Mononeuropathies

Question 1

What is the most common cause of radial nerve palsy?

Answer 1

Entrapment at the spinal groove known as ‘Saturday night palsy’

Question 2

Describe the presentation of radial nerve palsy

Answer 2

Wrist and finger drop
Usually painless
Weak wrist and finger extension
Weak elbow flexion in mid-pronation

Question 3

Which muscles are weakened by a radial nerve palsy?

Answer 3

Extensor carpi radialis longus
Extensor diggitorum communis
Brachioradialis

Question 4

What is the most common cause of ulnar nerve palsy?

Answer 4

Entrapment of the ulnar groove (medial epicondyle of humerus)

Question 5

Ulnar nerve palsy is usually painful. T/F?

Answer 5

False - it is usually painless

Question 6

Describe the presentation fo ulnar nerve palsy

Answer 6

Weak index finger abduction, wrist flexion and thumb adduction
Sensory disturbance

Question 7

Which muscles are weakened by ulnar nerve palsy?

Answer 7

Dorsal interosseous
Abductor digits minimis
Flexor carpi ulnaris
Adductor pollicus

Question 8

What is the most common cause of median nerve palsy?

Answer 8

Entrapment within the carpal tunnel at the wrist

Question 9

Describe the presentation of median nerve palsy

Answer 9

Intermittent nocturnal pain
Numbness and tingling, often relieved by shaking of the hand
Weak grip
Positive tinels or phalen’s test

Question 10

What is the most common cause of median nerve II anterior interosseous branch palsy?

Answer 10

Trauma to the forearm

Question 11

Describe the presentation of median nerve II anterior interosseous branch palsy?

Answer 11

History. of forearm pain

Patient may complain of ‘weak grip’ of keys

Question 12

What is the most common cause of femoral nerve palsy?

Answer 12

Haemorrhage

Trauma

Question 13

Describe the presentation of femoral nerve palsy?

Answer 13

Weak knee extension, hip flexion and numbness in medial shin

Question 14

What is the most common cause of peroneal nerve palsy?

Answer 14

Entrapment of the fibular head

Question 15

Describe the presentation of common peroneal nerve palsy?

Answer 15

History of trauma, surgery or external compression
Acute onset of foot drop and sensory disturbance
Painless

Question 16

What are the common causes of mono neuritis multiplex?

Answer 16

Diabetes
Vasculitis - polyarteritis nodosa
Rheumatological - RA, lupus, sjogre's syndrome
Infective - hep c, HIV
Sarcoidosis
Lymphoma

Question 17

What signs/symptoms occur in large myelinated sensory fibre neuropathy?

Answer 17

Sensory ataxia
Loss of vibration sense
Possible: numbness and tingling

Question 18

What signs/symptoms occur in large myelinated memory fibre neuropathy?

Answer 18

Weakness

Muscle atrophy

Question 19

What signs/symptoms occur in small thinly myelinated or unmyelinated sensory fibre neuropathy?

Answer 19

Impaired pin prick response / temperature sensation

Painful burning, numbness and tingling

Question 20

What signs/symptoms occur in autonomic neuropathy?

Answer 20

Postural hypotension
Erectile dysfunction
GI disturbance
Abnormal sweating

Question 21

Describe the presentation of length dependent axonal neuropathy?

Answer 21

Occurs in patients >50 years

Diffuse involvement of peripheral nerves which is symmetrical and slowly progressive with no significant sensory ataxia

Question 22

What are the possible causes of length dependent axonal neuropathy>

Answer 22

Diabetes
Alcohol
Folate/B12/thiamine/B6 deficiency
RA, lupus, vasculitis,
Renal failure, hypothyroidism
Drugs
HIV, hep B/C
Charcot Marie tooth
Myeloma
Paraneoplastic
Critical illness

Question 23

Guillain Barre syndrome occurs post-infection. Which infections can commonly result in GBS?

Answer 23

Campylobacter
CMV
EBV

Question 24

Describe the presentation of Guillain barre syndrome?

Answer 24

Progressive ascending weakness over a period fo days
Flaccidity
Quadraparesis
Areflexia
Possible respiratory, bulbar, autonomic involvement

Question 25

How is Guillain barre syndrome treated?

Answer 25

IV immunoglobulin or aphaeresis

Question 26

What is the chronic form of Guillain barre syndrome?

Answer 26

CIDP

Question 27

What are the possible symptoms of muscle disorders?

Answer 27

Proximal limb weakness - difficulty raising arms above head, arising from a seated position Facial weakness - characteristic myopathic faces, drooling Eyes - ptosis, ophthalmoplegia Bulbar - dysarthria, dysphagia Neck and spine - head drop, scoliosis Respiratory - breathlessness Myocardial - exercise intolerance, palpitations

Question 28

What are the possible causes of muscle disease?

Answer 28

``` Muscular dystrophies Metabolic muscle disorders (glycogen storage diseases, defects of fatty acid metabolism) Mitochondrial disorders Myotonic dystropies Inflammatory muscle disorders Neuromuscular junction disorders ```

Question 29

Describe the pathogenesis of myasthenia gravis?

Answer 29

Autoimmune disorder in which antibodies bind to and block the ACH receptor at the post synaptic neuromuscular junction

Question 30

What other conditions is myasthenia gravis associated with?

Answer 30

Autoimmune disorders Thymus hyperplasia Thymoma

Question 31

What age groups are typically affected by myasthenia gravis?

Answer 31

Women in their 20s | Older men in their 70s

Question 32

What are the symptoms of myasthenia gravis?

Answer 32

Fatiguable weakness of ocular, bulbar, neck, respiratory and/or limb muscles

Question 33

How is myasthenia gravis managed?

Answer 33

Pyridostigmine (anti-ACH esterase) | Immunosuppressive therapies such as steroids, IV immunoglobulins