Neuro Exam: Motor Impairments

Positive Signs

Excess/abnormal muscle activity

Spasticity

Velocity-dependent increase in tone.

Assess with Modified Ashworth

Rigidity

Increased tone independent of velocity.

Assess with rigidity scale

Hypotonia

Decr. muscle tone & reflexes

Assess PROM, palpation

Negative signs

Weakness/paresis, muscle atrophy. Decreased force

UMN lesion (stroke, MS)

Spasticity, weakness, synergy domination, hyper reflexes

Basal Ganglia lesion (e.g. Parkinson’s, Huntington’s)

Bradykinesia, rigidity, resting tremor

Cerebellar lesion (cerebellar stroke, tumor, degeneration)

Ataxia, dysmetria, intention tremour

Corticospinal tract lesion (stroke, MS)

Loss of fractioned movement, weakness, impaired dexterity

Premotor Cortex lesion

Poor motor planning, coordination

How would you assess tone?

MAS, ROM, obs, palp

How would you assess reflexes?

Patellar tendon, babinski

How would you assess coordination?

Finger-nose, heel-shin

How would you assess strength?

MMT, dynamometer, task-specific