Lars Wojtecki, MD; Alfons Schnitzler, MD; Jan Vesper, MD
Study 1: Achieving Therapeutic Control Of Unwanted Parkinson's Disease Side Effects Using Deep Brain Stimulation Interleaved Programs
|Lars Wojtecki, MD; Prof. Alfons Schnitzler, MD; Prof. Jan Vesper, MD; University Hospital, Dusseldorf, Germany|
|Young-onset Parkinson's disease|
With the Activa® RC, Activa SC, and Activa PC systems, programming clinicians have the ability to deliver two programs to each lead, otherwise known as interleaving. When interleaving two programs, each program can have a different combination of active electrodes, amplitude, and pulse width. The pulses are delivered in an alternating interleaved fashion, which has been engineered to optimize the stimulation field and overcome electrode location challenges through programming.
This case study describes how one deep brain stimulation programming center was having difficulty achieving satisfactory results with a patient's Parkinson’s disease-related hypokinesia and tremor. Because of this, the clinicians decided to try interleaving. The use of the interleaving function available with the Activa PC neurostimulator allowed differential therapeutic effects on both hypokinesia and tremor without causing unwanted side effects. These results would not have been possible through the normal interconnection of the contacts or an increase in amplitude. Thus, optimal motor results were achieved, without causing side effects.
The patient is 47 years old and has been diagnosed with young-onset Parkinson's disease for approximately 10 years. The patient has suffered from motor fluctuations with cardinal motor symptoms equally pronounced for the last 3 years, but has experienced off-time freezing episodes and severe tremor as of late.
Therapy Prior to Referral
The patient has reported having good mobility only 40% of the waking day. Most recently, the patient attempted to increase occupational performance with self-medication via the following regiment: a daily L-dopa dosage increase to 800 mg in addition to 3.5 mg pramipexole and 4 mg rotigotine.
This increase in medication led to a dopaminergic dysregulation syndrome, treated with COMT inhibitors and amantadine, as well as apomorphine pump therapy. These medication additions were found not to be effective in controlling the patient's symptoms.
Deep Brain Stimulation Therapy and Interleaved Programs
Recently, the patient received bilateral deep brain stimulation (DBS) therapy of the subthalamic nucleus (STN) with Medtronic’s 3389 electrodes and an Activa PC neurostimulator.
Monopolar stimulation of the right STN through contact 9 with a pulse width of 60 μsec, frequency of 125 Hz and amplitude of 3.5 V, led to good suppression of the cardinal symptoms of rigidity, hypokinesis and tremor.
Monopolar stimulation of the left STN through contact 1 with a pulse width of 60 μsec, frequency of 125 Hz and amplitude of 3.9 V, led to good effect on rigidity and hypokinesia. However, adequate tremor suppression could not be achieved through this contact. Stimulation through contact 3 led to a good anti-tremor effect with no significant improvement of hypokinesia.
Interconnection of the two contacts with the same amplitude caused dysarthria at 3.0 V or higher. Therefore, interleaving pulses through contact 1, with an amplitude of 3.9 V, and contact 3, with an amplitude of 1.5 V, was selected.
Interleaving led to a good reduction of all the cardinal symptoms without side effects. Motor fluctuations were still present; mostly in the evening when the patient was getting tired. The patient was able to reduce medications when using deep brain stimulation therapy. UPDRS motor scores improved from 59 points without therapy, to 27 points with DBS therapy, to 14 points with DBS therapy plus medication.
Individual results may vary. Not every individual will experience the same benefits. See Indications, Safety and Warnings for information about the risks associated with deep brain stimulation therapy.