clinical | how I do it
Managing Anti-PD Medication Before and After STN DBS Surgery
Elena Moro, France
Managing anti-PD medication before and after STN DBS surgery is not an easy task and requires deep knowledge of both the disease and the effects of STB DBS.
Immediately before surgery no changes of anti-PD medication are usually required. However, in order to allow a good evaluation of the stimulation effects during surgery, some anti-PD medication might be progressively reduced within 1-2 weeks before surgery. Reduction of dopaminergic drugs (especially dopamine agonists) might also be required in case of hyperdopaminergic syndrome. A very severe parkinsonism in the off condition might be managed by small doses of levodopa or apomorphine injection just before starting the neurophysiological and clinical assessment in the OR. Anxiety should also be appropriately managed by psychotherapy when possible.
Anti-PD drugs should be restarted immediately after surgery for the patient’s comfort and to avoid malignant hyperthermia syndrome. The same dosage should be given, unless the patient presents with severe dyskinesia induced by the subthalamotomy-like effect. In the latter case, levodopa should be appropriately reduced.
The reduction of anti-PD medication after starting the first programming of STN stimulation should take into account the effects induced by the stimulation and be reduced slowly accordingly. As a rule of thumb, levodopa can be slowly reduced by 50% within 2-3 weeks while increasing the amplitude of stimulation. Indeed, drastic and abrupt decrease of dopaminergic drug can easily induce apathy, depression and fatigue. A dopamine agonist is the preferred drug to be continued in young patients without preoperative hyperdopaminergic syndrome. At the 3-month follow-up the stimulation setting should have been optimized and further reduction of anti-PD medication can be done if appropriate.