Peripheral Nerves Flashcards
What are the steps to a peripheral nerve examination?
Introduce General Inspection Gait if lower limb Tone Power Co-ordination Reflexes Sensation
What signs can be seen on general inspection of the upper limb in the peripheral nerve examination?
- How well the pt appears
- Posture
- Habitus
- Hypomimia
- Muscle weakness
- Tremors
- Muscle wasting
- Skin lesions indicating systemic condtions
How is tone tested in the upper limb?
- Test pronator drift
- Test tone in arm by supporting a relaxed arm at each joint and repeatedly extending/flex elbow, pronate/supinate hand, and flex/extend wrist then rotate the wrist.
How is pronator drift tested?
Ask pt to hold arms out fully extended with palms facing upwards and eyes closed.
How can pronator drift be accentuated?
Rebound - push pts wrists down briskly and then quickly let go.
What can pronator drift test show?
Pyramidal weakness if pronator drift and distal flexion.
Upward drift indicates cerebellar lesion.
What signs might we see on rotation of the wrist wen testing tone?
Cogwheel rigidity indicating Parkinson’s disease
What are the MRC grades of muscle power?
5 - full power 4 - Some resistance 3 - active movement against gravity 2 - active movement with gravity eliminated 1 - Flicker/trace 0 - No contraction
What actions should be tested in power in the upper limb?
- Shoulder abduction
- Elbow flexion
- Elbow extension
- Wrist extension
- Finger extension
- Finger flexion
- Finger abduction
- Thumb abduction
What reflexes are tested fr the upper limb?
- Biceps (C5/6)
- Supinator (C4/6)
- Triceps (C7)
How is co-ordination tested in the upper limbs?
- Finger nose test
- Dysdiadokokinesia test with alternating hand slap test
What signs might be elicited on the finger-nose test?
Intention tremor and past-pointing = cerebellar lesion
What are the aspects of sensation that require testing in a peripheral nerve examination?
- Pain (neurotip)
- Light touch (cotton wool)
- Proprioception
- Vibration
- Temperature
How should the pt describe the sensation they feel when testing pain?
Sharp or blunt - this is compared to the sensation of neurotip on sternum.
How is proprioception tested in the upper limb?
Hold proximal phalynx of thumb with one hand an immobilise thumb at base with other hand.
Demonstrate when the thumb is moved up and own, then test the pts proprioception with their eyes closed. This should be done on both sides.
If a pt cannot identify whether their thumb is being moved up or down in proprioception test, where do we test next?
After 3 wrong attempts, move to metacarpophalangal joint, then wrist etc. Up the arm until they get it right.
Where on the arm should we test sensation? Give the dermatomes.
C5 - outer biceps C6 - radial aspect of forearm C7 - Tip of middle finger C8 - base of hypothenar eminence T1 - medial aspect of forearm T2 - medial aspect of upper arm
How is vibration sensation tested in the upper arm?
Start distally then work proximally.
128Hz tuning fork twanged - demonstrated on sternum, then placed on interphalangeal joint of thumb.
Ask if they can feel it and when it stops.
If they can’t feel it, work up via thumb base radial styloid etc.
What are the signs of an upper motor neurone lesion?
Increased tone
Spasticity
Weakness
Brisk reflexes/extensor plantar response
What are the signs of a lower motor neurone lesion?
Wasting Fasciculation Decreased tone Weakness Reduced reflexes
What signs might be elicited from gait inspection on lower limb neurological examination?
- Hemiplegic walk
- Spasticity
- Foot drop
- Ataxia
- Myopathic/waddling
- Parkinsonian gait
- Distal power
- Reduced stability
How is tone tested in the lower limbs?
- Pts relaxes legs flat while lying - roll leg side to side with a had either side of knee.
- Spasticity tested by briskly lifting the knee
- Clonus - wiggle foot to relax it with knee flexed, ten flex ankle and hold flexed position to feel for involuntary beats.
How many beats of the foot (clonus) indicates an UMN lesion?
More than 2 beats.
What is tested when testing power in the lower limb?
- Hip flexion
- Hip extension
- Knee extension
- Knee flexion
- Ankle dorsiflexion
- Ankle plantarflexion
- Big toe extension
What reflexes are tested on lower limb neurological examination?
- Knee (L3/4)
- Ankle (S1/2)
- Plantar/Babinski response
How is co-ordination in lower limb tested?
Heel-shin test
Describe the heel-shin test.
Ask pt to touch heel to contralateral knee, then move heel up and down tibia to contralateral ankle. Repeat 3 times.
How should gait be assessed?
- General walk from one point to another with turn assessment
- Walk on tip-toes
- Romberg test
