PSY2003 SEMESTER 1 - WEEK 8 Flashcards
what command do motor cortex issue based on
based on integration of sensory input via upper motor neuron
when motor cortex sends commands, where are copies sent, and where do these commands eventually reach
send copy to basal ganglia, cerebellum which feedbacks to cortex via thalamus
reaches lower motor neuron so is continually modulated by basal ganglia and cerebellum
where does the upper motor neuron begin
motor cortex
what are general symptoms of motor cortex damage?
impaired movement
poor high-level coordination
weakness of movement
what is cerebral palsy caused by
damage to motor control brain structures, like motor cortex
when does cerebral palsy originate
pre/perinatally, with 50% cases premature births
most common movement disorder in children, 2/1000 births
name general symptoms of cerebral palsy
stiffness and weakness of muscles
poor coordination
affects upper motor neurons
what type of motor neurons does cerebral palsy affect
upper motor neuron
what causes a stroke
interruption of blood supply to cortex, upper motor neuron affected, symptom depending on extent and location of damage
haemorrhage or ischaemia
what causes cerebral haemorrhage stroke
aneurism and blood toxic to our neural tissue
how can cerebral haemorrhage stroke be prevented
clip aneurism before rupture
maintain low BP, avoid strenuous activities
what causes cerebral ischaemia stroke
interruption of blood supply to part of brain due to blockage of blood vessel, by specific plugs (thrombus, emboli) or cardivascular disease (atherosclerosis)
lack of O2 and glucose cause excitotoxicity, neuronal cell death
what is goal of treatment for cerebral ischaemia strokes
rescue penumbra, via reopening blocked blood vessel
why is fine motor control issues a prominent symptom of motor cortical damage
due to homonculus (large representations for these activities) mean unlikely to be missed by damage and requires coordination across multiple subregions
in a stroke, positioning of middle cerebral artery means most likely to be damaged
what is upper motor neuron syndrome
collection of symptoms resulting from damage to upper motor neuron (in cortex where originate, or in pathway - spinal cord)
what does upper motor neuron syndrome cause
lack of voluntary control of muscles via lower motor neurons
lacking regulation of lower motor neurons/spinal reflex circuits
name test of upper motor neuron syndrome
Babinksi reflex
what babinski reflex indicates a problem
touch from heel, curving round to toes
toes curling under = normal
toes stretch out = issue, “positive response” needing further investigation
(baby shows positive response, is normal)
what is a difficulty in seperating impact of brain damage and cognitive/motor function
individual with cerebral palsy may be misdiagnosed with cognitive impairment = actually just issue with their speech
what are basal ganglia
group of nuclei lying deep within cerebral hemispheres, role in motor control not fully understood, implicated for many disorders
at rest, where do basal ganglia send inhibition and where do they reduce excitation
via thalamus, reduce excitation in motor cortex
when excited, what should happen to basal ganglia (via thalamus)
should be transiently inhibited then disinhibited by thalamus, causing increasing excitation in motor cortex
what disorders can basal ganglia be implicated within
parkinsons, huntingdons, tourettes
how common is parkinsons
2nd most common NDD (after AD)
50% more male>female
what % of PD is genetic
10% of cases due to mutation of one of several genes