Case 5 summary
General ILOs
- To demonstrate basic knowledge of the dysfunctions arising from lesions to
upper and lower motor neurones
- To demonstrate knowledge of the structural and functional organisation of
sensory and motor pathways to and from the cerebral cortex
Upper motor neurons
Upper motor neurons originate in the brain and brainstem and carry information about
desired movements or other responses. These descend from higher centres to influence local
circuits (lower motor neurons) in the brainstem and spinal cord.
Upper motor neuron dysfunction is initially marked by flaccidity of muscles (hypertonia) on
the contralateral side of the body and face. After a few days, the circuits regain function but
are marked with significant changes:
LMN
UMN damage damage
Weakness Weakness
Spasticity Hypotonia
Hypertonia Hyporeflexia
Hyperreflexia Fasciculations
Positive Muscle
Babinski atrophy
Lower motor neurons
Lower motor neurons regulate the activity of muscles or glands. There are three broad types
of lower motor neurons:
Somatic motor: control movement and muscle tone.
Special visceral motor: supply muscles in the head and neck
General visceral motor: involved in the autonomic nervous system
Within the spinal cord, neurons that innervate axial musculature are medial. As you travel
laterally, the lower motor neuron pools innervate progressively more lateral muscles.
1
Guillaume Antem – MBChB Y2
, - To demonstrate basic knowledge of the main theories of memory
The models of memory are as follows (in chronological order):
Three stages model
o Perception
o Storage
o Retrieval
Multi-store model
o Information is detected by sensory organs and relayed to sensory memory.
o If attended, information enters short term memory (STM).
o If rehearsed, STM transfers to long term memory (LTM).
o Skipping of either of the above results in memory displacement/decay.
Working memory model
o Memory is encoded (sensory memory) and filtered through a central
executive.
o The central executive co-ordinates sub-systems (phonological loop and visual-
spatial sketchpad).
o The phonological loop is involved in speech perception and production
o The visuo-spatial sketchpad stores and processes information in visual or
spatial forms (used for things like navigation)
There are different types of memory:
Procedural – relates to cognitive and motor skills
Declarative – involved in semantic (meaning) and episodic (autobiographical)
memories
Implicit – non-conscious learning from experiences
Explicit – involved in remembering, requires attention
Recall – reproducing information to which you were previously exposed
2
Guillaume Antem – MBChB Y2
, Faithful reproduction of previous learned ‘event’ – cue independent
Recognition – Realising a stimulus is one you have seen or heard before
Connecting present stimuli with previous ‘event’ – cue dependent
- To demonstrate knowledge of the repair processes that follows a cerebrovascular
accident (CVA)
In cases of ischaemic stroke, tissue ischaemia (and eventual infarction) leads to apoptosis
(initiated by caspase-3). This results in glutamate release/leak from dead cells. The glutamate
reduces the effect of Bcl-2, which is anti-apoptotic. This result in activation of caspase-3 in
neighbouring cells. A snowball effect occurs, resulting in the formation of a necrotic core and
a penumbra.
Tissue damage (via necrosis or apoptosis) stimulate:
Glial growth and proliferation – glial scarring, contains the damaged site.
Microglial activity, which inhibits growth of neurons within the damaged site.
The glial scarring prevents re-establishment of axons across the site of injury. Additionally,
within the scar, astrocytes release inhibitory molecules which prevent axon growth. This
results in a ‘dead zone’ at the focal site of the original stroke.
- To demonstrate knowledge of the structure, functional organisation and vascular
supply of the cerebral cortex
The cerebral arteries supply the cerebral cortex.
The anterior cerebral artery travels in the inter-hemispheric fissure to sweep back and over
the corpus callosum. It supplies the cortex on the anterior medial surface and bifurcates into:
Pericallosal artery
Callosomarginal artery
The middle cerebral artery travels via the Sylvian fissure where it bifurcates into:
Superior division – supplies cortex above the Sylvian fissure, including the lateral
frontal lobe.
Inferior division – supplies cortex below the sylvian fissure, including the lateral
temporal lobe.
The posterior cerebral artery arises from the top of the basilar artery and curves back to the
inferior and medial temporal lobes. It includes the inferior and medial temporal and occipital
cortices
3
Guillaume Antem – MBChB Y2
General ILOs
- To demonstrate basic knowledge of the dysfunctions arising from lesions to
upper and lower motor neurones
- To demonstrate knowledge of the structural and functional organisation of
sensory and motor pathways to and from the cerebral cortex
Upper motor neurons
Upper motor neurons originate in the brain and brainstem and carry information about
desired movements or other responses. These descend from higher centres to influence local
circuits (lower motor neurons) in the brainstem and spinal cord.
Upper motor neuron dysfunction is initially marked by flaccidity of muscles (hypertonia) on
the contralateral side of the body and face. After a few days, the circuits regain function but
are marked with significant changes:
LMN
UMN damage damage
Weakness Weakness
Spasticity Hypotonia
Hypertonia Hyporeflexia
Hyperreflexia Fasciculations
Positive Muscle
Babinski atrophy
Lower motor neurons
Lower motor neurons regulate the activity of muscles or glands. There are three broad types
of lower motor neurons:
Somatic motor: control movement and muscle tone.
Special visceral motor: supply muscles in the head and neck
General visceral motor: involved in the autonomic nervous system
Within the spinal cord, neurons that innervate axial musculature are medial. As you travel
laterally, the lower motor neuron pools innervate progressively more lateral muscles.
1
Guillaume Antem – MBChB Y2
, - To demonstrate basic knowledge of the main theories of memory
The models of memory are as follows (in chronological order):
Three stages model
o Perception
o Storage
o Retrieval
Multi-store model
o Information is detected by sensory organs and relayed to sensory memory.
o If attended, information enters short term memory (STM).
o If rehearsed, STM transfers to long term memory (LTM).
o Skipping of either of the above results in memory displacement/decay.
Working memory model
o Memory is encoded (sensory memory) and filtered through a central
executive.
o The central executive co-ordinates sub-systems (phonological loop and visual-
spatial sketchpad).
o The phonological loop is involved in speech perception and production
o The visuo-spatial sketchpad stores and processes information in visual or
spatial forms (used for things like navigation)
There are different types of memory:
Procedural – relates to cognitive and motor skills
Declarative – involved in semantic (meaning) and episodic (autobiographical)
memories
Implicit – non-conscious learning from experiences
Explicit – involved in remembering, requires attention
Recall – reproducing information to which you were previously exposed
2
Guillaume Antem – MBChB Y2
, Faithful reproduction of previous learned ‘event’ – cue independent
Recognition – Realising a stimulus is one you have seen or heard before
Connecting present stimuli with previous ‘event’ – cue dependent
- To demonstrate knowledge of the repair processes that follows a cerebrovascular
accident (CVA)
In cases of ischaemic stroke, tissue ischaemia (and eventual infarction) leads to apoptosis
(initiated by caspase-3). This results in glutamate release/leak from dead cells. The glutamate
reduces the effect of Bcl-2, which is anti-apoptotic. This result in activation of caspase-3 in
neighbouring cells. A snowball effect occurs, resulting in the formation of a necrotic core and
a penumbra.
Tissue damage (via necrosis or apoptosis) stimulate:
Glial growth and proliferation – glial scarring, contains the damaged site.
Microglial activity, which inhibits growth of neurons within the damaged site.
The glial scarring prevents re-establishment of axons across the site of injury. Additionally,
within the scar, astrocytes release inhibitory molecules which prevent axon growth. This
results in a ‘dead zone’ at the focal site of the original stroke.
- To demonstrate knowledge of the structure, functional organisation and vascular
supply of the cerebral cortex
The cerebral arteries supply the cerebral cortex.
The anterior cerebral artery travels in the inter-hemispheric fissure to sweep back and over
the corpus callosum. It supplies the cortex on the anterior medial surface and bifurcates into:
Pericallosal artery
Callosomarginal artery
The middle cerebral artery travels via the Sylvian fissure where it bifurcates into:
Superior division – supplies cortex above the Sylvian fissure, including the lateral
frontal lobe.
Inferior division – supplies cortex below the sylvian fissure, including the lateral
temporal lobe.
The posterior cerebral artery arises from the top of the basilar artery and curves back to the
inferior and medial temporal lobes. It includes the inferior and medial temporal and occipital
cortices
3
Guillaume Antem – MBChB Y2
