Clinical neurophysiology Flashcards
What are the different sections of the brachial plexus?
- roots
- trunks
- divisions
- cords
- nerves (median, ulnar and radial)
What three nerves does the brachial plexus end in?
Musculocutaneous axillary radial median ulnar
What does the median nerve supply?
thumb, index, middle and half ring finger
What does the ulnar nerve supply?
pinky and half ring finger
What does the radial nerve supply?
dorsal hand
What motor fibres does the median nerve supply?
median muscle forearm (proximal and distal) and hand
What nerve root fibres make up the median nerve?
C5 + C6 (lateral cord)
C8 + T1 (medial cord)
What is the primary function of the lateral and medial cord of the median nerve?
lateral is mainly sensory
medial is mainly motor
What nerve branches of the median nerve at the elbow?
anterior interosseous nerve
What is the most common median nerve pathology?
Carpal tunnel syndrome (entrapment neuropathy)
Who is entrapment of median nerve most common in?
females
45-65 yrs
What would be the main differential diagnosis of carpal tunnel syndrome?
Lesion of:
- C6-7
- Brachial plexus
- Proximal median nerve lesion
- motor neurone disease (shouldnt have sensory disturbance)
What are the symptoms of carpal tunnel syndrome?
- paraesthesia in median distribution (can present as whole hand)
- worse during sleep/ on wakening
- loss of dexterity
- can present in dominant hand first
What are the risk factors for carpal tunnel?
- small carpal tunnel
- diabetes mellitus
- inflammatory conditions
- pregnancy, menopause and obesity
- hypothyroidism or renal disorder
- occupational (farmers)
Where will sensation often be spared in carpal tunnel?
thenar eminence as supplied by palmar cutaneous sensory branch