Introduction: Primary generalized dystonia (PGD) is a genetic form of dystonia that frequently displays resistance to pharmacotherapy and progresses within the first few years after onset. Deep brain stimulation (DBS) has been used successfully in the treatment of refractory dystonia, specifically DBS of the Globus Pallidus Interna (GPi) for patients with DYT1-positive PGD. Long-term follow-up of the safety and efficacy falls short of the longevity seen in other diseases treated with DBS.
Methods: Case report and long term follow-up of continual GPi stimulation in a patient with DYT1-positive PGD.
Results: A male patient presented for neurosurgical evaluation with scapular winging, hand contractures, and violent truncal spasms which were debilitating to the point where he was bedridden. After failing conservative therapy, the patient was implanted with bilateral GPi-DBS at the age of 18. DBS parameter adjustments were made primarily within the first three years after implantation, with nominal changes in the ensuing years. Initial settings were contact of 3+0-, amplitude of 4.9 V, frequency of 185 Hz, and pulse width of 270 µsec on the left and 3+0-, 2.8 V, 185 Hz, and 120 µsec on the right. Current settings are 3+2+1-, 5.2 V, 130 Hz, 330 µsec on the left and 3+0-, 3.5 V, 185 Hz, and 180 µsec on the right and have been relatively unchanged in the past four years. Unified Dystonia Rating Scale (UDRS) scores reveal a significant decrease in dystonic symptoms.
Conclusions: While prior reports have shown that GPi-DBS is effective for dystonia, ours is the first with 15 years of long-term follow up showing disease stabilization, suggesting that stimulation is not only efficacious but prevents disease progression. This report reaffirms previous reports that recommend early surgical intervention prior to the onset of permanent musculoskeletal deficits.
Patient Care: This research suggests that early use of Deep Brain Stimulation (DBS) in patients with Primary Generalized dystonia (PGD) improves quality of life, provides significant symptom relief and prevents disease progression.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the use of Deep Brain Stimulation as an efficacious treatment for Primary Generalized Dystonia (PGD)
2) Recognize the importance of early intervention with DBS in patients with PGD