Deep brain stimulation Flashcards
Teacher: Murris
What are the clinical applications for DBS?
- Parkinsons
- MPTP model (most used mice model for PD)
- Physiological circuitry
- Surgical procedures
- Neural correlates
What is used to read brain activity?
Brain Computer Interfaces
What part of the brain is targeted for physiological circuitry DBS?
Subcortex
What is the direct pathway of the motor circuit?
D1 and cerebral cortex –> globus pallidus internal –> VA/VL complex of the thalamus –> frontal cortex
What is the indirect pathway of the motor circuit?
- D2 and cerebral cortex –> globus pallidus external –> subthalamic nucleus –> globus pallidus internal –> VA/VL –> frontal cortex
What is the difference in DBS treatment in PD in Europe and US?
EU: Stimulate the subthalamic nucleus
US: Stimulate the globus pallidus internal
What can be seen in muscle tension of a lesioned SN when there is stimulation in a contralateral limb?
The muscle tension has less fluctuations –> more stabilization
What are important DBS parameters?
Amplitude: intensity of stimulation in v or mA
Pulse width: duration of each stimulus in microseconds
Rate: number of pulses per second in Hz
What kinds of navigation are involved during surgical procedures?
Neuroimaging navigation, Electrophysiological navigation
Stimulation navigation
How can DBS influence the local brain environment (local and functional effects)?
- Local: Excitation of dendrites and synapses, inhibition of soma (cell body)
- Functional: mimics ablation (lesions), “information jam”
NOTE: DBS not just stimulates, it modulates the deep brain
What effect is important to study when looking at neural correlates?
What the distal/network effects are
How does on/off stimulation in a closed-loop (adaptive) DBS effect the brain state?
- Off in closed loop: normal brain state goes to an abnormal brain state
- On in closed loop: abnormal brain state stays into abnormal brain state
How does on/off stimulation in a open-loop DBS effect the brain state?
- On in open-loop:
normal brain state stays in normal brain state
Abnormal brain state goes to a normal brain state
Name a brain area that could be stimulated with DBS in depression, OCD and Tourette’s?
- Depression: GPi
- OCD: Ventral caudate, STN(subthalamic nucleus)
- Tourette’s: GPe
What are the underlying mechanisms of anaesthesia?
Cortico-cortical & cortico-thalamic coupling
