1. How and When to Consider DBS in the Older Patient
Erwin B. Montgomery, Jr. MD
The Dr. Sigmund Rosen Scholar and Professor of Neurology
University of Alabama at Birmingham

2. July 1, 2013 Medical Director Greenville Neuromodulation Center
Greenville Neuromodulation Scholar in Neuroscience and Philosophy
Thiel College
Greenville, PA

3. Disclaimers and Conflict of Interest
Material grants from Medtronic Neuromodulation Inc.
Consultant to Great Lakes Neurotechnology
Consultant Greenville Neuromodulation Services
Consultant FHC, Inc.

4. Experimental and Off-label Uses
Off-label uses of FDA approved devices and experimental and investigational uses will be identified when discussed
The role of the FDA is to regulate the interstate commerce in drugs and devices; not to regulate the practice of medicine

5. Deep Brain Stimulation (DBS)
Implantation of chromic electrical stimulation electrodes in various targets in the brain for the relief of symptoms and disabilities in neurological and psychiatric disease

7. 7

8. DBS The brain is basically an electrical device
Processes information electronically
Neurotransmitters (basis for pharmacology) are the messengers not the message
Disease is misinformation

9. DBS Unparalleled accuracy and precision
Spatial resolution on millimeters
Temporal resolution on the order of milliseconds

10. DBS Indications in the Elderly
The same as any age group
Certain indications more common in elderly
Primary affect of age is in the co-morbidities
Benefit may not be a much
Increased risks
NO specific age limit

11. Figure 2
Predictors of effective bilateral subthalamic nucleus stimulation for PD.
Charles, PD; Van Blercom, N; Krack, P; Lee, SL; MD, PhD; Xie, J; Besson, G; Benabid, A-L; MD, PhD; Pollak, P
Neurology. 59(6): , September 24, 2002.
Figure 2 . Scatter plot and linear regression with 95% confidence interval shown with the R2 value, i.e., the percent of the variation in improvement from stimulation accounted for by age. Individual data points are represented as black squares (n = 54 patients). Data values were calculated as in figure 1. The correlation coefficient, r (Spearman's rho), is significant at the 0.01 level (two-tailed).
©2002 American Academy of Neurology. Published by LWW_American Academy of Neurology. 2

12. Issue of Pre-existing Cognitive Decline
Concerns based on informed speculation
It just makes sense that invading the brain is going to make cognitive function worse even if not known complication such as intra-cerebral hemorrhage or stroke
Essentially untested
Most exclude patients with cognitive decline so hypothesis not tested

13. DBS effects on Cognitive Function
Only demonstrated consistent decline is in verbal fluency which is mild to moderate in severity
Liberalization of cognitive requirements

14. DBS in Parkinson’s Disease
More effective and less long-term side effects than best medical therapy
2-3% risk of severe or permanent adverse effect
Intra-cerebral hemorrhage
Infection
Rare complications
Seizures
Hardware failure

15. DBS in Parkinson’s Disease
Candidate criteria
Idiopathic Parkinson’s disease
Issue of atypical parkinsonism
Exhausted reasonable attempts at medication therapy
Parkinson related disability is the “rate limiting” condition, not cognition
Able to tolerate surgery

16. Exhausted Reasonable Attempts at Medication Therapy
Very problematic
Thousands of potential combinations
Think in terms of drug class rather than individual agents
Dopamine agonists
Is issue lack of efficacy or side effect
Agents within class
relatively the same efficacy
Special case in extended or long acting agents
differ in side effects

17. Current and Future Indications
FDA approved
Parkinson’s disease
Essential tremor
Dystonia
Obsessive-compulsive disorder
Off-label uses
Hemiballismus
Chorea
Tardive dyskinesia
Tardive dystonia
Cerebellar outflow tremor
Hyperkinetic disorders
Experimental or investigational
Alzheimer's disease
Epilepsy
Depression
Stroke

18. Role of the Gerontologist, Internist, Family Practitioner
Team
Patient referred for evaluation not DBS surgery
Refer to Movement Disorders/DBS expert not surgeon
Major selection criteria is medical not surgical
Low threshold
Movement Disorders/DBS expert = high threshold

19. Questions?