Basal Ganglia Flashcards
What are the components of Basal Ganglia?
- Corpus Stratium
- Substantia Nigra
- Subthalamic nucleus
- Ventral Stratium and ventral pallidum
What does the corpus stratium include?
- Stratium - Caudate nucleus and putamen
2. Pallidum - Globus pallidus (GP)
What does the Substantia Nigra contain?
- Pars Compacta (SNc)
2. Pars Reticulata (SNr)
What does the ventral stratium and ventral pallidum contain?
- Nucleus Accumbens Septi
2. Non-Cholinergic portion of Substantia Innominata
What is substantia nigra involved in?
- Globus pallidum
2. Subthalamic nucleusn
What are the treatment for Basal Ganglia?
Functional stereotactic NSG
- Ablation
- DBS
What are the guidance for Basal Ganglia?
- Atlas based - microelectrode recording
- Direct targeting (MR/CT)
- Grids/metal - orientate yourself in space
What are MR guidance for Basal Ganglia?
- Accuracy/safety
- Optimal technique
- Knowledge of anatomy
What are the subdivision of Basal Ganglia?
- Corpus stratium
- Claustrum
- Amygdala
- Closely related: subthalamus and substantia Nigra
What is the division of Corpus Stratium?
Neostratium - caudate and putamen
Paleostriatum - Pallidum
Lentiform nucleus
What is Lentiform nucleus?
A combination of putamen and pallidum
What are the dorsal and ventral division of Corpus Stratium?
- Dorsal - Caudate and putamen
2. Ventral - Nucleus Accumbens and Olfactory tubercle
How are Caudate and Putamen connected?
Anteriorly in the region of Nucleus Accumbens
What does stria connect?
Putamen to caudate
What is pallidum separated by?
Putamen by external medullary lamina
What is the order of identifying the corpus stratium?
Cortex of Insula –> Extreme capsule –> Claustrum – >External capsule –> Putamen –> Internal Capsule –> Caudate
What is the landmark for Corpus Stratium?
Anterior Commissure
What does the pallidum contain?
Iron
What is the function of Internal Capsule?
Connects from cortex goes down to the cord to other structures
It is very dense
How do you identify the internal medullary lamina as?
Lateral border
What are the Substantia Nigra divided into?
- Pars Reticularis (ant)
2. Pars Compacta (post)
What are Pars Reticularis?
- Intermingled with fibres of crus cerebri
- Continuous with GP
- Dense striatonigral fibres
- GABA receptors
What are Pars Compacta?
- Highly cellular, melanin
2. Dopamine receptors
Where does the pathology of Parkinson’s occur?
Pars Compacta
Loss of Dopamine
What is the aqueduct?
Connects the third ventricle with the fourth ventricle
What does mesencephalon consist of?
- Peduncle
2. Tegmentum and Tectum
What is the shape of Substantia Nigra?
- Semilunar (concave post)
What is the thickness of Substantia Nigra?
- Oblique coronal 4mm
2. Axial 1.7mm
What is the sequence of Substantia Nigra?
- T2 hypointensity
2. PD, Fast STIR
What is the shape of Subthalamic Nucleus?
- Biconvex lens-shaped
It is oblique in all 3 planes
What are the dimensions of Subthalamic nucleus?
- 13.2 (R-C)
- 6 (M-L)
- 3 (A-P)mm
What are the orientation of Subthalamic Nucleus?
Axial 20° Sagittal 35 ° Coronal 55 °
Where is MTT visualised?
Underneath the fornix
posterior ones
2-4 mm below AC-PC
STN tip - MTT
Lateral 5.9 mm SD 0.7
A-P 0.1 mm SD 0.7
