Neuropathies

Question 1

Presentation of a polyneuropathy generally

Answer 1

Diffuse, symmetrical. Long axons affected first - eg. to the feet. Then progresses proximally with legs and hands being affected.

Can be progressive, relapsing or transient

Can be sensory or motor or autonomic (or mixed)

‘Glove and stocking’ but stocking first

Question 2

What is a radiculopathy?

Answer 2

Disease affecting the nerve roots eg. root compression

Question 3

What is a plexopathy?

Answer 3

Disease affecting the brachial or lumbosacral plexus

Question 4

Sensory symptoms of large myelinated fibre disease

Answer 4

Loss of fine touch, vibration and joint position sense (feel like cotton wool, difficulty discriminating textures and unsteady gait)

Paresthesiae - pins and needles

Question 5

Sensory symptoms of small unmyelinated fibre disease

Answer 5

Loss of pain and temp - therefore painless burns and trauma and Charcot’s joints

Painful positive symptoms - burning sensations, dysaesthesia, hyperalgeisa, allodynia

Question 6

Motor symptoms of neuropathy

Answer 6

Weakness - usually distal - clearing the kerb or opening jam jars

But can be proximal - climbing stairs and combing hair

Question 7

What causes median nerve compression

Answer 7

Carpal Tunnel syndrome - entrapment at the wrist in the carpal tunnel

Question 8

Symptoms of CTS

Answer 8

Tingling, pain and numbness in the hand
Waking at night and relieved by shaking over the side of the bed “wake and shake”
May extend up the arm
Wasting of thenar eminence if chronic

Question 9

Tests to confirm CTS

Answer 9

Tinel’s Sign - taping the wrist over the nerve will may the pain/tingling worse and can give electric shock feeling

Phalen’s test positive - flex wrists and press against each other for 60seconds - tingling and numbness

Question 10

Causes/associations of CTS

Answer 10

Idiopathic, hypothyroidism, 3rd trimester pregnancy (oedema), RA, acromegaly, sarcoid, neoplasms and benign tumours eg. lipomas

Question 11

Treatment of CTS

Answer 11

Splint worn at night
Steroid injections locally
Surgical decompression

Question 12

What causes ulnar nerve compression, what are signs and what is treatment?

Answer 12

Cubital tunnel damage - at elbow - elbow fracture
Or Guyon’s canal at wrist (no sensory symptoms) - handlebar palsy

Clawing of the hand - wasting of interossei and hypothenar muscles
Sensory loss - little finger and half of ring finger

Treatment with decompression and transposition (at elbow)

Question 13

What causes radial nerve compression and what are the signs?

Answer 13

Compression against the humerus - eg. hanging arm over the back of the sofa
Causes wrist drop, weakness of brachioradialis and finger extensors

Sensory loss in the anatomical snuffbox

Question 14

What is the name of lateral cutaneous nerve of the thigh compression, what happens and what are signs?

Answer 14

Meralgia paraesthesia

Entrapment under inguinal ligament

Causes burning, tingling and numbness of anterolateral surface of the thigh

Usually occurs in overweight people therefore lose weight

Question 15

How do you get common peroneal nerve palsy? What does it cause?

Answer 15

Damage as winds around the fibular head - eg. cast, trauma, sitting cross-legged

Signs = foot drop, weak ankle dorsiflexion/eversion, sensory loss over dorsum of the foot and lateral calf

Question 16

What causes damage to sciatic nerve and what are symptoms?

Answer 16

Fracture of femur or pelvis or pelvic tumours

Affects hamstrings and all muscles below the knee and loss of sensation below the knee laterally

Question 17

What is mono-neuritis multiplex?

Answer 17

2 of more peripheral nerves are affected by neuropathy

Question 18

Causes of mono-neuritis multiplex?

Answer 18

WARDS PLC

Wegeners
AIDS/amyloid
RA
DM
Sarcoid 

PAN
Leprosy
Carcinomas

Question 19

What is Guillan-Barre Syndrome?

Answer 19

Postinfective polyneuropathy

Inflammatory demyelinating polyradiculoneuropathy

Question 20

Prevalence of GBS world-wide annual rate

Answer 20

3/100,000

Question 21

What usually precipitates GBS?

Answer 21

Often follows 1-3 weeks after resp or GIT infection

Can also be associated with CMV

Question 22

Pathology of GBS

Answer 22

Infecting organisms antibody responses against peripheral nerves - possible molecular mimicry

Question 23

Symptoms of GBS

Answer 23

Weakness of distal limb muscles
Distal numbness
Progresses proximally over period of time
Loss of tendon reflexes
20% progress to respiratory failure and facial muscles also affected
Can get autonomic features

Question 24

Diagnosis of GBS

Answer 24

Clinical
Nerve conduction studies
CSF protein often raised

Question 25

What is Miller-Fisher Syndrome?

Answer 25

Type of GBS with ocular muscle palsies and ataxia | Antibodies against GQ1b - ganglioside in 90%

Question 26

Management of GBS

Answer 26

Ventilation if resp failure - thromboprophylaxis If within 2 weeks - immunoglobulin

Question 27

What is Chronic Inflammatory Demyelinating Polyradiculoneuropathy?

Answer 27

Syndrome similar to GBS but with more prolonged onset and recovery Rarely associated with preceding infection Long-term immunosuppression with steroids or immunoglobulin

Question 28

How many diabetic patients get neuropathy

Answer 28

50% after 20 years - associated with poor glycaemic control Different types occur - can be sensory/motor/autonomic If autonomic get gastroparesis

Question 29

Neuropathy in renal disease?

Answer 29

Chronic renal failure with uraemia causes progressive sensorimotor neuropathy Response to dialysis is variable but renal transplant is curative usually

Question 30

What thyroid disease causes neuropathy

Answer 30

Both hypo and hyper

Question 31

What neuropathy is associated with porphyria?

Answer 31

Predominantly MOTOR neuropathy - mainly proximal

Question 32

Paraneoplastic polyneuropathy

Answer 32

Malignant disease (esp. small cell carcinoma of bronchus) can cause sensory neuropathy and ataxia Associated with anti-Hu/anti-neuronal antibodies Can pre-date appearance of malignancy by months or years

Question 33

Neuropathy in amyloidosis

Answer 33

Predominantly sensory, painful neuropathy - distortion caused by deposition of amyloid around vessels in the nerves Autonomic features are common

Question 34

Neuropathy in alcohol abuse

Answer 34

Up to 30% of all neuropathy cases Slowly progressive, distal sensory loss, parasethesia, burning pains Due to primary alcohol toxicity and also deficiency of vitamins Also get myopathy and muscle weakness Treatment by abstinence from alcohol, vitamin replacements Ease pain with TCAs or gabapentin

Question 35

What vitamin deficiency is caused by alcohol?

Answer 35

Thiamine - B1 - Deficiency

Question 36

What deficiency causes sensory neuropathy when having TB treatment?

Answer 36

Pyridoxine B6 deficiency - therefore when taking isonizid for TB - pyridoxine is given - 10mg daily

Question 37

What is Charcot-Marie-Tooth Disease?

Answer 37

Group of hereditary motor sensory neuropathies Present in puberty Distal limb wasting - peroneal muscles (reverse champagne bottles) Loss of sensation and reflexes too Pes cavus and toe clawing

Question 38

Clinical features of radiculopathy

Answer 38

Pain - sharp, shooting, burning - in cutaneous distribution affected - or in the myotome LMN signs Sensory Loss

Question 39

What do you get with lateral cervical disc protrusion?

Answer 39

Severe pain in the upper limb Most commonly C6-C7 disc affecting C7 root - therefore C7 dermatome/myotome (triceps, deep to scapula and extensor aspect of forearm - pain), weakness of these muscles, sensory loss - forearm and palm into middle finger Loss of triceps jerk (C7)

Question 40

What do you get with lateral lumbar disc protrusion

Answer 40

L5 and S1 commonly affected Low back pain and sciatica Loss of sensation in dermatome Ankle jerk lost - S1 reflex arc Weakness of plantar flexion (S1) or great toe extension (L5) Usually acute onset - following lifting, bending etc

Question 41

What do you get with central lumbar disc protrusion

Answer 41

Cauda Equina Polyradiculopathy not myelopathy (normal with central protrusions) ``` Lower back pain LMN weakness Areflexia Sacral numbness Urinary retention and bowel dysfunction ED ```

Question 42

General management of radiculopathy with disc protrusion?

Answer 42

Analgesia and may resolve with rest Can do decompressive surgery - urgent if central lumbar disc protrusion

Question 43

Features of Erbs Palsy

Answer 43

Waiters tip posture - sensory loss in C5/C6 distribution Caused by falling on shoulder or traction on neck/shoulder at birth

Question 44

Features of Klumpkes Palsy

Answer 44

Caused by forced abduction of arm - trauma or at birth Clawed hand - loss of intrinsic hand muscles and long flexors and extensors of fingers Sensory loss in C8/T1 dermatomes Horner's syndrome

Question 45

What is neuralgic amyotrophy

Answer 45

Severe pain in plexus (muscles of shoulder - brachial neuritis) Followed by rapid wasting of proximal muscles (demyelinating plexopathy) Sensory symptoms are rare Can also occur in lumbosacral plexus

Question 46

Pancoast tumour presentation

Answer 46

``` Apical lung tumour C8/T1 most common Severe pain in arm Weak and wasted hand - sensory loss Horner's syndrome ```

Question 47

What happens in thoracic outlet syndrome from cervical rib?

Answer 47

Compresses lower brachial plexus roots - C8/T1 - pain, wasting and sensory loss (thenar mostly - T1) Horners syndrome possible Can also cause subclavian artery/vein occlusion - Unilateral raynauds - Loss or radial pulse on abduction and external rotation of shoulder = ADSON's SIGN Neurological and vascular rarely occur together

Question 48

Lumbosacral plexus signs in upper plexus lesion and lower plexus lesion

Answer 48

Upper = weakness of hip flexion and adduction - anterior leg sensory loss Lower = weakness of hamstrings and foot muscles - posterior leg sensory loss

Question 49

What does cervical spondylosis cause?

Answer 49

Progressive spastic quadriparesis with sensory loss below the neck As flex and extend the neck, drags the cord over bony spurs Limited painful neck movement - neck flexion may produce L'Hermittes sign

Question 50

Management of cervical spondylosis

Answer 50

Firm neck collar Surgical root decompression Transforaminal steroid injection - because nerve root inflammation may be causing pain