Dissertation committee:
Σακάς Δαμιανός Καθ/της Νευροχειρουργικής. Στάθης Μποβιάτσης Αν. Καθ/της Νευροχειρουργικής, Στυλιανός-Στέργιος Γκατζώνης Αν. Καθ/της Νευροχειρουργικής, Γιώργος Στράντζαλης Αν. Καθ/της Νευροχειρουργικής, Ελίζαμπεθ Τζόνσον Αν. Καθ/τρια Ανατομίας, Κωνσταντίνος Πόταγας Επ. Καθ/της Νευρολογίας, Στέφανος Κορφιάς Λέκτορας Νευροχειρουργικής
Summary:
Introduction:
Deep Brain Stimulation of the Globus Pallidus internus (GPi-DBS) is an
effective treatment for medically refractive dystonia. Typically, DBS delivers
constant-voltage stimulation(V) through implantation of a four-contact
electrode lead. The use of constant-current (A) stimulation through an
eight-contact lead has certain theoretical advantages. In the current study we
explore whether constant-current DBS with the use of an octrode lead is a safe
and effective treatment for medically refractive idiopathic dystonia.
Materials and Methods:
The study was designed as a monocentric prospective study. For stimulation a
novel 8-contact lead connected to an internal pulse generator able to deliver
constant-current stimulation was used. A total of ten patients were enrolled in
the study and nineteen DBS leads were implanted. Patients were followed for
twelve months, using standard dystonia scales, with the patients serving as
their own controls. Changes in quality of life and pain were also quantified.
Follow-up was done by two independent investigators, blinded to each other
evaluation.
Results:
At month twelve, six patents (60%) had responded to treatment by over 50%,
achieving an improvement of 54% (BFMDRS), 55,2% (UDRS) and 48,9% (GDS).
Interestingly, 84% of the total improvement had been achieved by month 1, with
another 10,5% at months 1-6 and an additional 5,5% improvement at months 6-12.
Axonal symptoms (neck and trunk) showed the most improvement, by 68,87%.
Quality of Life and improved by 31,83% και 96,27% respectively. The new system
showed a good safety profile.
Conclusions:
Constant-current bilateral DBS of the GPi using an 8-contact lead appears to be
safe and efficacious for the treatment of medically refractory idiopathic
dystonia. Six patients (60.0%) achieved a > 50% reduction in their
Burke-Fahn-Marsden score as measured by the Month 6 assessment. Stimulation
produced significant improvement in pain and quality of life in all patients.
Nearly 84% of the overall improvement occurred by month 1, documenting an early
response to treatment, in contrast with current notions in the literature.
Whether this is associated with the advent of constant-current stimulation
remains to be elucidated. Additional studies comparing constant-current with
constant-voltage stimulation are needed.
Keywords:
Deep brain stimulation, Dystonia, Octrode, Electrode, Constant current
