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English translation please :-) defn of IPD and PN would help...... Ken ----- Original Message ----- From: "mschild" <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, August 04, 2010 1:19 AM Subject: Neuropathy in Parkinson’s Disease May Be Related to L-DopaExposure > Posted: 07/26/2010; AccessMedicine from McGraw-Hill © 2010 The McGraw-Hill > Companies > > > > > > Idiopathic Parkinson’s disease (IPD) is a central nervous system disorder > affecting the basal ganglia that is caused by death of dopamine-producing > cells > in the substantia nigra. Although IPD is thought classically to spare the > peripheral nervous system, an association between peripheral neuropathy > (PN) > and IPD has been demonstrated in some of the rare genetic forms of > Parkinson’s > disease. A recent study (Toth et al, 2010) aimed to examine the > relationship > between the more common form of IPD and PN. > > The authors conducted a prospective cohort study by randomly selecting > patients from a database of IPD patients at a tertiary center in Canada. > Patients as well as age- and gender-matched controls underwent detailed > clinical assessment, neurophysiologic testing using nerve conduction > studies, > and a thorough laboratory assessment for causes of neuropathy. Patients > who > could not tolerate these tests or who had known risk factors for PN such > as > diabetes were excluded. > > A total of 58 IPD patients were included in the study. Symptoms of PN were > present in 43% of the IPD patients but in only 5% of the control subjects. > There were no significant differences in risk factors for PN between the > IPD and > control patients. Three IPD patients were excluded because two > neurologists, > one blinded to the diagnosis of IPD, disagreed as to the diagnosis of PN. > Of > the remaining 55 IPD patients, 32 (58%) were diagnosed with PN using a > standard electrophysiologic and clinical assessment; 24 of these had > symptomatic PN. Only 5 of the 58 controls (9%) were diagnosed with PN. > Duration of IPD before assessment was similar in the IPD with and without > PN > groups, although severity of IPD was greater in the IPD with PN patients. > > To discern the etiology of PN in IPD patients, the authors examined a > number > of known causes of neuropathy, most of which were unrevealing. Although > similar cobalamin levels were found in the IPD groups with and without PN, > fasting homocysteine and methylmalonic acid (MMA) levels were > significantly > higher in the IPD group with PN. > > The odds ratio for exposure to L-dopa in the IPD patients with PN was 12.4 > (95% confidence interval, 1.4–109.1). There were no differences between > the > groups in the use of other PD drugs, including dopamine agonists, COMT > inhibitors, anticholinergic agents, and amantadine. Cumulative L-dopa > exposure > was associated not only with PN, but also with elevated fasting MMA levels > across all IPD patients in the study. L-dopa exposure was also associated > with > PN severity in the IPD patients with PN. > > This intriguing study demonstrates a somewhat unexpectedly high prevalence > of > PN in IPD patients and cites an association with elevated MMA levels, > perhaps > mediated by exposure to L-dopa. L-dopa may indeed interact with > methylation > pathways involved in folate metabolism, providing a mechanism for MMA > elevation. Although causation is not proven here, if verified, this study > may > change the way we care for patients with IPD. PN in IPD could > substantially > contribute to gait disturbance and disability in some patients with IPD, > and > prevention of PN would be an important advance. Exposure to L-dopa is > inevitable in most IPD patients at some point during their course, but > perhaps > we should be measuring MMA levels in these patients and treating with > cobalamin supplementation to reduce MMA levels and prevent neuropathy. > Further > studies, including treatment trials, seem warranted. > > ---------------------------------------------------------------------- > To sign-off Parkinsn send a message to: > mailto:[log in to unmask] > In the body of the message put: signoff parkinsn > ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn