Neuro 4: Motor Systems Disorders

Question 1

which tract is involved in voluntary movement?

Answer 1

lateral corticospinal tract

Question 2

which part of the brain is involved in volunatary movement?

Answer 2

Primary motor cortex.

Question 3

what sx might you see in a

UMN syndrome?

Answer 3

increased tone
brisk reflexes
preserved muscle bulk
voluntary-involuntary dissociation

Question 4

why is there hypertonia?

Answer 4

modulation of gamma motor neurone with net effect being interuption of flow of info to cortical spinal tract -> increased tone from overactive reflexes.

Question 5

What is the hierarchy of planning and execution of movement ?

Answer 5

1. cortex - planning and execution
2. subcortical structures - basal ganglia (planning)
3. ascending/descedning tracts and reflex arcs
4. final common pathway which is the LMN.

Question 6

how is voluntary movement executed?

Answer 6

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

Question 7

which parts of the brain plan voluntary movement?

Answer 7

somatosensory cortex, motor cortex, premotor

Question 8

how does the cortex plan volunatary movement?

Answer 8

selects motor programmes for series of complex muscles, muscle contraction culminating in an action.

Question 9

how does the basal ganglia plan voluntary movement and what else is it involved in?

Answer 9

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

Question 10

what does the cerebellum do?

Answer 10

monitors the trajectory of limb and provides real time feedback from proprioeptors.

Question 11

where does hemiparesis usually arise from?

Answer 11

CNS (need to think hemisphere/brainstem/cord?)

Question 12

what is the rule of 4s?

Answer 12

1. midbrain - III, IV
2. pons - V, VI, VII, VIII
3. medulla - IX, X, XI, XII

Question 13

what differentials would you consider from fast to slow ?

Answer 13

Vascular
toxic
Inflammatory/infective
Neoplastic
Metabolic
Degenerative

Question 14

how do you locate a lesion?

Answer 14

nature of problems- motor / sensory / cognitive
distribution of problems - symmetric / assymetric / proximal / distal
muscle bulk
muscle tone
reflexes

Question 15

describe the course of vascular problem?

Answer 15

rapid severity -> decrease over days

Question 16

describe the course of infective problem?

Answer 16

initial rapid severity over day/ weeks

Question 17

describe the inflammatory of vascular problem?

Answer 17

inflammatory will be over days and remitting and relapsing

Question 18

describe the course of neoplastic problem?

Answer 18

gradual increase over weeks/months

Question 19

describe the course of degenerative problem?

Answer 19

gradual increase over months/years.

Question 20

describe the spinal reflex

Answer 20

-sensory neurone -> relay neurone -> motor neurone.

contraction of flexors and relxation of extensors to remove limb away.

Question 21

when considering the PNS, which parts do you consider?

Answer 21

nerve root
plexus
peripheral polyneuropathy

Question 22

what are the sx of a LMN?

Answer 22

hypotonia
loss of muscle bulk
reduced/absent reflexes

Question 23

which parts are involved in balance?

Answer 23

sensory: vision, vestibular appartus, proprioceptors
these are integrated in the cerebellum and brainstem.
midline structures of the brainstem puts these together.

Question 24

which tracts are involved in balance?

Answer 24

vestibulospinal and reticulospinal tracts to adjust the centre of gravity.