On the substantive issue.

UCSF publish their DBS results [1]

"For bilateral DBS, the evaluations showed a 45-70% improvement in the scores on standard rating scales, off of medication, as a result of DBS. This is similar to the results from other major centers and represents a major improvement in mobility. In our series, the risk of stroke is 1.6%, the risk of severe stroke with death or permanent major disability is 0.5%, and the risk of device infection that requires further surgery for device removal is 4%."

Note that the 45-70% improvement is relative to the off state. It would be useful to have the figure relative to the prior, medicated on state as well.

I suspect that even if we agree on the accuracy of the figures, different people will react to them differently.

Reference

[1] http://neurosurgery.ucsf.edu/index.p...html#candidate

John