Relative efficacy of self-managed caffeine supplementation in maintaining daily activity in a patient with ADCY5-related dyskinesia: A Case Report

Introduction: ADCY5-related dyskinesia is an autosomal dominant movement disorder with limited treatment options because many standard medications are ineffective. Caffeine has shown efficacy in ADCY5-related dyskinesia as an adenosine A2A receptor antagonist, but optimal dosing remains uncertain. Case Presentation: We report a 24-year-old woman with paroxysmal dyskinesia since early childhood, consisting of chorea, dystonia, and myoclonus upon waking. More than 15 medications failed. Whole-exome sequencing identified a mosaic ADCY5 variant (p.R418Q, 7% variant allele frequency). Caffeine escalation from 100 to 600 mg worsened symptoms. Four months later, she found that unsweetened canned coffee containing approximately 100 mg of caffeine per can, taken 1-3 times daily, reduced her symptoms and helped her maintain daily employment. In a self-controlled analysis of 39 coffee-intake events, dyskinesia episodes during the 6 h after coffee intake were significantly fewer than during the preceding 6 h (P = 0.002). Conclusion: This case demonstrates successful symptom control in ADCY5-related dyskinesia using patient-directed, low-dose caffeine therapy. The striking response suggests a narrow therapeutic window for caffeine in this condition, and that patient self-titration may be valuable in optimizing treatment response.