Lecture 18

Question 1

briefly explain musician’s dystonia (MD) and its prevalence

Answer 1

affects 2/100 people -> loss of voluntary control of their extensively trained and complex sensorimotor skills

Question 2

what specific type of musicians does MD affect

Answer 2

keyboard players

Question 3

what is MD triggered by

Answer 3

fear of failure, overtraining, chronic pain, high demand for precision

Question 4

what are some factors that predispose someone to MD

Answer 4

higher anxiety levels, later start to training, muscular tension, soft tissue damage, problems with sensorimotor representations

Question 5

true or false - women are more susceptible to having problems with sensorimotor representations

Answer 5

false - males are more likely

Question 6

true or false - males are more likely to be diagnosed with MD

Answer 6

true

Question 7

list the 4 major changes from MD

Answer 7

1. reduced motor system inhibition
2. altered sensory integration
3. impaired sensorimotor integration
4. impaired network connectivity

Question 8

what does EMG recordings demonstrate about reduced inhibition in the motor system

Answer 8

patients with MD have prolonged muscle firing or spillover activation of nearby muscles

Question 9

where does reduction in inhibition occur in the brain

Answer 9

cortical, subcortical and spinal level

Question 10

explain the evidence of reduced inhibition at the spinal level

Answer 10

reduced inhibition at antagonist muscle groups involved with co-contraction -> agonist (contractions) and antagonist (relaxing and lengthening)

Question 11

explain the evidence of reduced inhibition at the cortical level

Answer 11

this can obtained through TMS in both hemispheres -> induced electrical current -> EPSP -> nerve impluse to target organ
- increased difficulty stopping a sequence of actions halfway through the execution

Question 12

describe the behavioral evidence for altered sensory integration

Answer 12

can be found in the form of difficulty in detecting spatial and temporal separation of subtly presented stimuli

Question 13

true or false - altered sensory integration is apparent in the somatosensory cortex

Answer 13

true

Question 14

where is the receptive field of a cortical neuron

Answer 14

area on the skin where tactile stimulation either excites or inhibits a cell

Question 15

what was the relationship between training and receptive fields in the fingers

Answer 15

training increased number of receptive fields in the distal tips of the phalanges of digits 2,3 and 4

Question 16

what happens to individuals with impaired sensorimotor integration

Answer 16

people with MD show improvements to fine motor control under experimental manipulations to somatosensory input

Question 17

true or false - increasing tactile stimulation can lead to improvements in dystonic symptoms

Answer 17

false - increasing stimulation can lead to worse symptoms

Question 18

what does combining vibrations with TMS do

Answer 18

decrease agonist muscle activity and increase antagonist muscle activity

Question 19

changes in what circuits implicate abnormal network connectivity

Answer 19

1. connecting the basal ganglia and cerebellum
2. region in premotor cortex -> transmission of information
3. sensorimotor and frontal-parietal areas

Question 20

what are the 3 ways for MD to be treated

Answer 20

1. exercises to increase inhibition of overactive motor groups
2. injecting botox to weaken muscles that are overactive
3. transcranial direct current stimulation

Question 21

example how transcranial direct current stimulation is done -> study was done

Answer 21

applied to bilateral motor cortices of pianists -> can increase activation in one hemisphere and decrease activation in the other

Question 22

what is the difference between anodal and cathodal stimulation

Answer 22

anodal -> increase activation
cathodal -> decrease activation

Question 23

define neural crosstalk

Answer 23

motor commands can shift from one hemisphere to another via the corpus callosum

Question 24

regarding the bimanual mirrored finger movements study, what was found

Answer 24

improvements in performance that remained four days after the stimulation -> larger benefits for those who had extreme symptoms