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Dive into the research topics where Panayiotis Patrikelis is active.

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Featured researches published by Panayiotis Patrikelis.


Schizophrenia Research | 2011

Apathy, cognitive deficits and functional impairment in schizophrenia

George Konstantakopoulos; Dimitris Ploumpidis; Panagiotis Oulis; Panayiotis Patrikelis; Aggeliki Soumani; George N. Papadimitriou; Antonis Politis

INTRODUCTION Apathy has been repeatedly highlighted as a core component of negative symptoms especially with regard to functional outcome of schizophrenia. The purpose of this study was to explore the relationships between apathy, cognitive deficits, and psychosocial functioning in chronic patients with schizophrenia. METHODS Thirty-six chronic patients with schizophrenia and an equal number of matched healthy participants were assessed with the clinician version of Apathy Evaluation Scale (AES-C) along with a comprehensive battery of neuropsychological measures. Functioning was assessed with the Personal and Social Performance scale (PSP) and other symptoms were measured with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. RESULTS Apathy was strongly and specifically associated with poorer performance on executive tests in patient group. AES-C was significantly correlated with PSP total score as well as its subscales for social useful activities, personal and social relationships, and self-care. Multiple regression analysis revealed that apathy was the most robust predictor of current psychosocial functioning, accounting for 70% of the variance in functioning, independently of co-existent cognitive deficits. Moreover, executive dysfunction did not predict functional impairment, independently of the effect of apathy. CONCLUSION Our findings confirm that apathy has a stronger relationship to functional impairment than cognitive deficits on a cross-sectional basis in schizophrenia. Moreover, they suggest that apathy and executive dysfunction might represent different manifestations of the same syndrome, probably sharing a common neural substrate.


Epilepsy & Behavior | 2009

Neurocognitive and behavioral functioning in frontal lobe epilepsy: A review

Panayiotis Patrikelis; Efthymios Angelakis; Stylianos Gatzonis

Frontal lobe epilepsy (FLE) is a seizure disorder with a lower prevalence than temporal lobe epilepsy (TLE). Despite its consequences on cognitive and emotional well-being, the neuropsychology of FLE has not been well studied. By contrast, TLE has been studied meticulously, leading to a relevant understanding of memory and the functional characteristics of the temporal and limbic circuits. The neuropsychological studies on FLE report deficits in motor coordination and planning, reduced attention span, and difficulties in response inhibition in complex cognitive tasks. This review aims to illustrate the most relevant neurocognitive dimensions, psychiatric comorbidity, and postoperative neuropsychological outcome of FLE. Methodological suggestions for future research are also included by critically reviewing the existing literature.


Schizophrenia Research | 2014

The relationship between insight and theory of mind in schizophrenia

George Konstantakopoulos; Dimitris Ploumpidis; Panagiotis Oulis; Panayiotis Patrikelis; Stavrina Nikitopoulou; George N. Papadimitriou; Anthony S. David

INTRODUCTION It has been proposed that theory of mind (ToM) deficits underlying difficulties in taking the perspective of others may substantially contribute to insight impairment in schizophrenia. The present study aimed to explore the effect of ToM deficits on insight impairment independently of co-existent neurocognitive deficits and symptom severity in chronic schizophrenia. METHODS Fifty-eight chronic patients with schizophrenia and 56 matched healthy participants were assessed with the Schedule for the Assessment of Insight (SAI-E) along with a series of ToM tasks and a comprehensive battery of neuropsychological measures. Symptoms were measured with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. RESULTS ToM impairment explained a substantial proportion of variance in overall insight and its three major components: awareness of illness, relabelling of symptoms and treatment compliance. Moreover, the effect of ToM deficits on insight remained significant even after controlling for all neurocognitive factors and symptom ratings. Regression analysis showed that symptoms and cognitive deficits also contribute to impaired insight in schizophrenia. General intellectual ability was negatively associated with both overall insight and relabelling of symptoms. Executive functions were negatively associated with relabelling. CONCLUSION Our findings confirm that ToM deficits negatively affect insight independently of neurocognitive deficits and symptom severity in chronic schizophrenia. The effect of ToM deficits on insight should be further examined in the broader context of the failures in metacognition and their relationships with insight impairment in schizophrenia.


Social Neuroscience | 2014

Self-rated and performance-based empathy in schizophrenia: The impact of cognitive deficits

George Konstantakopoulos; Panagiotis Oulis; Dimitris Ploumpidis; Panayiotis Patrikelis; Stavrina Nikitopoulou; George N. Papadimitriou; Anthony S. David

People may be much less empathic than they think they are. It is not clear whether patients with schizophrenia who have impaired empathic abilities also exhibit diminished ability to accurately appraise their own such skills. The present study aimed to examine: (a) the accuracy of self-appraisal of empathy and (b) the impact of specific cognitive functions on both self-rated and performance-based empathy in schizophrenia patients and healthy volunteers. Self-reported empathy and performance-based empathy were assessed in 52 chronic patients with schizophrenia and 45 matched healthy participants with the empathy quotient and the empathy score in the Faux Pas test, respectively. Neuropsychological functioning and symptom severity were also assessed. No significant correlations between self-reported and performance-based empathy scores were found in patients, whereas these correlations were significant and positive in the control group, with the exception of Faux Pas recognition. Cognitive deficits, specifically in processing speed and theory of mind, negatively affected performance-based but not self-rated empathy in schizophrenia. Patients with less negative and more positive symptoms and lower set shifting ability reported higher empathic abilities. Self-reported empathy and empathic abilities do not show a simple relationship. Our findings highlight a double deficit related to empathic responding in schizophrenia: diminished performance associated with cognitive deficits and inaccurate self-appraisal of empathic abilities.


Acta Neurochirurgica | 2016

Preoperative neuropsychological presentation of patients with refractory frontal lobe epilepsy

Panayiotis Patrikelis; Stylianos Gatzonis; Anna Siatouni; Elias Angelopoulos; George Konstantakopoulos; Maria Takousi; Damianos E. Sakas; Ioannis Zalonis

BackgroundThis study investigated whether certain cognitive deficits are associated with frontal lobe epilepsy (FLE) aiming to contribute with localization data to the preoperative assessment of epilepsy surgery candidates.MethodsWe evaluated 34 patients with refractory FLE, 37 patients with refractory medial temporal lobe epilepsy (MTLE), and 22 healthy individuals in attention, psychomotor speed, motor function, verbal memory span, verbal fluency, response inhibition/interference, concept formation and set shifting, anticipation and planning, global memory.ResultsNeuropsychological performances of FLE and MTLE were similar, with the only exception the WCST-number of categories index, measuring mental flexibility, in which MTLE patients performed significantly worse than FLE patients. Left-FLE patients presented more perseverative responding compared to both other patient groups and healthy controls (HCs), while left-MTLE patients showed worse sorting abilities than the other epilepsy groups.ConclusionsOur findings suggest a weak cognitive differentiation between FLE and MTLE, probably attributed to the intricate nature of fronto-temporal connectivity frequently resulting in overlapping deficits as well as the confounding effects of seizure-related variables. In clinical practice, a highly individualized (idiographic) neuropsychological approach along with the inclusion of concurrent EEG recordings (e.g., interictal coupling) may be of help for neuropsychologists in identifying FLE patients from those with medial temporal pathology presenting frontal dysfunction as a secondary cognitive symptom.


Neuropsychological Rehabilitation | 2013

Simulating memory outcome before right selective amygdalohippocampectomy

Panayiotis Patrikelis; Giuliana Lucci; Anna Siatouni; Ioannis Zalonis; Damianos E. Sakas; Stylianos Gatzonis

In this paper we present the case of a left-sided speech dominant patient with right medial temporal sclerosis (RMTS) and pharmacoresistant epilepsy who showed improved verbal memory during intracarotid amobarbital test (IAT) at his right hemisphere as compared with his own performance before the drug injection (baseline), as well as after right selective amygdalohippocampectomy. We suggest that the defective verbal memory shown by this patient is due to abnormal activity of his right hippocampus that interfered with the function of his left hippocampus. This hypothesis was demonstrated by the fact that disconnection of the two hippocampi, either by anesthetisation or by resection of the right hippocampus, disengaged the left hippocampus and, consequently improved its function. This paper main objective is twofold: first to contribute to the field of neuropsychology of epilepsy surgery by emphasising on postoperative memory outcomes in right medial temporal lobe epilepsy (RMTLE) patients, particularly those undergoing amygdalohippocampectomy, as the pattern of memory changes after resection of the right temporal lobe is less clear; second, by focusing on memory performance asymmetries during IAT, and comparatively considering them with neuropsychological memory performance, because of their possible prognostic-simulating value.


Epilepsy & Behavior | 2017

Potential implications of Luria's work for the neuropsychology of epilepsy and epilepsy surgery: A perspective for re-examination

Panayiotis Patrikelis; Giuliana Lucci; Anna Siatouni; Anastasia Verentzioti; Athanasia Alexoudi; Stylianos Gatzonis

The pioneeristic work of Alexander Romanovic Luria into the field of human neuropsychology offered eminent contributions to clinical praxis by providing theory guided methods and instruments for the study of higher cortical functions. However, lots of this knowledge corpus either remains untranslated and thus inaccessible, or in some cases selectively overlooked by academic authorities and consequently not passed to the future generations of experts. Although Luria was not exclusively devoted to the study of epilepsy, his theories and clinical approaches actually penetrate the whole neuropathology spectrum. His holistic and systemic approach to the brain sounds nowadays more than opportune and consistent with the network approach of the modern neuroimaging era. As to epilepsy, the logic underlying the Lurian approach (cognitive functions organized into complex functional systems with intra- and/or inter-hemispheric distribution, as opposed to the modularistic view of the brain) seems consistent with our current knowledge in epileptology with respect to epileptic networks, as well as the modern construct of the functional deficit zone. These contributions seem to be highly promising for the neuropsychology of epilepsy and epilepsy surgery, since they provide clinicians with valuable methods and theories to assist them in the localization -and lateralization- of cognitive deficits. Consequently they are of great applicability in the context of the preoperative neuropsychological monitoring of patients candidates for epilepsy surgery, where neuropsychologist are called upon to provide surgeons with anatomical data.


Clinical Neurology and Neurosurgery | 2017

Possible common neurological breakdowns for alexithymia and humour appreciation deficit: A case study

Panayiotis Patrikelis; George Konstantakopoulos; Giuliana Lucci; Vasileios Katsaros; Damianos E. Sakas; Stylianos Gatzonis; Giorgos Stranjalis

This brief work is an attempt to point to the possible common neurological breakdowns in giving rise to alexithymia, and impaired appreciation of humour. In particular, we present the case of a patient who lost the ability to enjoy humour after the surgical removal of a frontal groove meningioma, although he was still able to detect it, while at the same time was diagnosed with organic alexithymia. Our results indicate that problems in the affective appreciation of humour and in emotionalizing (alexithymic symptoms) may be the result of damage to the ventral-rostral portions of the ACG/mPFC, which prevent the patient from assessing the salience of emotion and motivational information, and generating emotional reactions; as a result he has trouble experiencing emotions, knowing how he and others feel, and enjoy humour.


Disability and Rehabilitation | 2018

Effects of anodal tDCS on motor and cognitive function in a patient with multiple system atrophy.

Athanasia Alexoudi; Panayiotis Patrikelis; Theodoros Fasilis; Spyros Deftereos; Damianos E. Sakas; Stylianos Gatzonis

Abstract Purpose: Multiple system atrophy (MSA) is a progressive neurodegenerative disease characterized by postural instability, autonomic failure, cerebellar ataxia, and cognitive deficits. There is currently no effective cure. Transcranial direct current stimulation (tDCS), offers promise in amendment of motor, and cognitive performance in advanced Parkinson’s disease. Case description: We estimated the effect of anodal tDCS on motor and cognitive function in a 66-year-old woman with moderate MSA. For the evaluation of the motor function, we used the Unified MSA Rating Scale II, the Unified Parkinson’s Disease Rating Scale Part III (UPDRS III), and the Timed Up and Go test (TUG). The battery of neuropsychological tests included the Rey’s Auditory Verbal Learning Test (RAVLT) and the Digit Symbol Substitution Test-Wechsler Adult Intelligence (DSST-WAIS-III), the Trail Making Test (TMT-A). tDCS was applied in 10 sessions. Clinical evaluations were performed at baseline, day 11, day 30, and at day 90. Results: Anodal stimulation was associated with improvement in UPDRS III and the TUG test. A positive effect was also seen in RAVLT the DSST-WAIS-III and the TMT-A. Conclusions: Our results suggest that tDCS has a beneficial effect mainly on motor performance in MSA, which lasts beyond the duration of the treatment. Implications for rehabilitation Multiple system atrophy is a progressive neurodegenerative disease characterized by postural instability, motor, and cognitive deficits. Transcranial direct current stimulation offers promise in amendment of motor and cognitive performance in advanced Parkinson’s disease. Stimulation was associated with significant improvement in Unified Parkinson’s Disease Rating Scale Part III and the Timed Up and Go test. A positive effect was also seen in auditory-verbal memory and learning in working memory and in visuomotor activity and processing speed. Transcranial direct current stimulation has a beneficial effect mainly on motor performance, which lasts beyond the duration of the treatment.


Journal of Neurology and Neurophysiology | 2017

Can Neuropsychological Rehabilitation Determine the Candidacy for Epilepsy Surgery? Implications for Cognitive Reserve Theorizing

Panayiotis Patrikelis; Giuliana Lucci; Athanasia Alexoudi; Mary Kosmidis; Anna Siatouni; Anastasia Verentzioti; Damianos E. Sakas; Stylianos Gatzonis

Objective: The purpose of this study was to explore the effectiveness of a neuro-optimization intervention to determine the suitability for surgery in a patient suffering from left medial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS). The rehabilitation program was aimed at amplifying cognitive resources and improving memory functioning, particularly in the non-dominant healthy hemisphere. Method: A preoperative neuro-optimization program, inspired by the functional reserve model and the right hemisphere’s verbal processing potential, was adopted. This neuro-optimization program targeted global cognitive and metacognitive enhancement with an emphasis on memory functions of the right temporal lobe, i.e., the functional upgrade of the healthy right hippocampus and related structures to assist memory after surgery. Results: After a 32 weeks neuro-optimization program, the patient once again underwent intracarotid amobarbital test (IAT). This time his right hemisphere memory functioning yielded a borderline score, allowing us to consider surgery. Immediately after surgery, the patient was seizure free and did not show any clinically significant memory impairment. At six months post-surgery he had largely preserved memory optimization gains. Conclusion: Preoperative optimization interventions aiming at enhancing cognition, in general and memory of the healthy hemisphere, in particular, may contribute to a positive memory outcome after left selective amygdalohippocampectomy.

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Stylianos Gatzonis

National and Kapodistrian University of Athens

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Anna Siatouni

National and Kapodistrian University of Athens

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Dimitris Ploumpidis

National and Kapodistrian University of Athens

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Athanasia Alexoudi

National and Kapodistrian University of Athens

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George N. Papadimitriou

National and Kapodistrian University of Athens

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Giuliana Lucci

Sapienza University of Rome

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Anastasia Verentzioti

National and Kapodistrian University of Athens

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