NEURO 110 Peripheral Neuropathy

Question 1

What is neuropathy?

Answer 1

Nerve disease

Question 2

How do you classify a neuropathy?

Answer 2

The type of and number of nerves affected, aetiology, timing and pathology

Question 3

How would a motor neuropathy present?

Answer 3

Weakness, wasting, fasiculations and areflexia

Question 4

How can a sensory neuropathy present?

Answer 4

Parasthesia, burning, allodynia, ataxia, loss of pain sensation or hypersensitivity, ulcers, loss of vibration sense, loss of proprioreception, areflexia

Question 5

What would an autonomic neuropathy present?

Answer 5

Dry eyes, dry mouth, GI disturbance, impotence, loss of heart rate variability, bladder hypersensitivity, excessive/inadequate sweating, orthostatic hypotension

Question 6

Describe a compression neuropathy

Answer 6

Focal demyelination where compression occurs, and reduced conduction velocity across compression area
Usually a mononeuropathy

Question 7

What are the two common mononeuropathies/compression neuropathies

Answer 7

Median nerve compression - Carpal Tunnel Syndrome

and Ulnar nerve compression

Question 8

What are the risk factors for carpal tunnel syndrome

Answer 8

Diabetes, pregnancy, acromegaly, weight gain, repetiitive wrist movements, wrist fracture, artritis

Question 9

What are the signs and symptoms of carpal tunnel syndrome?

Answer 9

Numbness - waking at night and with certain daytime postures, in the lateral 3.5 fingers, weak thumb abduction and wasting of the thenar eminence

Question 10

What are the treatments for carpal tunnel syndrome?

Answer 10

Wrist splints, steroids, decompression surgically

Question 11

what are the risk factors for ulnar nerve compression?

Answer 11

elbow trauma, RA, leaning on elbow

Question 12

what are the signs and symptoms of ulnar nerve compression?

Answer 12

hypothenar wasting, weakness of finger abduction and opposition of little finger, sensory changes to medial 1.5 fingers

Question 13

What are the treatments for ulnar nerve compression?

Answer 13

Avoid resting on elbows, night time splints, nerve gliding exercises, decompression surgery

Question 14

What is guillian barre syndrome?

Answer 14

Acute demyelinating polyneuropathy with preceding infection

Question 15

What are the signs and symptoms and GBS?

Answer 15

Numbness and paralysis beginning distally

Question 16

What will investigations show in GBS?

Answer 16

increased protein concentration in the CSF, slowed nerve conduction belocities and action potential delay and dispersion

Question 17

What are the treatments for GBS?

Answer 17

Intravenous immunoglobulin pooled from blood donations, or plasma exchange
Both expensive and high risk

Question 18

What is the potential difference between ICF and ECf?

Answer 18

~70mV

Question 19

What ion concentrations are higher extracellularly

Answer 19

Sodium, calcium and chloride

Question 20

What ion concentration is higher intracellularly and what maintains this balance?

Answer 20

Potassium - the Na+/K+ pump

Question 21

How is an AP initiated?

Answer 21

Na ligand gated channels open after binding of excitatory NT and Na+ floods in

Question 22

What is the rising phase of an AP?

Answer 22

Threshold reached due to ligand mediated Na+ influence and there is further Na+ influx and K+ efflux

Question 23

Why does the membrane hyperpolarise?

Answer 23

Due to the magnitude of K+ extracellularly

Question 24

What is the refractory period of an AP?

Answer 24

Peak depolarisation to hyperpolarisation and where Na+ channels become inactive for 1ms after closing

Question 25

What is the relative refractory period of an AP?

Answer 25

Re-establishment of resting potential

Question 26

What occurs when acetylcholine binds to its receptors at the NMJ?

Answer 26

It causes K+ channels to open post synaptically and triggers AcH reuptake

Question 27

What is Lambert Eaton Myasthenic syndrome?

Answer 27

An autoimmune disease with antibodies against the voltage gated calcium channel

Question 28

What is neuromyotonia?

Answer 28

When the muscles don’t relax there is twitches and cramp

Question 29

What is myasthesia gravis due to?

Answer 29

Antibodies against the acetylcholine receptor

Question 30

What does myasthesia gravis present with?

Answer 30

Fatiguable weakness
Eyes: diplopia, ptosis
Speech, chewing and swallowing trouble
Neck extension weakness
Respiratory failure
Late onset: thymic atrophy

Question 31

How would you treat Myasthesia gravis?

Answer 31

IV immunoglobulin exchange or plasma exchange, acetylcholinesterase inhibitors, immunosuprresants