• The study evaluated the impact of cannabis use on Parkinson's disease. 20 patients were selected for the study.

Background study

Cannabis can relieve the pains of various etiologies . This study assessed the effect of cannabis on motor symptoms and pain parameters in Parkinson's disease (PD) patients.


Twenty patients with PD who have been given cannabis authorization have undergone assessment before and after 30 cannabis consumption and again after prolonged use.

Motor function was evaluated by the Unified PD Rating (UPDRS) scale by two sensors, it is blind. Pain was assessed using the Pain Index (PRI) and the Visual Analog Scale (VAS) of the McGill Pain Questionnaire. Thermal quantitative sensory testing (QST) was performed in 18 patients.

Two consecutive QST measurements were validated in 12 patients without PD prescription.


Compared to baseline, there was a significant decrease from baseline to 30 minutes after cannabis consumption for mean motor UPDRS score (38.1 ± 18 to 30.4 ± 15.6, p <0.0001), total PRI (27 ± 13.5 to 9.7 ± 11, p = 0.001) and VAS scores (6.4 ± 2.8 to 3.6 ± 3.1, p = 0.0005).

The average cold threshold was significantly reduced in affected limbs but only after the exclusion of two patients who consumed cannabis rather than vaporization than smoking (19.5 ± 5.2 to 15.6 ± 8.7 ° C, p = 0, 02).

After prolonged exposure (median 14 weeks), all affected patients significantly reduced limb pain (43.6 ± 3.5 to 40.9 ± 3.3 ° C, p = 0.05) and cannabis smokers (43.7 ± 3.6 to 40.3). ± 2.5 ° C, p = 0.008).


Cannabis improved motor scores and pain symptoms in PD patients , along with dissociation effect on heat and winter pain thresholds. Peripheral and central pathways are probably modulated by cannabis.


Quantitative results of sensory tests are significantly altered after cannabis consumption in PD patients. Cannabis is likely to cause PD pain through peripheral and central pathways.