To describe the clinical course of the Δ9-tetrahydrocannabinol (Δ9-THC) treatment of a boy with Gilles de la Tourette Syndrome (TS) and comorbid attention-deficit/hyperactivity disorder (ADHD) in relation to Δ9-THC plasma levels and intracortical inhibition measured by transcranial magnetic stimulation.Methods:
The clinical course and pharmacological and neurophysiological measures are reported in a 15-year-old boy with treatment refractory TS plus ADHD leading to severe physical and psychosocial impairment.Results:
Administration of Δ9-THC improved tics considerably without adverse effects, allowing parallel stimulant treatment of comorbid ADHD. Along with the Δ9-THC treatment, intracortical inhibition was increased, reflected in the enhanced short-interval intracortical inhibition and the prolongation of the cortical silent period.Conclusions:
Our observation suggests that Δ9-THC might be a successful alternative in patients with severe TS refractory to classic treatment. Particularly in the case of stimulant-induced exacerbation of tics, Δ9-THC might enable successful treatment of comorbid ADHD. The enhancement of intracortical inhibition might be mediated by modulating release of several neurotransmitters including dopamine and γ-aminobutyric acid. Further studies are needed to substantiate our findings.