| 1 | Psychiatry Res 2000 Sep 95: 237-43 |
|---|---|
| PMID | 10974362 |
| Title | Factor structure of neurologic examination abnormalities in unmedicated schizophrenia. |
| Abstract | The heterogeneity and uncertain significance of neurologic exam abnormalities in schizophrenia prompted us to evaluate their factor structure. We administered a modified version of the Neurological Evaluation Scale (NES) to 103 unmedicated patients with schizophrenia. Data were distilled by combining right- and left-side scores, and by eliminating superfluous, rarely abnormal and unreliable items from the analysis. Exploratory principal components analysis yielded four factors: repetitive motor tasks (fist-ring, fist-edge-PALM, alternating fist-PALM, dysdiadochokinesis); cognitive-perceptual tasks (memory, audiovisual integration, right-left orientation, face-hand test, rhythm tapping reproduction); balancing tasks (Romberg, tandem gait); and the PALMomental reflex. Evaluation of the relationship between these factors and clinical and demographic variables revealed a robust correlation between the cognitive-perceptual factor and full-scale IQ score. This analysis is a step toward developing empirical subscales of a modified NES, which may provide insights into the nature of neurologic impairment in schizophrenia and may prove clinically useful. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 2 | Psychol Med 2000 Sep 30: 1131-9 |
| PMID | 12027049 |
| Title | The perception of self-produced sensory stimuli in patients with auditory hallucinations and passivity experiences: evidence for a breakdown in self-monitoring. |
| Abstract | To test the hypothesis that certain psychotic symptomatology is due to a defect in self-monitoring, we investigated the ability of groups of psychiatric patients to differentiate perceptually between self-produced and externally produced tactile stimuli. Responses to tactile stimulation were assessed in three groups of subjects: schizophrenic patients; patients with bipolar affective disorder or depression; and normal control subjects. Within the psychiatric groups subjects were divided on the basis of the presence or absence of auditory hallucinations and/or passivity experiences. The subjects were asked to rate the perception of a tactile sensation on the PALM of their left hand. The tactile stimulation was either self-produced by movement of the subject's right hand or externally produced by the experimenter. Normal control subjects and those psychiatric patients with neither auditory hallucinations nor passivity phenomena experienced self-produced stimuli as less intense, tickly and pleasant than identical, externally produced tactile stimuli. In contrast, psychiatric patients with these symptoms did not show a decrease in their perceptual ratings for tactile stimuli produced by themselves as compared with those produced by the experimenter. This failure to show a difference in perception between self-produced and externally produced stimuli appears to relate to the presence of auditory hallucinations and/or passivity experiences rather than to the diagnosis of schizophrenia. We propose that auditory hallucinations and passivity experiences are associated with an abnormality in the self-monitoring mechanism that normally allows us to distinguish self-produced from externally produced sensations. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 3 | Psychol Med 2000 Sep 30: 1131-9 |
| PMID | 12027049 |
| Title | The perception of self-produced sensory stimuli in patients with auditory hallucinations and passivity experiences: evidence for a breakdown in self-monitoring. |
| Abstract | To test the hypothesis that certain psychotic symptomatology is due to a defect in self-monitoring, we investigated the ability of groups of psychiatric patients to differentiate perceptually between self-produced and externally produced tactile stimuli. Responses to tactile stimulation were assessed in three groups of subjects: schizophrenic patients; patients with bipolar affective disorder or depression; and normal control subjects. Within the psychiatric groups subjects were divided on the basis of the presence or absence of auditory hallucinations and/or passivity experiences. The subjects were asked to rate the perception of a tactile sensation on the PALM of their left hand. The tactile stimulation was either self-produced by movement of the subject's right hand or externally produced by the experimenter. Normal control subjects and those psychiatric patients with neither auditory hallucinations nor passivity phenomena experienced self-produced stimuli as less intense, tickly and pleasant than identical, externally produced tactile stimuli. In contrast, psychiatric patients with these symptoms did not show a decrease in their perceptual ratings for tactile stimuli produced by themselves as compared with those produced by the experimenter. This failure to show a difference in perception between self-produced and externally produced stimuli appears to relate to the presence of auditory hallucinations and/or passivity experiences rather than to the diagnosis of schizophrenia. We propose that auditory hallucinations and passivity experiences are associated with an abnormality in the self-monitoring mechanism that normally allows us to distinguish self-produced from externally produced sensations. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 4 | Schizophr. Res. 2001 Dec 52: 181-93 |
| PMID | 11705712 |
| Title | Differentiating between low and high susceptibility to schizophrenia in twins: the significance of dermatoglyphic indices in relation to other determinants of brain development. |
| Abstract | Both the skin and the brain develop from the same ectoderm and it is thought, therefore, that dermatoglyphics are informative for early disturbances in brain development in schizophrenia. This study was aimed at investigating the differences in both digital and PALMar dermatoglyphic indices between twins discordant for schizophrenia and control twins. Furthermore, the significance of dermatoglyphic indices in relation to other determinants of brain development with regard to the susceptibility to schizophrenia was investigated. Data on dermatoglyphic indices of the hand and the PALM were obtained from 21 same-sex discordant and 37 same-sex control twins. For 19 discordant and 25 control twins, there was also data available on brain volumes. Non-genetic intra-uterine circumstances early in pregnancy (10-13 weeks of gestation) are associated with a susceptibility to schizophrenia, since both the twins with schizophrenia and the unaffected co-twins showed more fluctuating asymmetry of the finger ridges (P<0.01), and marginally higher absolute finger ridge counts (P=0.06) than control twin pairs. Fluctuating asymmetry of the finger ridges was as important as whole brain and left hippocampal volumes in differentiating twins with a high susceptibility to schizophrenia from those with a low susceptibility. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 5 | Neurosci. Lett. 2006 May 398: 189-94 |
| PMID | 16469446 |
| Title | The neural basis of motor sequencing: an fMRI study of healthy subjects. |
| Abstract | The present study used functional MRI to clarify the brain regions activated during a series of motor sequencing tasks in healthy volunteers. Ten subjects were scanned while performing three soft signs tasks ranging from simple (PT: PALM tapping), moderate (PS: pronation/supination) to complex movements (FEP: fist-edge-PALM). The FEP task induced significant activations within the cortical networks including bilateral sensorimotor, SMA, left parietal, and right cerebellum, but no activation in the prefrontal area. Moreover, the percentage signal changes within the left sensorimotor, left thalamus and right cerebellum showed an increase in activation with task complexity. The present findings challenge the traditional belief that FEP was a task for frontal lobe function but suggest that successful performance of more complex neurological soft sign tasks like FEP requires the participation of more brain areas than simple motor sequencing and coordination task like PS and PT. These also provide the empirical data on the neural basis of neurological soft signs for further study in other clinical group like schizophrenia in the near future. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 6 | Conscious Cogn 2006 Jun 15: 285-94 |
| PMID | 16157489 |
| Title | The ability to self-tickle following Rapid Eye Movement sleep dreaming. |
| Abstract | Self-produced tactile stimulation usually feels less tickly--is perceptually attenuated--relative to the same stimulation produced externally. This is not true, however, for individuals with schizophrenia. Here, we investigate whether the lack of attenuation to self-produced stimuli seen in schizophrenia also occurs for normal participants following REM dreams. Fourteen participants were stimulated on their left PALM with a tactile stimulation device which allowed the same stimulus to be generated by the participant or by the experimenter. The level of self-tickling attenuation did not differ between REM and non-REM sleep awakening conditions, where presence or absence of an accompanying dream was not controlled for. However, for the female participants, when awakening occurred from an REM sleep dream, self-stimulation ratings were higher than for external stimulation, whereas ratings after NREM sleep unaccompanied by a dream were lower for self-stimulation than for external stimulation. These results indicate deficits in self-monitoring and a confusion between self- and externally generated stimulation accompany REM dream formation. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 7 | Schizophr. Res. 2006 Sep 86: 172-80 |
| PMID | 16854564 |
| Title | Are neurologic examination abnormalities heritable? A preliminary study. |
| Abstract | Neurologic examination abnormalities (NEA) are more prevalent among patients with schizophrenia as well as their unaffected relatives when compared with healthy controls, suggesting that NEA may be endophenotypes for schizophrenia. We estimated the heritability of NEA in moderately sized pedigrees. We also evaluated correlations between NEA and cognitive performance in order to examine their construct validity. Members of eight extended families, each consisting of two first degree relatives with schizophrenia/schizoaffective disorders, as well as available first- to fifth-degree relatives were examined (n=96 participants). A modification of the Neurological Evaluation Scale (NES) was employed, augmented with localizing signs. Where feasible, we used untransformed data such as error counts and completion time, rather than ordinal measures. Heritability was estimated using the variance component method, implemented in SOLAR. Statistically significant heritability (h2) estimates were obtained for several measures (p<0.05, h2+/-standard error: rapid alternating movements, right-sided completion time, 0.99+/-0.19; alternating fist-PALM test, completion time, 0.77+/-0.19 s, errors, 0.70+/-0.32; fist-ring test, right-sided completion time, 0.53+/-0.23 s, left-sided completion time, 0.70+/-0.21 s; go-no go task, correct responses, 0.93+/-0.33; audio-visual integration, correct responses, 0.79+/-0.54). For most items, heritability analysis was hampered by insufficient data variability (infrequent errors). Correlational analyses show some degree of divergence among types of NEA, repetitive motor tasks being associated with most domains of cognitive functioning other than executive functioning, and cognitive-perceptual tasks being associated with memory and executive functioning. Significant familial influences on certain aspects of neurologic performance were detected. These heritable measures were also correlated with heritable neurocognitive measures. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 8 | Schizophr. Res. 2006 Jun 84: 365-77 |
| PMID | 16630708 |
| Title | Factor structure of the Neurological Evaluation Scale in a predominantly African American sample of patients with schizophrenia, unaffected relatives, and non-psychiatric controls. |
| Abstract | This study aimed to identify latent factors of the most widely used scale to measure neurological soft signs, the Neurological Evaluation Scale (NES), in a sample of schizophrenia patients, their relatives, and non-psychiatric controls. The NES was administered following the format and instructions of the original scale [Buchanan, R.W., Heinrichs, D.W., 1989. The Neurological Evaluation Scale (NES): a structured instrument for the assessment of neurological signs in schizophrenia. Psychiatry Res. 27, 335-350]. Three factor analyses were conducted using: (1) 23 items of the scale, (2) these 23 items in a sample restricted to African American participants, and (3) 12 items previously recommended based on adequate inter-rater reliability [Sanders, R.D., Forman, S.D., Pierri, J.N., Baker, R.W., Kelley, M.E., van Kammen, D.P., Keshavan, M.S., 1998. Inter-rater reliability of the neurological examination in schizophrenia. Schizophr. Res. 29, 287-292]. Exploratory factor analysis in the overall sample (n = 110) revealed three factors of interest: a "coordination/Romberg" factor (which included the fist-edge-PALM test, finger-thumb opposition, rapid alternating movements, and the Romberg test), a "sensory integration" factor (which included synkinesis, extinction, stereognosis, and audio-visual integration), and an "eye movements/tandem walk/overflow movements" factor (which included convergence, gaze impersistence, tandem walk, and adventitious overflow). Minimal differences were apparent when comparing these results with those obtained from an analysis including only African American participants (n = 99). Restricting the analysis to only 12 items resulted in two factors (with poor discriminant validity and internal consistency), which showed few similarities with previously reported exploratory factor analysis results. This study shows that results of empirically-derived factors of the NES vary substantially across study samples and research groups, though there appear to be at least two consistent latent variables, one related to the repetition of motor tasks and another tapping the processing of sensory stimuli. The factors demonstrated in the present study are more consistent with the original conceptually-derived subscales than prior factor analyses. Thus, until further research replicates consistent subscales of subtle neurological impairment in a variety of settings and samples, the total NES score may be more useful when comparing results across studies. Further research on latent neurological factors is needed. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 9 | J Psychiatr Res 2006 Apr 40: 221-30 |
| PMID | 16300791 |
| Title | Computerized experience sampling method (ESMc): assessing feasibility and validity among individuals with schizophrenia. |
| Abstract | The Experience Sampling Method (ESM) is an ecologically valid, time-sampling of self-reports developed to study the dynamic process of person-environment interactions. ESM with digital wristwatch and booklets (paper-based ESM; ESMp) has been used extensively to study schizophrenia. The present study is designed to test the feasibility and validity of using Computerized ESM (ESMc) among individuals with schizophrenia. ESMc is advantageous in allowing for recording of precise time-stamps of responses. We used PDAs ("Personal Digital Assistant"; PALM handheld computers) to collect data on momentary psychotic symptoms, mood, and thoughts over a one day period among 10 hospitalized schizophrenia patients and 10 healthy controls. ESMc was equally acceptable to both groups, with similar ratings of comfort carrying the PDAs and operating them, interference with daily activities, as well as response rates. The schizophrenia patients reported significantly higher ratings of auditory and visual hallucinations, suspiciousness, sense of unreality, lack of thought control, fear of losing control, difficulty expressing thoughts, as well as depression/sadness, loneliness and less cheerfulness. Significant inverse relationships were found among both groups between ratings of feeling cheerful and being stressed, irritated, and sad/depressed. Among the schizophrenia subjects, the correlation between ratings of suspiciousness on ESMc and Scale for Assessment of Positive Symptoms (SAPS) approached significance, as well as the link between suspiciousness and stress. Our results support the feasibility and validity of using ESMc for assessment of momentary psychotic symptoms, mood, and experiences among individuals with schizophrenia. The authors discuss the potential applications of combining ESMc with ambulatory physiological measures. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 10 | Early Interv Psychiatry 2008 Nov 2: 234-41 |
| PMID | 19884956 |
| Title | Use of Palm computer as an adjunct to cognitive-behavioural therapy with an ultra-high-risk patient: a case report. |
| Abstract | Recently, attempts have been made to develop cognitive-behaviour therapy (CBT) treatment models to target negative symptoms in individuals with schizophrenia, as well as individuals at ultra-high risk (UHR) for psychosis. Successful CBT treatment is founded on active patient participation including completion of homework assignments such as daily logs of activities and experiences. However, these very negative symptoms may themselves hinder the rate of homework assignment completion. We describe a case report of using experience sampling method with a PALM computer as an adjunct to CBT with a female patient at UHR status with predominantly negative symptoms. Our aim was to assess the feasibility and effectiveness of this methodology to improve homework completion and overcome treatment barriers associated with negative symptoms. Over the course of treatment, the patient was provided with a PALM computer to carry with her throughout her daily activities. The PALM computer was pre-programmed to beep randomly 10 times per day (10 a.m.-12 a.m.) over each three-day assessment period to elicit information on daily functioning. The use of the PALM computer was acceptable to the patient and resulted in a substantial increase in homework completion. This methodology resulted in rich information about the patients' daily functioning and patterns of improvement during treatment. The experience sampling method data were also successfully used in the application of treatment interventions. The findings support the feasibility and effectiveness of using PALM computers as adjunct to CBT with UHR individuals with predominantly negative symptoms. The implications for treatment and future research directions are discussed. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 11 | J Med Assoc Thai 2011 Mar 94: 386-94 |
| PMID | 21560848 |
| Title | Dermatoglyphic traits in Thai schizophrenia patients: a matching case-control study. |
| Abstract | To compare fingerprint patterns, means of dermatoglyphic variables i.e., total finger ridge count, total a-b ridge count, pattern complexity index, and fingerprint pattern asymmetry between patients with schizophrenia and normal controls. A cross-sectional, matching case-control was conducted. Thirty-four males and 34 females with schizophrenia and an equal number of age and sex matched normal controls were selected. Fingerprints and partial PALM prints of all of the subjects were obtained using the Automated Inkless Fingerprint Imaging Software and the transparent-adhesive tape technique, respectively. Using paired t-tests (p < 0.05), the cases and controls, males and females separately, were compared for fingerprint pattern asymmetry, total finger ridge counts (TFRC), a-b ridge counts of the right (RABRC), left (LABRC), and both hands (TABRC), and pattern complexity index (PCI). Between cases and controls, neither sex had any significant differences in the mean scores for the pattern asymmetries, TFRC, right-left-ABRC and TABRC. However, the mean scores for PCI were significantly different between the male cases and controls (2.82 vs. 4.94, p = 0 009). Only male patients exhibited average scores for complex patterns (whorls minus arches less than 2), which might be a biomarker for screening of schizophrenia in males. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 12 | Arch Clin Neuropsychol 2013 May 28: 254-61 |
| PMID | 23537559 |
| Title | The influence of semantic processing on odor identification ability in schizophrenia. |
| Abstract | Despite the well-documented observation of odor identification deficits in schizophrenia, less is known about where the disruption in the process of correctly identifying an odor occurs. This study aimed to determine the potential moderating effects of semantic processing on the observed olfactory dysfunction in schizophrenia. schizophrenia patients and healthy comparison subjects completed two versions of the University of Pennsylvania Smell Identification Test (UPSIT): an uncued free-response version and the standard multiple-choice paradigm, as well as three semantic measures: The Boston Naming Test, Animal Naming, and Pyramids and PALM Tree Test. schizophrenia patients yielded significantly lower scores than the comparison group on the standard UPSIT and on semantic measures. No relationship was observed between olfactory and semantic task performance in patients. These data suggest that odor identification deficits may not be primarily due to semantic processing deficits in schizophrenia. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 13 | Psychiatry Res 2014 Dec 220: 145-51 |
| PMID | 25200763 |
| Title | Luria revisited: complex motor phenomena in first episode schizophrenia and schizophrenia spectrum disorders. |
| Abstract | Patients with schizophrenia frequently exhibit motor deficits. However, to date, there are no studies comparing motor performance in first episode patients with schizophrenia and schizophrenia spectrum disorders (SSD; e.g. schizoaffective and brief psychosis). Participants comprised 57 first episode patients with schizophrenia, 32 first episode patients with SSD, and 51 healthy controls who underwent neuropsychological testing based on Luria?s systematic approach, including the following tests on complex motor sequencing: the Fist-Edge-PALM (FEP) test and the bimanual probe (BP). schizophrenia patients performed worse than SSD patients in FEP and BP, and both patient groups showed decreased scores compared to healthy controls. Furthermore, we found that a higher proportion of schizophrenia cases failed to correct their motor performance and needed external error correction, while SSD cases exhibited a higher proportion of self-correction in FEP and in BP. Lack of insight and poor executive functioning correlated with motor performance in schizophrenia, while impulse control and difficulties in abstract thinking were related to motor performance in schizophrenia spectrum disorder. Thus, psychomotor impairments appear already in first episode patients with schizophrenia and differ from impairments in SSD. Especially the inability to self-correct errors may be characteristic of schizophrenia, suggesting that impairments in error monitoring are related to psychomotor dysfunction in schizophrenia. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 14 | Int J Nanomedicine 2015 -1 10: 6469-76 |
| PMID | 26508853 |
| Title | Enhancement of encapsulation efficiency of nanoemulsion-containing aripiprazole for the treatment of schizophrenia using mixture experimental design. |
| Abstract | Aripiprazole is considered as a third-generation antipsychotic drug with excellent therapeutic efficacy in controlling schizophrenia symptoms and was the first atypical anti-psychotic agent to be approved by the US Food and Drug Administration. Formulation of nanoemulsion-containing aripiprazole was carried out using high shear and high pressure homogenizers. Mixture experimental design was selected to optimize the composition of nanoemulsion. A very small droplet size of emulsion can provide an effective encapsulation for delivery system in the body. The effects of PALM kernel oil ester (3-6 wt%), lecithin (2-3 wt%), Tween 80 (0.5-1 wt%), glycerol (1.5-3 wt%), and water (87-93 wt%) on the droplet size of aripiprazole nanoemulsions were investigated. The mathematical model showed that the optimum formulation for preparation of aripiprazole nanoemulsion having the desirable criteria was 3.00% of PALM kernel oil ester, 2.00% of lecithin, 1.00% of Tween 80, 2.25% of glycerol, and 91.75% of water. Under optimum formulation, the corresponding predicted response value for droplet size was 64.24 nm, which showed an excellent agreement with the actual value (62.23 nm) with residual standard error <3.2%. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 15 | Neuroimage Clin 2015 -1 9: 411-7 |
| PMID | 26594623 |
| Title | Prefrontal cortex connectivity dysfunction in performing the Fist-Edge-Palm task in patients with first-episode schizophrenia and non-psychotic first-degree relatives. |
| Abstract | Neurological soft signs have been considered one of the promising neurological endophenotypes for schizophrenia. However, most previous studies have employed clinical rating data only. The present study aimed to examine the neurobiological basis of one of the typical motor coordination signs, the Fist-Edge-PALM (FEP) task, in patients with first-episode schizophrenia and their non-psychotic first degree relatives. Thirteen patients with first-episode schizophrenia, 14 non-psychotic first-degree relatives and 14 healthy controls were recruited. All of them were instructed to perform the FEP task in a 3 T GE Machine. Psychophysiological interaction (PPI) analysis was used to evaluate the functional connectivity between the sensorimotor cortex and frontal regions when participants performed the FEP task compared to simple motor tasks. In the contrast of PALM-tapping (PT) vs. rest, activation of the left frontal-parietal region was lowest in the schizophrenia group, intermediate in the relative group and highest in the healthy control group. In the contrast of FEP vs. PT, patients with schizophrenia did not show areas of significant activation, while relatives and healthy controls showed significant activation of the left middle frontal gyrus. Moreover, with the increase in task complexity, significant functional connectivity was observed between the sensorimotor cortex and the right frontal gyrus in healthy controls but not in patients with first episode schizophrenia. These findings suggest that activity of the left frontal-parietal and frontal regions may be neurofunctional correlates of neurological soft signs, which in turn may be a potential endophenotype of schizophrenia. Moreover, the right frontal gyrus may play a specific role in the execution of the FEP task in schizophrenia spectrum disorders. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 16 | Neurosci. Lett. 2015 Mar 589: 110-4 |
| PMID | 25603475 |
| Title | The confirmatory factor structure of neurological soft signs in Nigerians with first episode schizophrenia. |
| Abstract | We describe empirically derived categories of NSS in first episode schizophrenia among indigenous Africans. A total of 84 Nigerian patients with the disease were assessed using the neurological evaluation scale. An exploratory factor analysis with orthogonal varimax rotation was first conducted and the factors derived based on a priori criteria were subjected to confirmatory analyses using SPSS 18.0 and AMOS 18.0. We tested four different competing models to identify the structure with the best fit to the data. The relationship of the derived NSS structure with the clinical characteristics of schizophrenia was then explored using the Pearson correlation method. The overall clinical status was assessed using the positive and negative syndrome scale and clinical global impression. Additional assessments included the pre-morbid adjustment scale and calgary depression scale for schizophrenia. A three factor structure in which stereognosis is prescribed to load into a 'perceptual and motor sequencing' category (audio-visual integration, fist-edge PALM, rhythm tapping, extinction, right-left confusion) provided the best fit to the data (chi-square goodness of fit test=1.25; comparative fit index=0.95; root square means error of approximation <0.05). The other two factors were: 'eye movement' (synkinesis, convergence, gaze impersistence) and 'motor co-ordination and graphaesthesia' (Tandem walk, adventitious flow, graphaesthesia). The signs were associated with severe negative (r=0.456, p<0.001), and disorganization (r=0.559, p<0.001) psychopathologies. NSS in this sample are heterogeneous, but aggregates into three correlated categories with significant overlap with previously described classifications. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |