Publications by authors named "Ashley Miles"

19 Publications

  • Page 1 of 1

Epilepsy surgery in stroke-related epilepsy.

Seizure 2021 May 5;88:116-124. Epub 2021 Apr 5.

Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, 339 Windermere Rd. London, Ontario, Canada, N6A 5A5; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, 339 Windermere Rd. London, Ontario, Canada, N6A 5A5; Neuro-Epidemiology Unit, Schulich School of Medicine and Dentistry, Western University, 339 Windermere Rd. London, Ontario, Canada, N6A 5A5. Electronic address:

Purpose: To provide a descriptive analysis on the presurgical evaluation and surgical management of a cohort of patients with stroke related epilepsy (SRE).

Methods: We retrospectively examined the clinical characteristics, results of non-invasive and invasive presurgical evaluation, surgical management and outcome of consecutive patients with drug-resistant SRE in our institution from January 1, 2013 to January 1, 2020.

Results: Twenty-one of 420 patients (5%) who underwent intracranial EEG (iEEG), resective epilepsy surgery and/or vagus nerve stimulation (VNS) placement, had SRE. Of 13 patients who had iEEG, the ictal onset (IO) was exclusively within the stroke lesion in only one patient. In five patients the IO was extra-lesional and in the remaining seven patients it included the stroke lesion as well as extra-lesional structures. The IO included the mesial temporal region in 11 of the 13 patients (85%). The posterior margin of the stroke lesion was always involved. Five patients underwent surgery without iEEG. In total, 10 patients underwent resective surgery, four VNS placement and two had both corpus callosotomy and VNS placement. Of the patients who had resective surgery, nine were Engel I or II at last follow up.

Conclusion: We found that seizures in patients with drug resistant SRE were more frequently originated in the mesial temporal region than in the stroke lesion itself. Despite the complex epileptic network underlying drug-resistant SRE, a thorough presurgical assessment and adequate use of surgical options can lead to excellent surgical outcomes.
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http://dx.doi.org/10.1016/j.seizure.2021.04.002DOI Listing
May 2021

Kinetics and isotype assessment of antibodies targeting the spike protein receptor-binding domain of severe acute respiratory syndrome-coronavirus-2 in COVID-19 patients as a function of age, biological sex and disease severity.

Clin Transl Immunology 2020 7;9(10):e1189. Epub 2020 Oct 7.

Department of Microbiology and Molecular Genetics Larner College of Medicine, University of Vermont Burlington VT USA.

Objectives: There is an incomplete understanding of the host humoral immune response to severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2, which underlies COVID-19, during acute infection. Host factors such as age and sex as well as the kinetics and functionality of antibody responses are important factors to consider as vaccine development proceeds. The receptor-binding domain of the CoV spike (RBD-S) protein mediates host cell binding and infection and is a major target for vaccine design to elicit neutralising antibodies.

Methods: We assessed serum anti-SARS-CoV-2 RBD-S IgG, IgM and IgA antibodies by a two-step ELISA and neutralising antibodies in a cross-sectional study of hospitalised COVID-19 patients of varying disease severities. Anti-RBD-S IgG levels were also determined in asymptomatic seropositives.

Results: We found equivalent levels of anti-RBD-S antibodies in male and female patients and no age-related deficiencies even out to 93 years of age. The anti-RBD-S response was evident as little as 6 days after onset of symptoms and for at least 5 weeks after symptom onset. Anti-RBD-S IgG, IgM and IgA responses were simultaneously induced within 10 days after onset, with anti-RBD-S IgG sustained over a 5-week period. Anti-RBD-S antibodies strongly correlated with neutralising activity. Lastly, anti-RBD-S IgG responses were higher in symptomatic COVID-19 patients during acute infection compared with asymptomatic seropositive donors.

Conclusion: Our results suggest that anti-RBD-S IgG reflect functional immune responses to SARS-CoV-2, but do not completely explain age- and sex-related disparities in COVID-19 fatalities.
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http://dx.doi.org/10.1002/cti2.1189DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7541824PMC
October 2020

Baseline Susceptibility of a Laboratory Strain of Northern Corn Rootworm, Diabrotica barberi (Coleoptera: Chrysomelidae) to Bacillus thuringiensis Traits in Seedling, Single Plant, and Diet-Toxicity Assays.

J Econ Entomol 2020 08;113(4):1955-1962

Plant Genetics Research Unit, USDA/ARS, University of Missouri, Columbia, MO.

The northern corn rootworm (NCR), Diabrotica barberi Smith & Lawrence, is an economic pest of maize in the U.S. Corn Belt. The objective of this study was to determine the baseline susceptibility of a laboratory NCR strain to Bt proteins eCry3.1Ab, mCry3A, Cry3Bb1, and Cry34/35Ab1 using seedling, single plant, and diet-toxicity assays. Plant assays were performed in greenhouse using corn hybrids expressing one of the Bt proteins and each respective near-isoline. Diet-toxicity assays, consisting of Bt proteins overlaid onto artificial diet were also conducted. In both plant assays, significantly more larvae survived Cry34/35Ab1-expressing corn compared with all other Bt-expressing corn, and larvae that survived eCry3.1Ab-expressing corn had significantly smaller head capsule widths compared with larvae that survived Cry34/35Ab1-expressing corn. In seedling assays, larvae surviving eCry3.1Ab-expressing corn also had significantly smaller head capsule widths compared with larvae that survived mCry3A-expressing corn. Additionally, larvae that survived mCry3A-expressing corn weighed significantly more than larvae surviving eCry3.1Ab- and Cry34/35Ab1-expressing corn. In single plant assays, no significant differences in larval dry weight was observed between any of the Bt-expressing corn. In diet assays, LC50s ranged from 0.14 (eCry3.1Ab) to 10.6 µg/cm2 (Cry34/35Ab1), EC50s ranged from 0.12 (Cry34/35Ab1) to 1.57 µg/cm2 (mCry3A), IC50s ranged from 0.08 (eCry3.1Ab) to 2.41 µg/cm2 (Cry34/35Ab1), and MIC50s ranged from 2.52 (eCry3.1Ab) to 14.2 µg/cm2 (mCry3A). These results establish the toxicity of four Bt proteins to a laboratory diapausing NCR strain established prior to the introduction of Bt traits and are important for monitoring resistance evolution in NCR field populations.
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http://dx.doi.org/10.1093/jee/toaa107DOI Listing
August 2020

Kinetics and Isotype Assessment of Antibodies Targeting the Spike Protein Receptor Binding Domain of SARS-CoV-2 In COVID-19 Patients as a function of Age and Biological Sex.

medRxiv 2020 Jul 16. Epub 2020 Jul 16.

SARS-CoV-2 is the newly emerged virus responsible for the global COVID-19 pandemic. There is an incomplete understanding of the host humoral immune response to SARS-CoV-2 during acute infection. Host factors such as age and sex as well the kinetics and functionality of antibody responses are important factors to consider as vaccine development proceeds. The receptor-binding domain of the CoV spike (RBD-S) protein is important in host cell recognition and infection and antibodies targeting this domain are often neutralizing. In a cross-sectional study of anti-RBD-S antibodies in COVID-19 patients we found equivalent levels in male and female patients and no age-related deficiencies even out to 93 years of age. The anti-RBD-S response was evident as little as 6 days after onset of symptoms and for at least 5 weeks after symptom onset. Anti-RBD-S IgG, IgM, and IgA responses were simultaneously induced within 10 days after onset, but isotype-specific kinetics differed such that anti-RBD-S IgG was most sustained over a 5-week period. The kinetics and magnitude of neutralizing antibody formation strongly correlated with that seen for anti-RBD-S antibodies. Our results suggest age- and sex- related disparities in COVID-19 fatalities are not explained by anti-RBD-S responses. The multi-isotype anti-RBD-S response induced by live virus infection could serve as a potential marker by which to monitor vaccine-induced responses.
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http://dx.doi.org/10.1101/2020.07.15.20154443DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7386516PMC
July 2020

Taurine activates glycine and GABA receptor currents in anoxia-tolerant painted turtle pyramidal neurons.

J Exp Biol 2018 11 5;221(Pt 21). Epub 2018 Nov 5.

Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada M5S 3G5

Unlike anoxia-intolerant mammals, painted turtles can survive extended periods without oxygen. This is partly accomplished by an anoxia-mediated increase in gamma-aminobutyric acid (GABA) release, which activates GABA receptors and mediates spike arrest in turtle neurons via shunting inhibition. Extracellular taurine levels also increase during anoxia; why this occurs is unknown but it is speculated that glycine and/or GABA receptors are involved. Given the general importance of inhibitory neurotransmission in the anoxia-tolerant painted turtle brain, we investigated the function of taurine as an inhibitory neuromodulator in turtle pyramidal neurons. Using whole-cell patch-clamp electrophysiological methods to record from neurons within a cortical brain sheet, we found that taurine depolarized membrane potential by ∼8 mV, increased whole-cell conductance ∼2-fold, and induced an inward current that possessed characteristics similar to GABA- and glycine-evoked currents. These effects were mitigated following glycine receptor antagonism with strychnine and GABA receptor antagonism with gabazine, bicuculine or picrotoxin, but were unchanged following GABA or glutamatergic receptor inhibition. These data indicate that a high concentration of taurine mediates its effects through both glycine and GABA receptors, and suggests that taurine, in addition to GABA, inhibits neuronal activity during anoxia in the turtle cortex.
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http://dx.doi.org/10.1242/jeb.181529DOI Listing
November 2018

Feasibility of Group Cognitive-Behavioral Treatment of Insomnia Delivered by Clinical Video Telehealth.

Telemed J E Health 2016 12 10;22(12):1041-1046. Epub 2016 Jun 10.

5 VA Connecticut Healthcare System , New Haven, Connecticut.

Background: Clinical video telehealth provides a means for increasing access to psychotherapy. Insomnia is prevalent, is associated with a number of negative sequelae, and can be effectively managed with cognitive behavioral treatment of insomnia (CBT-I). Telehealth technologies can provide a means for increasing access to CBT-I.

Materials And Methods: The Tele-Insomnia program is a Veterans Health Administration (VHA) initiative in which CBT-I is delivered in a group format by telehealth. Veterans received six weekly sessions of group CBT-I, completing the Insomnia Severity Index (ISI) and daily sleep diaries throughout treatment. Paired-samples t-tests were used to examine differences in each measure from the first to the last session of treatment.

Results: There were statistically and clinically significant improvements in the ISI and all sleep diary variables with the exception of total sleep time. Video quality was excellent, and there were few connectivity problems.

Conclusions: Clinical video telehealth technology can be used to deliver group CBT-I in a manner that produces clinically significant improvement. This model is scalable and has been used to develop a national clinical telehealth program.
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http://dx.doi.org/10.1089/tmj.2016.0032DOI Listing
December 2016

Phosphorylation of the mitochondrial ATP-sensitive potassium channel occurs independently of PKCε in turtle brain.

Comp Biochem Physiol B Biochem Mol Biol 2016 Oct 6;200:44-53. Epub 2016 Jun 6.

Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada. Electronic address:

Neurons from the western painted turtle (Chrysemys picta bellii) are remarkably resilient to anoxia. This is partly due to a reduction in the permeability of excitatory glutamatergic ion channels, initiated by mitochondrial ATP-sensitive K(+) (mK(+)ATP) channel activation. The aim of this study was to determine if: 1) PKCε, a kinase associated with hypoxic stress tolerance, is more highly expressed in turtle brain than the anoxia-intolerant rat brain; 2) PKCε translocates to the mitochondrial membrane during anoxia; 3) PKCε modulates mK(+)ATP channels at the Thr-224 phosphorylation site on the Kir6.2 subunit; and 4) Thr-224 phosphorylation sensitises mK(+)ATP channels to anoxia. Soluble and mitochondrial-rich particulate fractions of turtle and rat cerebral cortex were isolated and PKCε expression was determined by Western blot, which revealed that turtle cortical PKCε expression was half that of the rat. Following the transition to anoxia, no changes in PKCε expression in either the soluble or particulate fraction of the turtle cortex were observed. Furthermore, incubation of tissue with tat-conjugated activator or inhibitor peptides had no effect on the amount of PKCε in either fraction. However, we observed a 2-fold increase in Thr-224 phosphorylation following 1h of anoxia. The increased Thr-224 phosphorylation was blocked by the general kinase inhibitor staurosporine but this did not affect the latency or magnitude of mK(+)ATP channel-mediated mitochondrial depolarization following anoxia, as indicated by rhodamine-123. We conclude that PKCε does not play a role in the onset of mitochondrial depolarization and therefore glutamatergic channel arrest in turtle cerebral cortex.
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http://dx.doi.org/10.1016/j.cbpb.2016.06.002DOI Listing
October 2016

Community outcome in cognitively normal schizophrenia patients.

J Int Neuropsychol Soc 2014 Sep 1;20(8):805-11. Epub 2014 Aug 1.

1York University,Toronto,Ontario,Canada.

Recent reports suggest that cognition is relatively preserved in some schizophrenia patients. However, little is known about the functional advantage these patients may demonstrate. The purpose of this study was to identify cognitively normal patients with a recently developed test battery and to determine the functional benefit of this normality relative to cognitively impaired patients. Average-range cognitive ability was defined by the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) composite score (T≥40) and applied to 100 patients with schizophrenia or schizoaffective disorder and to 81 non-psychiatric research participants. With group assignment adjusted for demographic variables, this procedure yielded 14 cognitively normal patients, 21 cognitively impaired patients, and 21 healthy adults with normal-range MCCB scores. Cognitively normal patients were indistinguishable from controls across all MCCB scales. Furthermore, their performance was superior to impaired patients on all scales except Social Cognition. Cognitively normal patients were also superior to impaired patients on a summary index of simulated life skills and functional competence. Nevertheless, both patient groups were equally disadvantaged relative to controls in independent community living. These findings suggest that normal-range cognition exists in schizophrenia, but fails to translate into enhanced community outcome.
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http://dx.doi.org/10.1017/S1355617714000629DOI Listing
September 2014

Preserved, deteriorated, and premorbidly impaired patterns of intellectual ability in schizophrenia.

Neuropsychology 2014 May 17;28(3):353-8. Epub 2014 Mar 17.

Department of Psychology, McMaster University.

Objective: The main purpose of this investigation was to identify patterns of intellectual performance in schizophrenia patients suggesting preserved, deteriorated, and premorbidly impaired ability, and to determine clinical, cognitive, and functional correlates of these patterns.

Method: We assessed 101 patients with schizophrenia or schizoaffective disorder and 80 non-psychiatric control participants. The "preserved" performance pattern was defined by average-range estimated premorbid and current IQ with no evidence of decline (premorbid-current IQ difference <10 points). The "deteriorated" pattern was defined by a difference between estimated premorbid and current IQ estimates of 10 points or more. The premorbidly "impaired" pattern was defined by below average estimated premorbid and current IQ and no evidence of decline greater than 10 points. Preserved and deteriorated patterns in healthy controls were also identified and studied in comparison to patient findings. The groups were compared on demographic, neurocognitive, clinical and functionality variables.

Results: Patients with the preserved pattern outperformed those meeting criteria for deteriorated and compromised intellectual ability on a composite measure of neurocognitive ability as well as in terms of functional competence. Patients demonstrating the deteriorated and compromised patterns were equivalent across all measures. However, "preserved" patients failed to show any advantage in terms of community functioning and demonstrated cognitive impairments relative to control participants.

Conclusions: Our results suggest that proposed patterns of intellectual decline and stability exist in both the schizophrenia and general populations, but may not hold true across other cognitive abilities and do not translate into differential functional outcome.
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http://dx.doi.org/10.1037/neu0000026DOI Listing
May 2014

Stability and change in symptoms, cognition, and community outcome in schizophrenia.

Schizophr Res 2014 Feb 29;152(2-3):435-9. Epub 2013 Sep 29.

Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada. Electronic address:

It has been well established that neurocognitive deficits are a core feature in schizophrenia and predict difficulties in functional independence. However, few studies have assessed the longitudinal stability of cognition and key aspects of functional outcome concurrently. Even less attention has been directed at the contingency of cognitive change on real world outcome changes. Accordingly, this study will assess the extent to which significant changes in cognition and community status are independent or related. As a point of comparison, the stability of clinical symptom status and the relationship between symptom and outcome change are evaluated. Symptoms, cognitive abilities, and community outcome was assessed in 128 patients with schizophrenia at baseline and again one year later. Intraclass correlation coefficients were used to index stability and reliable change index analyses quantified the prevalence of significant improvement or deterioration in each of the three illness features. Results from these analyses revealed that symptom status, cognitive functioning, and community outcome are similarly stable in treated schizophrenia outpatients. A small proportion of the sample demonstrated significant improvement or deterioration in these domains, with only weak evidence that such change was predicted by changes in symptoms or cognition. Further, there was no strong evidence of a preferential relationship for cognition relative to symptoms in relation to functional outcome. These results shed light on the strength and nature of the cognition-real world outcome relationship in schizophrenia and have implications for pharmacological and behavioral interventions aimed at improving real world outcome.
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http://dx.doi.org/10.1016/j.schres.2013.09.006DOI Listing
February 2014

WAIS-IV profile of cognition in schizophrenia.

Assessment 2013 Aug 26;20(4):462-73. Epub 2013 Feb 26.

York University, Toronto, Ontario, Canada.

The Wechsler Adult Intelligence Scale (WAIS) has been used extensively to study impairment across a range of cognitive domains in schizophrenia. However, cognitive performance among those with the illness has yet to be examined using the newest edition of this measure. Hence, the current study aims first, to provide WAIS-IV normative data for Canadian individuals with schizophrenia of low average intelligence; second, to examine schizophrenia performance on all WAIS-IV subtest, index and general intelligence scores relative to healthy comparison subjects; and third, to revalidate the pattern of impairment identified in this clinical group using the WAIS-III, where processing speed (PS) was most affected, followed by working memory (WM), perceptual reasoning (PR) and verbal comprehension (VC). The WAIS-IV was administered to outpatients with schizophrenia and their performance compared with age, gender, and education matched controls. WAIS-IV schizophrenia performance data are provided. Analyses revealed significant impairment on several tasks, including the new Cancellation subtest and the VC supplemental subtest, Comprehension. At the index score level, group differences in PS were significantly larger than those observed in all other cognitive domains. Impairments were also observed in WM amid relatively preserved performance in VC, thereby confirming the pattern of impairment identified using the WAIS-III.
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http://dx.doi.org/10.1177/1073191113478153DOI Listing
August 2013

The Canadian Objective Assessment of Life Skills (COALS): a new measure of functional competence in schizophrenia.

Psychiatry Res 2013 Apr 27;206(2-3):302-6. Epub 2012 Nov 27.

Cleghorn Early Intervention in Psychosis Program, St. Joseph's Healthcare, Hamilton, Ontario, Canada.

This study examined the reliability and validity of a new performance-based measure of functional competence for individuals with serious mental illness, the Canadian Objective Assessment of Life Skills (COALS). The COALS assesses both routinized procedural knowledge routines (PKR) and executive operations (EXO) in order to capture functional outcome variance. The COALS was administered to 101 outpatients with schizophrenia and schizoaffective disorder and 80 non-psychiatric controls. One month later, 95 patients and 63 controls completed a follow-up assessment. Measures of psychopathology, neurocognition, functionality and community adjustment were also administered. Results indicated that the COALS summary scores had good test-retest reliability for patient data. Further, the COALS correlated with other measures of functionality and with negative symptoms, but was independent of positive symptoms, demonstrating concurrent and discriminant validity. The overall COALS summary score added incremental validity to the prediction of community independence over and above the contribution of symptoms, intellectual ability and neurocognitive performance. Inclusion of EXO scores provided incremental validity not available with PKR scores alone. The COALS increases the number of functional competence instruments and offers the advantage of specific validity while incorporating important distinctions in cognitive performance.
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http://dx.doi.org/10.1016/j.psychres.2012.10.020DOI Listing
April 2013

"Real world" functioning in schizophrenia patients and healthy adults: assessing validity of the Multidimensional Scale of Independent Functioning.

Psychiatry Res 2011 Mar 24;186(1):123-7. Epub 2010 Aug 24.

Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario M3J1P3, Canada.

As treatment efforts to enhance cognitive abilities in schizophrenia increase, so too does the need for a critical appraisal of instruments that measure functionality and adjustment to community living. The Multidimensional Scale of Independent Functioning (MSIF; Jaeger et al., 2003) is a promising instrument that assesses functionality in relation to different life settings, performance levels, responsibilities and environmental supports. However, its applicability to the schizophrenia population has been questioned because relevant data are scarce. This study provides descriptive and validity-related information by reporting MSIF scores in healthy community-dwelling adults (n=71) and in schizophrenia outpatients (n=156). Results show that healthy adults performed within defined "normal" ranges in most MSIF domains in comparison to schizophrenia patients who showed moderate to severe impairments. Moreover, the MSIF distinguished between the two groups with accuracy rates as high as 98% and effect sizes (standardized mean group difference) above 2.0 in almost all domains. Accordingly, the MSIF is a potentially valuable measure of community independence that can inform treatment initiatives and may be adaptable to the evaluation of functionality changes over time. The unique structure and content of information obtained by the MSIF makes it a candidate for inclusion in studies aimed at developing a new generation of instruments for the assessment of real world functioning in schizophrenia.
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http://dx.doi.org/10.1016/j.psychres.2010.07.052DOI Listing
March 2011

An investigation of 3 neurocognitive subtypes in schizophrenia.

Schizophr Res 2010 Aug 20;121(1-3):32-8. Epub 2010 Jun 20.

Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.

The purpose of this investigation was to identify patients with cognitively impaired, cognitively normal and verbal memory-impaired subtypes of schizophrenia and to examine their clinical and functional validity as distinct forms of the disorder. These subtypes occurred in 73 of 154 patients meeting DSM-IV criteria for schizophrenia or schizoaffective disorder. A control group comprised of 18 healthy participants was also analyzed. Patient subtype and healthy groups were compared on adjunct cognitive as well as clinical and functional measures. The data support the cognitive validity and differentiation of these subtypes, with evidence that the generalized cognitive normality/impairment distinction associates with important aspects of symptom severity and functional outcome. Support for the clinical and functional validity of the verbal memory subtype was more equivocal. Overall, cognitively-based subtyping merits additional attention in efforts to organize the heterogeneity of the schizophrenia syndrome.
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http://dx.doi.org/10.1016/j.schres.2010.04.014DOI Listing
August 2010

Psychopathology and cognition in divergent functional outcomes in schizophrenia.

Schizophr Res 2009 Apr 31;109(1-3):46-51. Epub 2009 Jan 31.

Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.

Cognitive performance rather than symptoms, especially positive symptoms, is regarded as the primary predictor of functional outcome in schizophrenia. However, contradictory evidence exists and many studies fail to sample from the extremes of outcome measures. This study tested whether the differential importance assigned to symptoms and cognitive impairment is supportable in patients with high and low levels of community independence. Schizophrenia patients with highly unfavorable (n=24) and highly favorable (n=28) functional outcomes as defined by community support requirements were studied. Standard cognitive and psychopathology measures were analyzed using independent groups comparisons and outcome prediction with logistic regression methods. Symptom severity and cognitive data separately accounted for significant amounts of variance in community independence. Positive as well as negative symptoms, non-psychotic psychopathology and cognition generated large effect sizes between highly unfavorable and favorable outcome groups. The conditional validity of both overall psychopathology and positive symptoms was significant over and above the contribution of cognition to outcome prediction. Results suggest researchers may have underestimated the role of psychopathology in general and positive symptoms in particular as potential determinants of functional status in schizophrenia.
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http://dx.doi.org/10.1016/j.schres.2009.01.001DOI Listing
April 2009

Cognitive performance and functional competence as predictors of community independence in schizophrenia.

Schizophr Bull 2010 Mar 30;36(2):381-7. Epub 2008 Jul 30.

Department of Psychology, York University, Toronto, ON M3J 1P3, Canada.

Measures of functional competence have been introduced to supplement standard cognitive and neuropsychological evaluations in schizophrenia research and practice. Functional competence comprises skills and abilities that are more relevant to daily life and community adjustment. However, it is unclear whether relevance translates into significantly enhanced prediction of real-world outcomes. The aim of this study was to assess the specific contribution of functional competence in predicting a key aspect of real-world outcome in schizophrenia: community independence. Demographic, clinical, cognitive, and functional competence data were obtained from 127 patients with schizophrenia or schizoaffective disorder and used to predict community independence concurrently and longitudinally after 10 months. Hierarchical regression analyses indicated that demographic, clinical, and cognitive predictors accounted jointly for 35%-38% of the variance in community independence across assessment points. Functional competence data failed to add significantly to this validity. Considered separately from demographic and clinical predictors, cognitive and functional competence data accounted for significant amounts of outcome variance. However, the addition of functional competence to standard cognitive test data yielded a significant increase in validity only for concurrent and not for longitudinal prediction of community independence. The specific real-world validity of functional competence is modest, yielding information that is largely redundant with standard cognitive performance.
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http://dx.doi.org/10.1093/schbul/sbn095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2833115PMC
March 2010

Cognitive, clinical, and functional characteristics of verbally superior schizophrenia patients.

Neuropsychology 2008 May;22(3):321-8

Department of Psychology, York University, Toronto, Ontario, Canada.

The existence of small numbers of schizophrenia patients with superior ability in specific cognitive domains is implied by meta-analytic evidence as well as by occasional empirical reports. The authors identified 25 patients with superior (i.e., > or =90th percentile) ability on the Vocabulary subtest of the Wechsler Adult Intelligence Scale 3rd edition (Wechsler, 1997). These cognitively advantaged patients were compared with 22 healthy participants performing at the superior level and with 126 schizophrenia patients and 50 healthy participants scoring below the superior range. Verbally superior schizophrenia patients and verbally superior healthy participants had similar cognitive profiles and life skills performance, but diverged markedly in terms of independent "real-world" functioning. Verbally superior patients significantly outperformed more typical patients in other aspects of cognitive performance, life skills, and support requirements. However, severity of positive and negative symptoms was equivalent in the patient groups. Detailed biobehavioral study of cognitively exceptional patients may offer new insights into mechanisms mediating psychotic disorders.
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http://dx.doi.org/10.1037/0894-4105.22.3.321DOI Listing
May 2008

Are schizophrenia and schizoaffective disorder neuropsychologically distinguishable?

Schizophr Res 2008 Feb 26;99(1-3):149-54. Epub 2007 Nov 26.

Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.

This study sought to objectify the distinction between schizophrenia and schizoaffective disorder in terms of standard tasks measuring verbal and non-verbal cognitive ability, auditory working memory, verbal declarative memory and visual processing speed. Research participants included 103 outpatients with a diagnosis of schizophrenia, 48 with schizoaffective disorder, and 72 non-patients from the community. Schizophrenia patients were impaired on all cognitive measures relative to schizoaffective patients and non-psychiatric participants. Regression-based prediction models revealed that cognitive measures classified schizophrenia patients accurately (91%), but not patients with schizoaffective disorder (35%). In addition, there was no statistical evidence for the unique predictive validity of any specific cognitive task. Patients with schizophrenia were significantly more symptomatic and had greater community support requirements than those with schizoaffective disorder. However, group differences in cognitive performance are insufficient to separate these syndromes of psychotic illness.
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http://dx.doi.org/10.1016/j.schres.2007.10.007DOI Listing
February 2008

Predictors of medication competence in schizophrenia patients.

Psychiatry Res 2008 Jan 25;157(1-3):47-52. Epub 2007 Sep 25.

Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada.

Competence in self-administration of a drug regimen is related to both treatment adherence and functional outcome. Previous research with middle-aged and older schizophrenia patients suggests a central role for cognitive performance in predicting this competence. We examined the relative and joint contributions of demographic, clinical and cognitive predictors of medication management ability in an age-representative group of patients. The study participants comprised 147 patients with schizophrenia or schizoaffective disorder ranging from 21 to 65 years of age. Measures included demographic variables, current symptoms, subjective treatment response and a battery of cognitive tests. Competence in medication management was indexed with the Medication Management Ability Assessment (MMAA). Multiple regression analyses revealed that cognitive variables accounted for a significant proportion of the variance in MMAA scores over and above the contribution of all other variables. Measures of word recognition and pronunciation, auditory working memory and verbal learning yielded unique contributions to prediction. Positive and negative symptoms and subject treatment evaluations did not independently predict medication competency. This study documents a considerable range in MMAA scores across a demographically broad schizophrenia sample and supports the unique contribution of specific cognitive factors in predicting medication competence.
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http://dx.doi.org/10.1016/j.psychres.2007.02.015DOI Listing
January 2008