Neurologic System

The Motor System and the Cerebellar Function

Motor Pathways & Type of Movements

• Corticospinal or Pyramidal Tract– Voluntary, skilled, discrete, purposeful (writing)

• Extrapyramidal Tracts– Maintain muscle tone and control body movements

(walking)

• Cerebellar System– Coordinates movement, maintains equilibrium and

posture….Operates on subconsious level

Question for Thought

• Describe 3 major motor pathways in the CNS including the type of movements mediated by each?

Figure 21-1. p. 688.

Chapter 21

• Cerebral Cortex

Upper and Lower Motor Neurons

• Upper motor neurons• All descending motor neurons that impact on the

lower motor neurons

• Located in the CNS

• Convey impulses from motor areas of cerebral cortex to lower motor neurons in the cord

• Diseases = CVA, Cerebral palsy, Multiple sclerosis

Upper and Lower Motor Neurons

• Lower motor neurons• In the peripheral nervous system

• 12 cranial nerves

• 31 pairs of spinal nerves and all branches

• Final direct contact with the muscles

• Movement translated into action

• Reflex arc

• Examples = cranial nerves, spinal nerves

• Diseases = spinal cord lesions, poliomyelitis, ALS

Question for Thought

• Differentiate an upper motor neuron from a lower motor neuron?

Subjective Data

• In the Interview– Any shakes or tremors in the hands or face?

• Worsen with anxiety, fatigue

• Relieved with activity, alcohol

• ADL’s affected

– Weakness• Where? When? Why?

Subjective Data

• Incoordination• Balance, falling,

• Legs give out

• Clumsy

• Numbness/ Tingling• Describe ( pins and needles)

• Significant past history • TIA’s, Atrial Fib.

Assessment of Motor System

• Body position

• Involuntary movements

• Muscle size ( bulk)

• Muscle tone

• Muscle strength

Body Position

• Observe during movement

• Observe at rest

Involuntary Movements

• Tremors, tics, fasciculations, myoclonus

• Note: • Location

• Quality

• Rate

• Rhythm

• Amplitude

Involuntary Movements

• Note the involuntary movement in relation to :

• Posture

• Activity

• Fatigue

• Emotion

• Other factors

Terms to Describe Movement

• Flexion

• Extension

• Abduction

• Adduction

• Pronation

• Supination

More Terms for Movement

• Circumduction

• Inversion

• Eversion

• Rotation

• Protraction

Terms of Movement Continued

• Retraction

• Elevation

• Depression

Muscle Size

• Compare size and contour– Atrophy

• Unilateral/bilateral

• Proximal/distal

Muscle Tone

• A relaxed muscle maintains a slight residual tension referred to as muscle tone.

• Hypo tonic, Flaccidity.

• Spasticity.

• Lead-pipe rigidity.

Muscle Strength

• Test muscle strength by asking the client to move actively against your resistance or to resist your movement.

• A muscle is strongest when shortest and weakest when longest.

Terms to Describe Strength

• Weakness (paresis)

• Paralysis (plegia)

• Hemiparesis

• Hemiplegia

• Paraplegia

• Quadriplegia

Grading Muscle Strength

• Scale 0-5

• 0 - no muscular contraction

• 1 – slight contraction

• 2 – Full ROM, gravity eliminated

Grading Muscle Strength

• 3 – Full ROM against gravity• 4 – Full ROM against gravity, some

resistance• 5 – Full ROM against gravity full resistance

without evident fatigue = Normal Muscle Strength

Cerebellar Function

• Balance tests– Gait

• Observe normal walk

• Tandem Walking ( heel – to- toe )

• Romberg Test (stand, feet together, arms at side, close eyes)

• Shallow knee bend or hop on one leg

• What findings would you expect to see when assessing gait and balance in an older adult?

Cerebellar Function

• Coordination and Skilled Movements– RAM ( Rapid alternating movements)

• Pat Knees

• Thumb to each finger

• Finger to finger

• Finger to nose

• Heel to shin

Question for Thought

• List and describe 3 tests of cerebellar function?

Charting Sample

• For Normal Muscle Strength (objective)– Able to maintain flexion against resistance and

without tenderness

• For Motor ( objective)– No atrophy, weakness or tremors. Gait smooth

and coordinated, able to tandem walk, negative Romberg. RAM, finger-to-nose smoothly intact