CLINICAL EEG and NEUROSCIENCE - Dynamic Memory Lab

More documents

Recommendations

Info

CLINICAL EEG and NEUROSCIENCE ©2007 VOL. 38 NO. 1Regarding the validation of the assumed serotonergicproperties of LDAEP in vivo combined studies with SinglePhoton Emission Computed Tomography (SPECT) usingthe monoaminergic (serotonergic and dopaminergic) radioligandβ-CIT, a marker of Serotonin- and Dopamintransporters(SERT, and DAT) have been performed. SPECTand β-CIT allow to semiquantitatively assess SERT andDAT availabilities within the brainstem/pons (SERT) and inthe striatum (DAT). In such studies it has been demonstratedthat the loudness dependence was highly significantlycorrelated with both nuclear imaging markers of the serotonergicand dopaminergic system, which is a first direct invivo evidence that LDAEP is associated with centralmonoaminergic function in psychiatric patients. 94The observation that allelic variants of the serotonintransporter gene differ with respect to the LD further supportsthe hypothesis of an association between the serotonergicsystem and neurophysiological measures. 95Nevertheless, the complexity of central monoaminergicsystems, which are strongly interconnected and showinteractions between different neurochemical subdivisions,has to be taken into account. Therefore, only a relativespecificity of this indicator for certain functional aspects,e.g., in terms of the serotonergic system can be expected.In spite of these limitations, the studies on psychiatricpatients treated with serotonergic agents suggest that theloudness dependence of the N1/P2 activity may well beclinically useful for a more carefully directed individualpharmacotherapy in neuropsychiatry. 96Affective disordersReports in the literature as well as own results indicatethat a pronounced LDAEP predicts a favorable response toSSRI treatment. Paige et al 97 reported that depressedpatients who responded to SSRI had a strong LDAEP (P2-component) before starting medication. During medication,no reduction of the LDAEP was observed. These findingswere supported by using a dipole source analysis ofLDAEP. Depressed patients responding to SSRI (sertraline,paroxetine) had a stronger LDAEP (N1/P2 component)at baseline, i.e., before starting medication. 93 Thisindicates that the LDAEP could give valuable informationto the clinician concerning the probability of individualresponse to SSRI in depressed patients. It remains unclearwhether or not LDAEP predicts response or nonresponsespecifically to SSRI or also to alternative therapies. Paigeet al 98 reported that a strong LDAEP also predicts favorableresponse to the noradrenergic and dopaminergic agentbuproprion, which supports the predictive quality of theLDAEP concerning response to antidepressants whereasthe specificity of this tool concerning serotonergic antidepressantsremains to be elucidated.Lithium has serotonin-agonistic eff e c t s , 9 9 which are supposedto be relevant for its acute antidepressant and antimanicas well as its relapse preventing effects. Therefore, itcan be assumed that especially those patients with lowserotonergic function, indicated by a strong LDAEP, will belithium responders. Several studies consistently reportedthat patients with a strong intensity dependence of sensoryevoked potentials (VEP, SEP) are responders to acute antidepressiveor antimanic lithium therapy. 7 7 , 1 0 0 - 1 0 2These findings have stimulated research on the predictivequality of LDAEP concerning clinical response to preventivelithium treatment. Predictors of response or nonresponseto preventive lithium medication would be especiallyvaluable, because of the high rate of nonresponse (up to45%), the long observation time needed to evaluate clinicalresponse and the risks of long-term lithium medication.In our laboratory, Hegerl et al found that patients with affectivepsychoses responding to preventive lithium medicationwere indeed characterized by a strong LDAEP. 103 Patientswere classified as responders, when they had no recurrenceleading to hospitalization under lithium during thepreceding 5 years. This finding was replicated in anotherretrospective study: responders to preventive lithium treatmentwere again characterized by a significantly strongerLDAEP. 104CONCLUSIONERPs are unique tools for evaluating the reactivity of corticalneuronal activity in psychiatric patients. Due to a closerelationship between ERPs and cortical release of neurotransmitters,ERPs are at least in part useful indicators ofneurochemical dysfunction. Therefore, these techniquesmight contribute to the prediction of response to pharmacotherapyor monitoring changes in brain function duringp s y c h o p h a r m a c o t h e r a p y. These approaches have led toconsistent results, which are not only of value for the developmentof pathogenetic models or to establish a sub classificationof psychiatric disorders, but also are of relevance forclinical and therapeutic decisions in psychiatric practice.30
CLINICAL EEG and NEUROSCIENCE ©2007 VOL. 38 NO. 1REFERENCES1. Walter WG, Cooper R, Aldridge VJ, McCallum WC, WinterAL. Contingent negative nariation: an electric sign of sensorimotorassociation and expectancy in the human brain.Nature 1964; 203: 380-384.2. Sutton S, Braren M, Zubin J, John ER. Evoked-potential correlatesof stimulus uncertainty. Science 1965; 150(700):1187-1188.3. Verleger R. Event related potentials and cognition: a critiqueof the context updating hypothesis and an alternative interpretationof P3. Behav Br Sci 1988; 11: 343-356.4. Halgren E, Baudena P, Clarke JM, Heit G, Liegeois C,Chauvel P, et al. Intracerebral potentials to rare target anddistractor auditory and visual stimuli. I. Superior temporalplane and parietal lobe. Electroencephalogr Clin Neurophysiol1995; 94(3): 191-220.5. Halgren E, Baudena P, Clarke JM, Heit G, Marinkovic K,Devaux B, et al. Intracerebral potentials to rare target anddistractor auditory and visual stimuli. II. Medial, lateral andposterior temporal lobe. Electroencephalogr Clin Neurophysiol1995; 94(4): 229-250.6. Baudena P, Halgren E, Heit G, Clarke JM. Intracerebralpotentials to rare target and distractor auditory and visualstimuli. III. Frontal cortex. Electroencephalogr Clin Neurophysiol1995; 94(4): 251-264.7. Mulert C, Jager L, Schmitt R, Bussfeld P, Pogarell O, MollerHJ, et al. Integration of fMRI and simultaneous EEG: towardsa comprehensive understanding of localization and timecourseof brain activity in target detection. Neuroimage 2004;22(1): 83-94.8. Dierks T, Frolich L, Ihl R, Maurer K. Event-related potentialsand psychopharmacology: cholinergic modulation of P300.Pharmacopsychiatry 1994; 27(2): 72-74.9. Antal A, Bodis-Wollner I, Ghilardi MF, Glover A, Mylin L, ToldiJ. The effect of levo-acetyl-carnitine on visual cognitiveevoked potentials in the behaving monkey. ElectroencephalogrClin Neurophysiol 1993; 86(4): 268-274.10. Brandeis D, Naylor H, Halliday R, Callaway E, Yano L.Scopolamine effects on visual information processing, attention,and event-related potential map latencies. Psychophysiology1992; 29(3): 315-336.11. Meador KJ. Cholinergic, serotonergic, and GABAergiceffects on the ERP. Electroencephalogr Clin Neurophysiol(suppl) 1995; 44: 151-155.12. Meador KJ, Loring DW, Davis HC, Sethi KD, Patel BR,Adams RJ, et al. Cholinergic and serotonergic effects on theP3 potential and recent memory. J Clin Exp Neuropsychol1989; 11 (2): 252-260.13. Harrison JB, Buchwald JS, Kaga K, Woolf NJ, Butcher LL.“Cat P300” disappears after septal lesions. ElectroencephalogrClin Neurophysiol 1988; 69(1): 55-64.14. Hammond EJ, Meador KJ, Aung-Din R, Wilder BJ.Cholinergic modulation of human P3 event-related potentials.Neurology 1987; 37(2): 346-350.15. Callaway E, Halliday R, Naylor H, Schechter G. Effects oforal scopolamine on human stimulus evaluation. Psychopharmacology(Berl) 1985; 85(2): 133-138.16. Pineda JA, Foote SL, Neville HJ. Effects of locus coeruleuslesions on auditory, long-latency, event-related potentials inmonkey. J Neurosci 1989; 9(1): 81-93.17. Blum K, Braverman ER, Dinardo MJ, Wood RC, Sheridan PJ.Prolonged P300 latency in a neuropsychiatric population withthe D2 dopamine receptor A1 allele. Pharmacogenetics1994; 4(6): 313-322.18. Noble EP, Berman SM, Ozkaragoz TZ, Ritchie T. ProlongedP300 latency in children with the D2 dopamine receptor A1allele. Am J Hum Genet 1994; 54(4): 658-668.19. Gallinat J, Bajbouj M, Sander T, Schlattmann P, Xu K, FerroEF, et al. Association of the G1947A COMT (Val (108/158)Met) gene polymorphism with prefrontal P300 during informationprocessing. Biol Psychiatry 2003; 54(1): 40-48.20. Pritchard WS, Raz N, August GJ. No effect of chronic fenfluramineon the P300 component of the event-related potential.Int J Neurosci 1987; 35(1-2): 105-110.21. Shutara Y, Koga Y, Fujita K, Takeuchi H, Mochida M,Takemasa K. An event-related potential study on the impairmentof automatic processing of auditory input in schizophrenia.Brain Topogr 1996; 8(3): 285-289.22. Rao KM, Ananthnarayanan CV, Gangadhar BN,Janakiramaiah N. Smaller auditory P300 amplitude in schizophrenicsin remission. Neuropsychobiology 1995; 32(3):171-174.23. Ford JM, White P, Lim KO, Pfefferbaum A. Schizophrenicshave fewer and smaller P300s: a single-trial analysis. BiolPsychiatry 1994; 35(2): 96-103.24. Laurent A, Garcia-Larrea L, Dalery J, Terra JL, D’Amato T,Marie-Cardine M, et al. The P 300 potential in schizophrenia.[In French] Encephale 1993; 19(3): 221-227.25. Eikmeier G, Lodemann E, Zerbin D, Gastpar M. Event-relatedpotentials in schizophrenic patients in the acute phase and inremission. [In German] EEG EMG Z ElektroenzephalogrElektromyogr Verwandte Geb 1991; 22(1): 15-20.26. Blackwood DH, St Clair DM, Muir WJ, Duffy JC. AuditoryP300 and eye tracking dysfunction in schizophrenic pedigrees.Arch Gen Psychiatry 1991; 48(10): 899-909.27. Juckel G, Muller-Schubert A, Gaebel W, Hegerl U. Residualsymptoms and P300 in schizophrenic outpatients. PsychiatryRes 1996; 65(1): 23-32.28. Schreiber H, Stolz-Born G, Kornhuber HH, Born J. Eventrelatedpotential correlates of impaired selective attention inchildren at high risk for schizophrenia. Biol Psychiatry 1992;32(8): 634-651.29. Murray RM, O’Callaghan E, Castle DJ, Lewis SW. A neurodevelopmentalapproach to the classification of schizophrenia.Schizophr Bull 1992; 18(2): 319-332.30. Hegerl U, Juckel G, Muller-Schubert A, Pietzcker A, GaebelW. Schizophrenics with small P300: a subgroup with a neurodevelopmentaldisturbance and a high risk for tardive dyskinesia?Acta Psychiatr Scand 1995; 91(2): 120-125.31. Strik WK, Dierks T, Franzek E, Maurer K, Beckmann H.Differences in P300 amplitudes and topography betweencycloid psychosis and schizophrenia in Leonhard’s classification.Acta Psychiatr Scand 1993; 87(3): 179-183.32. Strik WK, Dierks T, Maurer K. Amplitudes of auditory P300 inremitted and residual schizophrenics: correlations with clinicalfeatures. Neuropsychobiology 1993; 27(1): 54-60.33. Strik WK, Fallgatter AJ, Stoeber G, Franzek E, Beckmann H.Specific P300 features in patients with cycloid psychosis.Acta Psychiatr Scand 1996; 94(6): 471-476.31
Page 3 and 4: CLINICAL EEG and NEUROSCIENCE ©200
Page 35: CLINICAL EEG and NEUROSCIENCE ©200

CLINICAL EEG and NEUROSCIENCE - Dynamic Memory Lab

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?