Clinical Study Of Long-term Levodopa Therapy On Peripheral Nerve Injury In Patients With Parkinson’s Disease

Objective:To study the relationship between levodopa and peripheral neuropathy in patients with Parkinson’s disease.To analyze the effects of folic acid,vitamin B12,homocysteine level and other factors on neuropathy in PD patients.Methods:Demographic data such as gender and age of PD patients hospitalized in the Department of Neurology,Second Affiliated Hospital of Soochow University from June 2016 to February 2019 were collected.The medical history information of PD patients was recorded in detail,and the healthy control group was also collected.Patients who received levodopa were divided into two groups:levodopa exposure>3 years(LELD)and levodopa exposure<3 years(SELD).20 PD patients were de novo(NOLD).CPT values of PD patients and normal control group under three kinds of current stimulation(5Hz,250Hz,2000Hz)of median nerve of both hands were measured respectively,and CPT values of PD patients and normal control group with different medication time were compared.PD patients were divided into peripheral neuropathy group and non-peripheral neuropathy group.Univariate and multivariate logistic regression analysis was used to analyze the effects of levodopa dosage,folic acid,vitamin B12,homocysteine level and other factors on sensory nerve injury in PD patients.Results:CPT was higher at 250 Hz in LELD group than NOLD group,SELD group and control group(P<0.05).CPT was higher at 5 Hz in LELD group than those in NOLD group,SELD group and control groups(P<0.05).CPT was lower at 5 Hz in NOLD group than in HCs group(P<0.05).CPT at 5 Hz and 250 Hz was positively correlated with levodopa daily dose,levodopa equivalent daily dose,and levodopa cumulative dose(P<0.05).Multivariate logistic regression analysis showed that the risk factor of sensory nerve injury in PD patients was homocysteine level(OR=1.56,95%CI=1.22-1.98,P<0.01).Serum homocysteine levels in PD patients were positively correlated with levodopa daily dose,levodopa equivalent daily dose,and levodopa cumulative dose(P<0.05).The cumulative dose of levodopa in PD patients is the main influencing factor for elevated homocysteine levels([3=0.004,95%CI=0.002-0.007,P<0.05).Conclusion:The study results show that peripheral neuropathy can occur in the early stage of PD,which may be associated with disease itself and dopaminergic treatment.Long-term use of LD will cause peripheral nerve damage,especially for A8 and c nerve fibers.Elevated plasma homocysteine in PD patients is a risk factor for peripheral nerve damage.Quantitative detection of sensory nerve is more sensitive than traditional detection methods and has great significance for early diagnosis of PD peripheral neuropathy.