Longterm deep brain stimulation withdrawal: clinical stability despite electrophysiological instability

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Deep brain stimulation (DBS) is a key treatment for severe generalized dystonia.
• Some patients maintain clinical benefit after discontinuing DBS, suggesting functional restoration.
• The underlying neurophysiological mechanisms of this sustained benefit remain unclear.

Observation:

• This study investigated whether clinical stability after DBS cessation in dystonia patients is mirrored by stable motor network physiology.
• Physiological recordings were made in patients with severe genetic dystonia who had long-term benefit from DBS.
• DBS was temporarily turned off in these patients to assess physiological changes.

Findings:

• Despite maintained clinical stability, significant alterations in cortical excitatory and inhibitory motor circuit excitability were observed upon DBS withdrawal.
• These physiological changes exceeded typical fluctuations, indicating underlying neurophysiological instability.
• A discrepancy exists between the patients' stable clinical state and the dynamic changes in their motor networks.

Implications:

• The observed neurophysiological instability suggests that the apparent clinical stability may be fragile.
• This highlights a potential risk of symptom recurrence or treatment failure after DBS cessation.
• Further research is needed to understand and manage this physiological instability for long-term treatment success.