22. Numbness/paraesthesia/tingling

Question 1

History taking sensory disturbance?

Question 2

Examination sensory disturbance?

Question 3

Patterns of sensory loss

Answer 3

Single area of altered sensation
Multiple distal areas affected symmetrically
Multiple distal areas affected asymmetrically
Spinal symptoms
Hemisensory
Intermittent
Ischaemic symptoms
Functional

Question 4

ddx SD single area of altered sensation

Answer 4

mononeuropathies such as carpal tunnel, cubital tunnel, meralgia parasthetica.

Radiculopathy such as cervical radicluopathy, sciatica, cauda equina, foot drop, shingles, lyme disease

Question 5

ddx multiple distal areas affected symmetrically

Answer 5

predominant sensory loss: ABCDE - alcohol, b12 deficiency, cancer and CKD, diabetes and drugs, every vasculitis.

Motor loss: GBS, CIDP, charcot marie tooth, lead posioning,

Question 6

ddx multiple distal areas affected asymmetrically

Answer 6

Mononuritis multiplex

WARDS PLC

Wegeners
Aids/Amyloid
Rheuamtoid
Diabetes
Sarcoidosis
Polyarteritis nodosa
Leprosy
Cancer

Question 7

ddx spinal eg symmetrical, sensory level, signs mixed, sphincter involvement

Answer 7

degenertaive cervical myelopathy, lumbar spinal stenosis, neoplastic spinal cord compression, brown-sequard, subacute combined degeneration, friedrichs ataxia, syringomyelia,

Question 8

ddx hemisensory loss

Answer 8

stroke, MS, parietal lobe tumour

Question 9

ddx intermittent sensory loss

Answer 9

hyperventilation, migraine, TIA, parietal lobe epilepsy, peripheral arterial disease

Question 10

ddx functional sensory loss

Answer 10

conversion disorder

Question 11

Axillary nerve normal function

Answer 11

Motor: Shoulder abduction (deltoid muscle)

Sensory to inferior region of the deltoid muscle

Question 12

How may the axilliary nerve become damaged?

Answer 12

Humerus surgical neck fracture: usually by direct blow or falling on an outstretched hand

Question 13

Examination axillary nerve damage

Answer 13

flattened deltoid, loss of sensation over deltoid

weakness of shoulder abduction

Question 14

Normal function of radial nerve

Answer 14

Motor: “stop”
Extension of wrist, fingers, forearm, thumb

Sensory: area between the dorsal aspect of the 1st and 2nd metacarpals

Question 15

How may the radial nerve become damaged?

Answer 15

humeral midshaft fracture

Question 16

How would a damaged radial nerve present?

Answer 16

wrist drop

due to unopposed flexion of the wrist

weakness of thumb extension

Question 17

Normal function of median nerve

Answer 17

“power to the people”

Motor: LOAF muscles
Lateral lumbicals
Opponens pollicis
Abductor policis
Flexor policis brevis

wrist flexion, finger flexion, thumb opposition, pronation

Sensation : Palmar aspect of lateral 3½ fingers

Question 18

How does the median nerve become damaged

Answer 18

compression at the wrist (carpal tunnel syndrome)

Question 19

how would a damaged median nerve present?

Answer 19

weakness of thumb abduction (abductor pollicis brevis)
wasting of thenar eminence (NOT hypothenar)
Tinel’s sign: tapping causes paraesthesia
Phalen’s sign: flexion of wrist causes symptoms

sign of benediction

Anterior interosseous nerve: opposition of the thumb and index finger* ‘okay sign’

Question 20

Normal function of ulnar nerve?

Answer 20

“peace sign”

motor: abduction of fingers
Sensory: medial 1 1/2 fingers

adduction of thumb (adductor policis)

Question 21

How would the ulnar nerve become damaged?

Answer 21

medial epicondyle fracture

Question 22

How would a damaged ulnar nerve present?

Answer 22

frommets sign (cant adduct thumb properly)
inability to abduct/adduct fingers and adduct thumb
sensory loss over medial 1 1/2 fingers

cubital tunnel syndrome
Tingling and numbness of the 4th and 5th finger which starts off intermittent and then becomes constant.
Over time patients may also develop weakness and muscle wasting
Pain worse on leaning on the affected elbow

Medial epicondyle fracture -
Damage may result in a ‘claw hand’

Question 23

Normal function of long thoracic nerve

Answer 23

innervation of serratus anterior
- protraction of the scapula
- external rotation

Question 24

How would long thoracic nerve become damaged?

Answer 24

Often during sport e.g. following a blow to the ribs. Also possible complication of mastectomy

Question 25

how does damage to long thoracic nerve present?

Answer 25

winged scapula

Question 26

normal function of the lateral cutaneous nerve

Answer 26

no motor

sensation: Lateral and posterior surfaces of the thigh

Question 27

how would the lateral femoral cutaneous nerve become damaged?

Answer 27

As the nerve curves medially and inferiorly around the anterior superior iliac spine (ASIS), it may be subject to repetitive trauma or pressure. (meralgia paraesthetica)

Risk factors:
Obesity
Pregnancy
Tense ascites
Trauma
Iatrogenic, such as pelvic osteotomy, spinal surgeries, laparoscopic hernia repair and bariatric surgery. In some cases, may result from abduction splints used in the management of Perthe’s disease.
Various sports have been implicated, including gymnastics, football, bodybuilding and strenuous exercise.
Some cases are idiopathic.

Question 28

How would a damaged lateral cutaneous nerve pressent?

Answer 28

Lateral and posterior surfaces of the thigh

Burning, tingling, coldness, or shooting pain
Numbness
Deep muscle ache

Symptoms may be reproduced by deep palpation just below the ASIS (pelvic compression) and also by extension of the hip.
There is altered sensation over the upper lateral aspect of the thigh.
There is no motor weakness.

Symptoms are usually aggravated by standing, and relieved by sitting
They can be mild and resolve spontaneously or may severely restrict the patient for many years.

meralgia paraesthetica

Injection of the nerve with local anaesthetic will abolish the pain. Using ultrasound is effective both for diagnosis and guiding injection therapy in meralgia paraesthetica
Nerve conduction studies may be useful.

Question 29

What does the common peroneal nerve do?

Answer 29

Motor:
Foot dorsiflexion and eversion
Extensor hallucis longus

sensation: Dorsum of the foot and the lower lateral part of the leg

Question 30

How does the common peroneal nerve become damaged?

Answer 30

This is often secondary to compression at the neck of the fibula
- Tightly applied lower limb plaster cast
- Leg crossing, squatting or kneeling
- Recent weight loss
- Baker’s cysts

Question 31

Presentation of common peroneal nerve mononeuropathy

Answer 31

foot drop

unilateral (Bilateral foot drop is more likely to be due to peripheral neuropathy)

no weakness of hip abduction (weakness of hip abduction is a KEY sign of L5 radiculopathy)

Question 32

Causes carpal tunnel

Answer 32

idiopathic
pregnancy
oedema e.g. heart failure
lunate fracture
rheumatoid arthritis

Question 33

management carpal tunnel

Answer 33

NICE Clinical Knowledge Summaries currently recommends a 6-week trial of conservative treatments if the symptoms are mild-moderate
- corticosteroid injection
- wrist splints at night

if there are severe symptoms or symptoms persist with conservative management:
- surgical decompression (flexor retinaculum division)

Question 34

what invetsigation might you do for ?mononeuropathy

Answer 34

nerve conduction studies

Question 35

management cubital tunnel

Answer 35

Avoid aggravating activity
Physiotherapy
Steroid injections
Surgery in resistant cases

Question 36

what is radiculopathy?

Answer 36

Nerve root compression

99% patients have radiating limb pain, often in the pattern of the dermatome, sharp/shooting in character,

with only a small proportion (about 5%) having associated neurologic symptoms such as dermatomal sensory loss, and even less commonly myotomal muscle weakness.

The two nerve roots usually affected for the upper limb are C6 and C7. The two nerve roots usually affected for the lower limb are L5 and S1.

Question 37

Causes of radiculopathy

Answer 37

Spinal degenerative changes

Prolapsed disc (When a spinal disc becomes herniated in the neck, it can leak out into the spinal canal or nerve root tunnel and impinge on the exiting nerve root.)

Question 38

Presentation cervical radiculopathy

Answer 38

PC: pain in the neck with radiation down the shoulder and arm in a dermatomal distribution. Unilateral dermatomal numbness or tingling (C5–C7 levels are most commonly affected). Motor symptoms, although less common, are also usually unilateral and in a myotomal distribution.

HoPC: A more generalised non-dermatomal arm ache, occipital headache, or inter-scapular pain are other common presentations.

Positive spurling test

Question 39

plan ?cervical radiculopathy

Answer 39

Plan:
Management
1. Rule out all red flags, if any red flags: refer immediately
2. If present for <4-6 weeks and no objective neurological signs: treat conservatively for 4-6 weeks

+Reassurance
+Encourage activity and home exercise
+Analgesia: ibuprofen, paracetamol, codeine
+Consider amitriptyline, duloxetine, pregabalin or gabapentin
+Consider a referral for physiotherapy

2. If present for more than 4-6 weeks OR there are objective neurological signs
   Refer to confirm diagnosis with MRI and to consider invasive procedures, such as interlaminar cervical epidural injections, transforaminal injections, or spinal surgery.

Question 40

What is cervical spondylosis? presentation?

Answer 40

Cervical spondylosis is a term used to describe degeneration of the vertebral column in the cervical (neck) region. It is otherwise known as cervical osteoarthritis. It most commonly presents in clinical practice as neck pain.

PC: Pain and/or stiffness in cervical region
Referred pain: retro-orbital, temporal, occipital, interscapular, upper limbs.

Reduced range of movement of neck (in all directions)
Poorly localised tenderness
Signs of radiculopathy (most commonly affecting nerve roots C5 to C7)
Unilateral neck, shoulder or arm pain, paraesthesia, or hyperaesthesia
Diminished arm reflexes (triceps: C7, biceps: C5/C6, supinator: C5/C6).
A small number (<0.1% of patients with cervical spondylosis) of patients with associated acute myelopathy can develop quadriplegia.

Complications: cervical radiculopathy and myelopathy

Question 41

what nerve roots commonly cause cervical radiculopathy

Answer 41

C6/7

Question 42

What nerve roots commonly cause sciatica

Answer 42

L5/S1

Question 43

what special test is useful for diagnosing sciatica

Answer 43

straight leg raise

Question 44

abdominal pain and a motor periperal neuropathy

Answer 44

Lead poisoning
Ask about blue lines on gum margin

Question 45

Management of uncontrolled sciatica/sciatica not responded to conservative management

Answer 45

if symptoms persist e.g. after 4-6 weeks) then referral for consideration of MRI is appropriate

Question 46

most common cause of sciatica

Answer 46

A prolapsed lumbar disc at L5/S1

Question 47

features of back/leg pain in prolapsed disc

Answer 47

leg pain usually worse than back
pain often worse when sitting

Question 48

what is mononeuritis multiplex?

Answer 48

Multiple areas of sensory loss in an asymmetric pattern suggest a patchy process affecting peripheral nerves such as inflammatory neuropathy or vasculitis. The term mononeuritis multiplex—meaning ‘inflammation of multiple single nerves’—is used to describe this pattern of asymmetric sensory loss.

Question 50

what things should you ask about to investigate vasculitis as the cause of mononeuritis multiplex

Answer 50

ENT - sinusitis? epistaxis?
Respiratory - cough? SOB?, haemoptysis
Skin - purpura? mottled looking skin? tender nodules?
Neuro - mononeuritis multiplex?
Renal - haematuria, anuria?
other - heart problems?

Question 51

which vasculidities may present with mononeuritis multiplex?

Answer 51

microscopic polyangitis

granulomatosis with polyangitis (wegners)

polyarteritis nodosa

Question 52

features microscopic polyangitis? autoantibody?

Answer 52

ENT - none
Resp - alveolar haemorrhage
Skin - purpura
Neuro - mononeuritis multiplex
Renal - glomerulonephritis

p-ANCA

Question 53

features granulomatosis with polyangitis

Answer 53

ENT - saddle nose, epistaxis
Resp - SOB, haemoptysis
Skin
Neuro - mononeuritis multiplex
Renal - glomerulonephritis

c-ANCA positive in 90%

Question 54

features polyarteritis nodosa

Answer 54

ENT
Resp
Skin - livedo reticularis (mottled looking skin), tender skin nodules
Neuro - mononeuritis multiplex
Renal - haematuria, renal fialure
Other - HTN, CVS events, associated with hep B

Question 55

link between anxiety and sensory disturbance

Answer 55

Hyperventilation (e.g. in panic attacks and anxiety states) may cause tingling in lips, fingers and toes which can present in a similar way to a polyneuropathy but the paraesthesia is transient with no permanent neurological deficit.

Question 56

paraesthesia that seems to move around?

Answer 56

migraine

parietal lobe epilepsy

The onset of migraine can cause an aura of altered sensation that starts in one area and slowly spreads to other areas. A typical presentation is paraesthesia or tingling occurring in the face, which over 15 minutes spreads to the arm and 15 minutes later has spread down the leg. The sensory disturbance of migraine usually consists of positive phenomenology (i.e. buzzing and tingling) as opposed to loss of sensation or numbness. The presence of visual aura, photophobia and headache enable a confident diagnosis but it is important to remember that migrainous phenomena can occur without headache.

Question 57

recurrent sensory symptoms in different parts of the body, each lasting more than a day could indicate

Answer 57

multiple sclerosis

Question 58

paraestheia in the leg, need to consider?

Answer 58

ischaemia

Question 59

what positive features suggest functional sensory loss

Answer 59

non-dermatomal

inconsistent on repeat examination

sharp delineation between normal and abnormal sensation at the midline or at the proximal end of a limb