Neuro Exam of Limbs

How many spinal nerves are there

31

Dorsal/Ventral roots carry sensory/motor fibres

Dorsal roots carry sensory fibres

Ventral /anterior roots carry motor fibres

Dermatome

An area of skin supplied by peripheral nerve fibres originating from a single dorsal root ganglion

Myotomes

groups of muscles innervated by a single spinal nerve root

What groups of muscles & actions does C5,C6 supply

Shoulder abduction: Deltoid/supraspinatus

Elbow flexion: biceps & brachoradialis

What group of muscles & action does C6, C7 supply

Wrist flexion: flexor carpi ulnaris & radialis

What group of muscles & action does C6,C7, C8 supply

Shoulder adduction: Pertoralis major/latissimis dorsi

What groups of muscles & actions does C7, C8 supply

Elbow extension: triceps

Wrist extension: extensor carpi group

Finger flexion: flexor digitorum profundus & sublimis

Finger extension: extensor digitorum communis, extensor

indicis, extensor digiti minimi

What groups of muscles & actions does C8, T1 supply

Finger abduction: dorsal interossei

Finger adduction: palmar interossei

What group of muscles & action does L2,L3 supply

Hip flexion: iliopsoas (psoas & iliacus)

What group of muscles & action does L2,L3,L4 supply

Hip adduction: adductors longus, brevis & magnus

What group of muscles & action does L3,L4 supply

Knee extension: quadriceps

What group of muscles & action does L4, L5 supply

Ankle dorsiflexion: tibialis anterior, extensor digitorum longus, extensor hallicus longus

What group of muscles & action does L4,L5,S1 supply

Hip abduction: gluteus medius & minimus

What groups of muscles & actions does L5,S1 supply

Knee flexion: hamstrings

Tarsal joint inversion: tibialis posterior, gastronemius, hallucis longus

Tarsal joint eversion: peroneus longus & brevis, extensor digitorum longus

What group of muscles & action does L5, S1,S2 supply

Hip extension: gluteus maximus

What group of muscles & action does S1, S2 supply

Ankle plantar flexion:gastrocnemius, plantaris, soleus

On 1st inspection of a neuro exam of the limbs what would you look out for

Muscle wasting

Abnormal movements (tremor)

Fasiculations

Skin changes e.g. neurofibromatosis

What could cause increased muscle tone

claspknife / leadpipe rigidity

UMN lesion e.g. stroke, MS

Parkinson’s disease

What could cause reduced tone

LMN disease

Cerebellar disease

Explain the power scale from 5/5 to 0/5

5/5 normal

4/5 moderate movement against resistance

3/5 movement against gravity but not against resistance

2/5 movement when gravity excluded

1/5 flicker of contraction possible

0/5 complete paralysis / no movement

How to test someone’s coordination

Finger nose test/ heel shin test

Rapid alternating movements

What is Diadochokinesis

the ability to perform rapid, alternating movements

What is disdiadokinesis

inability to perform rapid, alternating movements smoothly

Patient presents with Intention tremor, Past-pointing, & disdiadokinesis. What is the diagnosis?

These are signs of cerebellar disease

Cerebellum function

cerebellum is concerned with smooth coordination of movement

A disruption to smooth coordination of movement is caused by a lesion to the same/opposite side as the signs

Same side

Sensation uses what neural tract

spinothalamic tract

Route of passage of the spinothalamic tract

Fibres enter & ascend ipsilaterally in spinal cord → decussate in medulla (nucleus gracilis, nucleus cuneatus) → thalamus → somatosensory cortex & limbic system

How does a reinforcement manoeuvre aid in testing reflexes

A reinforcement manoeuvre (e.g. clenching teeth) is used to make it easier to elicit a reflex when the reflex is difficult to see or feels weak

Name the spinal roots involved in each reflex

Babinski signs tests what nerve roots

L5, S1, S2

What are the 5 levels that you can report a reflex as

0 = absent

+ = present but reduced

++ = normal

+++ = increased, possibly normal

++++ = greatly increased

Greatly increased reflexes can be associated with what

clonus

Clonus is associated with upper/lower motor neuron damage

UMN - Upper Motor Neuron

Clonus is associated with hyper/hypotonia & hyper/hyporeflexia

hypertonia & hyper-reflexia

What happens when you suddenly stretch a muscle of someone with clonus

There is a sustained rhythmic contraction of muscles when put under sudden stretch

What specifically happens in Ankle clonus

sharply dorsiflex of the ankle

What specifically happens in Knee/patellar clonus

sharply push down on patella and maintain stretch