Biomedical subjects
Fotis Fotiou
Publications and source records attributed to Fotis Fotiou.
Is there a dysfunction in the visual system of depressed patients?
BACKGROUND: The aim of the current study was to identify a possible locus of dysfunction in the visual system of depressed patients. MATERIALS AND METHODS: Fifty Major Depressive patients aged 21-60 years and 15 age-matched controls took part in the study The diagnosis was obtained with the SCAN v 2.0. The psychometric assessment included the HDRS, the HAS, the Newcastle Scales, the Diagnostic Melancholia Scale and the GAF scale. Flash Electroretinogram and Electrooculogram were performed in all subjects. The statistical analysis included ANCOVA, Student's t-test and Pearson Product Moment Correlation Coefficient were used. RESULTS: The Electro-oculographic findings suggested that all subtypes of depressed patients had lower dark trough and light peak values in comparison to controls (p < 0.001), while Arden ratios were within normal range. Electroretinographic recordings did not reveal any differences between patients and controls or between subtypes of depression. DISCUSSION: The findings of the current study provide empirical data in order to assist in the understanding of the international literature and to explain the mechanism of action of therapies like sleep deprivation and light therapy.
Lateralization of pupillary light reflex parameters. Comment on the paper: Bär KJ, Boettger MK, Till S, Dolicek J, Sauer H. Clin Neurophysiol 2005;116:790-798.
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The relationship of regional cerebral blood flow with subtypes of major depression.
UNLABELLED: The aim of the present study was to search for differences between subtypes of major depression with the use of single photon emission tomography. MATERIALS AND METHODS: Fifty (50) patients aged 21-60 years suffering from Major Depression according to DSM-IV took part in the study. The SCAN v 2.0 was used to assist clinical diagnosis. The psychometric assessment included the HDRS, the HAS, the GAF, the Newcastle scales and the Diagnostic Melancholia Scale (DMS). Single Photon Emission Computerized Tomography (HMPAO SPECT) was used to assess regional cerebral blood flow. The methods of analysis included chi-square test, ANCOVA, and Discriminant Function Analysis. RESULTS: Forty one (82%) depressed patients had abnormal SPECT findings. The most consistent finding in all patients across all subtypes was a global brain hypoperfusion, which did not include the frontal lobes. The most impressive finding was the relative increase of right frontal lobe perfusion in atypicals, in contrast to the relative decrease of perfusion in both the melancholic and the 'undifferentiated' patients in that particular region. The reverse was true for the right occipital lobe. CONCLUSION: The results of the current study provide support for the old hypothesis on the existence of two distinct types of depression, characterized by different underlying psychopathologies, but also provide strong evidence for a neurobiological abnormality underlying atypical depression, the subtype closer to the old concept of 'neurotic' depression, which was considered to be psychological or reactive in origin.
Biological markers and psychophysiological methods as long term response predictors to fluoxetine treatment.
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Is there a role for pupillometry in the diagnostic approach of Alzheimer's disease? a review of the data.
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Neurobiological and psychological correlates of suicidal attempts and thoughts of death in patients with major depression.
Suicide is a major problem for psychiatry. Depression is the most common mental disorder related to suicidal behavior. The present study aimed at investigating the relationship between the symptomatology related to death, dying, and suicide and neurobiological factors in depressed patients. Fifty patients aged 21-60 years suffering from major depression were investigated. Schedules for Clinical Assessment in Neuropsychiatry version 2.0 and the International Personality Disorder Examination were used to assist the clinical diagnosis. The psychometric assessment included the Hamilton Depression Rating Scale, the Hamilton Anxiety Scale, the 1965 and 1971 Newcastle Depression Diagnostic Scales, the Diagnostic Melancholia Scale, the General Assessment of Functioning Scale, and the Personality Deviance Scale. Psychophysiological methods included electro-oculogram, flash electroretinogram under photopic and scotopic conditions, and pattern-reversal visual evoked potentials. Biological markers included the 1-mg dexamethasone suppression test, the 30-mg dexfenfluramine challenge test, and brain (99m)Tc-HMPAO SPECT. Statistical analysis included one-, two-, and three-way Manova and Mancova and the Scheffé test as post hoc test. Patients without thoughts of death had higher self-confidence levels and less overdependency on others and intropunitiveness. The suicidal patients had a significantly prolonged pattern-reversal visual evoked potential latency in comparison with the other patients. The findings of this were related to the status of the patient at the time of the interview but not to his/her history. They also provide neurobiological data to support the need for a combined presence of self-directed aggression and a higher arousal level or disinhibition of self-directed aggressive thoughts in order for a patient to become suicidal. Further study is needed to test whether psychophysiological methods, which are noninvasive and easy to perform, are of value in the therapeutic planning and monitoring of responses.
Clinical and neuroimaging correlates of abnormal short-latency Somatosensory Evoked Potentials in elderly vascular dementia patients: A psychophysiological exploratory study.
BACKGROUND: Short Latency Somatosensory Evoked Potentials (SEPs) may serve to the testing of the somatosensory tract function, which is vulnerable and affected in vascular encephalopathy. The aim of the current study was to search for clinical and neuroimaging correlates of abnormal SEPs in vascular dementia (VD) patients. MATERIALS AND METHODS: The study included 14 VD patients, aged 72.93 PlusMinus; 4.73 years, and 10 controls aged 71.20 PlusMinus; 4.44 years. All subjects underwent a detailed clinical examination, blood and biochemical testing, brain MRI and were assessed with the MMSE. SEPs were recorded after stimulation from upper and lower limbs. The statistical Analysis included 1 and 2-way MANCOVAs and Factor analysis RESULTS: The N13 latency was significantly prolonged, the N19 amplitude was lower, the P27 amplitude was lower and the N11-P27 conduction time was prolonged in severely demented patients in comparison to controls. The N19 latency was prolonged in severely demented patients in comparison to both mildly demented and controls. The same was true for the N13-N19 conduction time, and for the P27 latency. Patients with subcortical lesions had all their latencies prolonged and lower P27 amplitude. DISCUSSION: The results of the current study suggest that there are significant differences between patients suffering from VD and healthy controls in SEPs, but these are detectable only when dementia is severe or there are lesions located in the subcortical regions. The results of the current study locate the abnormal SEPs in the white matter, and are in accord with the literature.
Pattern-reversed visual evoked potentials in subtypes of major depression.
There are no articles in the international psychiatric literature reporting subclinical visual system disorders in depressed patients, although a disturbance of circadian rhythms is one of the prominent theories of the etiopathogenesis of depression. Fifty patients aged 21-60 years suffering from major depression according to DSM-IV criteria, and 20 controls took part in the study. Diagnosis was obtained with the aid of the Schedules for Clinical Assessment in Neuropsychiatry version 2.0. Psychometric assessment included the Hamilton Depression Rating Scale, the Hamilton Anxiety Scale, the 1965 and 1971 Newcastle Scales, and the Diagnostic Melancholia Scale. All subjects had normal electroretinographic and flash-visual evoked potential (VEP) recordings. Pattern-reversed VEPs (PR-VEPs) were recorded from each eye separately. Three-way analysis of covariance, Student's t-test and Pearson product-moment correlation coefficients were used for the analysis. All recordings were within the normal range. N80 and P100 latency were significantly shorter in atypical and significantly longer in melancholic patients. There was a positive correlation between N80 and P100 latency and age of onset and melancholic indices, and a negative correlation with the presence and the number of life events precipitating onset. The results of the current study suggest that PR-VEPs are consistent with other biological data supporting the atypical-melancholic distinction. The most important finding was the strong negative relationship between PR-VEP latency and stressful life events. The current study also provided data inconsistent with the hyperarousal theory and in support of an arousal dysregulation hypothesis for major depression.