Week 4 Flashcards
What are the 3 types of stroke?
- Ischemic (artery blockage)
- intracerebral haemorrhagic (bleed in brain)
- Subarachnoid haemorrhage (bleed into subarachnoid space)
What is the most common type of stroke?
Ischemic stroke (85% of cases)
What are the symptoms of middle cerebral artery obstruction?
-Neglect
- Apraxia (impaired fine motor functions)
- Anosognosia (not aware they’ve had stroke
- Contralateral arm/leg weakness
What are the symptoms of a anterior cerebral artery stroke?
- Muteness
- Perseveration (get ‘stuck’ on a topic/idea)
- Abulia (lack of motivation to act or think)
- Contralateral arm/leg weakness
What are the symptoms of posterior cerebral artery obstruction?
- Contralateral hemianopia (loss of lateral visual field)
- Memory loss
- Confusion
- Alexia
What are the symptoms of Cerebellar artery obstruction?
Ipsilateral ataxia (clumsiness)
What are lacunar strokes, and what are the symptoms?
Smaller arteries in the brain are obstructed
- Contralateral motor/sensory/both loss
Why are scans need for stroke?
Needed to determine if caused by blockage or bleed as the medications for these two may exacerbate the other if given incorrectly
how can you differentiate between infarcts and bleeds on the CT scans of a stroke patient?
Infarcts take several ours to show up (~8 hrs) and show large dark spots where there has been tissue damage due to lack of blood
Haemorrhages show up immediately as large white patches
how can you tell between a large vessle stroke in the right hemisphere vs the left?
Left
- left gaze preference
- aphasia
Right
- right gaze preference
- neglect
What treatments can be used for stroke?
Thrombolysis (infarcts only)
tPa (blood thinner, for infarcts only)
Surgery (remove clots and clip bleeds)
What are the 3 systems of motor control?
- Corticospinal
- Basal Ganglia
- Cerebellar
What four brain regions are involved with the initiation and activation of muscle movements?
- Primary motor cortex
- Supplementary motor area
- Premotor cortex
- Posterior parietal cortex
What is the role of the primary motor cortex?
To plan and execute movements
What is the role of the supplementary motor cortex?
Plays role in motor planning initiation of movements based on past experience (motor memory)
What is the role of the Premotor cortex?
Regulates posture and is responsive to visual and sensory cues
What is the role of the posterior parietal cortex?
Receives sensory/proprioceptive/visual inputs to determine the position of body parts in space and assess the context in which movements are made
What is responsible for inhibiting the stretch reflex?
Reticulospinal tracts in the spinal cord
What is spacsticity?
A velocity dependant increase in muscle tone
Describe the Direct pathway of the basil ganglia
Striatum inhibits the internal globus palidus, which would normally inhibit the thalamus. Therefore the thalamus sends excitatory signals to the motor cortex
Describe the indirect pathway of the basal ganglia
Striatum inhibits external globus palidus which would normal inhibit the subthalamic nucleus. Therefore the subthalamic nucleus excites the internal globus palidus which inhibits the thalamus. Therefore there is an inhibitory effect on the motor cortex
What are the main neurotransmitters in the basal ganglia pathways?
The cortex uses glutamate to signal the striatum
The rest of the pathways all use GABA
What is the dividing line between the hemispheres of the cerebellum called?
The Vermis
