Peripheral Polyneuropathy

Question 1

Presentation of peripheral polyneuropathy

Answer 1

Altered sensation

Pain

Weakness

Autonomic symptoms

Question 2

Clinical features of sensory polyneuropathy

Answer 2

Feet usually affected first

Paraesthesia, numbness, burning pain, loss of vibration and position sense

Muscle wasting may occur

May be subacute with ataxia cause by loss of sense of posture

Question 3

Clinical features of autonomic neuropathy

Answer 3

Constipation

Loss of bowel or bladder control

Orthostatic hypotension

Skin may become pale and dry

Sweating may be reduced

Question 4

Investigations in peripheral polyneuropathy

Answer 4

Urine: glucose, protein

Bloods: FBC, ESR, B12, folate

Fasting glucose, renal function, liver function, thyroid function

Question 5

Management of peripheral polyneuropathy

Answer 5

Preventative and palliative treatments: foot care, weight reduction, sensible footwear and foot orthoses

Walking aids

Simple wrist splints can help weak wrist extension

MDT care including OT/PT

Question 6

Complications of peripheral polyneuropathy

Answer 6

With loss of sensation, recurrent injury to joints may lead to permanent destruction (Charcot joint)

Disability, social isolation or loss of independence, especially in elderly

Question 7

What is neruopathic pain?

Answer 7

Abnormal functioning of sensory nerves delivering abnormal and painful signals to the brain

Question 8

Presentation of neuropathic pain

Answer 8

Post-herpetic neuralgia from shingles in distribution of a dermatome (usually on trunk)

Nerve damage form surgery

MS

Diabetic neuralgia typically affects feet

Trigeminal neuralgia

Complex regional pain syndrome (CRPS)

Question 9

Clinical features of neuropathic pain

Answer 9

Burning

Tingling

Pins and needles

Electric shocks

Loss of sensation to affected area

Question 10

Management of neuropathic pain

Answer 10

Amitriptyline (tricyclic antidepressant)

Duloxetine (SNRI)

Gabapentin (anticonvulsant)

Pregabalin (anticonvulsant)

Question 11

What is Guillain-Barré syndrome?

Answer 11

Ascending inflammatory demyelinating polyneuropathy

Question 12

Aetiology of Guillain-Barré syndrome

Answer 12

Typically 1-3 weeks after infection e.g. Campylobacter, mycoplasma, EBV

40% of cases are idiopathic

Question 13

Clinical features of Guillain-Barré syndrome

Answer 13

Progressive ascending symmetrical limb weakness (affects lower limbs first)

Paraesthesia may precede onset of motor symptoms

Some cases present with cranial nerve palsies e.g. diplopia, facial droop

Lower motor neurone signs in the lower limbs (hypotonia, flaccid paralysis, arreflexia)

Type 2 respiratory failure due to respiratory muscle weakness (CO2 flap, bounding pulse)

Autonomic dysfunction may be present (arrhythmia, labile blood pressure)

Question 14

Investigations in Guillain-Barré syndrome

Answer 14

Spirometry

ABG (type 2 respiratory failure)

Anti-ganglioside antibodies

LP - raised protein with normal cell counts and glucose

Question 15

Management of Guillain-Barré syndrome

Answer 15

Monitor ventilation (serial spirometry + ABG)

Ventilation

VTE prophylaxis

Protect pressure areas

IV immunoglobulin

If IVIG ineffective, plasmapheresis