Session 6 - Lecture 1 - Movement Disorders Flashcards
1 - Define scotoma.
Scotoma = a partial loss of vision or blind spot in an otherwise normal visual field.
Movement disorders - need to know clinical features and some basic mechanisms - but DON’T need to know normal function of basal ganglia and cerebellum.
2 - Slide images
{Basal ganglia (BG) bit of a misnomer – first lecture defined ganglion as collection of cell bodies in PNS – but actually all the BG found in CNS – but specifically, it is a collective term referring to a whole load of grey matter / nuclei sitting deep in the cerebral hemispheres.
BG themselves can be split up into a number of subcomponents which interact / communicate with each other complexly.
1. SN (PC) - different parts to SN, specifically we are thinking of the PC. This is found within the midbrain – cross section through midbrain – recognisable as inverted face – here are the cerebral peduncles; substantia nigra are the eyebrows sitting just above the red nuclei – SN sits just beneath the cerebral peduncles in the midbrain. The SN is of course a vital source of dopamine.
2a. Caudate n. C-shaped (reflects morphology of lateral ventricle - has head, body and tail), curved structure, actually sitting in the walls of the lateral ventricles – in red on this diagram here is the caudate n. Coronal section - won’t see the C-shaped morphology, you’ll just see the caudate cut in cross-section; so don’t see much of it in coronal section – is cut through plane here, so will only see one or two blobs.
2b. Caudate associated with a second nucleus called the putamen. This red blob sitting superficially is the putamen, and the caudate and the putamen are joined together by these thin strands of grey matter. Collectively between them, caudate and putamen are known as the striatum. So the striatum specifically refers to the caudate and putamen together (depicted in red together). That’s whyin this diagram caudate and putamen are depicted in red – bc they are the striatum. They were once back in evolutionary history together as one structure – the caudate and putamen – which was essentially shot through by the internal capsule. These gaps here between caudate and putamen as you can see are holes created by IC puncturing through striatum. IC part of corticospinal system. Have striatum, have the corticospinal tract essentially, and As the corticospinal pathway developed/got bigger, it punctured its way through the caudate putamen to separate them from each other.
3. globus pallidus – so here’s the putamen in the coronal section, and here’s a bit of a caudate, the GP is here, sitting just medial to the putamen and actually has two components: an internal component that sits medially and an external component that sits laterally. So this medial part we abbreviate to Gpi (internal, deep), this External (superficial) lateral part we abbreviate to GPE – the external part of GP. GP has no functional or evolutionary relation to the putamen, but sits together next to it to form a large structure called the lentiform nucleus, which is actually composed of putamen + globus pallidus). However, don’t have any common functional ancestor – come together by coincidence - good landmark for interpreting sections in the brain.
4. subthalamic nucleus – see thalamus sitting in midline close to 3rd ventricle, subthalamic nucleus (one on each side) sit just beneath the thalamus See Panopto (image, left) – hence the name. Now clinically, these structures can be examined by certain scanning protocols – classic one is a PET scans – can set it up so you can see where dopamine is expressed through the brain. Actually what we’re looking at is the putamen in a transverse section of the brain during a PET scan, and in a normal person you get lots of dopamine signal because the substantia nigra projects to the putamen – see lots of dopamine in the putamen - Putamen is receiving lots of dopamine from the substantia nigra. However in a Parkinson’s disease patient, where there are low levels of dopamine, we see much lower signalling in the PET scan – Parkinson’s disease pt – much less dopamine in their putamen. so We can actually see these regions of the brain in their normal function – can see them functioning, not just static anatomy.}
2 - Visualiser
{Basal ganglia (BG) bit of a misnomer – first lecture defined ganglion as collection of cell bodies in PNS – but actually all the BG found in CNS – but specifically, it is a collective term referring to a whole load of grey matter / nuclei – a whole load of nuclei sitting deep in the cerebral hemispheres.
BG themselves can be split up into a number of subcomponents which interact and communicate with each other in a remarkably complex way.
1. SN (PC) - different parts to SN, specifically we are thinking of the PC. This is found within the midbrain – cross section through midbrain – recognisable as inverted face – here are the cerebral peduncles; substantia nigra are the eyebrows sitting just above the red nuclei – SN sits just beneath the cerebral peduncles in the midbrain. The SN is of course a vital source of dopamine.
2a. Caudate n. C-shaped (reflects morphology of lateral ventricle - has head, body and tail), curved structure, actually sitting in the walls of the lateral ventricles – in red on this diagram here is the caudate n. Coronal section - won’t see the C-shaped morphology, you’ll just see the caudate cut in cross-section; so don’t see much of it in coronal section – is cut through plane here, so will only see one or two blobs.
2b. Caudate associated with a second nucleus called the putamen. This red blob sitting superficially is the putamen, and the caudate and the putamen are joined together by these thin strands of grey matter. Collectively between them, caudate and putamen are known as the striatum. So the striatum specifically refers to the caudate and putamen together (depicted in red together). That’s whyin this diagram caudate and putamen are depicted in red – bc they are the striatum. They were once back in evolutionary history together as one structure – the caudate and putamen – which was essentially shot through by the internal capsule. These gaps here between caudate and putamen as you can see are holes created by IC puncturing through striatum. IC part of corticospinal system. Have striatum, have the corticospinal tract essentially, and As the corticospinal pathway developed/got bigger, it punctured its way through the caudate putamen to separate them from each other.
3. globus pallidus – so here’s the putamen in the coronal section, and here’s a bit of a caudate, the GP is here, sitting just medial to the putamen and actually has two components: an internal component that sits medially and an external component that sits laterally. So this medial part we abbreviate to Gpi (internal, deep), this External (superficial) lateral part we abbreviate to GPE – the external part of GP. GP has no functional or evolutionary relation to the putamen, but sits together next to it to form a large structure called the lentiform nucleus, which is actually composed of putamen + globus pallidus). However, don’t have any common functional ancestor – come together by coincidence - good landmark for interpreting sections in the brain.
4. subthalamic nucleus – see thalamus sitting in midline close to 3rd ventricle, subthalamic nucleus (one on each side) sit just beneath the thalamus See Panopto (image, left) – hence the name. Now clinically, these structures can be examined by certain scanning protocols – classic one is a PET scans – can set it up so you can see where dopamine is expressed through the brain. Actually what we’re looking at is the putamen in a transverse section of the brain during a PET scan, and in a normal person you get lots of dopamine signal because the substantia nigra projects to the putamen – see lots of dopamine in the putamen - Putamen is receiving lots of dopamine from the substantia nigra. However in a Parkinson’s disease patient, where there are low levels of dopamine, we see much lower signalling in the PET scan – Parkinson’s disease pt – much less dopamine in their putamen. so We can actually see these regions of the brain in their normal function – can see them functioning, not just static anatomy.}
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