Muscle Tone

Question 1

What causes spasticity?

Answer 1

Hyper excitability of stretch reflex

• UMN lesion; descending motor pathways from the cortex (pyramidal tracts) or BS (M and L vestibulospinal tracts, dorsal reticulospinal tract)
• corticospinal tracts- moreso lateral
• lesion produces disinhibition of spinal reflexes with hyperactive tonic stretch reflexes or a failure of reciprocal inhibition
• Hyperexcitability of alpha motor neuron pool

Question 2

What Dx’s do you most often see spasticity?

Answer 2

1. CP
2. MS
3. SCI (even at same level)

Question 3

What is chronic spasticity associated with?

Answer 3

1. contracture
2. abnormal posturing
3. deformity
4. functional limitations
5. disability

Question 4

during rapid movement, initial high resistance (spastic catch) followed by a sudden inhibition or letting go of the limb (relaxation) in response to a stretch stimulus

Answer 4

Clasp-knife response

Question 5

cyclical, spasmodic alternation of muscular contraction and relaxation in response to sustained stretch of a spastic muscle

Answer 5

clonus

Question 6

how do you elicit ankle clonus? how do you stop it?

Answer 6

quick stretch of PF (put into ankle DF)

• leg in slight flexion
• document if any beats are present, if you can count them, how many
• stop = sustained pressure on the foot

Question 7

Resistance to passive movements involving both agonist and antagonist muscles; both directions whether or not the muscle is on stretch

Answer 7

rigidity

- observed in PD

Question 8

Indicates Corticospinal lesion in the BS btwn the Superior Colliculus and the Vestibular Nucleus

Answer 8

Decerebrate

- abnormal extensor posturing

Question 9

Indicates Corticospinal Tract lesion at the level of the diencephalon (above the superior colliculus)

Answer 9

Decorticate

- abnormal flexion posturing

Question 10

Impaired tone; Hyperkinetic movement disorder characterized by tone and involuntary repetitive twisting movements in large portions of body

Answer 10

Dystonia

Question 11

What are the causes of dystonia?

Answer 11

1. CNS lesion - Usually BG
2. Genetic (Primary Idiopathic Dystonia)
3. Neurodegenerative Disorders - PD; Wilson’s Disease = if on excessive l-DOPA
4. Metabolic Disorders - Amino Acid or Lipid disorders

Question 12

What are they types of dystonia?

Answer 12

1. Focal = spastic torticollis, isolated writer’s cramp

2. Segmental = toritcollis, dystonic posturing of the arm

Question 13

Diminished resistance to passive movement; Decreased or absent stretch reflexes; Hyperextension of joints common

Answer 13

hypotonia

- LMN lesion and spinal shock

Question 14

What are the causes of hypotonia?

Answer 14

1. lesions of ANT horn cells
2. PN Lesions - Peripheral neuropathy, Cauda Equina Lesion. andRadiculopathy
3. Cb Lesions = can produce mild decreases in tone and weakness
4. UMN Lesions = cause temporary hypotonia = Spinal Shock or Cerebral Shock, depending on lesion location

Question 15

When there is a problem with tone, what area of the brain is often involved?

Answer 15

BG

Question 16

What is tone affected by?

Answer 16

1. Medication*
2. Environmental temperature*
3. State of CNS (arousal and alertness)* – esp anxiety – if pt has this then can definitely increase spasticity
4. Volitional movement
5. Stress and anxiety
6. Position
7. Health

Question 17

What is the procedure for assessing tone?

Answer 17

1. Palpation of the muscle belly
2. Passive motion and speed up as you go
3. All limbs/joints
4. Compare right and left
5. Compare UE’s and LE’s
6. Cue your pt to stay relaxed

Question 18

What are the levels on the modified ashworth scale?

Answer 18

0 = No increase in muscle tone 
1 = Slight increase in muscle tone, manifested by a catch and release or by minimal resistance at the end of the range of motion when the affected part(s) is moved in flexion or extension 
1+ = Slight increase in muscle tone, manifested by a catch, followed by minimal resistance throughout the remainder (less than half) of the ROM 
2 = More marked increase in muscle tone through most of the ROM, but affected part(s) easily moved 
3 = Considerable increase in muscle tone, passive movement difficult 
4 = Affected part(s) rigid in flexion or extension

Question 19

What are the grades for DTRs?

Answer 19

0 = absent
1+ = present but depressed
2+ = normal
3+ = brisk
4+ = very brisk, hyperactive, w/clonus

Question 20

Abnormal obligatory movements that emerge w/spasticity [w/someone w/CNS disorder]; Inability to perform isolated movements at each joint, and will move in a certain pattern

Answer 20

Synergistic pattern

• Ex: Stroke – reach out to grab something, & elbow flexes towards trunk – can’t stop this
• PT records when the patterns occur, under what circumstances, and what variations are observed; Under moments of increased stress, increased fatigue, etc
• decrease in synergy = condition improving

Question 21

How can you test strength in neuro patients who cannot isolate movements?

Answer 21

observe active movements

1. Squats
2. Sit/stands
3. Heel raises
4. Toe raises
   - can they do it? how long? how far down can pt go? what does the movement look like?