Control of movement Flashcards
label the image (areas)
supplementary motor cortex function
coordination of complex learned responses (throwing, typing)
coordination of large muscles for posture
primary motor cortex function
intentions produce output to spinal cord that yield motor outcomes
primary somatosensory cortex
touch input from entire body (homunculus)
some output to prefrontal and spinal cord
posterior parietal cortex
integrates body position and location of external objects
output goes to prefrontal cortex
primary visual cortex
identification of colours, lines edges, depth
brainstem function
species-specific behaviours
origin of motor neurons to spinal cord
cerebellum function
motor learning
fine correction of speed and distance of ongoing movements
prefrontal cortex function
overall planning of movements
specifies goal of movement, not details
premotor cortex function
organises semences of movements
location of some mirror neurons
label image of motor cortex
motor pathways
corticospinal
corticobulbar
label the 2 tracts
signs of an upper motor neurone UMN lesion
weakness
no atrophy but mild may develop due to disease
no fasciculation’s
increased reflexes
increased tone
signs of a lower motor neurone LMN lesion
weakness
atrophy
fasciculation’s
decreased reflexes
decreased tone
3 different paralysis patterns
quadriplegia
paraplegia
hemiplegia
what is in the image
quadriplegia
what is in the image
paraplegia
what is in the image
hemiplegia
label the anatomy of the cerebellum
vermis function
has a little homunculus or representation of the body
trunk in the middle of the vermis, legs and arms in the paravermal area (intermediate zone)
gets lots of sensory input
to do with balance
vermis lesions lead to loss of axial or truncal balance
alcohol is a typical cause and on scan will see vermis atrophy
lesion in cerebellar hemispheres
lead to same side incoordination of the limb
e.g. ipsilateral unlike motor cortex supplies contralateral hand
corticocerebellum
cortex and pontine connections, thalamus, visually guided movements
spinocerebellum
lots of proprioceptive information, vermis and paravermal
vestibulocerebellum
equivalent of floculonodular lobe
balance and ocular fixation
purpose of the cerebellum
tone
posture and balance
coordination
all subconscious
motor learning
movement disorder is caused by what
cerebellar dysfunction
cerebellar dysfunction
impairs motor function of the body ipsilateral to the lesion
most apparent on movement not at rest
no numbness/paralysis
ataxia
defect in force/range/direction/rate of movement
move more consciously than normal
past pointing
overshoot touching object with finger
intention tremor
more tremor of hand towards a target
dysdiadochokinesis
difficult repetitive supin/pronation
scanning speech/decomposition of movement
examples of movement disorders caused by cerebellar function
ataxia
past pointing
intention tremor
dysdiadochokinesis
cerebellum location
back of the brain
immediately inferior to the occipital and temporal lobes
within the posterior cranial fossa
separated from loves by tentorium cerebelli (dura mater)
lies at same level and posterior to the pons, separated by the 4th ventricle
rhombencephalon
white and grey matter
white matter has deep nuclei
function of the cerebellum
doesn’t initiate movement
contributes to coordination, precision and accurate timing
receives input from sensory systems of the spinal cord and from other parts of the brain including cerebral cortex and integrates these inputs to fine tune motor
what does the image show
cerebellar lesion
functions of the basal ganglia
plays an important role in planning and programming of movement by selecting and inhibiting specific motor synergies
cognitive processes (caudate nucleus specifically) including the awareness of the body orientation in space
ability to adapt behaviour as task requirements change and motivation
neurotransmitters and pathways in basal ganglia
categories of basal ganglia disorders
hyperkinetic
hypokinetic
hyperkinetic basal ganglia disorders
athetosis
chorea
hemiballismus
resting tremor
hypokinetic basal ganglia disorders
bradykinesia
rigid increase in muscle tone
athetosis
slow writhing hands and fingers
chorea
fidgety distal limb
hemiballismus
sudden flinging/chorea
resting tremor
rhythmic oscillatory movement
classic triad of Parkinson’s symptoms
bradykinesia- slowness
rigidity- stiffness, increased tone
tremor- pill rolling, 4-6 Hz, resting
also postural instability
what is seen in cut section of the midbrain in Parkinsons
diminished substantially nigra
what is Parkinsonism
refers to group of disorders that produce abnormalities of basal ganglia function
most common form of Parkinsonism
parkinsons disease or idiopathic Parkinsonism
cause of secondary Parkinsonism
virus
toxins
drugs
tumours
Parkinsonism plus syndromes
refer to those conditions that mimic PD is some respects
symptoms are caused by some other neurodegenerative disorders
typical presentation of parkinsons
gradual onset
tremor at rest usually first noticed in the hands
stiffness and slowness of movement
difficulty initiating movements
falls but not frequent early on
smaller hand writing
signs of Parkinsons disease
abnormal stooped posture leads to festinating gait, shorter stride length and greater speed
small steps, shuffling especially on turns
parche a petit pieds
stooped
slow
examination of parkinsons and Parkinsonism
face- expressionless, mask like, reduced blinking
motor features of parkinsons disease
cogwheel type, mostly upper limbs: rigidity with superimposed tremor, felt as tightness, stiffness of muscles, catch release catch release like movement
stiffness in: neck, trunk, shoulders
posture: head bowed, body bent forward, arms flexed, thumbs turned into palms, knees bent
parkinsons examinations
monotonous speech
slurred
asymmetrical resting pillrolling tremor
increased tone cog wheeling
dyskinesias
power normal
reflexes normal
sensation normal
coordination normal but may be slow
gait
stooped posture
shuffling
reduced arm swing
difficulty turning
draw spiral
open and close hands
