Neuropathy

Question 1

What is a Radiculopathy?

Answer 1

Process affecting nerve roots

Question 2

What is a Neuropathy?

Answer 2

Pathological process affecting a peripheral nerve(s)

Question 3

What is a Mononeuropathy?

Answer 3

Process affecting a single nerve

Question 4

What is a Mononeuritis multiplex?

Answer 4

Process affecting several individual nerves

Question 5

What is a Polyneuropathy/peripheral neuropathy?

Answer 5

Diffuse, symmetrical disease, beginning peripherally

• motor, sensory, autonomic or a combination
• demyelinating/axonal types
• loss of tendon reflexes, ‘glove & stocking’ sensory loss

Question 6

What are the causes of a polyneuropathy/peripheral neuropathy?

Answer 6

Metabolic
Toxic
Autoimmune
Inflammatory
Drugs
Infective
Vascular
Neoplastic
Inherited

Question 7

What are the metabolic causes of a polyneuropathy/peripheral neuropathy?

Answer 7

Diabetes mellitus
B12/folate/thiamine deficiency
Uraemia (CKD)

Question 8

What are the toxic causes of a polyneuropathy/peripheral neuropathy?

Answer 8

Alcohol
Chronic liver disease
Lead
Radiation

Question 9

What are the autoimmune causes of a polyneuropathy/peripheral neuropathy?

Answer 9

RA
CTDs
Myxoedema

Question 10

What are the inflammatory causes of a polyneuropathy/peripheral neuropathy?

Answer 10

Guillain-Barre syndrome

Chronic inflammatory demyelinating polyneuropathy (CIDP)

Question 11

What are the drug causes of a polyneuropathy/peripheral neuropathy?

Answer 11

Amiodarone
Statins
Hydralazine
Phenytoin
Antibiotics

Question 12

What are the infective causes of a polyneuropathy/peripheral neuropathy?

Answer 12

Syphilis

HIV

Question 13

What are the vascular causes of a polyneuropathy/peripheral neuropathy?

Answer 13

Vasculitis

Question 14

What are the neoplastic causes of a polyneuropathy/peripheral neuropathy?

Answer 14

Myeloma

Paraneoplastic syndromes

Question 15

What are the inherited causes of a polyneuropathy/peripheral neuropathy?

Answer 15

Charcot-Marie-Tooth
-present <20yrs w/ progressive neuropathy
Freidrich’s ataxia
-cerebellar ataxia in 1st decade, UMN limb signs & peripheral neuropathy

Question 16

What are the most common causes of a polyneuropathy/peripheral neuropathy?

Answer 16

Diabetes mellitus
Carcinomatous neuropathy
B vitamin deficiency
Drugs

Question 17

What problems can longstanding polyneuropathy/peripheral neuropathy cause?

Answer 17

Claw deformities of foot (pes cavus)
Joint arthropathies (charcot foot)
Ulceration

Question 18

What are the two broad pathological types of polyneuropathy/peripheral neuropathy?

Answer 18

Demyelinating

Axonal

Question 19

What are the features of demyelinating polyneuropathy/peripheral neuropathy?

Answer 19

Damage affects Schwann cells
More common in immune-mediate disease (GBS)
-decreased conduction velocity
-Schwann cells regrow, improves w/ treatment

Question 20

What are the features of axonal polyneuropathy/peripheral neuropathy?

Answer 20

Nerve cell body damage, degeneration starts at periphery and progresses towards neuronal cell

• reduced amplitude of nerve impulses
• axons cannot regrow, treatment outcomes poor

Question 21

What other, less common patters of nerve damage are there?

Answer 21

Wallerian degeneration - following nerve section/microinfarction
Compression neuropathy - leads to focal demyelination
Nerve infiltration - malignancy/granulomatous infiltration

Question 22

At what rate can nerves regenerate?

Answer 22

1mm/day

Requires intact cell bodies

Question 23

What investigations are appropriate in suspected polyneuropathy/peripheral neuropathy?

Answer 23

Bloods - FBC, U&Es, LFTs, HbA1c, B12/folate, ANCA, VDRL, autoantibodies
Nerve conduction studies (demyelinating/axonal)
LP (raised protein in GBS/CIDP)
Peripheral nn biopsy

Question 24

What is the underlying pathology of Guillain-Barre syndrome (GBS)?

Answer 24

Most common acute polyneuropathy
Demyelinating
Autoallergic basis, does not recur

Question 25

How does GBS present?

Answer 25

Paralysis 1-3wks after infection - ascending paralysis, loss of tendon reflexes - sensory loss rare - affects lower limbs initially - ascends/progresses over several days/weeks

Question 26

What are the infective causes of severe GBS?

Answer 26

Campylobacter | CMV

Question 27

What are the common complications of GBS?

Answer 27

Venous thrombo embolism Autonomic involvement -BP lability -arrhythmias

Question 28

What is required for a diagnosis of GBS?

Answer 28

Clinical Nerve conduction studies (slowed conduction) CSF (protein raised)

Question 29

What is the management of GBS?

Answer 29

Severe cases progress rapidly over hrs/days Admit to HDY (prevent sores, chest infections, DVTs etc.) -s.c. heparin + TED stockings High dose IVIG w/i 2wks -reduce duration/severity

Question 30

What is the prognosis of GBS?

Answer 30

Mild - little disability before spontaneous recovery Complete recovery over months in 80-90% May be left w/ residual weakness Mortality high in acute phase (10%

Question 31

What features suggest a poor prognosis of GBS?

Answer 31

Older age Rapid onset of sx Axonal patterns of damage

Question 32

What is Shingles?

Answer 32

Reactivation of VZV infection w/i dorsal root ganglia

Question 33

How does Shingles present?

Answer 33

``` Occurs in lower thoracic dermatomes Pain/paraesthesia for several days Erythema/dermatomal eruption of vesicles -become pustular 2-3/7 later -may separate 3wks later ```

Question 34

What is Ophthalmic herpes?

Answer 34

Infection of 1st division of CN5 | Can lead to uveitis, corneal scarring, 2o panopthalmitis

Question 35

What is Ramsey-hunt syndrome?

Answer 35

``` Infection of geniculate ganglion Facial palsy (often severe/irreversible) Facial/ear pain Vesicles in ear canal/pinna/soft palate Sensorineural deafness Vertigo Neuropathy of CN 5/9/10 ```

Question 36

What is the management of Shingles?

Answer 36

5-7 days Acyclovir PO | Paracetamol + Amitryptyline for pain

Question 37

What is Post-herpetic neuralgia?

Answer 37

Common complication of shingles (10%) Pain in prev shingles zone -burning, continuous pain -responds poorly to anaesthesia

Question 38

How is Post-herpetic neuralgia managed?

Answer 38

Amitryptyline Topical capsaicin Recover over 2yrs