Peripheral Nerves - Notes from Year 3 PDF

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Notes from Year 3...

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PERIPHERAL NERVE EXAMINATION

1. INTRODUCTION 2. GENERAL INSPECTION 3. PALPATION 4. UPPER LIMB TONE 5. UPPER LIMB POWER 6. UPPER LIMB REFLEXES 7. UPPER LIMB COORDINATION 8. UPPER LIMB SENSATION 9. LOWER LIMB TONE 10. LOWER LIMB POWER 11. LOWER LIMB RELEXES 12. LOWER LIMB COORDINATION 13. LOWER LIMB SENSATION 14. COMPLETE THE EXAMINATION

1. INTRODUCTION a. Name b. Explain c. Consent d. Wash hands e. Position patient f.

Exposure and Privacy

2. GENRAL INSPECTION a. Around the bed Eg: Walking aids, Catheters

b. Asymmetry Muscle bulk 1. Lower motor neurone lesions may cause wasting of muscles 2. Longstanding or developmental upper motor neurone damage can result in disuse atrophy

A picture of muscle wasting

http://www.bubblews.com/news/551846muscle-atrophy-after-injury

A picture ofa foot with pes cavas deformity

c. Deformity Clawing of hand Pes cavus

d. Position Pyramidal – flexed arm, extended leg

e. Fasciculation

http://en.wikipedia.org/wiki/File:Cha rcot-marie-tooth_foot.jpg

Irregular ripples or twitches under skin overlying muscles at rest occurring in lower motor neurone disease

f.

Tremor Oscillatory contraction and relaxation of muscle describe d according to: 1. Speed (fast or slow) 2. Amplitude (fine or coarse) 3. Maximal at rest, on maintaining a posture or on active movement

g. Other involuntary movements

3. PALPATION a. Wasted muscles feel ‘flabby’ b. Hypertrophic muscles in muscular dystrophy feel ‘doughy’ c. Inflammation of muscles may be accompanied by tenderness and feel ‘woody’

4. ASSESS UPPER LIMB TONE a. “Do you have any pain in the shoulder or arm? Relax your arm/ go floppy” b. Passively move each joint through its full range of movement i. Cirumduct the shoulder ii. Flex and extend elbow iii. Pronate and supinate the forearm iv. Circumduct the wrist

Abnormalities of tone

c. Clonus Rhythmic contractions evoked by a sudden stretch of muscles which when sustained (>3 beats) indicated upper motor neurone damage

5. ASSESS UPPER LIMB POWER a. Test the following against resistance and grade power according to MRC Score i. Abduction of shoulders (C5) ii. Adduction of shoulders (C6, C7, C8) iii. Flexion at the elbow (C5, C6) iv. Extension at the elbow (C6, C7, C8) v. Flexion/ Extension at the wrist (C7, C8) vi. Flexion/ Extension of fingers (C7, C8) vii. “Squeeze my hand” (C7, C8, T1) viii. Finger abduction (C8, T1) ix. Opposition of thumb (C8, T1)

6. ASSESS UPPER LIMB REFLEXES a. Biceps (C5, C6) b. Triceps (C6, C7) c. Supinator (C5, C6) d. To reinforce upper limb reflexes ask patient to clench teeth Reflex grading

7. ASSESS UPPER LIMB COORDINATION a. Rapid alternating movements i. Ask patient to repeatedly strike one hand with the other alternating palmar and volar surfaces with the striking hand as fast as possible ii. Dysdiadochokinesis is a feature of cerebellar disorders and is also seen in Parkinson’s

b. Finger-nose test i. Ask the patient to touch his nose with their forefinger and then touch your finger held just within the patient’s arm’s reach, repeating this as quickly as possible and changing the position of the target finger ii. Past-pointing/ dysmetria and intention tremor are signs of a cerebellar lesion

Finger nose test

http://emj.bmj.com/cgi/content-nw/full/22/2/128/F10

8. ASSESS UPPER LIMB SENSATION a. Light touch (Dorsal columns) i. Us e a fine wisp of cotton to touch the skin lightly and ask the patient to respond “yes” whenever a touch is felt while their eyes are closed ii. Compare symmetrical areas on both sides and move from proximal to distal 1. C4 – Top of shoulder 2. C5 – Lateral shoulder 3. C6 – Radial aspect of forearm 4. C7 – Middle finger 5. C8 – Little finger

6. T1 – Ulnar aspect of forearm Diagram of Dermatomes

b. Pin-prick (Spinothalamic) i. Using a neurotip ask the patient close their eyes and say “yes” if they feel sharp comparing symmetrical areas as above

c. Vibration sense (Dorsal columns) i. Place a low pitched tuning fork (128Hz) on the sternum and ask if the patient feels it buzzing ii. Repeat over the base over the distal interphalangeal joint of the patient’s thumb iii. If vibration sense is absent move proximally until sensation returns: 1. Proximal interphalangeal joint 2. Radial or ulnar styloid 3. Olecranon 4. Clavicle iv. Keeping their eyes closed ask the patient to tell you when the vibration stops

d. Joint position sense (Dorsal columns) i. Grasp the DIPJ of the thumb at the medial and lateral edges between two fingers ii. Show the patient “up” and “down” iii. With the patient’s eyes closed ask the patient to identify the direction you move the thumb iv. Move proximally in sensation is impaired

e. Temperature (Spinothalamic) i. Often omitted if pin-prick sensation normal as stimuli travel through same pathways as pain ii. Use tuning fork heated or cooled in hot/ cold water

9. ASSESS LOWER LIMB TONE a. Roll the knee from side to side b. Lift leg briskly off the bed from behind the knee and watch the heel to see if it leaves the bed

c. Clonus >3 beats is abnormal

Checking ankle clonus

http://geekymedics.com/2010/10/02/lower-limbneurological-examination/

10. ASSESS LOWER LIMB POWER a. Hip flexion (L1,2,3) “Lift your leg straight up off the bed and don’t let me push it down” b. Hip extension (S1) “Push your leg down into the bed” c. Knee flexion (S1) “Pull your heel towards your bottom” d. Knee extension (L3, L4) “Kick your leg straight against me” e. Dorsiflexion (L4, L5) “Cock your foot up and don’t let me push it down” f.

Plantar flexion (S1) “Push your foot down against me”

11. ASSESS LOWER LIMB REFLEXES a. Knee jerk (L3, L4) b. Ankle (S1, S2)

c. Plantar (L5, S1, S2) – Babinski reflex d. To reinforce the patient can interlock fingers and pull one hand against the other immediately before striking the tendon

Planter reflex

http://upload.wikimedia.org/wikipedia/commons/2/2e/B abinski%27s_sign_%28de%29.png

12. ASSESS LOWER LIMB COORDINATION Heel-shin test i. Ask the patient to raise one leg and place the heel on the opposite knee and then slide the heel tip up and down between knee and ankle ii. When the heel wavers away from the line of the shin this may indicate a cerebellar lesion

Other signs of cerebellar lesion

13. ASSESS LOWER LIMB SENSATION a. Light touch i. L2 – Groin ii. L3 – medial thigh to knee iii. L4 – Medial lower leg

iv. L5 – Lateral lower leg to big toe v. S1 – Little toe and lateral plantar vi. S2 – Medial popliteal fossa Diagram of dermatomes

b. Pin prick c. Vibration sense d. Joint position sense e. Temperature

14. COMPLETE THE EXAMINATION a. Thank the patient b. Offer to help them get dressed c. Wash hands d. Complete cerebellar and cranial nerve examination

Other involuntary movements i.

Dystonia – slow development of a maintained abnormal posture

ii.

Chorea – irregular, jerky and brief writhing movements

iii.

Athetosis – slower, sustained writhing movements

iv.

Choreoathetoid – somewhere between the two

v.

Dyskinesia – a group term for these involuntary movements particulary when they arise as an adverse effect of neuroleptics and antiparkinsonian

vi.

Tics/ habit spasms – normal movements which recur involuntarily

Back

Abnormalities of tone Tone can be decreased (hypotonia) or increased (hypertonia) a. Hypotonia i. Lower motor neurone lesion often associated with muscle wasting, weakness and hyporeflexia ii. Can be caused by Cerebellar disease or occur in early cerebral or spinal shock when the limbs are atonic prior to developing spasticity b. Hypertonia i. Spasticity is a velocity dependent resistance to passive movement and is a feature of upper motor neurone pathology and is usually accompanied by weakness, hypereflexia and an extensor plantar response ii. Rigidity is sustained resistance through a range of movement described in Parkinson’s as ‘lead-pipe’ rigidity which is termed ‘cog-wheel’ rigidity where there is a superimposed tremor Back

Medical Research Council Score for Power 0 No muscle contraction visible 1 Flicker of contraction but no movement 2 Joint movement when effect of gravity eliminated 3 Movement against gravity but not against resistance 4 Movement against resistance but weaker than normal 5 Normal power Back

Reflex grading scale Hyperactive +++ Normal ++ Diminished + Present with reinforcement ± Absent – Back

Other cerebellar signs

Dysdiadochokinesia Ataxia – present with eyes open/close (broad base gait) Nystagmus- fast component towards the lesion Intention tremor (=dysmetria) Speech – slow, slurred, explosive, scanning Hypotonia

Dermatomes

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