Deep Brain Stimulation and Parkinson's Disease
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does a marked cognitive dysfunction indicate regarding Deep Brain Stimulation (DBS) benefits in Parkinson's Disease (PD)?

  • It enhances the quality-of-life benefit of DBS.
  • It diminishes the quality-of-life benefit of DBS. (correct)
  • It improves motor function outcomes from DBS.
  • It has no effect on the quality-of-life benefit of DBS.
  • Which symptom is likely to improve with DBS in a patient with Parkinson's Disease?

  • Tremor (correct)
  • Postural instability
  • Autonomic function
  • Cognition
  • What symptom is unlikely to benefit from DBS according to the provided content?

  • Cognition (correct)
  • Rigidity
  • Motor fluctuations
  • Dyskinesias
  • What is considered a relative contraindication to DBS in Parkinson's Disease patients?

    <p>Low score on Mattis Dementia Rating Scale</p> Signup and view all the answers

    What effect does an increase in mobility have on a severely demented patient with PD after DBS?

    <p>It is dangerous.</p> Signup and view all the answers

    Which of the following symptoms represents a classic feature of idiopathic Parkinson's Disease that DBS does not address?

    <p>Cognition</p> Signup and view all the answers

    In the context of the basal ganglia-thalamocortical circuit, which state is characterized by inhibitory and excitatory projections alterations in PD?

    <p>Parkinsonian state</p> Signup and view all the answers

    What is a potential negative outcome of improving motor function in a patient with severe dementia undergoing DBS?

    <p>Increased risk of falls</p> Signup and view all the answers

    What is a major advantage of targeting the subthalamic nucleus (STN) for deep brain stimulation compared to its counterpart?

    <p>It allows for greater reduction of levodopa.</p> Signup and view all the answers

    What significant factor makes STN placement contraindicated in certain patients?

    <p>Underlying psychiatric illness.</p> Signup and view all the answers

    Which imaging technique first improved the safety and accuracy of deep brain surgery?

    <p>Computed Tomography (CT)</p> Signup and view all the answers

    In what year did Benabid and colleagues demonstrate the reversible effects of high-frequency stimulation for Parkinson's symptoms?

    <p>1987</p> Signup and view all the answers

    Which type of DBS target is specifically mentioned as only aiding tremor symptoms?

    <p>Ventralis intermedius thalamic nucleus</p> Signup and view all the answers

    What condition is Parkinson's disease categorized as?

    <p>A synucleinopathy</p> Signup and view all the answers

    What percentage of the population is estimated to be affected by Parkinson's disease?

    <p>1%</p> Signup and view all the answers

    What surgical procedure was commonly performed in the early 1990s to address Parkinson’s symptoms?

    <p>Pallidotomy</p> Signup and view all the answers

    Who initially described the condition now known as Parkinson's disease?

    <p>James Parkinson</p> Signup and view all the answers

    What hypothesis forms the basis for the use of deep brain stimulation (DBS) in treating motor symptoms of Parkinson's disease?

    <p>Segregated circuit hypothesis</p> Signup and view all the answers

    Which structure overlies the choroidal fissure and optic tract in the basal ganglia?

    <p>Globulus pallidus internus (GPi)</p> Signup and view all the answers

    What is the role of the GPi in the basal ganglia–thalamocortical circuit?

    <p>It serves as the main output structure.</p> Signup and view all the answers

    What specific frequency band is typically increased in Parkinson's disease, indicating abnormal neuronal synchronization?

    <p>Beta activity (13-30 Hz)</p> Signup and view all the answers

    What is a key consideration in the effectiveness of DBS for Parkinson's disease?

    <p>Patient selection process</p> Signup and view all the answers

    What anatomical area is the STN located medial to?

    <p>Internal capsule</p> Signup and view all the answers

    In which frequency range does high-frequency stimulation for DBS usually occur, especially for planning and execution of movement?

    <p>76-100 Hz</p> Signup and view all the answers

    What is the primary technique used to achieve high spatial resolution in neuronal recordings?

    <p>Microelectrode Recording</p> Signup and view all the answers

    What type of electrode is typically used for recording single-unit extracellular action potentials?

    <p>Tungsten or platinum-iridium microelectrodes</p> Signup and view all the answers

    What potential benefit does the use of microelectrodes provide in preoperative imaging?

    <p>Augmentation of accuracy lost due to nonlinear distortions</p> Signup and view all the answers

    During microelectrode recordings, how is the position for each pass determined?

    <p>Based on recordings gathered during previous passes</p> Signup and view all the answers

    When entering the globus pallidus internus (GPi), what is the typical range of frequency increase observed?

    <p>60 to 100 Hz</p> Signup and view all the answers

    What is a noted characteristic of 'border' cells located between the GPi and GPe?

    <p>Regular discharge patterns of 20 to 40 Hz</p> Signup and view all the answers

    What is the consequence of the greater deformability of the DBS electrode compared to the microelectrode?

    <p>A more rigid guide tube is required for guidance</p> Signup and view all the answers

    What is the typical distance from the anatomical target to begin recordings in the GPi?

    <p>15 mm dorsal</p> Signup and view all the answers

    What is a potential postoperative concern associated with stimulator implantation?

    <p>Worsening of voice strength</p> Signup and view all the answers

    Why might unilateral implantation be considered as a surgical option?

    <p>There is gross asymmetry in the patient's symptoms</p> Signup and view all the answers

    How do unilateral STN-DBS and GPi-DBS compare regarding cognitive performance?

    <p>GPi-DBS tends to maintain cognitive function better than unilateral STN-DBS</p> Signup and view all the answers

    What impact does STN-DBS have on decision making under stress?

    <p>It may increase impulsive behavior and errors in judgment</p> Signup and view all the answers

    Which factor may lead to a more prudent choice for unilateral surgery in patients?

    <p>Having advanced age or preoperative cognitive deficits</p> Signup and view all the answers

    What does recent evidence suggest about the timing of bilateral implantation?

    <p>Unilateral implantation first may be more effective for severely affected sides</p> Signup and view all the answers

    What complication may arise from the deterioration of swallowing function in patients with PD?

    <p>Aspiration pneumonia and death</p> Signup and view all the answers

    What characteristic of frame-based stereotaxy is critical to its function?

    <p>It requires preoperatively acquired magnetic resonance images</p> Signup and view all the answers

    Study Notes

    Deep Brain Stimulation and Parkinson's Disease

    • Levodopa/carbidopa therapy can cause long-term side effects, prompting interest in surgical solutions for Parkinson's Disease (PD).
    • Subthalamic nucleus (STN) and globus pallidus internus (GPi) are common targets for deep brain stimulation (DBS); STN allows for greater levodopa reduction.
    • Significant psychiatric illness contraindicates STN placement.
    • Modern imaging techniques like CT and MRI have enhanced the safety and precision of DBS surgeries.

    Historical Context

    • High-frequency stimulation was first described in 1987 by Benabid, demonstrating a controllable, reversible method mimicking lesions.
    • Effective pallidotomies in the 1990s revived interest in GPi lesioning for PD symptoms.
    • PD affects roughly 1% of the population and is the second most common neurodegenerative disease.

    Basal Ganglia Anatomy and Function

    • STN is closely located to the internal capsule and substantia nigra; GPi is medial to the medial medullary lamina.
    • The basal ganglia circuitry plays a pivotal role in motor control, with distinct inputs and outputs potentially targeted during DBS.

    Patient Selection for DBS

    • Proper patient selection involves a multidisciplinary evaluation, considering factors like cognitive function and movement disorder severity.
    • Cognitive impairment impacts treatment efficacy and can increase risk after surgery.
    • Improved motor function following unilateral DBS suggests it might be safer for patients with cognitive deficits.

    DBS Target Selection Factors

    • Studies comparing STN and GPi show no significant difference in motor symptom improvement.
    • Unilateral STN-DBS on the severely affected side often results in better motor function without increasing cognitive decline compared to bilateral DBS.

    Surgical Techniques in DBS

    • Early DBS techniques combined anatomical targets with physiological recordings for precision.
    • Frame-based stereotaxy and magnetic resonance imaging are utilized to identify targets accurately.
    • Microelectrode recording (MER) provides high spatial resolution to augment preoperative imaging, confirming electrode placement during surgery.

    Microelectrode Recording Procedure

    • High-impedance microelectrodes are used to record action potentials, ensuring accurate trajectories and minimizing risk during electrode advancement.
    • Activity patterns change notably as electrodes approach the GPi, revealing somatotopic organization relevant to targeted DBS.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Description

    Explore the role of deep brain stimulation in treating Parkinson's Disease, including the implications of levodopa therapy and the anatomical considerations of STN and GPi. This quiz covers historical advancements, imaging techniques, and psychiatric considerations related to DBS surgeries.

    More Like This

    Use Quizgecko on...
    Browser
    Browser