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At 02:53 9-8-99 -0400, Tom Riess wrote: >>Dyskinesia is the body's attempt to conform to pathologic processing of perceived visual information. There is an autonomic component to dyskinesia (for example tension potentiates dyskinesia). Normally visual feedback is a consequence of the motor activity. In this case the motor activity is a consequence of the feedback. The actual pathology lies in the processing of low velocity motion and small changes in velocity.. Tom, Do you really think that a PWP can end all that tormenting and terribly invalidating dyskinesia by merely laying down and close his/her eyes? If you don't, I don't understand your article, If you do, I do understand what you are saying but I can't believe you are talking about the de same phenomenon that I am talking about. So I can't relate your theory to my experience. For example after my pallidotomy the dyskinesia has totally disapeared in one half of my body. That half sided dyskinesia does not fit into your model as conforming to the discrepancies, that you mention. I have tried to find an answer to the dyskinesia question in quite another way, by searching the literature. IMHO one interesting thread in the publications of the last years is a new view on the task of the basal ganglia (this are relay stations for messages from the higher part of the brain, the cortex, were all willfull action is initiated, to the places were the actions are executed). It is the system that doesn't function well in PWP's because the lack of dopamine. The dopamine has not only a task in the dopamine synapses, but also a broader one as modulator of the whole system ( modulation is changing the excitability of a system). So it is important to know what exactly is the function of the basal ganglia. In 1982 there has been a publication of C. D. Marsden. The function of the b.g. was supposed to be the fine tuning of the excecution of motor tasks. Because the b.g. receive messages from nearly every part of the cortex and after integrating them send messages back to the cortex, their task must be more complex and more "cognitive". Marsden's assumption was that an important task of the basal ganlia is the inhibition of movements that don't fit in the planned action. So inside the basal ganglia there has to be a very accurate "model" of planned action. That is why Marsden said the model is "cognitive". This assumption has got many adherents among researchers, and is supported by experiments. In this "cognitive" and "braking" task glutamate is the transmitter that has a mutual antagonistic relation with dopamine and has too much influence if dopamine is lacking. That is why some researchers think that anti-glutamates might be helpful. This model seems to predict that top of meds dyskinesa is fundamentally different from wearing off dyskinesia. The much more complex role of the basal ganglia sounds to me rather revolutionary. So I looked for my old physiology book from 1966 to seewhat it said about it and was amazed to read: "The lack of a clear picture of the function of the basal ganglia is disconcerting. Stimulation of the caudate and other basal ganglion structures produces complex sterreotyped movement- a turning of the body or a sudden arrest of ongoing movement. Inhibitory effects on lower reflexes has been obtained. In Parkinsons disease destruction of the efferent outflow of the globus pallidus by electrocoagulation has resulted in dramatic relief." Litterature: Neurology,32 May 1982 Marsden C. D. The mysterious function of the basal ganglia: The Robert Wartenberg Lecture. Progress Neurobiol. 1996 Nov;50(4) 381-425 Mink J.W. The basal ganglia;focused selection and inhibition of competimg moter programs. Brain Res.Rev. 1995 Jan.20 (1) 97-127. Parent A. Hazrati I.N. Functional anatomy of the basal ganglia, The cortico-basal ganglia-thalamo-cortical loop. Can J Neurol Sci 1993 Aug;20(3):177-83 Hallett M. Physiology of basal ganglia disorders: an overview. Behav Brain Res 1996 May;77(1-2):45-52 Decety J. The neurophysiological basis of motor imagery. -------------------------------------------------------------- Vriendelijke Groeten / Kind regards, Ida Kamphuis mailto: [log in to unmask]