Battery Longevity Comparison of Two Commonly Available Dual Channel Implantable Pulse Generators Used for Subthalamic Nucleus Stimulation in Parkinson's Disease.

OBJECTIVES: Deep brain stimulation for Parkinson's disease (PD) utilises an implantable pulse generator (IPG) whose finite lifespan in non-rechargeable systems necessitates their periodic replacement. We wish to determine if there is any significant difference in longevity of 2 commonly used IPG systems; the Medtronic Kinetra, and the Medtronic Activa Primary Cell (PC), which has come to replace it. METHODS: All patients with bilateral Subthalamic Nucleus stimulators for PD performed in our centre were included. Battery life was then assessed using a Kaplan-Meier approach and comparisons between the Kinetra and Activa PC batteries were performed using log-rank tests. RESULTS: Complete data was available for 183 patients. There was a significant difference in the average battery duration with an estimated median battery life in the Kinetra cohort of 6.6 years (95% CI 6.4-6.7), compared to 4.5 years (95% CI 4.4-4.5) in the Activa PC cohort (p < 0.001). CONCLUSION: The Activa PC IPG demonstrates a significantly reduced battery life of 2.1 years, with a median battery life of 4.5 years in comparison to 6.6 years in the Kinetra IPG. Future technology developments should therefore be focused on improving the battery life of the newer IPG systems.

Comparison of the Battery Life of Nonrechargeable Generators for Deep Brain Stimulation.

OBJECTIVE: Nonrechargeable deep brain stimulation (DBS) generators must be replaced when the battery capacity is exhausted. Battery life depends on many factors and differs between generator models. A new nonrechargeable generator model replaced the previous model in 2008. Our clinical impression is that the earlier model had a longer battery life than the new one. We conducted this study to substantiate this. METHODS: We determined the battery life of every DBS generator that had been implanted between 2005 and 2012 in our department for the treatment of Parkinson's disease, and compared the battery lives of the both devices. We calculated the current used by estimating the total electrical energy delivered (TEED) based on the stimulation parameters in use one year after electrode implantation. RESULTS: One hundred ninety-two patients were included in the study; 105 with the old and 86 with the new model generators. The mean battery life in the older model was significantly longer (5.44 ± 0.20 years) than that in the new model (4.44 ± 0.17 years) (p = 0.023). The mean TEED without impedance was 219.9 ± 121.5 mW * Ω in the older model and 145.1 ± 72.7 mW * Ω in the new one, which indicated significantly lower stimulation parameters in the new model (p = 0.00038). CONCLUSION: The battery life of the new model was significantly shorter than that of the previous model. A lower battery capacity is the most likely reason, since current consumption was similar in both groups.

Do Adaptors Shorten the Battery Life of Nonrechargeable Generators for Deep Brain Stimulation?

OBJECTIVE: Generators implanted for deep brain stimulation must be replaced after several years. If a Kinetra generator is replaced by the Activa-PC, an adaptor will be required to attach it to the original extension cables. On the basis of our clinical impression that the battery life of the Active-PC generator was shorter when an adaptor was used, we performed this retrospective study. METHODS: We determined the battery lifetimes of deep brain stimulation generators that had been implanted in our department. The inclusion criterion was the initial implantation of a Kinetra generator that was later replaced by an Activa-PC with adaptor, which itself was subsequently also replaced. These patients were compared with an Activa-PC control group without an adaptor but identical with regard to number of battery exchanges, disease, and target. RESULTS: There were 28 patients in the study group and 14 in the control group. Battery lifetime of the Activa-PC with adaptor (32.4 ± 7.7 months) was significantly shorter than that of the Kinetra (53.5 ± 15.7 months, P = 0.000006). The battery life of Activa-PC without an adaptor (35.3 ± 8.2 months) did not differ significantly from that of the Activa-PC with an adaptor (P = 0.333). CONCLUSIONS: The battery lifetime in a replacement Activa-PC is shorter than that in the original Kinetra generator. Adaptors have no significant effect on battery life. Patients should be informed that the battery in their new generator must be checked more frequently than before.