Anecdotal reports in Tourette's syndrome (TS) have suggested that marijuana (cannabis sativa) and delta-9-tetrahydrocannabinol (Delta(9)-THC), the major psychoactive ingredient of marijuana, reduce tics and associated behavioral disorders. We performed a randomized double-blind placebo-controlled crossover single-dose trial of Delta(9)-THC (5.0, 7.5 or 10.0 mg) in 12 adult TS patients. Tic severity was assessed using a self-rating scale (Tourette's syndrome Symptom List, TSSL) and examiner ratings (Shapiro Tourette's syndrome Severity Scale, Yale Global Tic Severity Scale, Tourette's syndrome Global Scale). Using the TSSL, patients also rated the severity of associated behavioral disorders. Clinical changes were correlated to maximum plasma levels of THC and its metabolites 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) and 11-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH). Using the TSSL, there was a significant improvement of tics (p=0.015) and obsessive-compulsive behavior (OCB) (p = 0.041) after treatment with Delta(9)-THC compared to placebo. Examiner ratings demonstrated a significant difference for the subscore "complex motor tics" (p = 0.015) and a trend towards a significant improvement for the subscores "motor tics" (p = 0.065), "simple motor tics" (p = 0.093), and "vocal tics" (p = 0.093). No serious adverse reactions occurred. Five patients experienced mild, transient side effects. There was a significant correlation between tic improvement and maximum 11-OH-THC plasma concentration. Results obtained from this pilot study suggest that a single-dose treatment with Delta(9)-THC is effective and safe in treating tics and OCB in TS. It can be speculated that clinical effects may be caused by 11-OH-THC. A more long-term study is required to confirm these results.
High densities of cannabinoid receptors were found in the basal ganglia and hippocampus, indicating a putative functional role of cannabinoids in movement and behaviour. Anecdotal reports suggested beneficial effects of marijuana in Tourette's syndrome (TS). We therefore interviewed 64 TS patients with regard to use of marijuana and its influence on TS symptomatology. Of 17 patients (27%) who reported prior use of marijuana, 14 subjects (82%) experienced a reduction or complete remission of motor and vocal tics and an amelioration of premonitory urges and obsessive-compulsive symptoms. Our results provide more evidence that marijuana improves tics and behavioural disorders in TS. It can be speculated that cannabinoids might act through specific receptors, and that the cannabinoid system might play a major role in TS pathology.
Studies of resting regional cerebral glucose consumption (rCMRGlc) in nondemented patients with Parkinson's disease (PD) have produced conflicting results, reporting both reduced and normal metabolism in advanced disease and reduced or normal metabolism after dopaminergic therapy. To investigate these issues, [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) was performed in 11 nondemented PD patients with advanced disease and 10 age-matched controls. PD patients were studied after withdrawal of all dopaminergic medication to produce a practically defined off condition, and a second time 1 hour after levodopa, resulting in a clinical on state. Dynamic PET scans and simultaneous arterialised venous blood samples of [(18)F] activity were obtained. A graphical approach was used to generate parametric images of rCMRGlc and statistical parametric mapping to localise significant metabolic changes in PD. Compared with controls, global rCMRGlc was reduced in the on but not in the off condition in PD. In both states, significant regional reductions of glucose uptake were found in the parietal, frontal, temporal cortex, and caudate nucleus. Reductions correlated with the severity of disability in frontal and temporal cortex. Direct comparison between on and off conditions revealed relatively greater reductions of uptake in the ventral/orbital frontal cortex and the thalamus during on. Results suggest that cortical and caudate hypometabolism are common in advanced PD and that caution is mandatory if [(18)F]FDG PET is being used to differentiate advanced PD from dementia and progressive supranuclear palsy where similar reductions are seen. Furthermore, in PD, administration of levodopa is associated with further hypometabolism in orbitofrontal cortex; an area known to be relevant for reversal learning where performance is typically impaired after dopaminergic treatment.
Preliminary studies in patients with Gilles de la Tourette syndrome (TS) provided evidence of presynaptic dopaminergic dysfunction, demonstrating increased reuptake sites. Therefore we investigated striatal dopamine transporter binding in 12 TS patients and 9 control subjects using single photon emission computed tomography and 123I-labeled 2beta-carbomethoxy-3beta-(4-iodophenyl)tropane. In TS patients we found significantly higher relative striatal activity ratios (mean +/- SD 12.33 +/- 3.58) than in controls (9.36 +/- 1.35, P< 0.05). Only five patients, however, showed striatum/occipital cortex ratios more than 2 SD above the normal means. Seven patients had activity ratios within the average ratio of the control group plus 2 SD. Regarding the relationship between clinical parameters and striatum/occipital cortex ratios, we found an association between binding ratios and "self-injurious behavior" and "lack of impulse control." This study corroborates previous data suggesting an involvement of the dopaminergic system in TS pathology. Our results demonstrate that an increase in dopamine transporter capacity is a possible but not a necessary alteration, and which appears more likely when self-injurious behavior and lack of impulse control are associated.
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