Neuro 4: Motor Systems Disorders Flashcards
which tract is involved in voluntary movement?
lateral corticospinal tract
which part of the brain is involved in volunatary movement?
Primary motor cortex.
what sx might you see in a
UMN syndrome?
increased tone
brisk reflexes
preserved muscle bulk
voluntary-involuntary dissociation
why is there hypertonia?
modulation of gamma motor neurone with net effect being interuption of flow of info to cortical spinal tract -> increased tone from overactive reflexes.
What is the hierarchy of planning and execution of movement ?
- cortex - planning and execution
- subcortical structures - basal ganglia (planning)
- ascending/descedning tracts and reflex arcs
- final common pathway which is the LMN.
how is voluntary movement executed?
fibres from PMC coverge at the internal capsule and run through posterior capsule.
the cortical spinal tract crosses at level of medulla
PMC only contributes such as direction and force of muscle not for complex tasks
which parts of the brain plan voluntary movement?
somatosensory cortex, motor cortex, premotor
how does the cortex plan volunatary movement?
selects motor programmes for series of complex muscles, muscle contraction culminating in an action.
how does the basal ganglia plan voluntary movement and what else is it involved in?
feedback loops with large areas of cortex and gauge sitatuion and most strategic action
also connected to limbic system -> facial expression and gesturing of emotion
what does the cerebellum do?
monitors the trajectory of limb and provides real time feedback from proprioeptors.
where does hemiparesis usually arise from?
CNS (need to think hemisphere/brainstem/cord?)
what is the rule of 4s?
- midbrain - III, IV
- pons - V, VI, VII, VIII
- medulla - IX, X, XI, XII
what differentials would you consider from fast to slow ?
Vascular toxic Inflammatory/infective Neoplastic Metabolic Degenerative
how do you locate a lesion?
nature of problems- motor / sensory / cognitive
distribution of problems - symmetric / assymetric / proximal / distal
muscle bulk
muscle tone
reflexes
describe the course of vascular problem?
rapid severity -> decrease over days
describe the course of infective problem?
initial rapid severity over day/ weeks
describe the inflammatory of vascular problem?
inflammatory will be over days and remitting and relapsing
describe the course of neoplastic problem?
gradual increase over weeks/months
describe the course of degenerative problem?
gradual increase over months/years.
describe the spinal reflex
-sensory neurone -> relay neurone -> motor neurone.
contraction of flexors and relxation of extensors to remove limb away.
when considering the PNS, which parts do you consider?
nerve root
plexus
peripheral polyneuropathy
what are the sx of a LMN?
hypotonia
loss of muscle bulk
reduced/absent reflexes
which parts are involved in balance?
sensory: vision, vestibular appartus, proprioceptors
these are integrated in the cerebellum and brainstem.
midline structures of the brainstem puts these together.
which tracts are involved in balance?
vestibulospinal and reticulospinal tracts to adjust the centre of gravity.
