Parkinson's Parkinson's Surgery and Advanced Therapies 2 — Questions and Answers
Question 1: Carbidopa/levodopa intestinal gel (LCIG, brand name Duopa) is administered via which route?
- Subcutaneous injection under the skin
- Intrajejunal infusion through a PEG-J tube (Correct answer)
- Intravenous drip into the bloodstream
- Transdermal patch on the arm
Correct answer: Intrajejunal infusion through a PEG-J tube
LCIG (Duopa) is continuously infused directly into the jejunum via a percutaneous endoscopic gastrojejunostomy (PEG-J) tube, bypassing the stomach for more stable absorption.
Question 2: Apomorphine, used as an advanced therapy for Parkinson's disease, is classified as which type of drug?
- Dopamine antagonist
- MAO-B inhibitor
- Dopamine agonist (Correct answer)
- Anticholinergic agent
Correct answer: Dopamine agonist
Apomorphine is a potent, fast-acting dopamine agonist that can be given as a subcutaneous injection (rescue pen) or continuous infusion to manage motor fluctuations.
Question 3: What is the primary advantage of continuous infusion therapies (LCIG or apomorphine infusion) over standard oral medications in advanced Parkinson's disease?
- They cost significantly less than oral medications
- They reduce motor fluctuations by maintaining stable drug levels (Correct answer)
- They require no surgical or needle-based procedures
- They eliminate the need for all other Parkinson's medications
Correct answer: They reduce motor fluctuations by maintaining stable drug levels
Continuous infusion maintains more stable plasma drug concentrations, which reduces the on-off motor fluctuations and dyskinesias caused by the peaks and troughs of oral dosing.
Question 4: In a DBS system, the implanted pulse generator (IPG) serves primarily to:
- Monitor brain electrical activity and record seizures
- Generate and deliver programmed electrical pulses to the brain electrodes (Correct answer)
- Release medication directly into the cerebrospinal fluid
- Provide heat to improve local dopamine synthesis
Correct answer: Generate and deliver programmed electrical pulses to the brain electrodes
The IPG, often called the neurostimulator or brain pacemaker, generates electrical pulses that travel through extension wires to the electrodes implanted in the target brain structure.
Question 5: A surgical procedure that permanently destroys a small area of the globus pallidus internus to reduce Parkinson's motor symptoms, especially dyskinesias, is called:
- Thalamotomy
- Pallidotomy (Correct answer)
- Subthalamotomy
- Cingulotomy
Correct answer: Pallidotomy
Pallidotomy is a lesioning procedure that creates a permanent thermal lesion in the globus pallidus internus, reducing dyskinesias and improving motor control in Parkinson's disease.
Question 6: Before being approved for DBS surgery, patients must typically undergo which type of evaluation?
- Genetic testing to confirm LRRK2 mutation status only
- Multidisciplinary evaluation including neurological, neuropsychological, and psychiatric assessment (Correct answer)
- Physical fitness and cardiac stress testing only
- Radiation sensitivity testing to assess focused ultrasound eligibility
Correct answer: Multidisciplinary evaluation including neurological, neuropsychological, and psychiatric assessment
DBS candidacy requires comprehensive multidisciplinary assessment including neurological evaluation, neuropsychological testing to assess cognition, and psychiatric screening to identify contraindications.
Question 7: What minimum percentage improvement in UPDRS motor score during a levodopa on state is typically used as a threshold for predicting good DBS outcomes?
- 10-15%
- 20-25%
- 30-33% (Correct answer)
- Over 60%
Correct answer: 30-33%
A minimum of 30-33% improvement in the UPDRS motor score during the levodopa challenge is generally used as a threshold predictor of a favorable DBS surgical outcome.
Parkinson's Parkinson's Surgery and Advanced Therapies 2
Carbidopa/levodopa intestinal gel (LCIG, brand name Duopa) is administered via which route?