Spasticity

Question 1

Modified Ashworth Scale grade?
Catch and release at end range

Answer 1

MAS 1

Question 2

Modified Ashworth Scale grade?
Limb is easily ranged, but there is a catch and resistance to movement for < 50% of the ROM

Answer 2

MAS 1+

Question 3

Modified Ashworth Scale grade?
Limb is easily ranged, but there is catch and resistance to movement for > 50% of ROM

Answer 3

MAS 2

Question 4

Modified Ashworth Scale grade?
Limb is difficult to range

Answer 4

MAS 3

Question 5

Modified Ashworth Scale grade?
Limb is rigid and cannot be fully ranged

Answer 5

MAS 4

Question 6

MOA of baclofen?

Answer 6

centrally acting GABA-B agonist (inhibit synaptic transmission and firing of neurons)

*GABA-B1 - inhibits presynaptic Ca++ influx into the neurons
*GABA-B2 - increases postsynaptic K+ conductance out of the neuron

(ClCaK = GABA-A -> Cl; GABA-B1 -> Ca; GABA-B2 -> K)

Question 7

Withdrawal symptoms/risk of baclofen?

Answer 7

withdrawal: Itchy, bitchy, twitchy

Side effects: sedation, respiratory depression, constipation, lower seizure threshold

Question 8

Clearance of baclofen?

Answer 8

renally cleared, use lower doses in pts w/ CKD or select another agent

Question 9

MOA of dizepam?

Answer 9

centrally acting GABA-A agonist (Cl- channel activator)

GABA-A - increases presynaptic Cl- influx into the neuron

(ClCaK = GABA-A -> Cl; GABA-B1 -> Ca; GABA-B2 -> K) “CLACK”

Question 10

Diazepam side effects?

Answer 10

sedation, respiratory depression

Question 11

Clearance of diazepam?

Answer 11

hepatically cleared (check LFTs)

Question 12

MOA of tizanidine?

Answer 12

centrally acting α-2 agonist (as is clonidine) - inhibits spinal reflex arc

SE: sedation, respiratory depression, lower seizure threshold

Question 13

Withdrawal symptoms of tizanidine?

Answer 13

HTN, tachycardia, anxiety, worsened spasticity

Question 14

Clearance of tizanidine?

Answer 14

hepatically cleared (check LFTs prior to dosing, monitor 1x per week for several weeks)

Question 15

MOA of Dantrolene?

Answer 15

peripherally acting, binds to ryanodine receptors on sarcoplasmic reticulum to inhibit Ca++ influx

Question 16

Clearance of dantrolene?

Answer 16

hepatically cleared (check LFTs prior to dosing, monitor 1x/week for several weeks, continue to check over time)

Question 17

MOA of botulinum toxin?

Answer 17

inhibits presynaptic syntaxin, synaptobrevin and SNAP-25 proteins (neecessary to release ACh into synapse)

Chemodenervation

Question 18

Black box warning of botulinum toxin?

Answer 18

Distant toxin spread can cause dysphagia, respiratory depression

*use caution w/ existing motor neuron diseases (ALS)