Intolerance to Acute Levodopa Challenge: a Tool for Clinical Diagnosis of MSA?

S. ESTÉVEZ; S. PÉREZ- LLORET; M. MERELLO

Chicago

Congreso; Congreso Internacional de Movimientos Anormales; 2008

Objective: To determine if DS or sleepiness may be related to differences in basal ganglia and brainstem pathology between different parkinsonian disorders, revealing the existence of a predisposing autonomic dysfunction, and therefore determine its usefulness in the diagnosis of MSA.To determine if DS or sleepiness may be related to differences in basal ganglia and brainstem pathology between different parkinsonian disorders, revealing the existence of a predisposing autonomic dysfunction, and therefore determine its usefulness in the diagnosis of MSA. Background: Overall sensitivity and specificity of acute L-dopa challenge to predict clinical diagnosis of PD is 70.9% and 81.4%, respectively. A significant number of patients who undergo an acute L-dopa challenge, even if pre-treated with Domperidone, develop sleepiness and disautonomic symptoms (DS) such as nausea, vomiting, hypotension and profuse perspiration.Overall sensitivity and specificity of acute L-dopa challenge to predict clinical diagnosis of PD is 70.9% and 81.4%, respectively. A significant number of patients who undergo an acute L-dopa challenge, even if pre-treated with Domperidone, develop sleepiness and disautonomic symptoms (DS) such as nausea, vomiting, hypotension and profuse perspiration. Methods: 507 Dopaminergic Acute Challenge Tests performed for different purposes in the last ten years in a movement disorders clinic were revisited, searching for those patients who manifested DS during test performance. Only those tests with diagnostic purpose were included and matched by test result, sex, and age, with a group of patients undergoing acute challenge without any DS. Presumptive diagnosis for each patient was performed by means of clinical accepted criteria after a significant followup period. Only patients with final diagnosis of IPD or MSA were analyzed. Data were comapared by chi-square test. Sensitivity, specificity, predictive values and likelihood ratios as were as their 95% confidence intervals (95%CI) were calculated.507 Dopaminergic Acute Challenge Tests performed for different purposes in the last ten years in a movement disorders clinic were revisited, searching for those patients who manifested DS during test performance. Only those tests with diagnostic purpose were included and matched by test result, sex, and age, with a group of patients undergoing acute challenge without any DS. Presumptive diagnosis for each patient was performed by means of clinical accepted criteria after a significant followup period. Only patients with final diagnosis of IPD or MSA were analyzed. Data were comapared by chi-square test. Sensitivity, specificity, predictive values and likelihood ratios as were as their 95% confidence intervals (95%CI) were calculated. Results: 53 patients of the 507 (10.4%) presented DS but only 23 of them (12 women -52.2%-) received a final diagnosis of IPD or MSA, and underwent further analysis. The test was considered positive in 11 cases (47.8%). Four out the 23 patients with DS (17%) and 1 out the 16 patients from the control group (6%) were diagnosed as having MSA (Chi-sq=1.05, p=0.3).Overall sensivity and specificity of DS to predict diagnosis of MSA was 80% (95%IC: 45-100) and 44% (95%CI: 27-61) respectively. Positive predictive value was 17% (95%CI: 2-33) while negative predictive value achieved 94% (95%CI: 82-106). Postitive and negative likelihood ratios were 1.43 (95%CI: 0.84 - 2.43) and 0.45 (95%CI: 0.08-2.72).53 patients of the 507 (10.4%) presented DS but only 23 of them (12 women -52.2%-) received a final diagnosis of IPD or MSA, and underwent further analysis. The test was considered positive in 11 cases (47.8%). Four out the 23 patients with DS (17%) and 1 out the 16 patients from the control group (6%) were diagnosed as having MSA (Chi-sq=1.05, p=0.3).Overall sensivity and specificity of DS to predict diagnosis of MSA was 80% (95%IC: 45-100) and 44% (95%CI: 27-61) respectively. Positive predictive value was 17% (95%CI: 2-33) while negative predictive value achieved 94% (95%CI: 82-106). Postitive and negative likelihood ratios were 1.43 (95%CI: 0.84 - 2.43) and 0.45 (95%CI: 0.08-2.72). Conclusions: DS during L-dopa acute challenge doesn t help to differentiate MSA from IPD patients.