During review of a deep brain stimulator with an n'vision programmer, model 8840, the pt experienced severe rebound tremor which lasted approximately 5 minutes.
The pt appeared rigid, not responding verbally to command and unable to talk.
The tremor decreased in severity and the pt was able to relax.
There was no loss of consciousness, no pain experienced, no drowsiness, no focal seizures and once the rigidity improved the pt was able to speak with no apparent dysarthria or dysphasia.
Immediately after the incident the settings of the stimulator had altered to ov, pw 210 usec, rate 30hz.
Electrode settings were as normal.
The stimulator had been switched off and the battery was showing ok.
The programmer was later needed to check the pt's stimulator again and to reprogram it.
After reprogramming there was an immediate improvement in the pt's tremor.
The pt remained in the hosp for another hour iwth a relative after the changes were made to ensure the pt was safe to go home.
Previously in the same clinic the n'vision programmer had been used on three other outpatients, using the same routine, with no apparent problems.
A follow-up report will be sent when additional info is received.