Neurological Worsening After Implantable Pulse Generator Replacement

Area of Science:

• Neurology
• Biomedical Engineering
• Neurosurgery

Background:

• Non-rechargeable implantable pulse generators (IPGs) in deep brain stimulation (DBS) require replacement, posing risks.
• Adverse events, including neurological worsening, have been reported following IPG replacement surgery.

Purpose of the Study:

• To determine the incidence of neurological worsening after IPG replacement in Parkinson's disease (PD) patients.
• To investigate the electrophysiological basis of this worsening.
• To identify therapeutic interventions for managing these adverse events.

Main Methods:

• Retrospective chart review of PD patients on chronic DBS therapy (CDT) from January 2010 to December 2016.
• Inclusion criteria: patients who underwent one or more IPG replacements.
• Analysis of neurological status, stimulation parameters, and hardware before and after IPG replacement.

Main Results:

• Neurological worsening occurred in 35.5% of PD cases (27.4% of IPG replacements), specifically after dual-channel IPG replacements.
• Most common symptoms included worsening tremor, speech, and gait.
• Deviation in stimulation parameters (voltage, impedance) affecting Total Electrical Energy Delivered (TEED) was the primary correlate (82.4%), including switched laterality.
• Hardware issues accounted for the remaining 17.6% of worsening.

Conclusions:

• Neurological worsening is a significant risk following IPG replacement in PD patients on CDT.
• The majority (82.4%) of these adverse events are avoidable.
• Careful monitoring and matching of pre-replacement stimulation parameters, particularly TEED, are crucial to prevent neurological worsening.