Neurological Examination : Motor Function Flashcards
What do you check for in motor function ?
Muscular atrophy
Involuntary movement
Assessing muscle tone
Assessing muscle strength
Compare left/right
Compare to what is expected based on the age, build of the patient
What is muscle tone ?
The tension in the muscle felt when a relaxed patient move
What is the scale to assess muscle strength ?
5 = normal strength
4 = movement against gravity and resistance possible but less than expected
3 = movement against gravity possible but not against resistance
2 = movement possible but not enough to overcome gravity
1 = slight contraction without movement
0 = no contraction
What are the types of involuntary movement ?
Fasciculation = muscle twitch. Spontaneous contraction and relaxation involving fine muscle fibers
Dystonia = repetitive/twisting movement. Can affect several part of the body.
Chorea = sudden, uncontrollable jerky movement of arms, legs, facial muscles
Tremors = shaking movement in one or more parts of the body, often in hands
How do you examine upper limb muscle tone ?
Supine relaxed patient :
- grasp forearm at the wrist
- place finger on biceps tendon
- extend and flex patient elbow slowly then faster
How do you examine lower limb muscle tone ?
Supine relaxed patient :
- grasp thigh and lower leg
- extend and flex the hip and knee a few times
What are the general rules to test muscular strength ?
Determine for each muscle their strength on the MRC scale (0-5).
Ask patient to tense muscle examined.
Test at a resistance angle less than the maximum angle of contraction.
What do you do if a latent paralysis of the arm muscle is suspected ?
Barré test :
- seated patient with eyes closed
- arms extended in front, palms facing up, finger spread
- during max 1 min
Positive test => hand pronate or arm drop
What do you do if latent paralysis of the leg muscle is suspected ?
Leg drift test / Mingazzi test :
- flex supine patient leg at the hip and knee joints
- eyes closed, they try to keep them in the air
Positive test => leg drop and touch the examination table
What is the clinical significance of muscular atrophy and asymmetry ?
Means a long standing loss of strength.
- clues to disorder of peripheral nerve or muscle
What are the different types of hand deformities ?
Claw hand => ulnar nerve lesion
Wrist drop => radial nerve lesion
Preacher’s hand / hand of benediction => median nerve lesion
What is the clinical significance of fasciculation ?
It can cause the skin to wrinkle like worms under the skin.
Often benign if it follows exertion or isolated. But combined with atrophy and loss of strength => anterior horn cell disorder.
What are the different types of tremors ?
Resting tremors => Parkinson disease
Postural tremor
Intention tremor => while performing intentional movement
What causes hypotonia ?
Caused by impulse conduction => severe peripheral nerve injury or pyramidal tract in acute stage injury
Caused by reduced transmission to the muscle
What are the types of hypertonia ?
Rigidity : constant resistance across the entire range of motion, sometimes with tremors.
=> extrapyramidal system disorder
Spasticity : increasing resistance that suddenly drop when more pressure is applied
=> pyramidal tract disorder
