A 62-year-old man with a 15-year history of Parkinson's disease managed with multiple medications, including carbidopa/levodopa and a dopamine agonist, undergoes successful placement of a deep brain stimulation (DBS) system in the subthalamic nucleus. Two weeks after the initial programming, he reports significant improvement in his 'off' time and a reduction in dyskinesias. However, he has developed new problems with his speech, which has become soft and slurred.
This patient's new-onset dysarthria is most likely a complication of what aspect of his recent management?
- Disease progression independent of his treatment.
- Worsening of levodopa side effects.
- Stimulation-related effects from the DBS. (correct answer)
- A postoperative intracranial hemorrhage.
Explanation: Dysarthria is a well-known potential side effect of subthalamic nucleus (STN) deep brain stimulation (DBS). It is considered a stimulation-related side effect, likely due to current spread to adjacent pathways involved in speech production. This can often be managed by adjusting the DBS programming parameters. While disease progression occurs, the acute onset after DBS initiation makes a stimulation effect most likely. DBS typically allows for a reduction in medication, making levodopa side effects less likely to be the cause. A postoperative hemorrhage would have presented more acutely with more severe neurologic deficits.