). Patients diagnosed with one or more personality disorders answered the questionnaire Index of Self Esteem as part of a comprehensive evaluation within the setting of a treatment trial. Our hypotheses were that (1) both patients with APD and patients with BPD would report low levels of self-esteem, (2) patients with APD would report lower self-esteem than patients with BPD. We further expected that (3) patients with higher levels of depression would report lower levels of self-esteem, but that (4) both borderline and avoidant personality pathology would contribute to explained variance in self-esteem beyond what would be accounted for by depression. All of our hypotheses were supported. The results from our study showed a significant difference in self-esteem level between the two personality disorders, patients with APD reporting lower self-esteem than patients with BPD. Subjects with both disorders were measured to have self-esteem levels within the range that presumes clinical problems. Self-esteem represents an important quality of subjective experience of the self, and the study of self-esteem in PDs can offer new and important knowledge of PDs as self-pathology.     

Social problem-solving skills in boys with conduct and oppositional defiant disorders

The current study compared the social problem-solving skills of a clinic-based sample of 30 boys diagnosed with conduct disorder (CD) and 25 boys diagnosed with oppositional defiant disorder (ODD). Past research has indicated that contextual factors influence children's social problem-solving; thus, three hypothetical conflict situations (i.e., child-child, teacher-child, and parent-child) and situations which differed by degree of negative intent of the provocateur (i.e., hostile vs. Ambiguous intent) were examined. Problem-solving strategies were aggregated into three broad dimensions: 1) aggressive/antisocial solutions; 2) nonverbal-nonaggressive solutions; and 3) verbal-nonaggressive solutions. Compared to ODD boys, CD boys proposed more aggressive/antisocial solutions in parent-child conflicts when parental intent was ambiguous and in teacher-child conflicts regardless of intent. Compared to ODD boys, CD boys proposed fewer verbal-nonaggressive solutions in child-child conflicts. The implications of these findings for treatment intervention with CD and ODD boys were discussed. Aggr. Behav. 23:457–469, 1997. © 1997 Wiley-Liss, Inc.     

Selective attention, memory bias, and symptom perception in idiopathic environmental intolerance and somatoform disorders

Idiopathic environmental intolerance (IEI) refers to a polysymptomatic condition, similar to somatoform disorders. Various processes seem to contribute to its yet unknown etiology. Attention and memory for somatic symptom and IEI-trigger words was compared among participants with IEI (n = 54), somatoform disorders (SFD; n = 44) and control participants (n = 54). Groups did not differ in a dot-probe task. However, in an emotional Stroop task, attention was biased in IEI and SFD groups toward symptom words but not toward IEI-trigger words. Only the IEI group rated trigger words as more unpleasant and more arousing, and participants remembered them better in a recognition task. These implicit and explicit cognitive abnormalities in IEI and SFD may maintain processes of somatosensory amplification.     

工作记忆训练在精神疾病中的应用

随着工作记忆缺损与各类精神疾病的关联被逐渐阐明,研究者开始关注工作记忆训练能否作为干预手段应用在精神疾病领域中。当前,在对ADHD、精神分裂症、抑郁、焦虑、成瘾障碍和自闭症患者进行的工作记忆训练中发现了训练近迁移、远迁移以及临床症状缓解的相应证据,以及直接(通过提升工作记忆能力起效)和间接(通过提升其他关联能力起效)两条效益路径。此外,一个针对精神疾病患者的有效训练范式应当就三个层面进行考察:训练的一般成分(即受训的核心加工过程),训练的疾病特异成分(例如情绪工作记忆训练);以及训练的辅助性成分(例如动机、策略、慢波睡眠等)。未来研究需要关注适用不同精神疾病的训练范式与程序,促进工作记忆训练的定制化,并且通过完善评估手段进一步澄清工作记忆训练在病患中的效益机制。     

Adaptation in Visuomanual Tracking Depends on Intact Proprioception

The role of arm proprioception in motor learning was investigated in experiments in which, by moving the arm, subjects followed the motion of a target displayed on a monitor screen. Adaptive capabilities were tested in visuomanual tracking tasks following alterations in the relationship between the observer's actual arm movement and visual feedback of the arm movement given by a cursor motion on the screen. Tracking performance and adaptive changes, measured in terms of spatiotemporal error, tracking trajectory curvature, and spatial gain, were compared in 7 control subjects (CSs) and in 1 deafferented subject (DS). CSs adapted appropriately to altered visuomanual relationships; those changes were present in trials immediately after restoration of normal scaling. In contrast, although the DS modified his tracking strategy from trial to trial according to the altered conditions, he did not show plastic changes in internal visuomanual scaling. Like the results of prismatic adaptation experiments, the present results suggest that arm proprioception contributes to the plastic changes that follow alterations in the scaling of visuomanual gain.     

Perfectionism in depression, obsessive-compulsive disorder and eating disorders

High levels of perfectionism have been observed in major depression, anxiety disorders and eating disorders. Though few studies have compared levels of perfectionism across these disorders, there is reason to believe that different dimensions of perfectionism may be involved in eating disorders than in depression or anxiety [Bardone-Cone, A. M. et al. (2007). Perfectionism and eating disorders: Current status and future directions. Clinical Psychology Review, 27, 84-405]. The present study compared patients with major depression, obsessive-compulsive disorder, and eating disorders on dimensions of perfectionism. Concern over Mistakes was elevated in each of the patient groups while Pure Personal Standards was only elevated in the eating disorder sample. Doubts about Actions was elevated in both patients with obsessive-compulsive disorder and eating disorders, but not in depressed patients. Analyses of covariance indicated that Concern over Mistakes accounted for most of the variance in the relationship of perfectionism to these forms of psychopathology.     

Heartbeat perception in social anxiety before and during speech anticipation

According to current cognitive models of social phobia, individuals with social anxiety create a distorted image of themselves in social situations, relying, at least partially, on interoceptive cues. We investigated differences in heartbeat perception as a proxy of interoception in 48 individuals high and low in social anxiety at baseline and while anticipating a public speech. Results revealed lower error scores for high fearful participants both at baseline and during speech anticipation. Speech anticipation improved heartbeat perception in both groups only marginally. Eight of nine accurate perceivers as determined using a criterion of maximum difference between actual and counted beats were high socially anxious. Higher interoceptive accuracy might increase the risk of misinterpreting physical symptoms as visible signs of anxiety which then trigger negative evaluation by others. Treatment should take into account that in socially anxious individuals perceived physical arousal is likely to be accurate rather than false alarm.     

Prevalence of personality disorders among bulimics,nonbulimic binge eaters,and normal controls

We examined the comorbidity of bulimia and personality pathology among college women. Subjects included women (n=23) meeting DSM-III-R criteria for bulimia nervosa (bulimics), women (n=23) who reported binge eating but did not fulfill the criteria for bulimia nervosa (binge eaters), and women (n=23) who did not binge eat (normals). The subjects completed an assessment battery consisting of the Personality Disorders Examination and the SCID as well as the Beck Depression Inventory, the Rosenberg Self-Esteem Index, and measures of impulsivity and self-defeating tendencies. Fourteen of 23 bulimics (61%) met criterion for a personality disorder using DSM-III-R Axis II criteria. In comparison, 3 of 23 (13%) binge eaters and 1 of 23 (4%) normal subjects received an Axis II diagnosis. Borderline and self-defeating diagnoses were the predominant personality disorders in 96% of the bulimics exhibiting clinically significant personality pathology. Bulimics also exhibited significantly more depression, impulsivity, and self-defeating behavior and lower self-esteem than binge eaters and normals. The findings are discussed within a conceptual framework that posits an interaction between personality pathology and restrained eating.     

Prevalence of anxiety symptoms and disorders in the transgender population: A systematic review of the literature

Introduction: Anxiety disorders are the most common mental illness in the general population, affecting 18% of the population in the United States (12 months prevalence) and 13.6% in Europe (life time prevalence). Several studies have also described high rates of anxiety disorders and symptoms of anxiety among the transgender population. There is, however, a great variation of results (particularly related to gender prevalence), and few studies have described the type of anxiety disorders specific to the transgender population.

Aim: To collect and critically appraise the information from the available studies describing prevalence rates of anxiety disorders and symptoms.

Results: A total of 25 cross-sectional (n = 17) and longitudinal (n = 8) studies were found. Cross-sectional studies described higher prevalence rates of anxiety symptoms in the transgender group than in the cis population. The prevalence of anxiety disorders range from 17% to 68%. The most common anxiety disorders found were specific phobias, social phobias, panic disorders, and obsessive-compulsive disorders. Most of the large studies suggest higher levels of anxiety symptoms and disorders in transgender men compared with transgender women; however, considerable variation in results was found.

Conclusions: The findings identified that there is considerable variation in anxiety disorders and symptoms among transgender people attending transgender health services. These findings are likely to be the result of the tools used, the lack of matching controls, and the lack of homogeneity of the group studied. Overall this review indicates high levels of anxiety symptoms and disorders among transgender people attending gender services, primarily (but not exclusively) before commencement of cross-sex hormone treatment. Anxiety disorders related to social interaction (such as social anxiety) and panic attack appear to be particularly common, however more rigorous studies to confirm those findings are needed.     

Identification of preschool children at risk for emotional and behavioral disorders: development and validation of a universal screening system

Three studies were designed to measure various indicators of the reliability and validity of the Preschool Behavior Screening System (PBSS) as a screening instrument for emotional and behavioral disorder risk status of children of preschool age. Study 1 and Study 2 served to establish evidence for content validity. Study 3 investigated one type of reliability evidence (i.e., internal consistency) and four types of validity evidence (i.e., internal structure validity, validity evidence based on external relations, concurrent validity, and cross-informant agreement).Teachers and parents of children (N = 113) enrolled in preschool and childcare programs completed Phase 1 and Phase 2 of the PBSS and the Behavior Assessment System for Children (BASC-2). Cross-informant agreement between parent and teacher ratings on the PBSS was generally moderate, and internal consistency was high. PBSS Phase 1 and PBSS Phase 2 were correlated in the expected directions, and sensitivity and negative predictive value were high. Results suggest that the PBSS may yield psychometrically sound scores for helping states meet child-find requirements. Directions for future development of the PBSS are provided.     

Eye contact elicits bodily self-awareness in human adults

Eye contact is a typical human behaviour known to impact concurrent or subsequent cognitive processing. In particular, it has been suggested that eye contact induces self-awareness, though this has never been formally proven. Here, we show that the perception of a face with a direct gaze (that establishes eye contact), as compared to either a face with averted gaze or a mere fixation cross, led adult participants to rate more accurately the intensity of their physiological reactions induced by emotional pictures. Our data support the view that bodily self-awareness becomes more acute when one is subjected to another’s gaze. Importantly, this effect was not related to a particular arousal state induced by eye contact perception. Rejecting the arousal hypothesis, we suggest that eye contact elicits a self-awareness process by enhancing self-focused attention in humans. We further discuss the implications of this proposal.     

Use of the Beck Scale for suicide ideation with psychiatric inpatients diagnosed with schizophrenia,schizoaffective, or bipolar disorders

To ascertain how useful the Beck Scale for Suicide Ideation (BSI; Beck & Steer, Manual for Beck Scale for Suicide Ideation (1991)) would be for assessing the severity of suicidal ideation in patients who were diagnosed with schizophrenia, schizoaffective, or bipolar disorders, 142 inpatients were asked to complete the BSI. Eight (6%) patients refused, and four patients (3%) were unable to complete the BSI because they were unable to concentrate. Of the 130 patients who completed the BSI, 53 (41%) had schizoaffective, 37 (28%) had paranoid schizophrenia, 30 (23%) had manic bipolar, and 10 (8%) had depressed bipolar disorders. The coefficient alpha for the BSI was .96, and its one-week test-retest reliability for a subsample of 15 inpatients was 0.88, p < 0.001. The BSI total scores were positively correlated with having ever attempted suicide, r = 0.46, p < 0.001. According to the BSI, 36 (28%) patients were classified as current suicide ideators. The results were discussed as supporting the use of the BSI with inpatients who are diagnosed with schizophrenia, schizoaffective, or bipolar disorders.     

Attitudes of clinical psychologists towards clients with personality disorders

Previous studies have found that a variety of mental health professionals hold negative attitudes towards clients diagnosed with a personality disorder. These negative attitudes may lead to clients receiving a lower quality of service. Specialist training has been found to improve attitudes towards personality disorders but no empirical studies in Australia have examined this among clinical psychologists. In this study, the attitudes of 81 clinical psychologists towards clients with personality disorders were examined. We were specifically interested in investigating the relationship between recency of specialist training and clinician's attitudes as well as the influence of percentage of personality disorder clients on the clinician's caseload. Results demonstrated that both recency of specialist training and percentage of clients seen were associated with more positive attitudes; however, a higher caseload of clients with personality disorders was the most important predictor of positive attitudes. The implication is that recent participation in specialist training for personality disorders appears to be valuable in improving clinician's attitudes but that more positive attitudes are associated with seeing a greater number of individuals with personality disorders.     

Effects of perceived criticism on anxiety and depression during behavioral treatment of anxiety disorders

The present study explored the effect of perceived criticism (PC) on levels of anxiety and depression during behavioral treatment among patients diagnosed with obsessive-compulsive disorder (OCD) or panic disorder with agoraphobia (PDA). We posited that patients' perceptions of relatives' criticism and the degree to which they were upset by the criticism (UC) would be related to negative affect and discomfort during exposure. The sample included 75 patients with a primary diagnosis of OCD (n=43) or PDA (n=32) and their participating relatives. Measures of patients' weekly ratings of PC and upset about the criticism, anxious and depressed mood, and subjective discomfort during exposure treatment were analyzed using a mixed model regression approach (SAS Proc Mixed). Patients' anxious and depressed mood predicted greater discomfort during exposure. Patients who were more UC also had higher weekly ratings of anxiety and depression, and more discomfort during exposure sessions. Findings suggest that treatment outcome may be improved by attention to patients' reactions to their interpersonal environment.     

Heartbeat perception in depression

Alterations in bodily awareness have been implicated in depression but there has been little detailed empirical characterisation of the degree and accuracy of body perception in the disorder. The present study examined the objective accuracy of heartbeat perception (using the Schandry mental tracking task) and the subjective degree of bodily focus (using the Bodily Consciousness Questionnaire; BCQ) in healthy control volunteers, a moderately depressed community sample, and a more severely depressed clinic sample (n=18 in each group). The community sample showed less accurate heartbeat perception than the control group as expected. Counter to prediction, however, the more severely depressed clinic sample performed better than the community depressed sample and equivalently to control volunteers on the Schandry task. There were no group differences on subjective bodily awareness. Implications for theories of depression are discussed.     

Direct assessment of the cognitive correlates of attention deficit disorders with and without hyperactivity

The cognitive functioning of children identified as attention deficit disorder with hyperactivity (ADD/H) was compared to that of children identified as attention deficit disorder without hyperactivity (ADD/WO). Based on information on symptoms supplied by teachers, 20 ADD/H and 15 ADD/ WO children were selected according to DSM-III criteria from a large elementaryschool learning disabilities and behavior disorders population. For comparison purposes, 16 normal children from regular classrooms were also selected. Children from all three groups were evaluated with a battery of cognitive tests. Intelligence test scores differentiated the two ADD groups, with the ADD/H children obtaining significantly lower Full Scale IQ scores than both ADD/WO and control children. In addition, ADD/H children obtained significantly lower Verbal IQ scores than ADD/WO children. Both ADD groups performed more poorly than controls on Spelling and Reading Achievement, and the ADD/WO group performed more poorly on Math Achievement. The two ADD groups took longer to complete six Stroop and rapid naming tasks than the control groups but did not differ among themselves. The ADD/WO group made more errors on a visual matching task than the controls, but neither ADD group differed from controls on the accuracy of the Stroop tasks, rapid naming tasks, measures of receptive and expressive language, visual-motor integration, or sustained visual attention. The differences between the two ADD groups were fewer than expected on the basis of previous research and are more global than specific.The assistance of John Junginger, Jason Walker, and Cynthia Jones at various stages of the project is gratefully acknowledged. Particular thanks are extended to the teachers and staff of Clarke County schools.