ABSTRACT
BACKGROUND: Patients suffering from Parkinson's disease (PD) describe painful sensations that could be related to neuropathic pain. Experimental data have indicated the involvement of basal ganglia and dopaminergic pathways in central nociceptive processing. AIM: The objective of this study was to assess and compare the effect of levodopa on the objective pain threshold in patients with PD and healthy subjects. METHODS: The objective pain threshold was assessed by the nociceptive flexion reflex (RIII) in 13 PD patients and 10 healthy subjects. Patients and healthy subjects were evaluated under two randomised conditions: with levodopa (ON) and without (OFF). RESULTS: Levodopa significantly increased the RIII threshold of PD patients (6.9 (1.2) mA in the OFF condition vs 8 (1.1) mA in the ON position; p = 0.02). RIII threshold was significantly lower in PD patients than in healthy subjects in the OFF condition (6.9 (1.2) mA vs 9.7 (3.4) mA; p = 0.02). RIII threshold did not change after levodopa administration in healthy subjects. CONCLUSION: These results provide evidence of a dopaminergic modulation of objective pain threshold in PD patients. In addition, the decrease in RIII threshold in PD patients, in the OFF condition, compared with controls, confirms the existence of an objective pain perception disturbance in PD.
Subject(s)
Levodopa/therapeutic use , Pain Threshold/drug effects , Pain/drug therapy , Pain/etiology , Parkinson Disease/complications , Adult , Aged , Female , Humans , Male , Middle Aged , Pain/physiopathologyABSTRACT
OBJECTIVE: To assess levodopa dose effect on pain thresholds in Parkinson's disease (PD) patients using an experimental nociceptive thermal stimulation. PATIENTS AND METHODS: We evaluated pain thresholds in 20 PD patients treated by dopaminergic drugs. We assessed heat and cold pain thresholds by using 2 different methods (method of limits and method of levels), intensity-response curve and tolerance threshold. Each PD patient was evaluated in two conditions: ON (after administration of leovdopa and OFF (after acute levodopa withdrawal). The order was randomized. RESULTS: The mean age of patients was 652+/-9.9 years and the mean duration was 9.3+/-3.3 years. Heat pain thresholds were statistically higher in ON versus OFF condition using both methods (44.1+/-3,6 degrees C versus 42.3+/-3,1 degrees C, method of levels, p=0.02). Cold pain thresholds were statistically higher in ON versus OFF condition only using method of levels (17.9+/-4,4 degrees C versus 19.6+/-4,2 degrees C, p=0.02). Heat pain tolerance was statistically higher in ON versus OFF condition (21.4+/-21.6 seconds versus 14.7+/-20.3 seconds, p=0.02). CONCLUSION: This study showed that levodopa increased heat and cold pain thresholds and heat pain tolrance in PD patients. This suggests that dopaminergic drugs could have an analgesic effects on PD related pain.
Subject(s)
Antiparkinson Agents/pharmacology , Levodopa/pharmacology , Pain Threshold/drug effects , Parkinson Disease/physiopathology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle AgedABSTRACT
BACKGROUND: A substantial proportion of ischemic strokes have an embolic mechanism, but the source of embolism is not detected. Coexistence of subdiaphragmatic visceral infarction (SDVI; e.g., renal, splenic, hepatic, bowel infarction) may be a suggestion of a common source of embolism. One large autopsy study found SDVI in 21.5% of patients with fatal stroke. METHOD: We performed diffusion-weighted magnetic resonance abdominal imaging and subsequently performed it in consecutive patients with stroke or TIA and a history of nonvalvular atrial fibrillation. RESULTS: Among 27 patients, 6 had SDVI (3 recent renal, 1 recent splenic, and 3 old splenic infarction). The median time between onset of ischemic stroke and abdominal MRI was 8 days (interquartile range 3-15 days). No predictive factor of SDVI was found in this study population with respect to demographic or ultrasound characteristics. CONCLUSIONS: One in 5 patients with nonfatal cardioembolic stroke or TIA may be associated with subdiaphragmatic visceral infarction (SDVI). Further study should evaluate the frequency of SDVI in patients with stroke of unknown cause.