Peripheral Neuropathies

Question 1

What is a good approach to PNS problems?

Answer 1

Which nerves are damaged?
Where are they damaged?
How are they damaged (myelin or axonal)?
Why are they damaged?
Can we stop it?

Question 2

What are symptoms of large alpha/beta fibre motor problems?

Answer 2

Weakness, unsteadiness, wasting of muscles

Question 3

Will power be reduced in pathologies of large alpha/beta motor fibres of the PNS?

Answer 3

Yes

Question 4

Will sensation be intact in pathologies of large alpha/beta motor fibres of the PNS?

Answer 4

Yes

Question 5

Will reflexes be normal in pathologies of large alpha/beta motor fibres of the PNS?

Answer 5

No - absent

Question 6

What will the symptoms be in pathologies of large alpha/beta sensory fibres of the PNS?

Answer 6

Numbness, paraesthesia, unsteadiness

Question 7

Will power be preserved in pathologies of large alpha/beta sensory fibres of the PNS?

Answer 7

Yes, normal power

Question 8

Will reflexes be normal in pathologies of large alpha/beta sensory fibres of the PNS?

Answer 8

Yes

Question 9

Will sensation be preserved in pathologies of large alpha/beta sensory fibres of the PNS?

Answer 9

No; vibration and proprioception reduced

Question 10

Will reflexes be normal in pathologies of large alpha/beta sensory fibres of the PNS?

Answer 10

No - absent

Question 11

What symptoms will occur with pathologies of the small delta and C fibres of the PNS?

Answer 11

Pain, dysethesia

Question 12

Will power be preserved with pathologies of the small delta and C fibres of the PNS?

Answer 12

Yes, normal

Question 13

Will sensation be preserved with pathologies of the small delta and C fibres of the PNS?

Answer 13

No; pin-prick and temperature perception reduced

Question 14

Will reflexes be normal with pathologies of the small delta and C fibres of the PNS?

Answer 14

Yes

Question 15

What symptoms will occur with pathologies of delta and C fibres the ANS?

Answer 15

Dizziness (postural hypotension)
Impotence
N+V (gastroparesis)

Question 16

Will power be preserved with pathologies of delta and C fibres the ANS?

Answer 16

Yes

Question 17

Will sensation be preserved with pathologies of delta and C fibres the ANS?

Answer 17

Yes

Question 18

Will reflexes be normal with pathologies of delta and C fibres the ANS?

Answer 18

Yes

Question 19

What is a high stepping gait?

Answer 19

Foot drop due to weakness of ankle dorsiflexion

Question 20

What are DDx of a high stepping gait?

Answer 20

Common fibular nerve palsy
L5 palsy
Motor neuropathies; bilateral due to alcohol or diabetes

Question 21

Where is the nerve damaged in a radiculopathy?

Answer 21

Nerve root; commonly due to a prolapsed disc

Question 22

What is a mononeuropathy?

Answer 22

Single nerve problem for example a wrist drop due to radial nerve palsy or carpal/ cubital syndrome

Question 23

What is mononeuritis multiplex?

Answer 23

Vasculitis affecting the blood supply to nerves

Question 24

What is a length dependent peripheral neuropathy?

Answer 24

Neuropathy due to underlying systemic condition such as diabetes or alcoholism

Question 25

What distribution of sensory loss will length dependent peripheral neuropathy show?

Answer 25

Glove and stocking | Symmetrical

Question 26

Are plexopathies painful?

Answer 26

YES

Question 27

What is the difference between guillan barre syndrome and MS?

Answer 27

Guillain barre = demyelinating disorder of PNS | MS = demyelinating disorder of CNS

Question 28

What are the acute and chornic demyelinating neuropathies of the PNS?

Answer 28

Acute (days to week): GBS | Chronic (months to years): CIDP, charcot-marie-tooth disease

Question 29

What are the symptoms of GBS?

Answer 29

Progressive paraplegia over days up to 4 weeks Assoc sensory symptoms proceed weakness PAIN very common

Question 30

When are the peak symptoms of GBS?

Answer 30

10-14 days into onset of illness

Question 31

What commonly precedes GBS?

Answer 31

Campylobacter | Resp infections

Question 32

What % of people with GBS will require ventilation?

Answer 32

25%

Question 33

What will cause the majority of deaths in GBS?

Answer 33

Autonomic failure; cardiac arrhythmias | It will strip the ANS of its myelin

Question 34

What is the treatment for GBS?

Answer 34

IVIg and/or plasma exchange | Minimal role for steroids

Question 35

What is charcot marie tooth disease?

Answer 35

Pure motor, sensory, sensorimotor, small fibre and autonomic variants Demyelinating and axonal variation Genetic

Question 36

What is typically seen in CMT?

Answer 36

Wasting of tibial muscles Deforming arthropathy of hands Pes cavus

Question 37

What are the different types of axonal neuropathies?

Answer 37

``` Vasculitis Paraneoplastic Infections Drugs/ toxins Metabolic ```

Question 38

What causes vasculitis axonal neuropathies?

Answer 38

ANCA +ve RA Sjogren's

Question 39

What causes paraneoplastic axonal neuropathies?

Answer 39

``` Myeloma Antibody mediated (breast cancer, small cell lung cancer) ```

Question 40

What causes infectious axonal neuropathies/

Answer 40

HIV Syphilis Lyme disease Hep B/C (cryoglobulin mediated)

Question 41

What drugs/toxins cause axonal neuropathies?

Answer 41

ALCOHOL Amiodarone Phenytoin Chemo; cisplatin/ vincristine

Question 42

What metabolic disorders cause axonal neuropathies?

Answer 42

Diabetes B12/ folate deficiency Chronic uraemia Porphyria - acute intermittent porphyria

Question 43

What causes chronic autonomic neuropathies?

Answer 43

Diabetes; gastroparesis Amyloidosis Hereditary

Question 44

What will cause acute autonomic neuropathies?

Answer 44

GBC | Porphyria

Question 45

What is the treatment for axonal neuropathies in general?

Answer 45

Treat cause | Symptomatic; physio, orthotics, neuropathic pain relief

Question 46

What is the treatment for vasculitis related axonal neuropathies?

Answer 46

Pulsed IV methylprednisolone + cyclophosphamide

Question 47

What is the treatment for demyelinating neuropathies?

Answer 47

``` IVIg Steroids Azathioprine Mycophenolate Cyclophosphamide ```