Relation of Neurological Soft Signs to Nonverbal Memory Performance in Obsessive-Compulsive Disorder

Few studies have examined the relation between neurological soft signs (NSS) and neuropsychological performance in Obsessive-Compulsive Disorder (OCD). Thirty outpatients with primary OCD and 30 matched normal controls were administered the Cambridge Neurological Inventory and the Rey-Osterrieth Complex Figure Test (RCFT). A series of multiple regression models tested the relationship between NSS and performance on the RCFT. Patients presented significantly more neurological soft signs than controls on both sides of the body, and were impaired on the free recall and organization scores of the RCFT. Nonverbal memory deficits in OCD were predicted independently by organizational strategies during the copy condition of the RCFT, and neurological soft signs. There might be at least two variables independently mediating nonverbal memory deficits in OCD: (1) a cognitive organization and planning component, and (2) a complex motor regulatory component.     

Neurological soft signs in OCD patients with early age at onset, versus patients with schizophrenia and healthy subjects

Compelling evidence suggests that both schizophrenia and obsessive compulsive disorder (OCD) are related to deviant neurodevelopment. Neurological soft signs (NSS) have been proposed to be a marker of abnormal brain development in schizophrenia. The purpose of this study is to examine whether NSS are also a marker in patients with OCD, in particular, in early-onset OCD. The authors included 162 subjects and compared patients with OCD, patients with schizophrenia (SCZ), and healthy control subjects. They were all examined for NSS (Krebs' Scale), extrapyramidal symptoms (Simpson-Angus Scale), and were rated on the Abnormal Involuntary Movements Scale (AIMS). The authors found no differences between NSS total scores and subscores in OCD versus controls, whereas total NSS, motor coordination, and motor integration were significantly lower in OCD than in SCZ. OCD patients with early-onset (before age 13) did not differ from those with later-onset OCD. These results support the idea that NSS, as determined by current scales, is relatively specific to schizophrenia, although they do not preclude the existence of a neurological dysfunction in OCD. Further studies are required to determine the type of neurological signs that could be useful trait-markers in the phenotypic characterization of subtype OCD.     

Neurological soft signs in obsessive-compulsive disorder: The effect of co-morbid psychosis and evidence for familiality

Patients with obsessive-compulsive disorder (OCD) have increased rates of neurological soft signs (NSS) when compared to healthy controls. However, previous findings have been confounded by the presence of co-morbidity with disorders themselves associated with increased NSS, such as schizophrenia. Moreover, it remains unclear whether NSS in OCD reflect a vulnerability to this disorder. This study aimed to examine: 1) the severity of NSS in patients with OCD alone, in patients with OCD and co-morbid psychosis (schizophrenia or bipolar disorders), and in healthy controls; and b) whether unaffected first-degree relatives of patients with OCD also demonstrate a higher prevalence rate of NSS than healthy controls. NSS were assessed with the Cambridge Neurological Inventory (CNI) in 100 patients with OCD, 38 patients with OCD and psychosis (22 with bipolar disorders and 16 with schizophrenia), and 101 healthy controls. Forty-seven unaffected first-degree relatives of patients with OCD only were also administered the CNI. Patients with OCD showed significantly higher scores in motor coordination and total NSS than controls, and patients with OCD co-morbid with psychosis also showed significantly higher scores in motor coordination and total NSS than controls. Although there were no differences in NSS between patients with OCD only and OCD and psychosis as a whole, patients with OCD co-morbid with schizophrenia showed significantly higher scores in motor coordination than patients with OCD, patients with OCD and bipolar disorder, and healthy controls. Unaffected first-degree relatives only showed a higher prevalence rate than healthy controls in specific motor coordination signs, such as Opposition and Extinction. These findings suggest that patients with OCD exhibit more NSS than healthy controls, and that motor coordination signs may be even more extensive when OCD is co-morbid with psychosis. Some of these abnormalities may be indicative of a vulnerability to these disorders, as indicated by their presence in un-affected first-degree relatives.     

Characteristics of memory dysfunction in body dysmorphic disorder.

Although body dysmorphic disorder (BDD) is receiving increasing empirical attention, very little is known about neuropsychological deficits in this disorder. The current study investigated the nature of memory dysfunction in BDD, including the relationship between encoding strategies and verbal and nonverbal memory performance. We evaluated 17 patients with BDD and 17 healthy controls using the Rey-Osterrieth Complex Figure Test (RCFT) and the California Verbal Learning Test (CVLT). BDD patients differed significantly from healthy controls on verbal and nonverbal learning and memory indices. Multiple regression analyses revealed that group differences in free recall were statistically mediated by deficits in organizational strategies in the BDD cohort. These findings are similar to patterns previously observed in obsessive-compulsive disorder (OCD), suggesting a potential relationship between OCD and BDD. Studies in both groups have shown that verbal and nonverbal memory deficits are affected by impaired strategic processing.     

Neurological soft signs in schizophrenic patients with obsessive-compulsive disorder

The purpose of this study was to examine neurological soft signs (NSS) in schizophrenic patients with obsessive-compulsive disorder (OCD). Neurological soft signs were assessed in 15 schizophrenic patients with OCD (OCD-schizophrenia), 38 schizophrenia patients without OCD (non-OCD-schizophrenia), and 24 healthy controls (HC) by means of the Neurological Evaluation Scale (NES). The OCD-schizophrenia group had significantly higher scores on total and subscales of 'sensory integration' and 'others' of NES than the HC group. Subscale scores of 'sequencing of motor acts' in-non-OCD-schizophrenia patients were significantly higher compared to OCD-schizophrenia patients. Total NES scores of both groups were significantly correlated with Scale for the Assessment of Negative Symptoms (SANS) scores. Only the subscale of 'sequencing of motor acts' was significantly correlated with SANS within the OCD-schizophrenia group. These results suggest that NSS do not significantly differ between schizophrenia patients with and without OCD, contrary to expectations. The NES scores in OCD-schizophrenic patients do not appear to be related to a more severe form of schizophrenia. Neurological signs and negative symptoms in schizophrenia patients with and without OCD may be considered as neurodevelopmental predisposing factors. Further research is required in schizophrenia patients with OCD to investigate the relationships between NSS and several neuroimaging or neuropsychological findings, constituting a subgroup within the schizophrenia spectrum.     

Neurological soft signs in patients with obsessive-compulsive disorder

Neurological soft signs (NSS) are minor neurological deviations signifying unspecific brain dysfunction. Several studies have reported an abnormally high prevalence of NSS in obsessive-compulsive disorder (OCD); however, the significance of their presence in OCD patients is not yet clear. We reviewed studies that investigated NSS in OCD patients, using a clinical examination or kinematical methods. In most studies, OCD patients showed an excess of NSS, especially in the areas of motor coordination, sensory integration and primitive reflexes. NSS in OCD patients may be associated with more severe obsessions as well as disturbances of visuo-spatial function and visual memory. Moreover, they may be already present at childhood, combined with anxiety disorders, thus possibly representing a marker of high risk for OCD. In conclusion, more studies are needed in order to assess both sensory and motor soft signs associated with OCD in a methodologically rigorous manner, to integrate the results with neuroimaging findings and to elucidate the role of NSS as markers of neuropsychological dysfunction in OCD.     

Executive function and nonverbal memory in obsessive-compulsive disorder

It has been suggested that memory impairments found in obsessive-compulsive disorder (OCD) are mediated by organizational problems in encoding that are caused by primary executive dysfunction. Performance on different nonverbal memory and executive skills was tested in 68 subjects (35 non-depressed OCD sufferers and 33 healthy controls). Multiple regression models were performed to analyze the role of different cognitive variables, especially organizational encoding strategies in nonverbal memory. OCD patients performed significantly worse than controls in immediate nonverbal memory [Rey-Osterrieth Complex Figure Test (RCFT)] and on all the executive functions such as interference control (Stroop test), mental set shifting (Trail-Making Test), and organizational strategies (copy organization). As no differences were found in the memory of faces, where organizational strategies are minimal, it is possible to speculate that immediate nonverbal memory problems in OCD appear only when organizational strategies mediate the recalling process. Thus, memory deficits appear to have less to do with memory, per se, and more to do with the degree of organization necessary to effectively complete the task. Statistical analyses of mediation models showed the highest explanatory power for the organizational approach and demonstrated the mediation effect of organizational strategies in nonverbal impairment.     

Nonverbal memory dysfunction in obsessive-compulsive disorder patients with checking compulsions

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous disorder; nonetheless, most of the previous neuropsychological studies for assessing the involvement of memory dysfunction grouped together patients with different symptoms, thereby potentially accounting for the inconsistencies of results. The goals of this study were to compare the memory dysfunction of two main subtypes of OCD and to identify the type of memory dysfunction that is associated with the checking symptoms in OCD patients. The sample population comprised the cleaning-type OCD group (N=23), checking-type OCD group (N=24), and a control group of healthy volunteers (N=20). All the OCD patients were selected from the outpatient clinic. All the subjects underwent the Rey-Osterreith Complex Figure Test (RCFT) for the assessment of nonverbal memory function, the Hopkins Verbal Learning Test (HVLT) for verbal memory function, the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and the Wisconsin Card Sorting Test (WCST). The immediate and delayed memory scores of RCFT were significantly lower in the checking-type OCD group; there were no significant differences in HVLT scores amongst the three groups. Our results indicate that the checking-type compulsion of OCD patients is associated with nonverbal memory deficits and not with verbal memory deficits.     

Schizo-obsessive and obsessive-compulsive disorder: comparison of clinical characteristics and neurological soft signs

The purpose of the study was to examine whether schizophrenia with obsessive-compulsive disorder (OCD) represents a severe form of OCD-spectrum disorders on the basis of neurological soft signs (NSS) and obsessive-compulsive (OC) symptoms. Sixteen patients with OCD-schizophrenia, 25 OCD patients and 23 healthy controls (HC) were studied. Scales for the Assessment of Positive (SAPS) and Negative Symptoms (SANS), Clinical Global Impressions Scale and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) were used to assess the schizophrenic and OC symptomatology. NSS were evaluated with the Neurological Evaluation Scale (NES). OCD-schizophrenics had significantly higher scores on total NES than HC. The patients with OCD were more likely to have total Y-BOCS and subscale scores of compulsions than patients with OCD-schizophrenia. The rate of symmetry obsessions and cleaning/washing compulsions were significantly higher in patients with OCD compared to OCD-schizophrenics. We have found no correlation of OC symptoms with schizophrenic symptomatology. Our findings may suggest that OCD-schizophrenia is a distinct subtype of schizophrenia, not a more severe form of OCD-spectrum disorder.     

Patterns of co‐altered brain structure and function underlying neurological soft signs in schizophrenia spectrum disorders

Neurological soft signs (NSS) comprise a broad range of subtle neurological deficits and are considered to represent external markers of sensorimotor dysfunction frequently found in mental disorders of presumed neurodevelopmental origin. Although NSS frequently occur in schizophrenia spectrum disorders (SSD), specific patterns of co‐altered brain structure and function underlying NSS in SSD have not been investigated so far. It is unclear whether gray matter volume (GMV) alterations or aberrant brain activity or a combination of both, are associated with NSS in SSD. Here, 37 right‐handed SSD patients and 37 matched healthy controls underwent motor assessment and magnetic resonance imaging (MRI) at 3 T. NSS were examined on the Heidelberg NSS scale. We used a multivariate data fusion technique for multimodal MRI data—multiset canonical correlation and joint independent component analysis (mCCA + jICA)—to investigate co‐altered patterns of GMV and intrinsic neural fluctuations (INF) in SSD patients exhibiting NSS. The mCCA + jICA model indicated two joint group‐discriminating components (temporoparietal/cortical sensorimotor and frontocerebellar/frontoparietal networks) and one modality‐specific group‐discriminating component (p < .05, FDR corrected). NSS motor score was associated with joint frontocerebellar/frontoparietal networks in SSD patients. This study highlights complex neural pathomechanisms underlying NSS in SSD suggesting aberrant structure and function, predominantly in cortical and cerebellar systems that critically subserve sensorimotor dynamics and psychomotor organization.     

Cognitive retraining for organizational impairment in obsessive-compulsive disorder

Individuals with obsessive-compulsive disorder (OCD) have difficulties in organizing information during encoding associated with subsequent memory impairments. This study was designed to investigate whether impairments in organization in individuals with OCD can be alleviated with cognitive training. Thirty-five OCD subjects and 36 controls copied and recalled the Rey-Osterrieth Complex Figure Test (RCFT) [Osterrieth, P.A., 1944. Le test de copie d'une figure complexe: Contribution a l'étude de la perception et de la memoire (The test of copying a complex figure: A contribution to the study of perception and memory). Archive de Psychologie 30, 286-350.] before being randomly assigned to a training or non-training condition. The training condition was designed to improve the ability to organize complex visuospatial information in a meaningful way. The intervention phase was followed by another copy and recall trial of the RCFT. Both OCD and control subjects who underwent training improved more in organization and memory than subjects who did not receive organizational training, providing evidence that the training procedure was effective. OCD subjects improved more in organizational during encoding than control subjects, irrespective of whether or not they had received training. This suggests that organization impairment in OCD affects primarily the ability to spontaneously utilize strategies when faced with complex, ambiguous information but that the ability to implement such strategies when provided with additional trials is preserved. These findings support a distinction in OCD between failure to utilize a strategy and incapacity to implement a strategy.     

Neurological soft signs are associated with APOE genotype, age and cognitive performance

Neurodegeneration is associated with increased frequency of neurological soft signs (NSS). We designed the present study to investigate the association between NSS and subjective memory complaints, cognitive function and apolipoprotein E genotype in a community-dwelling sample of volunteers participating in an ongoing longitudinal program investigating predictors of cognitive decline. NSS were found to be associated with apolipoprotein E (APOE) epsilon4 genotype (p = 0.015), age (p = 0.012) and poor cognitive performance, as assessed by the Mini Mental State Examination (p = 0.053). There was no significant difference between subjects with and without memory complaints in relation to the frequency of NSS (p = 0.130). The association with age and the APOE epsilon4 genotype suggests that the systematic investigation of NSS may contribute to identify subjects at risk of clinically significant cognitive decline in later life.     

Signs of central nervous system dysfunction in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) has been linked to altered neurological function following head trauma, encephalitis, abnormal birth events, and Gilles de la Tourette's syndrome. Abnormalities in computed tomographic scans, electroencephalograms, positron emission tomographic scans, and evoked potentials have been described in this disorder, but are neither consistent nor pathognomonic of OCD. Neurological soft signs are nonlocalizing signs of deviant performance on a motor or sensory test where no other sign of a neurological lesion is present. We studied 41 medication-free patients with OCD who met DSM-III-R criteria, as well as 20 normal controls, matched for age, sex, and handedness, on 20 individual tasks that involved fine motor coordination, involuntary movements, and sensory and visuospatial function. There were significantly more signs of central nervous system dysfunction in the OCD group, as shown by abnormalities in fine motor coordination, involuntary and mirror movements, and visuospatial function. An excess of findings on the left side of the body and abnormalities of cube drawing may suggest right hemispheric dysfunction in a subgroup of patients with OCD. Soft signs correlated with a severity of obsessions. There was also a correlation between abnormalities in visual memory and recognition on neuropsychological testing and total soft signs. These findings provided additional evidence for a neurological deficit in some patients with OCD. However, further comparisons with other psychiatric populations are needed to determine whether these findings are unique to OCD or are a property of other psychiatric disorders as well.     

Neuropsychological profile in patients with obsessive-compulsive disorder over a period of 4-month treatment

This study investigated the changes of the neuropsychological functions over a 4-month period of treatment in patients with obsessive-compulsive disorder (OCD). Thirty-nine OCD patients and 31 healthy controls were evaluated with neuropsychological and clinical tests. The same tests were readministered 4-months after pharmacological treatment for the OCD patients. At the first series of tests, compared to the controls, the OCD patients were significantly impaired on the immediate and delayed recall of Rey-Osterrieth Complex Figure Test (RCFT), and on the letter and category of Controlled Oral Word Association Test (COWA). They also showed a prolonged response time on Trail Making Test (TMT), part A. The severity of OCD measured by Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) correlated well with the performance on the immediate and delayed recall of RCFT and the response time on TMT, part A. After 4-months' follow-up, the OCD patients still showed impairment on the immediate and delayed recall of RCFT and COWA category. This is despite the fact that they had improved significantly on these functions in comparison with the controls over the period of treatment. In addition, an association between OCD symptoms and the performance on the neuropsychological tests was not observed. The neuropsychological profile of the OCD patients found in the present study is consistent with current theories proposing that the frontal-striatal system is the possible pathophysiological mechanism underlying the development of OCD.     

Neuroanatomical correlates of neurological soft signs in antipsychotic-naive schizophrenia

Recent imaging studies suggest that the so-called “soft” neurological signs in schizophrenia might have neuroanatomical validity. We examined gray matter volume correlates of neurological soft signs (NSS) in antipsychotic-naive schizophrenia patients using an automated image analysis technique. NSS were assessed using a modified neurological evaluation scale with good inter-rater reliability. Magnetic resonance images of 30 schizophrenia patients and 27 age-, sex-, education- and handedness-matched healthy controls were processed using optimized voxel-based morphometry (VBM). Logistic regression analysis showed that only the Motor Sequencing Signs (MSS) sub-score was a significant predictor of subject's status among the NSS sub-scores. Optimized VBM analysis showed that the MSS sub-score had a significant negative correlation with total and regional gray matter volumes (prefrontal, posterior cingulate, temporal cortices, putamen, and cerebellum) in schizophrenia patients but not in controls. Prefrontal and temporal cortices, putamen and cerebellum had significant volume deficits in patients. Cortical and cerebellar correlates of the sub-score MSS support the concept of “cognitive dysmetria” in schizophrenia.     

Evidence for specific cognitive deficits in visual information processing in patients with OCD compared to patients with unipolar depression

Objective

Neuropsychological studies comparing cognitive performance in patients suffering from Obsessive-Compulsive Disorder (OCD) or Major Depressive Disorder (MDD) revealed deficits in the domains of verbal fluency and viso-motor speed/set shifting in both groups. Spatial working memory deficits, however, have been identified as specific markers of OCD. As yet, it has not been substantiated whether deficits in visual organization and complex visual memory are also specific to OCD and are not shared by MDD.

Method

Test performance in seven cognitive domains was assessed in 40 OCD patients, 20 MDD patients, and 40 healthy controls. Patient groups were matched according to severity of depressive symptoms.

Results

Deficits shared by both patient groups, as compared to controls, were found in delayed spatial recall and verbal fluency while verbal memory was normal in both patient groups. Only patients with OCD, but not MDD patients were impaired in the domains visual memory, viso-motor speed/set shifting, visual organization, and problem solving. In addition, OCD patients differed significantly from MDD subjects in visual organization and problem solving. Visual organization scores correlated significantly with severity of current compulsions in the OCD group (r = −.324).

Conclusions

OCD patients demonstrate difficulties in visual organization and mental manipulation of complex visual material, which are not accounted for by depressive symptoms and which constitute a specific cognitive deficit of the disorder.     

Extent, profile and specificity of visuospatial impairment in obsessive-compulsive disorder (OCD)

Recent reviews on the neurocognitive profile of patients diagnosed with obsessive-compulsive disorder (OCD) have converged on the assumption that both visuospatial and especially nonverbal memory performance are impaired in OCD. However, as most prior studies have contrasted performance of OCD patients with healthy controls only, no inferences can yet be drawn about the specificity of these deficits to OCD. Further, the administration of complex and multifunctional tasks limit conclusions about clearly defined cognitive deficits. The present study compared 71 OCD patients to 30 healthy and 33 psychiatric control participants on a large battery of visuospatial and nonverbal memory tasks at two time-points. In addition, a visuospatial battery (VS battery), which assesses a wide range of elementary visuospatial functions, was administered. While OCD patients performed worse than healthy controls on some complex tasks (e.g., Block Design), no visuospatial component proved to be impaired specifically in OCD. OCD patients and controls performed similarly on parameters of nonverbal memory. Regarding organizational strategy, OCD patients performed worse than healthy (but not psychiatric) control participants on two out of three Rey-figure trials (copy and immediate). It is suggested that prior research overestimated the severity and significance of visuospatial and nonverbal memory impairment in OCD.     

Smooth pursuit and saccadic eye movements and neurological soft signs in obsessive-compulsive disorder.

Patients with obsessive-compulsive disorder (OCD) demonstrate an increased number of neurological soft signs as well as neuroanatomic abnormalities detected with modern imaging techniques. Quantitative analysis of eye movements has proved fruitful in investigations of other neuropsychiatric disorders with similar findings. Therefore, we studied the smooth pursuit and saccadic eye movements of 8 OCD patients and 12 normal controls using infrared oculography and computerized pattern recognition software. We also measured neurologic soft signs using a standardized rating instrument. Despite having an increased number of neurological soft signs, OCD patients' performance on a variety of measures of eye movement was not significantly impaired. Neither the severity of obsessions or compulsions nor the number of neurologic soft signs correlated with any of the parameters of eye movement function. We conclude that OCD patients do not have prominent oculomotor dysfunction and that eye movement dysfunction and neurologic soft signs are not inextricably linked.     

Deficit of executive functions in schizophrenia: relationship to neurological soft signs and psychopathology

Cognitive deficits and neurological soft signs (NSS) have frequently been reported in schizophrenic patients and they both appear related to prominent negative symptoms. The aim of the present study was to examine the relationship between deficit of executive functioning, assessed by the Wisconsin Card Sorting Test (WCST), NSS and psychopathological dimensions of schizophrenia in order to address the issue of whether a typology of schizophrenic patients may be identifiable by clinical, neurological and neuropsychological features. A sample of 26 male schizophrenic patients was divided, on the basis of the performance on the WCST, into two subgroups ('good performers' and 'poor performers') that were compared for the prevalence and severity of NSS, assessed by the Neurological Evaluation Scale (NES), and for the psychopathological features, assessed using the Positive and Negative Syndrome Scale (PANSS). To test for between-group differences, ANOVA was conducted. The 'poor performers' group showed greater severity of NSS: significant differences emerged for the NES total score and for the 'sequencing of complex motor acts' score. However, no significant differences between the groups emerged for any PANSS score. These findings seem to indicate that a common neurobiological abnormality could underlie cognitive deficits, especially concerning executive functioning, and subtle neurological abnormalities often present in schizophrenia, but they appear to deny that such dysfunctional correlates of schizophrenia are related to a prominent negative symptomatology.     

Organizational strategies mediate nonverbal memory impairment in obsessive-compulsive disorder.

BACKGROUND: Previous neuropsychological studies of obsessive-compulsive disorder (OCD) have indicated impaired executive functioning and nonverbal memory. The extent to which impaired executive functioning impacts nonverbal memory has not been established. The current study investigated the mediating effects of organizational strategies used when copying a figure on subsequent nonverbal memory for that figure. METHODS: We examined neuropsychological performance in 20 unmedicated subjects with OCD and 20 matched normal control subjects. Subjects were administered the Rey-Osterrieth Complex Figure Test (RCFT) and neuropsychological tests assessing various aspects of executive function. RESULTS: OCD subjects differed significantly from healthy control subjects in the organizational strategies used to copy the RCFT figure, and they recalled significantly less information on both immediate and delayed testing. Multiple regression analyses indicated that group differences in immediate percent recall were significantly mediated by copy organizational strategies. Further exploratory analyses indicated that organizational problems in OCD may be related to difficulties shifting mental and/or spatial set. CONCLUSIONS: Immediate nonverbal memory problems in OCD subjects were mediated by impaired organizational strategies used during the initial copy of the RCFT figure. Thus, the primary deficit was one affecting executive function, which then had a secondary effect on immediate memory. These findings are consistent with current theories proposing frontal-striatal system dysfunction in OCD.