Author/Editor		Ružička, E; Roth, J
Title		Apomorphine and cognitive function in Parkinson's disease
Translated title		Apomorfin in kognitivna funkcija pri Parkinsonovi bolezni
Type		članek
Source		Zdrav Vestn
Vol. and No.		Letnik 65, št. Suppl 3
Publication year		1996
Volume		str. III-79-81
Language		eng
Abstract		Apomorphine (APO), a potent dopamine agonist drug, has been increasingly used in the treatment of Parkinson's disease (PD). In order to investigate the effects of APO on cognition in PD patients, we performed electrophysiological and neuropsychological studies using acute APO challenge. In total, 17 nondemented patients with PD were examined first when "off" after an overnight withdrawal from all dopaminergic medication and second when "on" after a subcutaneous dose of Apomorphine (0.05 mg/kg of weight). Besico standard clinical examination and motor soring. Benton visual retention (BVRT), Stroop, verbal fluency, and digit span tests were performed. Moreover, we recorded event-related potentials (ERP) in the auditory odd-ball paradigms. As a major finding of the studies, in contrast to decreased motor scores, ERP mean latencies were delayed "on" compared to "off". In addition, more BVRT figure rotation errors were shown after APO while other neuropsychological test results stayed unchanged. The treatment with APO thus differently affects motor and cognitive performances in PD patients. The post-treatment delays of the ERP presumably reflect a slowing down of auditory stimulus evaluation, and an increased in rotation errors on the BVRT corresponds to an involvement of visual perception. Similar contrasting effects on motor and cognitive functioning in PD patients were previously reported for levodopa. These findings can reflect various mechanisms such as presynaptic inhibiton of the mesocortical and mesolimbic dopaminergic systems, demodulation of prefrontal cortex via the complex neuronal loop, or different effects on the subtypes of postsynaptic receptors.
Summary		Apomorfin je učinkovit dopaminski agonist, ki se vse bolj uporablja pri zdravljenju Parkinsonove bolezni. Da bi preučili učinke apomorfina na kognitivne procese pri Parkinsonovi bolezni, smo ob akutni aplikaciji apomorfina bolnike testirali z elektrofiziološkimi in nevropsihološkimi testi. Sedemnajst nedementnih bolnikov s Parkinsonovo boleznijo smo testirali najprej v "izklopljenem" stanju po odvzemu nočnih odmerkov dopaminergičnih zdravil in nato v "vklopljenem" stanju, ki smo ga dosegli s podkožno injekcijo apomorfina (0,05 mg/kg telesne teže). Ob standardni klinični preiskavi smo bolnike testirali z Bentonovim testom vizualne retencije, Stroopovim testom, testom verbalne fluentnosti in razpona števil. Pri bolnikih smo posneli pozne možganske odzive s slušno paradigmo "oddball". Najpomembnejši rezultat študije so podaljšane latence poznih odzivov v "vklopljenem" stanju, takrat torej, ko se je motorika izboljšala. V tem stanju so bolniki naredili tudi več napačnih rotacij likov na Bentonovem testu vizualne retencije, ostali nevropsihološki testi pa niso pokazali sprememb. Zdravljenje z apomorfinom torej drugače vpliva na motoriko in drugače na kognitivno procesiranje. Z apomorfinom povezane daljše latence poznih kognitivnih odzivov odsevajo upočasnitev obdelave slušne informacije, več napak rotacij likov na Bentonovem testu vizialne retencije pa nakazuje prizadetost vidne zaznave. Nasprotni učinki na motoriko in kongnicijo so bili že prej opisani tudi za levodopo. Tak rezultat lahko pojasnimo z različnimi mehanizmi, npr. s presinaptično inhibijo mezokortikalnih in mezolimbičnih dopaminergičnih sistemov, demodulacijo prefrontalnega korteksa prek kompleksne zanke, ali pa z delovanjem na različne podskupine postsinaptičnih receptorjev.
Descriptors		PARKINSON DISEASE APOMORPHINE